WO2023017149A1

WO2023017149A1 - Thioredoxin 1 antibodies

Info

Publication number: WO2023017149A1
Application number: PCT/EP2022/072665
Authority: WO
Inventors: Carolina TRKULJA; Max Davidson; Sreesha P. Srinivasa; Owe Orwar; Gabriella WILLMAN
Original assignee: Oblique Therapeutics Ab
Priority date: 2021-08-13
Filing date: 2022-08-12
Publication date: 2023-02-16

Abstract

The present invention relates to antibodies that bind to Thioredoxin 1. The invention also relates to immunoconjugates and compositions comprising such antibodies. The invention also provides methods of producing such antibodies. The invention further provides the use of such antibodies for therapeutic purposes, for example in the treatment of cancer.

Description

Thioredoxin 1 Antibodies

This invention relates generally to the field of antibodies, in particular antibodies that bind to Thioredoxin 1 (Trx1). Such anti-Thioredoxin 1 antibodies have therapeutic uses, such as in the treatment of cancer. Antibody-based compositions and methods and uses of the invention also extend to the use of conjugates and other therapeutic combinations, kits (e.g. diagnostic kits) and methods.

Thioredoxin 1 (Trx1) is a 12kDa redox protein that contains a conserved Trp-Cys- Gly-Pro-Cys-Lys catalytic site. Trx1 is a redox-active protein containing two active site cysteines (Cys-32 and Cys-35) that cycle between the dithiol and disulfide forms as Trx1 reduces target proteins. Trx1 is able to counteract oxidative stress, for example by acting as a scavenger of reactive oxygen species (ROS) and by regulating enzymes that participate in H2O2 metabolism. Extracellular Trx1 can also have cytokine-like effects.

Trx1 is expressed in many cancer types. Trx1 is produced and secreted by many types of cancer, and extracellular Trx1 is typically found in the cancer (or tumour) microenvironment.

Regulatory T cells (also called Tregs or Treg cells) are typically characterized by being CD4+ CD25+ FoxP3+. Tregs have immunosuppressive activity. Tregs have been implicated in various diseases, including cancer. Levels of Treg cells are typically increased in the cancer (or tumour) microenvironment.

In the context of cancer, Tregs are involved in cancer (or tumour) development and progression by suppressing anti-cancer immune responses. Inhibiting/reducing levels of Treg cells can thus be therapeutically beneficial, e.g. in cancer.

Treg cells can differentiate from naive CD4+ T-cells. Naive CD4+ T-cells can typically be found, for example, in the cancer (or tumour) microenvironment.

There is a clear need for further therapies for diseases that are associated with the immunosuppressive properties of Tregs, for example cancer therapies.

The present inventors have identified antibodies that bind to Thioredoxin 1 and are able to reduce the levels of Tregs. The present inventors have shown that Trx1 is an important factor in the differentiation of naive CD4+ T-cells into Tregs and have identified monoclonal anti-Trx1 antibodies which are able to reduce levels of Tregs. These antibodies are promising candidates for therapies in which reducing Tregs would be beneficial, e.g. in cancer therapies. In vivo efficacy in experimental mouse models of cancer has also been shown in experiments described herein.

In one aspect, the present invention provides an antibody, for example an isolated antibody, that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein

(i) said heavy chain variable region comprises: (a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:6 or a sequence substantially homologous thereto, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:7 or a sequence substantially homologous thereto, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:8 or a sequence substantially homologous thereto; and/or (preferably “and”) said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:9 or a sequence substantially homologous thereto, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO: 10 or a sequence substantially homologous thereto, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:11 or a sequence substantially homologous thereto; or

(ii) said heavy chain variable region comprises: (a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:24 or a sequence substantially homologous thereto, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:25 or a sequence substantially homologous thereto, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:26 or a sequence substantially homologous thereto; and/or (preferably “and”) said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:27 or a sequence substantially homologous thereto, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or a sequence substantially homologous thereto; or

(iii) said heavy chain variable region comprises: (a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:42 or a sequence substantially homologous thereto, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:43 or a sequence substantially homologous thereto, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or a sequence substantially homologous thereto; and/or (preferably “and”) said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:45 or a sequence substantially homologous thereto, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:46 or a sequence substantially homologous thereto, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:47 or a sequence substantially homologous thereto; or

(iv) said heavy chain variable region comprises: (a) a variable heavy (VH)

CDR1 that has the amino acid sequence of SEQ ID NQ:60 or a sequence substantially homologous thereto, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:61 or a sequence substantially homologous thereto, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:62 or a sequence substantially homologous thereto; and/or (preferably “and”) said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:63 or a sequence substantially homologous thereto, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:64 or a sequence substantially homologous thereto, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:65 or a sequence substantially homologous thereto.

Substantially homologous sequences are described elsewhere herein. Preferably, said substantially homologous sequence is a sequence containing 1 , 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

In some embodiments, the present invention provides an antibody, for example an isolated antibody, that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein

(i) said heavy chain variable region comprises: (a) a variable heavy (VH)

CDR1 that has the amino acid sequence of SEQ ID NO:6, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:7, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:8; and/or (preferably “and”) said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:9, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO: 10, and (f) a VL CDR3 that has the amino acid sequence of SEQ I D NO: 11 ; or

(ii) said heavy chain variable region comprises: (a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:24, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:25, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:26; and/or (preferably “and”) said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:27, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:28, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:29; or

(iii) said heavy chain variable region comprises: (a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:42, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:43, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:44; and/or (preferably “and”) said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:45, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:46, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:47; or

(iv) said heavy chain variable region comprises: (a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NQ:60, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:61, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:62; and/or (preferably “and”) said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:63, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:64, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:65.

In some embodiments, the present invention provides an antibody, for example an isolated antibody, that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises:

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:6, or a sequence substantially homologous thereto, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:7, or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:8, or a sequence substantially homologous thereto; and/or (preferably “and”) wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:9, or a sequence substantially homologous thereto,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO: 10, or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:11, or a sequence substantially homologous thereto. Substantially homologous sequences are described elsewhere herein. Preferably, said substantially homologous sequence is a sequence containing 1 , 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:6,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:7, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:8; and/or wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:9,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO: 10, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:11.

In a preferred embodiment, the present invention provides an antibody, for example an isolated antibody, that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises: (a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:6,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:7, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:8; and wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:9,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO: 10, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:11.

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:24, or a sequence substantially homologous thereto,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:25, or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:26, or a sequence substantially homologous thereto; and/or (preferably “and”) wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:27, or a sequence substantially homologous thereto,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:28, or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:29, or a sequence substantially homologous thereto. Substantially homologous sequences are described elsewhere herein. Preferably, said substantially homologous sequence is a sequence containing 1 , 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:24,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:25, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:26; and/or wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:27,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:28, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:29.

In a preferred embodiment, the present invention provides an antibody, for example an isolated antibody, that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises:

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:25, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:26; and wherein said light chain variable region comprises:

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:28, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:29.

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:42, or a sequence substantially homologous thereto, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:43, or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:44, or a sequence substantially homologous thereto; and/or (preferably “and”) wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:45, or a sequence substantially homologous thereto,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:46, or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:47, or a sequence substantially homologous thereto. Substantially homologous sequences are described elsewhere herein. Preferably, said substantially homologous sequence is a sequence containing 1 , 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:42,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:43, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:44; and/or wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:45,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:46, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:47.

In a preferred embodiment, the present invention provides an antibody, for example an isolated antibody, that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises: (a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:42,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:43, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:44; and wherein said light chain variable region comprises:

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:46, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:47.

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NQ:60, or a sequence substantially homologous thereto,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:61, or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:62, or a sequence substantially homologous thereto; and/or (preferably “and”) wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:63, or a sequence substantially homologous thereto,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:64, or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:65, or a sequence substantially homologous thereto. Substantially homologous sequences are described elsewhere herein. Preferably, said substantially homologous sequence is a sequence containing 1 , 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NQ:60,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:61 , and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:62; and/or wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:63,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:64, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:65.

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:61 , and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:62; and wherein said light chain variable region comprises:

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:64, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:65.

In another aspect, the present invention provides an antibody, for example an isolated antibody, that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:92 (or a sequence substantially homologous thereto) or preferably SEQ ID NO:93 (or a sequence substantially homologous thereto).

In some embodiments, the present invention provides an antibody that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises:

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:92 or preferably SEQ ID NO:93, or a sequence substantially homologous thereto,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:25 or SEQ ID NO:43, or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:26 or SEQ ID NO:44, or a sequence substantially homologous thereto; and/or (preferably “and”) wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:27 or SEQ ID NO:45, or a sequence substantially homologous thereto,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or SEQ ID NO:46, or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or SEQ ID NO:47, or a sequence substantially homologous thereto. Substantially homologous sequences are described elsewhere herein. Preferably, said substantially homologous sequence is a sequence containing 1 , 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

In some embodiments of the present invention, the VH CDR1 has or comprises an amino acid sequence of SEQ ID NO: 92 (G Y T F Xs Xs X? Xs). In these embodiments Xs, Xs, X? and Xs can be any amino acid. Preferably, X5 is T or S, Xs is D or N, X7 is Y or S, and Xs is Y or W. Thus, a preferred VH CDR1 has or comprises the amino acid sequence of SEQ ID NO: 93. For example, preferred VH CDR1 sequences of this embodiment have or comprise SEQ ID NOs: 24 or 42.

In some preferred embodiments, the antibody comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs wherein said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:92 or preferably SEQ ID NO:93 or a sequence substantially homologous thereto, and wherein

(i) said heavy chain variable region comprises a VH CDR2 that has the amino acid sequence of SEQ ID NO:25 or a sequence substantially homologous thereto and a VH CDR3 that has the amino acid sequence of SEQ ID NO:26 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:27 or a sequence substantially homologous thereto, a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto, and a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or a sequence substantially homologous thereto; or

(ii) said heavy chain variable region comprises a VH CDR2 that has the amino acid sequence of SEQ ID NO:43 or a sequence substantially homologous thereto and a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:45 or a sequence substantially homologous thereto, a VL CDR2 that has the amino acid sequence of SEQ ID NO:46 or a sequence substantially homologous thereto, and a VL CDR3 that has the amino acid sequence of SEQ ID NO:47 or a sequence substantially homologous thereto.

In some embodiments of the invention, for antibodies that comprise a VH CDR1 that has the amino acid sequence of SEQ ID NO:24 or SEQ ID NO:42 or sequences substantially homologous thereto, the VH CDR1 may have an amino acid sequence of (i.e. that meets the criteria of) SEQ ID NO:92 or SEQ ID NO:93.

In another aspect, the present invention provides an antibody, for example an isolated antibody, that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a variable heavy (VH) CDR2 that has the amino acid sequence of SEQ ID NO:94 (or a sequence substantially homologous thereto) or preferably SEQ ID NO: 95 (or a sequence substantially homologous thereto).

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:24 or SEQ ID NO:42, or a sequence substantially homologous thereto, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:94 or SEQ ID NO:95, or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or SEQ ID NO:47, or a sequence substantially homologous thereto. Substantially homologous sequences are described elsewhere herein. Preferably, said substantially homologous sequence is a sequence containing 1, 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

In some embodiments of the present invention, the VH CDR2 has or comprises an amino acid sequence of SEQ ID NO: 94 (I Y P X4 X5 G D T). In these embodiments X4 and X5 can be any amino acid. Preferably, X4 is Y or G and X5 is N or D. Thus, a preferred VH CDR2 has or comprises the amino acid sequence of SEQ ID NO: 95. For example, preferred VH CDR2 sequences of this embodiment have or comprise SEQ ID NOs: 25 or 43.

In some preferred embodiments, the antibody comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs wherein said heavy chain variable region comprises a VH CDR2 that has the amino acid sequence of SEQ ID NO:94 or preferably SEQ ID NO:95 or a sequence substantially homologous thereto, and wherein

(i) said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:24 or a sequence substantially homologous thereto and a VH CDR3 that has the amino acid sequence of SEQ ID NO:26 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:27 or a sequence substantially homologous thereto, a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto, and a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or a sequence substantially homologous thereto; or (ii) said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:42 or a sequence substantially homologous thereto and a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:45 or a sequence substantially homologous thereto, a VL CDR2 that has the amino acid sequence of SEQ ID NO:46 or a sequence substantially homologous thereto, and a VL CDR3 that has the amino acid sequence of SEQ ID NO:47 or a sequence substantially homologous thereto.

In some embodiments of the invention, for antibodies that comprise a VH CDR2 that has the amino acid sequence of SEQ ID NO:25 or SEQ ID NO:43 or sequences substantially homologous thereto, the VH CDR2 may have an amino acid sequence of (i.e. that meets the criteria of) SEQ ID NO:94 or SEQ ID NO:95.

In another aspect, the present invention provides an antibody, for example an isolated antibody, that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said light chain variable region comprises a variable light (VL) CDR3 that has the amino acid sequence of SEQ ID NO:96 (or a sequence substantially homologous thereto) or preferably SEQ ID NO:97 (or a sequence substantially homologous thereto).

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:42 or SEQ ID NQ:60, or a sequence substantially homologous thereto,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:43 or SEQ ID NO:61, or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or SEQ ID NO:62, or a sequence substantially homologous thereto; and/or (preferably “and”) wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:45 or SEQ ID NO:63, or a sequence substantially homologous thereto,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:46 or SEQ ID NO:64, or a sequence substantially homologous thereto, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:96 or SEQ ID NO:97, or a sequence substantially homologous thereto. Substantially homologous sequences are described elsewhere herein. Preferably, said substantially homologous sequence is a sequence containing 1 , 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

In some embodiments of the present invention, the VL CDR3 has or comprises an amino acid sequence of SEQ ID NO: 96 (Q Q X3 X4 S Xe P XsT). In these embodiments X3, X4, Xe and Xs can be any amino acid. Preferably, X3 is D or W, X4 is Y or S, Xe is S or N and Xs is W or Y. Thus, a preferred VL CDR3 has or comprises the amino acid sequence of SEQ ID NO: 97. For example, preferred VL CDR3 sequences of this embodiment have or comprise SEQ ID NOs: 47 or 65.

In some preferred embodiments, the antibody comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs wherein said light chain variable region comprises a VL CDR3 that has the amino acid sequence of SEQ ID NO:96 or preferably SEQ ID NO:97 or a sequence substantially homologous thereto, and wherein

(i) said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:42 or a sequence substantially homologous thereto and a VH CDR2 that has the amino acid sequence of SEQ ID NO:43 or a sequence substantially homologous thereto, and a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:45 or a sequence substantially homologous thereto and a VL CDR2 that has the amino acid sequence of SEQ ID NO:46 or a sequence substantially homologous thereto; or

(ii) said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NQ:60 or a sequence substantially homologous thereto and a VH CDR2 that has the amino acid sequence of SEQ ID NO:61 or a sequence substantially homologous thereto, and a VH CDR3 that has the amino acid sequence of SEQ ID NO:62 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:63 or a sequence substantially homologous thereto and a VL CDR2 that has the amino acid sequence of SEQ ID NO:64 or a sequence substantially homologous thereto.

In some embodiments of the invention, for antibodies that comprise a VL CDR3 that has the amino acid sequence of SEQ ID NO:47 or SEQ ID NO:65 or sequences substantially homologous thereto, the VL CDR3 may have an amino acid sequence of (i.e. that meets the criteria of) SEQ ID NO:96 or SEQ ID NO:97.

In another aspect, the present invention provides an antibody, for example an isolated antibody, that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said light chain variable region comprises a variable light (VL) CDR2 that has the amino acid sequence of SEQ ID NO:28 (or a sequence substantially homologous thereto).

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:24 or SEQ ID NO:42, or a sequence substantially homologous thereto,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto, and

In some embodiments of the present invention, the VL CDR2 has or comprises an amino acid sequence of SEQ ID NO:28.

In some preferred embodiments, the antibody comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs wherein said light chain variable region comprises a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto, and wherein

(i) said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:24 or a sequence substantially homologous thereto and a VH CDR2 that has the amino acid sequence of SEQ ID NO:25 or a sequence substantially homologous thereto, and a VH CDR3 that has the amino acid sequence of SEQ ID NO:26 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:27 or a sequence substantially homologous thereto and a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or a sequence substantially homologous thereto; or

(ii) said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:42 or a sequence substantially homologous thereto and a VH CDR2 that has the amino acid sequence of SEQ ID NO:43 or a sequence substantially homologous thereto, and a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:45 or a sequence substantially homologous thereto and a VL CDR3 that has the amino acid sequence of SEQ ID NO:47 or a sequence substantially homologous thereto.

In another aspect, and in some embodiments, the antibody comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:92 or preferably SEQ ID NO:93 or a sequence substantially homologous thereto, and a VH CDR2 that has the amino acid sequence of SEQ ID NO:94 or preferably SEQ ID NO:95 or a sequence substantially homologous thereto.

In another aspect, and in some embodiments, the antibody comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:92 or preferably SEQ ID NO:93 or a sequence substantially homologous thereto, and a VH CDR2 that has the amino acid sequence of SEQ ID NO:94 or preferably SEQ ID NO:95 or a sequence substantially homologous thereto, wherein

(i) said heavy chain variable region comprises a VH CDR3 that has the amino acid sequence of SEQ ID NO:26 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:27 or a sequence substantially homologous thereto, a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto, and a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or a sequence substantially homologous thereto; or

(ii) said heavy chain variable region comprises a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:45 or a sequence substantially homologous thereto, a VL CDR2 that has the amino acid sequence of SEQ ID NO:46 or a sequence substantially homologous thereto, and a VL CDR3 that has the amino acid sequence of SEQ ID NO:47 or a sequence substantially homologous thereto.

In another aspect, and in some embodiments, the antibody comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:92 or preferably SEQ ID NO:93 or a sequence substantially homologous thereto, and wherein said light chain variable region comprises a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto.

In another aspect, and in some embodiments, the antibody comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:92 or preferably SEQ ID NO:93 or a sequence substantially homologous thereto, and wherein said light chain variable region comprises a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto, wherein

(i) said heavy chain variable region comprises a VH CDR2 that has the amino acid sequence of SEQ ID NO:25 or a sequence substantially homologous thereto and a VH CDR3 that has the amino acid sequence of SEQ ID NO:26 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:27 or a sequence substantially homologous thereto and a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or a sequence substantially homologous thereto; or

(ii) said heavy chain variable region comprises a VH CDR2 that has the amino acid sequence of SEQ ID NO:43 or a sequence substantially homologous thereto and a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:45 or a sequence substantially homologous thereto and a VL CDR3 that has the amino acid sequence of SEQ ID NO:47 or a sequence substantially homologous thereto.

In another aspect, and in some embodiments, the antibody comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a VH CDR2 that has the amino acid sequence of SEQ ID NO:94 or preferably SEQ ID NO:95 or a sequence substantially homologous thereto, and wherein said light chain variable region comprises a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto, wherein

(i) said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:24 or a sequence substantially homologous thereto and a VH CDR3 that has the amino acid sequence of SEQ ID NO:26 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:27 or a sequence substantially homologous thereto and a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or a sequence substantially homologous thereto; or

(ii) said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:42 or a sequence substantially homologous thereto and a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:45 or a sequence substantially homologous thereto and a VL CDR3 that has the amino acid sequence of SEQ ID NO:47 or a sequence substantially homologous thereto.

In another aspect, and in some embodiments, the antibody comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:92 or preferably SEQ ID NO:93 or a sequence substantially homologous thereto and a VH CDR2 that has the amino acid sequence of SEQ ID NO:94 or preferably SEQ ID NO:95 or a sequence substantially homologous thereto, and wherein said light chain variable region comprises a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto. In another aspect, and in some embodiments, the antibody comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a VH CDR1 that has the amino acid sequence of SEQ ID NO:92 or preferably SEQ ID NO:93 or a sequence substantially homologous thereto and a VH CDR2 that has the amino acid sequence of SEQ ID NO:94 or preferably SEQ ID NO:95 or a sequence substantially homologous thereto, and wherein said light chain variable region comprises a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto, wherein

(i) said heavy chain variable region comprises a VH CDR3 that has the amino acid sequence of SEQ ID NO:26 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:27 or a sequence substantially homologous thereto and a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or a sequence substantially homologous thereto; or

(ii) said heavy chain variable region comprises a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or a sequence substantially homologous thereto, and/or (preferably “and”) said light chain variable region comprises a VL CDR1 that has the amino acid sequence of SEQ ID NO:45 or a sequence substantially homologous thereto and a VL CDR3 that has the amino acid sequence of SEQ ID NO:47 or a sequence substantially homologous thereto.

In one embodiment the invention provides an antibody comprising a VH domain that has the amino acid sequence of SEQ ID NO:4 or a sequence substantially homologous thereto, and/or a VL domain that has the amino acid sequence of SEQ ID NO:5 or a sequence substantially homologous thereto.

In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:5, or a sequence having at least 80% sequence identity thereto (e.g. at least 85%, 90%, 95% or 98%) and/or wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:4, or a sequence having at least 80% sequence identity thereto (e.g. at least 85%, 90%, 95% or 98%).

In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:5 and/or wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:4. In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:5 and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:4.

In one embodiment the invention provides an antibody comprising a VH domain that has the amino acid sequence of SEQ ID NO:22 or a sequence substantially homologous thereto, and/or a VL domain that has the amino acid sequence of SEQ ID NO:23 or a sequence substantially homologous thereto.

In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:23, or a sequence having at least 80% sequence identity thereto (e.g. at least 85%, 90%, 95% or 98%) and/or wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:22, or a sequence having at least 80% sequence identity thereto (e.g. at least 85%, 90%, 95% or 98%).

In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:23 and/or wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:22.

In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:23 and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:22.

In one embodiment the invention provides an antibody comprising a VH domain that has the amino acid sequence of SEQ ID NQ:40 or a sequence substantially homologous thereto, and/or a VL domain that has the amino acid sequence of SEQ ID NO:41 or a sequence substantially homologous thereto.

In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:41, or a sequence having at least 80% sequence identity thereto (e.g. at least 85%, 90%, 95% or 98%) and/or wherein the heavy chain variable region has the amino acid sequence of SEQ ID NQ:40, or a sequence having at least 80% sequence identity thereto (e.g. at least 85%, 90%, 95% or 98%).

In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:41 and/or wherein the heavy chain variable region has the amino acid sequence of SEQ ID NQ:40. In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:41 and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:40.

In one embodiment the invention provides an antibody comprising a VH domain that has the amino acid sequence of SEQ ID NO:58 or a sequence substantially homologous thereto, and/or a VL domain that has the amino acid sequence of SEQ ID NO:59 or a sequence substantially homologous thereto.

In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:59, or a sequence having at least 80% sequence identity thereto (e.g. at least 85%, 90%, 95% or 98%) and/or wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:58, or a sequence having at least 80% sequence identity thereto (e.g. at least 85%, 90%, 95% or 98%).

In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:59 and/or wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:58.

In a preferred embodiment, the present invention provides an antibody, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:59 and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:58.

The CDRs of antibodies of the invention are preferably separated by appropriate framework regions such as those found in naturally occurring antibodies and/or effective engineered antibodies. Thus, the VH, VL and individual CDR sequences of the invention are preferably provided within or incorporated into an appropriate framework or scaffold to enable antigen binding. Such framework sequences or regions may correspond to naturally occurring framework regions, FR1, FR2, FR3 and/or FR4, as appropriate to form an appropriate scaffold, or may correspond to consensus framework regions, for example identified by comparing various naturally occurring framework regions. Alternatively, nonantibody scaffolds or frameworks, e.g. T cell receptor frameworks can be used.

Appropriate sequences that can be used for framework regions are well known and documented in the art and any of these may be used. Preferred sequences for framework regions are one or more of the framework regions making up the VH and/or L domains of the invention, i.e. one or more of the framework regions of the 7C8, 1 B7, 1 F5 or 9B6 antibodies, as disclosed in Tables A, B, C or D herein, or framework regions substantially homologous thereto, and in particular framework regions that allow the maintenance of antigen specificity, for example framework regions that result in substantially the same or the same 3D structure of the antibody.

In certain preferred embodiments, all four of the variable light chain (SEQ ID NOs:16, 17, 18 and 19) and/or variable heavy chain (SEQ ID NOs:12, 13, 14 and 15) framework regions (FR), as appropriate, or FR regions substantially homologous thereto, are found in the antibodies of the invention.

In other preferred embodiments, all four of the variable light chain (SEQ ID NOs:34, 35, 36 and 37) and/or variable heavy chain (SEQ ID NQs:30, 31, 32 and 33) framework regions (FR), as appropriate, or FR regions substantially homologous thereto, are found in the antibodies of the invention.

In other preferred embodiments, all four of the variable light chain (SEQ ID NOs:52, 53, 54 and 55) and/or variable heavy chain (SEQ ID NOs:48, 49, 50 and 51) framework regions (FR), as appropriate, or FR regions substantially homologous thereto, are found in the antibodies of the invention.

In other preferred embodiments, all four of the variable light chain (SEQ ID NQs:70, 71, 72 and 73) and/or variable heavy chain (SEQ ID NOs:66, 67, 68 and 69) framework regions (FR), as appropriate, or FR regions substantially homologous thereto, are found in the antibodies of the invention.

Some preferred embodiments are Ig (e.g. IgG) forms of antibodies described herein, e.g. IgG forms of the 7C8, 1 B7, 1 F5 or 9B6 antibodies (or antibodies based thereon), preferably full length IgG forms. In some embodiments, the IgG is I gGi or lgG2 (e.g. lgG2b). Thus, in some embodiments the antibody is an Ig antibody comprising CDR sequences and/or a heavy chain variable region and/or a light chain variable region as described herein. It is of course understood that full IgG antibodies will typically comprise two substantially identical heavy chains and two substantially identical light chains.

In some embodiments, antibodies based on the 7C8, 1 B7, 1F5 or 9B6 antibody sequences set forth in Tables A, B, C and D herein are preferred.

Some examples of antibodies of the present invention are the monoclonal antibodies 7C8, 1B7, 1F5 and 9B6, sequences of which are shown in Tables A, B, C and D herein. The monoclonal antibodies 7C8, 1B7, 1F5 and 9B6 were identified using hybridoma technology, with human Thioredoxin 1 (SEQ ID NO:1) as the immunogen. The CDR domains, VH and VL domains are shown in Tables A, B, C and D herein. Antibodies comprising these CDR domains or VH and VL domains (or sequences substantially homologous thereto) are preferred aspects of the invention. The term "substantially homologous" as used herein in connection with an amino acid or nucleic acid sequence includes sequences having at least 65%, 70% or 75%, preferably at least 80%, and even more preferably at least 85%, 90%, 95%, 96%, 97%, 98% or 99%, sequence identity to the amino acid or nucleic acid sequence disclosed. Substantially homologous sequences of the invention thus include single or multiple base or amino acid alterations (additions, substitutions, insertions or deletions) to the sequences of the invention. At the amino acid level preferred substantially homologous sequences contain up to 5, e.g. only 1, 2, 3, 4 or 5, preferably 1, 2 or 3, more preferably 1 or 2, altered amino acids, in one or more of the framework regions and/or one or more of the CDRs making up the sequences of the invention. Said alterations can be with conservative or nonconservative amino acids. Preferably said alterations are conservative amino acid substitutions.

Other preferred examples of substantially homologous sequences are sequences containing conservative amino acid substitutions of the amino acid sequences disclosed.

Other preferred examples of substantially homologous sequences are sequences containing 1, 2 or 3, preferably 1 or 2 (more preferably 1), altered amino acids in one or more of the CDR regions disclosed. Thus, in some embodiments, a “substantially homologous” CDR sequence may be a sequence containing 1, 2 or 3, preferably 1 or 2 (more preferably 1), altered amino acids in (or in comparison to) a given CDR sequence described herein. Such alterations might be conserved or non-conserved amino acid substitutions, or a mixture thereof. In some embodiments, preferred alterations are conservative amino acid substitutions.

Other preferred examples of substantially homologous sequences are sequences having at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90% or at least 95% sequence identity to one or more of the CDR sequences disclosed. Thus, in some embodiments, a “substantially homologous” CDR sequence may be a sequence having at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90% or at least 95% sequence identity to a given CDR sequence described herein. Altered residues might be conserved or non-conserved amino acid substitutions, or a mixture thereof. In some embodiments, preferred alterations are conservative amino acid substitutions.

In some embodiments, in antibodies having a “substantially homologous” sequence as compared to a given sequence, or having a certain degree of sequence identity as compared to a given sequence, the altered amino acid residues(s) are not in a CDR region. For example, in some embodiments, in antibodies having a VH domain sequence and/or a VL domain sequence that has a certain degree of sequence identity to given a VH domain and/or a given VL domain sequence of a particular antibody of the invention (e.g. 7C8, 1B7, 1F5 or 9B6), the altered (or variant) residue(s) are not in a CDR region. Thus, in some embodiments, in antibodies having a “substantially homologous” sequence as compared to a given sequence, or having a certain degree of sequence identity as compared to a given sequence, the altered amino acid residues(s) are in one or more framework regions.

As is evident from elsewhere herein, in other embodiments, in antibodies having a “substantially homologous” sequence as compared to a given sequence, or having a certain degree of sequence identity as compared to a given sequence, the altered amino acid residues(s) may be in a CDR region.

In some embodiments, in an antibody having a “substantially homologous” sequence as compared to a given sequence, or having a certain degree of sequence identity as compared to a given sequence, the three VL CDR amino acid sequences and the three VH CDR amino acid sequences (i.e. all six CDR sequences taken together) are considered together to be the whole (or entire) CDR complement of the antibody, and the amino acid sequence of said whole CDR complement of said antibody is at least 70%, preferably at least 80%, or at least 90%, or at least 95% identical to the corresponding whole (or entire) CDR complement of a given starting (or reference) antibody. The starting (or reference) antibody may have the CDR sequences of a particular antibody of the invention. Thus, the starting (or reference) antibody may have the CDR sequences of the 7C8, 1 B7, 1 F5 or 9B6 antibodies of the present invention.

Methods of carrying out the above described manipulation of amino acids (e.g. to generate “substantially homologous” sequences) are well known to a person skilled in the art.

A "conservative amino acid substitution", as used herein, is one in which the amino acid residue is replaced with another amino acid residue having a similar side chain. Families of amino acid residues having similar side chains have been defined in the art, including basic side chains (e.g. lysine, arginine, histidine), acidic side chains (e.g. aspartic acid, glutamic acid), uncharged polar side chains (e.g. asparagine, glutamine, serine, threonine, tyrosine, cysteine), nonpolar side chains (e.g. glycine, cysteine, alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), beta-branched side chains (e.g. threonine, valine, isoleucine) and aromatic side chains (e.g. tyrosine, phenylalanine, tryptophan, histidine).

In certain embodiments, if a given starting sequence is relatively short (e.g. three amino acids in length), then fewer amino acid substitutions may be present in sequences substantially homologous thereto as compared with the number of amino acid substitutions that might optionally be made in a sequence substantially homologous to a longer starting sequence. For example, in certain embodiments, a sequence substantially homologous to a starting VL CDR2 sequence in accordance with the present invention, e.g. a starting VL CDR2 sequence which in some embodiments may be three amino acid residues in length, preferably has 1 or 2 (more preferably 1) altered amino acids in comparison with the starting sequence. Accordingly, in some embodiments the number of altered amino acids in substantially homologous sequences (e.g. in substantially homologous CDR sequences) can be tailored to the length of a given starting CDR sequence. For example, different numbers of altered amino acids can be present depending on the length of a given starting CDR sequence such as to achieve a particular % sequence identity in the CDRs, for example a sequence identity of at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99%.

Homology (e.g. sequence identity) may be assessed by any convenient method. However, for determining the degree of homology (e.g. identity) between sequences, computer programs that make multiple alignments of sequences are useful, for instance Clustal W (Thompson, Higgins, Gibson, Nucleic Acids Res., 22:4673-4680, 1994). If desired, the Clustal W algorithm can be used together with BLOSLIM 62 scoring matrix (Henikoff and Henikoff, Proc. Natl. Acad. Sci. USA, 89:10915-10919, 1992) and a gap opening penalty of 10 and gap extension penalty of 0.1 , so that the highest order match is obtained between two sequences wherein at least 50% of the total length of one of the sequences is involved in the alignment. Other methods that may be used to align sequences are the alignment method of Needleman and Wunsch (Needleman and Wunsch, J. Mol. Biol., 48:443, 1970) as revised by Smith and Waterman (Smith and Waterman, Adv. Appt. Math., 2:482, 1981) so that the highest order match is obtained between the two sequences and the number of identical amino acids is determined between the two sequences. Other methods to calculate the percentage identity between two amino acid sequences are generally art recognized and include, for example, those described by Carillo and Lipton (Carillo and Lipton, SIAM J. Applied Math., 48:1073, 1988) and those described in Computational Molecular Biology, Lesk, e.d. Oxford University Press, New York, 1988, Biocomputing: Informatics and Genomics Projects.

Generally, computer programs will be employed for such calculations. Programs that compare and align pairs of sequences, like ALIGN (Myers and Miller, CABIOS, 4:11-17, 1988), FASTA (Pearson and Lipman, Proc. Natl. Acad. Sci. USA, 85:2444-2448, 1988; Pearson, Methods in Enzymology, 183:63-98, 1990) and gapped BLAST (Altschul et al., Nucleic Acids Res., 25:3389-3402, 1997), BLASTP, BLASTN, or GCG (Devereux, Haeberli, Smithies, Nucleic Acids Res., 12:387, 1984) are also useful for this purpose. Furthermore, the Dali server at the European Bioinformatics institute offers structure-based alignments of protein sequences (Holm, Trends in Biochemical Sciences, 20:478-480, 1995; Holm, J. Mol. Biol., 233:123-38, 1993; Holm, Nucleic Acid Res., 26:316-9, 1998).

By way of providing a reference point, sequences according to the present invention having 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% homology, sequence identity etc. may be determined using the ALIGN program with default parameters (for instance available on Internet at the GENESTREAM network server, IGH, Montpellier, France).

In all embodiments, antibodies containing substantially homologous sequences retain the ability to bind to Thioredoxin 1. Preferably, antibodies containing substantially homologous sequences retain one or more (preferably all) of the properties described in relation to antibodies of the invention, e.g. the 7C8, 1B7, 1F5 and/or 9B6 antibodies.

Further examples of substantially homologous amino acid sequences in accordance with the present invention are described elsewhere herein.

Routine methods in the art such as alanine scanning mutagenesis and/or analysis of crystal structure of the antigen-antibody complex can be used in order to determine which amino acid residues of the CDRs do not contribute or do not contribute significantly to antigen binding and therefore are good candidates for alteration or substitution in the embodiments of the invention involving substantially homologous sequences.

The term "substantially homologous" also includes modifications or chemical equivalents of the amino acid and nucleotide sequences of the present invention that perform substantially the same function as the proteins (e.g. antibodies) or nucleic acid molecules of the invention in substantially the same way. For example, any substantially homologous antibody should retain the ability to bind to Thioredoxin 1 as described above. Preferably, any substantially homologous antibody should retain one or more (or all) of the functional capabilities of the starting antibody.

Substantially homologous sequences of antibodies of the invention also include, without limitation, for example alterations that do not affect the VH, VL or CDR domains of the antibodies, e.g. antibodies where tag sequences or other components are added that do not contribute to the binding of antigen, or alterations to convert one type or format of antibody molecule or fragment to another type or format of antibody molecule or fragment (e.g. conversion from Fab to scFv or whole antibody or vice versa), or the conversion of an antibody molecule to a particular class or subclass of antibody molecule (e.g. the conversion of an antibody molecule to IgG or a subclass thereof, e.g. lgG2 or lgG4 or I gGi) .

Preferably, any substantially homologous antibody should retain the ability to specifically bind to the same (or substantially the same) epitope of Thioredoxin 1 as recognized by the antibody in question, for example, the same epitope recognized by the CDR domains of the invention or the VH and VL domains of the invention as described herein. Thus, preferably, any substantially homologous antibody should retain the ability to compete with one or more of the various antibodies of the invention (e.g. one or more of the described monoclonal antibodies 7C8, 1 B7, 1 F5 or 9B6) for binding to Thioredoxin 1. Binding to the same epitope/antigen can be readily tested by methods well known and described in the art, e.g. using binding assays, e.g. a competition assay. Retention of other functional properties can also readily be tested by methods well known and described in the art or herein.

Thus, a person skilled in the art will appreciate that binding assays can be used to test whether "substantially homologous" antibodies have the same binding specificities as the antibodies and antibody fragments of the invention, for example, binding assays such as competition assays or ELISA assays as described elsewhere herein. BIAcore assays could also readily be used to establish whether "substantially homologous" antibodies can bind to Thioredoxin. The skilled person will be aware of other suitable methods and variations.

As outlined below, a competition binding assay can be used to test whether "substantially homologous" antibodies retain the ability to specifically bind to substantially the same epitope (or the same epitope) of Thioredoxin 1 as recognized by the antibodies of the invention (e.g. antibodies 7C8, 1 B7, 1 F5 or 9B6, or antibodies based on these antibodies), or have the ability to compete with one or more of the various antibodies of the invention (e.g. antibodies 7C8, 1B7, 1 F5 or 9B6, or antibodies based on these antibodies). The method described below is only one example of a suitable competition assay. The skilled person will be aware of other suitable methods and variations.

An exemplary competition assay involves assessing the binding of various effective concentrations of an antibody of the invention to Thioredoxin 1 in the presence of varying concentrations of a test antibody (e.g. a substantially homologous antibody). The amount of inhibition of binding induced by the test antibody can then be assessed. A test antibody that shows increased competition with an antibody of the invention at increasing concentrations (i.e. increasing concentrations of the test antibody result in a corresponding reduction in the amount of antibody of the invention binding to Thioredoxin 1) is evidence of binding to substantially the same epitope. Preferably, the test antibody significantly reduces the amount of antibody of the invention that binds to Thioredoxin 1. Preferably, the test antibody reduces the amount of antibody of the invention that binds to Thioredoxin 1 by at least about 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95%. ELISA and flow cytometry assays may be used for assessing inhibition of binding in such a competition assay but other suitable techniques would be well known to a person skilled in the art. In some embodiments, “substantially homologous” antibodies which retain the ability to specifically bind to substantially the same (or the same) epitope of Thioredoxin 1 as recognized by the antibodies of the invention (e.g. antibodies 7C8, 1B7, 1F5 or 9B6, or antibodies based on these antibodies) or which have the ability to compete with one or more of the various antibodies of the invention (e.g. antibodies 7C8, 1 B7, 1 F5 or 9B6, or antibodies based on these antibodies) are preferred.

The term "competing antibodies", as used herein, refers to antibodies that bind to about, substantially or essentially the same, or even the same, epitope as a "reference antibody". "Competing antibodies" include antibodies with overlapping epitope specificities. Competing antibodies are thus able to effectively compete with a reference antibody for binding to Thioredoxin 1. Preferably, the competing antibody can bind to the same epitope as the reference antibody. Alternatively viewed, the competing antibody preferably has the same epitope specificity as the reference antibody.

"Reference antibodies" as used herein include antibodies of the present invention (e.g. the monoclonal antibodies described herein). “Reference antibodies” include antibodies which can bind to Thioredoxin 1 and which preferably have a VH and a VL domain as defined herein, more preferably a VH domain of SEQ ID NO:4 and a VL domain of SEQ ID NO:5; or a VH domain of SEQ ID NO:22 and a VL domain of SEQ ID NO:23; or a VH domain of SEQ ID NQ:40 and a VL domain of SEQ ID NO:41; or a VH domain of SEQ ID NO:58 and a VL domain of SEQ ID NO:59. Certain preferred reference antibodies are selected from antibodies 7C8, 1 B7, 1 F5 or 9B6, or antibodies based on these antibodies.

As the identification of competing antibodies is determined in comparison to a reference antibody, it will be understood that actually determining the epitope to which either or both antibodies bind is not in any way required in order to identify a competing antibody. However, epitope mapping can be performed using standard techniques, if desired.

As described above, antibodies of the invention bind to (or are capable of binding to) Thioredoxin 1.

Thioredoxin 1 may also be referred to herein as Trx1 (or TRXI). Unless otherwise clear from the context, references herein simply to Thioredoxin or Trx (or TRX) are references to Thioredoxin 1 (Trx1).

In preferred embodiments, the Thioredoxin 1 is human Thioredoxin 1 (hTrxl). The amino acid sequence of human Thioredoxin 1 is set forth herein as SEQ ID NO:1.

Antibodies of the invention bind to (or are capable of binding to) full-length (or wildtype or native) Thioredoxin 1 (preferably human Thioredoxin 1 ; SEQ ID NO:1). The Thioredoxin 1 (preferably human Thioredoxin 1) may be Thioredoxin 1 that is (or has been) expressed and/or secreted by cells, preferably by mammalian cells (e.g. human cells). The Thioredoxin 1 may be secreted Thioredoxin 1 (Thioredoxin 1 that has been secreted by cells, preferably mammalian cells (e.g. human cells)). Such cells may be cancer cells or cancer cell lines. The Thioredoxin 1 may be extracellular Thioredoxin 1 (e.g. Thioredoxin 1 in extracellular space or extracellular matrix or in extracellular fluid). The Thioredoxin 1 may be circulatory Thioredoxin 1 (i.e. Thioredoxin 1 in a circulatory fluid of a subject or obtained from (or isolated from) a circulatory fluid of a subject). Thus, the Thioredoxin 1 may be a soluble form of Thioredoxin 1 (preferably human Thioredoxin 1). Thus, the Thioredoxin may be Thioredoxin 1 that is in solution.

The Thioredoxin 1 may be a native or natural form of Thioredoxin 1 (or a have a native or natural conformation or configuration of Thioredoxin 1), for example be a form naturally produced or secreted by cells.

The Thioredoxin 1 may be recombinant (or be a recombinant form of) Thioredoxin 1 (preferably human Thioredoxin 1). Such a recombinant Thioredoxin may be in solution or may be immobilized on a solid support (e.g. immobilized on a plate for an ELISA assay). In some embodiments, antibodies of the present invention are capable of binding to a recombinant form of Thioredoxin 1 (preferably human Thioredoxin 1) as assessed in (or by or using) an ELISA assay (e.g. as described elsewhere herein) and/or as assessed in (or by or using) an appropriate functional assay (e.g. an assay that analyses the differentiation of naive CD4+ T-cells into Tregs in the presence of Trx1, e.g. as described elsewhere herein).

The binding of an antibody of the invention to Thioredoxin 1 may be assessed (or as assessed) by any suitable means, and the skilled person will be familiar with suitable methods (e.g. an ELISA or by using a functional assay e.g. as described elsewhere herein).

In some embodiments, an antibody of the invention binds to (or is capable of binding to) Thioredoxin 1 in an ELISA assay in which an ELISA plate (or well(s)) is coated with hTrxl (SEQ ID NO:1).

In some embodiments, an antibody of the invention binds to (or is capable of binding to) Thioredoxin 1 in an ELISA assay comprising

(a) Coating an ELISA plate with hTrxl (SEQ ID NO:1), for example using 10OpI per well of 5pg/mL hTrxl (SEQ ID NO:1) in 0.58M carbonate-bicarbonate buffer, pH9.5, and incubating for about 2h at 37°C;

(b) Washing the coated plate (wells of the coated plate), for example with PBS (phosphate-buffered saline) containing 0.1% Tween; (c) Incubating the plate (e.g. overnight) at about 4°C in the presence of blocking buffer (e.g. PBS, 3% BSA, pH 7.4);

(d) Preparing a serial dilution of antibody (antibody to be tested), typically in blocking buffer, and incubating the dilution series of antibody in wells of the ELISA plate, for example for 1 h at 37°C;

(e) Washing the wells of the plate, for example with PBS containing 0.1% Tween;

(f) Incubating a secondary antibody (e.g. 0.5 pg/mL in PBS) having (e.g. conjugated to) a detectable label in the wells of the plate, for example for about 30 minutes, for example at 37°C;

(g) Washing the wells of the plate, for example with PBS containing 0.1% Tween;

(h) Detecting (and quantifying) the detectable label. For example, if HRP is used as the detectable label a substrate for HRP (e.g. TMB substrate) may be added to the wells (e.g.100pl/well) and incubated (e.g. 5 min at 37°C) and the reaction may then be stopped (e.g. 50pl/well of 2M HCI) and absorbance measured, e.g. at 450nm.

A particularly preferred ELISA assay is described in the Example section herein.

ELISA assays may be used to determine an ECso value (or concentration). An ECso value represents the concentration of antibody that gives half-maximal binding to the antigen (Thioredoxin 1 in the context of the present invention). The skilled person is readily able to determine ECso values for antibodies. ECso values may be calculated by any suitable means (and be based on any suitable tests, methods or assays, for example methods as described herein). For example, ECso values may be established (or calculated) based on the results of an ELISA assay (e.g. as described herein). A particularly preferred ELISA method is described in the Example section herein.

In some embodiments, antibodies of the present invention have an ECso value for binding to Thioredoxin 1 that is <5pg/ml, <4pg/ml, <3pg/ml, <2pg/ml, <1 pg/ml, <0.5pg/ml, <0.4pg/ml, <0.3pg/ml, <0.25pg/ml, <0.2pg/ml, <0.15pg/ml, <0.1 pg/ml, <0.09pg/ml, <0.08pg/ml, <0.07pg/ml, <0.06pg/ml, <0.05pg/ml, <0.04pg/ml, <0.03pg/ml, <0.02pg/ml, <0.01 pg/ml or <0.005 pg/ml. Preferably, the ECso value for binding to Thioredoxin 1 is <0.2pg/ml, more preferably <0.1 pg/ml. In some embodiments, the ECso value may be in the range of 0.005 pg/ml to 5 pg/ml, for example 0.01 pg/ml to 5 pg/ml, 0.01 pg/ml to 3pg/ml, 0.01 pg/ml to 2 pg/ml, 0.01 pg/ml to 1 pg/ml, 0.01 pg/ml to 0.5 pg/ml, 0.01 pg/ml to 0.25 pg/ml, 0.01 pg/ml to 0.2 pg/ml, or 0.01 pg/ml to 0.1 pg/ml. In some embodiments, the ECso value may be up to 5pg/ml, up to 4pg/ml, up to 3pg/ml, up to 2pg/ml, up to 1 pg/ml, up to 0.5pg/ml, up to 0.4pg/ml, up to 0.3pg/ml, up to 0.25pg/ml, up to 0.2pg/ml, up to 0.15pg/ml, up to 0.1 pg/ml, up to 0.09pg/ml, up to 0.08pg/ml, up to 0.07pg/ml, up to 0.06pg/ml, up to 0.05pg/ml, up to 0.04pg/ml, up to 0.03pg/ml, up to 0.02pg/ml, up to O.OIpg/ml.

In some embodiments, the above ECso values apply when the ECso value is determined in an ELISA assay (e.g. an ELISA assay as described herein). In some embodiments, the above ECso values apply when the antibody is a monoclonal antibody (e.g. a mouse monoclonal antibody).

In preferred embodiments, antibodies of the invention which bind to (or specifically recognise or specifically bind to) Thioredoxin 1 reduce or inhibit (or are capable of reducing or inhibiting) the differentiation (or polarization, or production) and/or survival and/or activation of Tregs. Preferably, antibodies of the invention which bind to (or specifically recognise or specifically bind to) Thioredoxin 1 reduce or inhibit (or are capable of reducing or inhibiting) the differentiation (or polarization or production) of Tregs. For the avoidance of doubt, references herein to differentiation of Tregs mean differentiation into Tregs.

Tregs are typically characterized as being CD4+ CD25+ FOXP3+ cells (i.e. they are typically positive (+) for these three cell marker proteins). Types of Tregs include induced Tregs (iTregs) and naturally occurring Tregs (nTregs). Induced Tregs (iTregs) can be generated in vitro.

Such a reduction (or inhibition or decrease) of the differentiation (or polarization or production) and/or survival and/or activation of Tregs may be assessed by any appropriate assay or method (e.g. a T-regulatory polarization assay as described elsewhere herein).

In some embodiments, reduction (or inhibition or decrease) of the differentiation (or polarization or production) and/or survival and/or activation of Tregs is any measurable or significant reduction or inhibition or decrease, more preferably a statistically significant reduction or inhibition or decrease (e.g. as compared to a control with no antibody or as compared to a control with an antibody that does not bind to Thioredoxin 1 , e.g. an isotype control).

In some embodiments, the level (or amount) of differentiation (or polarization or production) and/or survival and/or activation of Tregs observed with (or in the presence of) a control (e.g. a control antibody that does not bind to (or does not specifically bind to) Thioredoxin 1 , e.g. an isotype control) represents a control level. Thus, in some embodiments, % inhibitions of differentiation (or polarization or production) and/or survival and/or activation of Tregs discussed elsewhere herein are as compared to (or relative to) such a control level. In some embodiments, reduction (or decrease or inhibition) of differentiation (or polarization or production) and/or survival and/or activation of Tregs is a reduction of at least 5%, at least 10%, at least 15%, preferably at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or 100%.

In some embodiments, reduction (or decrease or inhibition) of differentiation (or polarization or production) and/or survival and/or activation of Tregs is a reduction of at least at least 25%.

In some embodiments, reduction (or decrease or inhibition) of differentiation (or polarization or production) and/or survival and/or activation of Tregs is a reduction of at least 50%.

In some embodiments, reduction (or decrease or inhibition) of differentiation (or polarization or production) and/or survival and/or activation of Tregs is a reduction of at least 75%.

In some embodiments, reduction (or decrease or inhibition) of differentiation (or polarization or production) and/or survival and/or activation of Tregs is a reduction of up to 5%, up to 10%, up to 15%, up to 20%, up to 25%, up to 30%, up to 35%, up to 40%, up to 45%, up to 50%, up to 55%, up to 60%, up to 65%, up to 70%, up to 75%, up to 80%, up to 85%, up to 90%, up to 95% or up to 100%.

Thus, in some embodiments, reduction (or decrease or inhibition) of differentiation (or polarization or production) and/or survival and/or activation of Tregs is a reduction of 5%- 100%, 10%-100%, 15%-100%, 20%-100%, 25%-100%, 30%-100%, 35%-100%, 40%-100%, 45%-100%, 50%-100%, 55%-100%, 60%-100%, 65%-100%, 70%-100%, 75%-100%, 80%- 100%, 85%-100%, 90%-100% or 95%-100%.

In some embodiments, reduction (or decrease or inhibition) of differentiation (or polarization or production) and/or survival and/or activation of Tregs is a reduction of 5%- 75%, 10%-75%, 15%-75%, 20%-75%, 25%-75%, 30%-75%, 35%-75%, 40%-75%, 45%- 75%, 50%-75%, 55%-75%, 60%-75%, 65%-75% or 70%-75%.

In some embodiments, the above reductions (or decreases or inhibitions), e.g. % reductions, of differentiation (or polarization or production) and/or survival and/or activation of Tregs are as determined when said antibody is monoclonal antibody, such as a mouse monoclonal antibody.

In some embodiments, the above reductions (or decreases or inhibitions), e.g. % reductions, of differentiation (or polarization or production) and/or survival and/or activation of Tregs are as determined when said antibody (e.g. a monoclonal antibody such as a mouse monoclonal antibody) is used at a concentration of 10pg/ml (e.g. in a T-regulatory polarization assay as described elsewhere herein).

The levels of reduction (or decrease) (e.g. % reductions or decreases) discussed above are also preferred levels of reduction (or decrease) in respect of all, i.e. any, property or function of antibodies of the invention for which a reduction (or decrease) in that property or function is described. For example, the levels of reduction (or decrease) (e.g. % reductions or decreases) discussed above are also preferred levels of reduction (or decrease) in the differentiation of naive CD4+ T-cells into Tregs, or levels of reduction in FOXP3 expression, or levels of reduction in CD25 expression, or levels of reduction in cell viability, or levels of reduction of the proportion (e.g. %) of CD4+ CD25+ cells in (or within) a population of live cells.

In particularly preferred embodiments, antibodies of the invention which bind to (or specifically recognise or specifically bind to) Thioredoxin 1 reduce or inhibit (or are capable of reducing or inhibiting) the differentiation of naive CD4+ T-cells into Tregs. Levels (or amounts) of reduction (or decrease or inhibition) as described elsewhere (e.g. % reductions), and relevant controls etc. as described elsewhere herein, may be applied to these embodiments of the invention.

Naive CD4+ T-cells are a well-known T-cell population. Naive CD4+ T-cells are typically characterized as being CD3+ CD4+ CD45RA+ CD45RO- cells (i.e. they are typically positive (+) for CD3, CD4 and CD45RA, and typically negative (-) for CD45RO). Naive CD4+ T-cells may be readily isolated from (or purified from) a sample (e.g. a PBMC sample) using negative selection, for example as described elsewhere herein.

In some embodiments, unless it is otherwise clear from the context, cells referred to herein may be human cells. For example, in some embodiments, naive CD4+ T-cells may be human naive CD4+ T-cells, and/or Tregs may be human Tregs.

Differentiation of naive CD4+ T-cells into Tregs and reduction (or inhibition) of differentiation of naive CD4+ T-cells into Tregs may be assessed by any appropriate method. In some embodiments, the differentiation of naive CD4+ T-cells into Tregs may be assessed (or be as assessed) using an in vitro cell assay, such as a T-regulatory polarization assay as described herein.

In some embodiments, such an in vitro cell assay comprises steps of:

(a) Incubating naive CD4+ T-cells (preferably human naive CD4+ T-cells) in the presence of TGF-pi (preferably human TGF-pi), IL-2 (preferably human IL- 2), Trx1 (preferably human Trx1 ; SEQ ID N0:1) and antibody (antibody of the invention or control antibody, e.g. isotype control);

(b) Stimulating (or activating) the cells by contacting with a CD3 antibody and a CD28 antibody;

(c) Culturing the cells (e.g. for 3 days);

(d) Determining (or measuring) the amount or level of differentiation of naive CD4+ T-cells into Tregs (e.g. using flow cytometry, e.g. as described elsewhere herein).

The amount (or level of) differentiation of naive CD4+ T-cells into Tregs may be determined (or measured) by determining (or measuring), e.g. by using flow cytometry, a proportion of (e.g. %) of cells that are FOXP3+ within the live CD4+ CD25+ population of cells, e.g. at the end of the assay (e.g. after 3 days). Such flow cytometry may be performed after staining the cells with a viability marker (a marker for live cells), an antibody that binds to CD4 (typically conjugated to an appropriate fluorophore or fluorochrome), an antibody that binds to CD25 (typically conjugated to an appropriate fluorophore or fluorochrome) and an antibody that binds to FOXP3 (typically conjugated to an appropriate fluorophore or fluorochrome). Preferred flow cytometry methods are described elsewhere herein (e.g. in the Example section).

Typically, differentiation of naive CD4+ T-cells into Tregs is measured in the presence of an antibody of the invention and also (e.g. in a parallel test(s)) with (or in the presence of) a control antibody (e.g. a control antibody that does not bind to (or does not specifically bind to) Thioredoxin 1, e.g. an isotype control antibody).

A reduction (or decrease or inhibition) in differentiation of naive CD4+ T-cells into Tregs in the presence of an antibody of the invention (e.g. as compared to a control antibody such as an isotype control antibody, or in comparison to a vehicle only control) is typically indicative that an antibody of the invention reduces differentiation of naive CD4+ T-cells into Tregs. Preferred levels (or amounts) of reduction (or decrease or inhibition) are described elsewhere (e.g. % reductions).

A preferred in vitro cell assay is a T-regulatory polarization assay. A preferred T- regulatory polarization assay comprises steps of:

(a) Providing (a population of) isolated naive CD4+ T-cells. Naive CD4+ T-cells may be obtained or isolated (or may have been obtained or isolated) from PBMCs (preferably human PBMCs), e.g. by using negative selection (e.g. by using a commercially available negative selection kit, e.g. StemCell EasySep™ Human Naive CD4+ Isolation Kit II, Cat. No. 17555). PBMCs may be may be obtained or isolated (or may have been obtained or isolated) from donor buffy coats (e.g. healthy human donor buffy coats);

(b) Resuspending (e.g. at 1x 10⁶ cells/ml) said isolated naive CD4+ T-cells in a medium (e.g. RPMI-10 (RPMI-1640, 10 % heat inactivated FBS, 100 U/rnL penicillin, 100 pg/mL streptomycin, 2 mM L-glutamine and 50 pM p- mercaptoethanol));

(c) Plating the resuspended cells (e.g. 50p I aliquot) in wells of a culture plate (e.g. a 96-well flat bottom plate, e.g. to give 5 x 10⁴ cells/well);

(d) Adding to wells of the plated cells TGF- i (preferably recombinant human TGF-pi), IL-2 (preferably recombinant human IL-2), Trx1 (preferably human Trx1; SEQ ID NO:1) and an antibody of the invention (or control antibody, e.g. isotype control), and stimulating the cells with a CD3 antibody and a CD28 antibody. Preferably, 5 ng/ml TGF-pi is used. Preferably, 100U/ml IL-2 is used. Preferably, 100 ng/ml Trx1 (final concentration) is used. Preferably, the antibody is used at 10 pg/ml (final concentration). The CD3 and CD28 antibodies may be conveniently provided attached covalently to beads (e.g. Dynabeads human T-Activator CD3/CD28 (ThermoFisher, Cat. No. 11132D), and such beads may be used at a ratio of 1:2 (cells:beads). The final volume in each well may be 200pl; and

(e) Culturing the cells. Preferably the cells are cultured in a humidified atmosphere at approximately 37°C at e.g. 5 % CO2. Preferably, the culturing is for 3 days. After culturing (e.g. on day 3), cultures may be agitated by gentle pipetting and may be transferred to a round bottom plate for flow cytometry staining.

A particularly preferred T-regulatory polarization (or differentiation) assay is described in the Example section herein.

The amount (or level) of differentiation of naive CD4+ T-cells into Tregs may be determined (or measured) by determining, e.g. by using flow cytometry, the proportion of (e.g. %) of cells that are FOXP3+ within the live CD4+ CD25+ population of cells, e.g. at the end of the assay (e.g. after 3 days). Such flow cytometry may be performed after staining the cells with a viability marker (a marker for live cells), an antibody that binds to CD4 (typically conjugated to an appropriate fluorophore or fluorochrome), an antibody that binds to CD25 (typically conjugated to an appropriate fluorophore or fluorochrome) and an antibody that binds to FOXP3 (typically conjugated to an appropriate fluorophore or fluorochrome). Preferred flow cytometry methods are described elsewhere herein (e.g. in the Example section).

For a preferred suitable flow cytometry method, the flow cytometry method comprises steps of:

(a) Washing the cells (e.g. in PBS, e.g. 200pl PBS);

(b) Centrifuging the cells (e.g. 300 x g, e.g. for 5 minutes) and discarding the supernatant;

(c) Resuspending the cells with a viability dye. The viability dye may be used at a 1 :1000 dilution, e.g. in PBS. The cells may be incubated with the viability dye for 20 minutes. The cells may be incubated in the viability dye at 2-8°C. The viability dye may in some embodiments be e-fluor 780 fixable viability dye (ThermoFisher, Cat. No. 65-0865-18);

(d) Centrifuging the cells (e.g. after addition or topping up with 10OpI PBS), for example at 300 x g (for e.g. 5 minutes) and discarding the supernatant;

(e) Washing the cells (e.g. in FACS buffer (e.g. 200pl), such as PBS supplemented with 2 % FCS and 0.1 % sodium azide), centrifuging the cells (e.g. at 300 x g, for e.g. 5 minutes), and discarding the supernatant;

(f) Incubating (or resuspending) the cells with (e.g. 25pl of) an antibody cocktail containing an anti-CD4 antibody (conjugated to a fluorophore or fluorochrome) and an anti-CD25 antibody (conjugated to a fluorophore or fluorochrome), for example, for 30 minutes, for example at 2-8°C. Typically, this incubation is done in the dark;

(g) Washing the cells, typically twice, (e.g. in FACS buffer (e.g. 200pl), such as PBS supplemented with 2 % FCS and 0.1 % sodium azide);

(h) Permeabilising the cells for intracellular staining (as FoxP3 is an intracellular marker). The permeabilising agent may be eBioscience™ FOXP3 / Transcription Factor Staining Buffer (ThermoFisher, Cat. No. 00-5523-00);

(i) Incubating the cells with an anti-FOXP3 antibody. The incubation may be for 30 minutes, e.g. at room temperature. The cells are typically protected from light during this incubation; and

(j) Performing flow cytometry to detect (or measure) viable (or live) cells (e.g. % live cells), CD4+CD25+ cells within live cell population (e.g. % CD4+CD25+ cells within live cell population), CD25 expression level (e.g. MFI) within live CD4+ cell population, FOXP3+ cells within live CD4+CD25+ cell population (e.g. % FOXP3+ cells within live CD4+CD25+ cell population), and/or FOXP3 expression level (e.g. MFI) within live CD4+ CD25+ cell population.

In some flow cytometry methods, plates may be stored (e.g. at 2-8°C) and protected from light for up to three days between steps (i) and (j), until flow cytometry is performed.

A particularly preferred flow cytometry (or flow staining) method is described in the Example section herein.

The amount (or level) of differentiation of naive CD4+ T-cells into Tregs may be determined (or measured) by determining (or measuring) by flow cytometry the proportion of (e.g. %) of cells that are FOXP3+ within the live CD4+ CD25+ population of cells, e.g. at the end of a T-regulatory polarization (or differentiation) assay (e.g. after 3 days). A reduction (or decrease or inhibition) in differentiation of naive CD4+ T-cells into Tregs in the presence of an antibody of the invention (e.g. as compared to a control antibody such as an isotype control antibody, or in comparison to a vehicle only control) is typically indicative that an antibody of the invention reduces differentiation of naive CD4+ T-cells into Tregs. Preferred levels (or amounts) of reduction (or decrease or inhibition) are described elsewhere (e.g. % reductions).

In some embodiments, antibodies of the invention which bind to (or specifically recognise or specifically bind to) Thioredoxin 1 may reduce or inhibit (or are capable of reducing or inhibiting) the differentiation (or polarization, or production) and/or survival and/or activation of Tregs in the cancer (e.g. tumour) microenvironment. In some embodiments, antibodies of the invention which bind to Thioredoxin 1 may reduce or inhibit (or be capable of reducing or inhibiting) the differentiation of naive CD4+ T-cells into Tregs in the cancer (e.g. tumour) microenvironment. In some embodiments, antibodies of the invention which bind to Thioredoxin 1 may reduce or inhibit (or be capable of reducing or inhibiting) other properties or functions as described herein in the cancer (e.g. tumour) microenvironment.

In some embodiments, the level (or amount) of differentiation (or polarization or production) and/or survival and/or activation of Tregs observed with (or in the present of) an antibody that has a VH domain that has the amino acid sequence of SEQ ID NO:76 and a VL domain that has the amino acid sequence of SEQ ID NO:77 (or an antibody that has a VH CDR1 of SEQ ID NO:78, a VH CDR2 of SEQ ID NO:79, a VH CDR3 of SEQ ID NQ:80, a VL CDR1 of SEQ ID NO:81 , a VL CDR2 of SEQ ID NO:82 and a VL CDR3 of SEQ ID NO:83) represents a control level. Thus, in some embodiments, levels (or amounts) of reductions (or inhibitions), e.g. % reductions, of differentiation (or polarization or production) and/or survival and/or activation of (or into) Tregs discussed elsewhere herein are as compared to (or relative to) such a control level.

In some embodiments, the level (or amount) of differentiation of naive CD4+ T-cells into Tregs observed with (or in the presence of) an antibody that has a VH domain that has the amino acid sequence of SEQ ID NO:76 and a VL domain that has the amino acid sequence of SEQ ID NO:77 (or an antibody that has a VH CDR1 of SEQ ID NO:78, a VH CDR2 of SEQ ID NO:79, a VH CDR3 of SEQ ID NQ:80, a VL CDR1 of SEQ ID NO:81, a VL CDR2 of SEQ ID NO:82 and a VL CDR3 of SEQ ID NO:83) represents a control level. Thus, in some embodiments, levels (or amounts) of reductions (or inhibitions) of differentiation (e.g. % reductions) of naive CD4+ T-cells into Tregs discussed elsewhere herein are as compared to (or relative to) such a control level.

In some embodiments, antibodies of the invention which bind to Thioredoxin 1 reduce (or decrease) the expression (or expression level) of FOXP3 in live CD4+ CD25+ cells (within a live CD4+ CD25+ population). A reduction (or decrease) in FOXP3 expression is typically a reduction or decrease as compared to the FOXP3 expression observed with an appropriate control (e.g. a control antibody that does not bind to Thioredoxin 1 , e.g. an isotype control). Preferred levels (or amounts) of reduction (or decrease or inhibition) are described elsewhere (e.g. % reductions) in relation to other embodiments of the invention and may also be applied, mutatis mutandis, to these embodiments of the invention. Expression of FOXP3 may be as determined after (i.e. at the end of) an in vitro assay (e.g. a T-regulatory polarization assay) as described herein. Expression of FOXP3 may be determined (or be as determined) by flow cytometry. Expression (or expression level) may thus be as determined in flow cytometry after cells have been stained with a viability dye, a CD4 antibody, a CD25 antibody and a FOXP3 antibody. In preferred embodiments, expression (or expression level) of FOXP3 may thus be as determined by flow cytometry (e.g. as described elsewhere herein) of cells after (i.e. at the end of) an in vitro assay (e.g. a T-regulatory polarization assay) as described herein. Levels (or amounts) of reduction (or decrease) as described elsewhere (e.g. % reductions) in connection with other embodiments of the invention, and relevant controls etc. as described elsewhere herein, may be applied to these embodiments of the invention.

In some embodiments, the expression (or expression level) of FOXP3 in live CD4+ CD25+ cells (within a live CD4+ CD25+ population) observed with (or in the presence of) an antibody that has a VH domain that has the amino acid sequence of SEQ ID NO:76 and a VL domain that has the amino acid sequence of SEQ ID NO:77 (or an antibody that has a VH CDR1 of SEQ ID NO:78, a VH CDR2 of SEQ ID NO:79, a VH CDR3 of SEQ ID NQ:80, a VL CDR1 of SEQ ID NO:81 , a VL CDR2 of SEQ ID NO:82 and a VL CDR3 of SEQ ID NO:83) represents a control level. Thus, in some embodiments, reductions (or decreases), e.g. % reductions, in the expression (or expression level) of FOXP3 in live CD4+ CD25+ cells (within a live CD4+ CD25+ population) discussed elsewhere herein are as compared to (or relative to) such a control level.

In some embodiments, antibodies of the invention which bind to Thioredoxin 1 may reduce (or decrease) the viability of cells (e.g. T-cells as described herein). In some embodiments, antibodies of the invention which bind to Thioredoxin 1 may reduce (or decrease) the viability of cells (e.g. T-cells as described herein) in an in vitro assay as described elsewhere herein (e.g. in a T-regulatory polarization assay). A reduction (or decrease) in viability is typically a reduction or decrease as compared to the viability observed with an appropriate control (e.g. a control antibody that does not bind to Thioredoxin 1 , e.g. an isotype control). Levels (or amounts) of reduction (or decrease or inhibition) described elsewhere (e.g. % reductions) in relation to other embodiments of the invention may also be applied, mutatis mutandis, to these embodiments of the invention also. Viability may be as determined after (i.e. at the end of) an in vitro assay (e.g. a T- regulatory polarization assay) as described herein. Viability of cells may be determined (or be as determined) by flow cytometry. Viability may thus be as determined in flow cytometry after cells have been stained with a viability dye (and optionally after having been stained with other antibodies as described herein). In preferred embodiments, viability may thus be as determined by flow cytometry (e.g. as described elsewhere herein) of cells after (i.e. at the end of) an in vitro assay (e.g. a T-regulatory polarization assay) as described herein. Levels (or amounts) of reduction (or decrease) as described elsewhere (e.g. % reductions) in connection with other embodiments of the invention, and relevant controls etc. as described elsewhere herein, may be applied to these embodiments of the invention also.

In some embodiments, viability observed with (or in the presence of) an antibody that has a VH domain that has the amino acid sequence of SEQ ID NO:76 and a VL domain that has the amino acid sequence of SEQ ID NO:77 (or an antibody that has a VH CDR1 of SEQ ID NO:78, a VH CDR2 of SEQ ID NO:79, a VH CDR3 of SEQ ID NQ:80, a VL CDR1 of SEQ ID NO:81, a VL CDR2 of SEQ ID NO:82 and a VL CDR3 of SEQ ID NO:83) represents a control level. In some embodiments, reductions (or decreases), e.g. % reductions, in viability discussed herein are as compared to (or relative to) such a control level.

In some other embodiments, antibodies of the invention which bind to Thioredoxin 1 do not reduce (or decrease), or do not significantly or substantially reduce (or decrease), the viability of cells (e.g. T-cells as described herein). In some embodiments, antibodies of the invention which bind to Thioredoxin 1 do not reduce (or decrease), or do not significantly or substantially reduce (or decrease), the viability of cells (e.g. T-cells as described herein) in an in vitro assay as described elsewhere herein (e.g. in a T-regulatory polarization assay).

In some embodiments, antibodies of the invention which bind to Thioredoxin 1 reduce (or decrease) the proportion (e.g. %) of CD4+ CD25+ cells in (or within) a population of live cells. A reduction (or decrease) in the proportion (e.g. %) of CD4+ CD25+ cells in (or within) a population of live cells is typically a reduction (or decrease) as compared to the proportion observed with an appropriate control (e.g. a control antibody that does not bind to Thioredoxin 1 , e.g. an isotype control). Preferred levels (or amounts) of reduction (or decrease or inhibition) are described elsewhere (e.g. % reductions) in relation to other embodiments of the invention and may also be applied, mutatis mutandis, to these embodiments of the invention. The proportion may be as determined after (i.e. at the end of) an in vitro assay (e.g. a T-regulatory polarization assay) as described herein. The proportion (e.g. %) of CD4+ CD25+ cells in (or within) a population of live cells may be determined (or be as determined) by flow cytometry. The proportion may thus be as determined in flow cytometry after cells have been stained with a viability dye, a CD4 antibody, a CD25 antibody (and optionally a FOXP3 antibody). In preferred embodiments, the proportion may thus be as determined by flow cytometry (e.g. as described elsewhere herein) of cells after (i.e. at the end of) an in vitro assay (e.g. a T-regulatory polarization assay) as described herein. Levels (or amounts) of reduction (or decrease) as described elsewhere (e.g. % reductions) in connection with other embodiments of the invention, and relevant controls etc. as described elsewhere herein, may be applied to these embodiments of the invention. The reduction may be, for example, at least 5%, at least 10%, at least 20%, at least 30%, or at least 40%.

In some embodiments, the proportion (e.g. %) of CD4+ CD25+ cells in (or within) a population of live cells observed with (or in the presence of) an antibody that has a VH domain that has the amino acid sequence of SEQ ID NO:76 and a VL domain that has the amino acid sequence of SEQ ID NO:77 (or an antibody that has a VH CDR1 of SEQ ID NO:78, a VH CDR2 of SEQ ID NO:79, a VH CDR3 of SEQ ID NQ:80, a VL CDR1 of SEQ ID NO:81, a VL CDR2 of SEQ ID NO:82 and a VL CDR3 of SEQ ID NO:83) represents a control level. Thus, in some embodiments, reductions (or decreases), e.g. % reductions, in the proportion (e.g. %) of CD4+ CD25+ cells in (or within) a population of live cells discussed elsewhere herein are as compared to (or relative to) such a control level.

In some embodiments, antibodies of the invention which bind to Thioredoxin 1 reduce (or decrease) the expression (or expression level) of CD25 in live CD4+ cells (within a live CD4+ cell population). A reduction (or decrease) in CD25 expression is typically a reduction or decrease as compared to the CD25 expression observed with an appropriate control (e.g. a control antibody that does not bind to Thioredoxin 1, e.g. an isotype control). Preferred levels (or amounts) of reduction (or decrease or inhibition) are described elsewhere (e.g. % reductions) in relation to other embodiments of the invention and may also be applied, mutatis mutandis, to these embodiments of the invention. Expression of CD25 may be as determined after (i.e. at the end of) an in vitro assay (e.g. a T-regulatory polarization assay) as described herein. Expression of CD25 may be determined (or be as determined) by flow cytometry. Expression (or expression level) may thus be as determined in flow cytometry after cells have been stained with a viability dye, a CD4 antibody, a CD25 antibody (and optionally a FOXP3 antibody). In preferred embodiments, expression (or expression level) of CD25 may thus be as determined by flow cytometry (e.g. as described elsewhere herein) of cells after (i.e. at the end of) an in vitro assay (e.g. a T-regulatory polarization assay) as described herein. Levels (or amounts) of reduction (or decrease) as described elsewhere (e.g. % reductions) in connection with other embodiments of the invention, and relevant controls etc. as described elsewhere herein, may be applied to these embodiments of the invention. The reduction may be, for example, at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, or at least 70%.

In some embodiments, the expression (or expression level) of CD25 in live CD4+ cells (within a live CD4+ population) observed with (or in the presence of) an antibody that has a VH domain that has the amino acid sequence of SEQ ID NO:76 and a VL domain that has the amino acid sequence of SEQ ID NO:77 (or an antibody that has a VH CDR1 of SEQ ID NO:78, a VH CDR2 of SEQ ID NO:79, a VH CDR3 of SEQ ID NQ:80, a VL CDR1 of SEQ ID NO:81, a VL CDR2 of SEQ ID NO:82 and a VL CDR3 of SEQ ID NO:83) represents a control level. Thus, in some embodiments, reductions (or decreases), e.g. % reductions, in the expression (or expression level) of CD25 in live CD4+ cells (within a live CD4+ population) discussed elsewhere herein are as compared to (or relative to) such a control level.

As indicated above, preferably antibodies of the invention bind to human Thioredoxin 1. In some embodiments of the present invention, antibodies may bind to mouse Thioredoxin 1. Thus, in some preferred embodiments, antibodies may bind to human Thioredoxin 1 and mouse Thioredoxin 1. Such cross- reactivity between species and in particular between humans and species commonly used as pre-clinical animal models (e.g. mouse) may be an advantage as it may allow a more effective translation from pre-clinical studies to clinical use. For example, having an antibody which cross reacts with the native Thioredoxin 1 present in a mouse model used may mean that the results in this model are more likely to reflect the situation in a human patient, thereby allowing a more accurate assessment of for example dosing to be made and an increased likelihood of identifying any potentially relevant or problematic side effects. For example, the ability of an antibody of the invention to bind to both human Thioredoxin 1 and mouse Thioredoxin 1 means that such antibodies may be tested in preclinical toxicity studies in mice to assess adverse side effects of the treatment and to find appropriate tolerated dosages. Antibodies which do not bind to mouse Thioredoxin 1 cannot be used in syngeneic mouse models. The ability of an antibody to bind to Thioredoxin 1 (e.g. human and/or mouse Thioredoxin 1) may be assessed by any suitable method, for example an SPR assay or an ELISA assay.

In some embodiments, antibodies of the invention may increase (or be capable of increasing) the survival of an experimental mouse model of cancer when administered to said mouse model. Alternatively viewed, in some embodiments antibodies of the invention may increase (or be capable of increasing) the survival of mice of an experimental mouse model of cancer when administered to said mice. Alternatively viewed, in some embodiments antibodies of the present invention may increase survival as determined in an experimental mouse model of cancer. Such a mouse model may be a syngeneic mouse model of cancer. The increase in survival may be an increase as compared to the survival observed (or measured or determined) with an appropriate control (e.g. an isotype control antibody or a vehicle only control). The increase in survival may be any measurable or significant increase, more preferably a statistically significant increase (e.g. as compared to a control such as an isotype control or a vehicle only control). Preferably, the statistically significant difference as compared to a relevant control or other comparative entity or measurement has a probability value of < 0.1 or < 0.05, preferably < 0.01 , < 0.001 or < 0.0005.

Any suitable mouse model of cancer (e.g. a syngeneic mouse model of cancer) may be used to determine the ability of an antibody of the invention to increase survival of an experimental mouse model of cancer, and the skilled person is familiar with suitable models. For example, a syngeneic mouse model of breast cancer may be used (e.g. a syngeneic 4T 1 model of breast cancer may be used; 4T1 is a breast cancer cell line derived from the mammary gland tissue of a mouse BALB/c strain). When determining survival in an experimental mouse model of cancer, any suitable study endpoint may be used and the skilled person is familiar with suitable study endpoints. For example, when determining (or performing a study to determine) survival in an experimental mouse model of cancer the study endpoint may be death (e.g. due to any cause) or a tumour volume (e.g. mean tumour volume) of at least (or about) 1500mm³. In some cases, the study endpoint may be death (e.g. due to any cause) or a tumour volume (e.g. mean tumour volume) of at least (or about) 1500mm³, whichever happens sooner. In some preferred embodiments, antibodies of the invention may increase (or be capable of increasing) the survival of an experimental mouse model of cancer when administered to said mouse model, wherein the increase in survival is determined using (or is as determined using, or has been determined using) the following method:

(a) injecting mice (e.g. immunocompetent Balb/c mice) with a given number (e.g. 300,000) mouse cancer cells (e.g. 4T 1 cells), for example into the flank of said mice;

(b) matching (or separating) said mice of (a) into treatment (i.e. mice to be administered with a test antibody) or control groups, e.g. based on tumour volume once a given average tumour volume (e.g. 50-120mm³) has been reached;

(c) administering (e.g. intravenously) to said mice of (b) a test antibody (antibody of the invention) or a control (e.g. an isotype control). The dose may be 10mg/kg in an appropriate dosing volume (e.g. 10ml/kg). Administration may be done twice a week, for example for three weeks;

(d) determining (or measuring) the survival of said mice. The endpoint (i.e. the study endpoint of survival) may be death (e.g. due to any cause) or a given tumour volume (e.g. at least (or about) 1500mm³). Tumour volume may be determined by any means, e.g. as described elsewhere herein.

A method for determining survival may be run for (i.e. performed over) any appropriate period of time after the first administration of the antibody being tested (and control) (e.g. it may be run for 21 days, with day 0 being the day of the first administration of the antibody (or control)). Thus, the results of a method for determining survival may be determined after any appropriate time period (e.g. at 21 days, with day 0 being the day of the first administration of the antibody (or control)). Typically, multiple doses (multiple administrations) of the antibody (or control) would be given to the mouse model, but in some cases there may be only a single dose (so in such cases the first administration would be the only administration).

A particularly preferred syngeneic mouse model of cancer is as described in Example 2 herein (or is substantially as described in Example 2). A particularly preferred method of determining whether or not an antibody increases the survival of an experimental mouse model of cancer when administered to said mouse model is described in Example 2 herein (or is substantially as described in Example 2). Thus, features of the mouse model and method as described in Example 2 are preferred. In some preferred embodiments, antibodies of the invention may increase (or be capable of increasing) the survival of an experimental mouse model of cancer when administered to said mouse model, wherein the increase in survival is determined using (or is as determined using, or has been determined using) the model and method as described in Example 2 herein.

In some embodiments, antibodies of the invention inhibit the growth of tumours (e.g. human tumours or human cell derived tumours) in an experimental mouse model of cancer when administered to said mouse model. In some such embodiments, the experimental mouse model of cancer has a humanized immune system. Alternatively viewed, in some embodiments antibodies of the invention may inhibit the growth of tumours (e.g. human tumours or human cell derived tumours) in mice of an experimental mouse model of cancer when administered to said mice. Alternatively viewed, in some embodiments antibodies of the present invention may inhibit the growth of a tumour (e.g. a human tumour or human cell derived tumours) as determined in an experimental mouse model of cancer.

The inhibition of tumour growth by an antibody of the invention may be an inhibition of tumour growth as compared to the tumour growth observed (or measured or determined) with an appropriate control (e.g. an isotype control antibody or a vehicle only control). The inhibition of tumour growth may be any measurable or significant inhibition, more preferably a statistically significant inhibition (e.g. as compared to a control such as an isotype control or a vehicle only control). Preferably, the statistically significant difference as compared to a relevant control or other comparative entity or measurement has a probability value of < 0.1 or < 0.05, preferably < 0.01 , < 0.001 or < 0.0001. In some embodiments, the tumour growth inhibition (TGI) (or % tumour growth inhibition (TGI) value) may be at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30% or at least 35% (e.g. about 20% to 35%), for example as compared to the tumour growth observed (or measured or determined) with an appropriate control (e.g. an isotype control or vehicle only control). Tumour growth inhibitions (or TGI values) may be as determined at a given time point after the first administration of the antibody (or at a given time point after the start of the administration regimen), e.g. at day 13 after the first administration of the antibody or at day 30 after the first administration of the antibody or at day 35 after the first administration of the antibody or at day 60 after first administration of the antibody, or tumour growth inhibitions (or TGI values) may be as determined between given time points after the first administration of the antibody, e.g. they may be TGIs at a number of assessment dates between two time points (e.g. between day 13 and day 30). In such embodiments, day 0 is the day of the first administration of the test antibody (or control)). Typically, multiple doses (multiple administrations) of the antibody (or control) would be given to the mouse model, but in some cases there may be only a single dose (so in such cases the first administration would be the only administration). In some embodiments, a tumour growth inhibition (or %TGI value) may be the average (e.g. mean or median) tumour growth inhibition (e.g. %TGI value) in a group of mice (i.e. in a group of mice being tested).

Any suitable mouse model of cancer may be used to determine the ability of an antibody of the invention to inhibit tumour growth, and the skilled person is familiar with suitable models. For example, a mouse model of breast cancer (e.g. triple negative breast cancer) may be used (e.g. a MDA-MB-231 model of triple negative breast cancer may be used).

As indicated above, in some embodiments the experimental mouse model of cancer used to determine the ability of an antibody to inhibit tumour growth has a humanized immune system. The skilled person is familiar with suitable mouse models. For example, an immunodeficient mouse strain (e.g. NOD/Shi-scid/IL-2Rynull) that has been engrafted (e.g. intravenously) with human cord-blood derived CD34+ hematopoietic stem and progenitor cells may be used. In some such embodiments, mice with a humanization rate (or engraftment level) (hCD45/TotalCD45) of above 25% are preferred. Humanization rate (or engraftment level) may be determined by any appropriate means, e.g. by analysing the proportion of human CD45+ cells among total blood leukocytes (mouse and human), for example by flow cytometry.

As indicated above, in some embodiments the experimental mouse model of cancer used to determine the ability of an antibody to inhibit tumour growth is an experimental mouse model of a human cancer (or a human tumour). Thus, in some embodiments, the cancer (or tumour) in the mouse model is derived from human tumour cells that have been implanted into the mouse (e.g. implanted into the mammary fat pad). Such human tumour cells may, for example, be MDA-MB-231 cells. MDA-MB-231 is a human triple-negative breast cancer (TNBC) cell line.

In some preferred embodiments, antibodies of the invention may inhibit (or be capable of inhibiting) tumour growth in an experimental mouse model of cancer (or model of a tumour) when administered to said mouse model, wherein the tumour growth inhibition (or TGI) is determined using (or is as determined using, or has been determined using) the following method:

(a) implanting into mice (e.g. into the mammary fat pad) a given number (e.g. 5x10⁶) cancer cells (e.g. human cancer cells, preferably MDA-MD-231 cells). In some preferred embodiments the mice have a humanized immune system (e.g. in some embodiments an immunodeficient mouse strain (e.g. NOD/Shi- scid/l L-2Rynull) that has been engrafted (e.g. intravenously) with human cord- blood derived CD34+ hematopoietic stem and progenitor cells is used (and in some such embodiments mice with a humanization rate (hCD45/TotalCD45) of above 25% are preferred);

(b) matching (or separating) said mice of (a) into treatment (i.e. to be administered with a test antibody) or control groups, e.g. based on tumour volume once a given average tumour volume (e.g. 80-150mm³) has been reached (and optionally also based on donor (i.e. donor of cord blood cells) and/or humanization rate when a mouse with a humanized immune system is used);

(c) administering (e.g. intravenously) to said mice of (b) a test antibody (antibody of the invention) or a control (e.g. an isotype control). The dose may be 10mg/kg in an appropriate dosing volume (e.g. 10ml/kg). Administration may be done twice a week, for example for five weeks;

(d) determining (or measuring) tumour growth inhibition (TGI) in said mice (e.g. by determining tumour volume (e.g. determining or measuring tumour volume twice per week), for example using digital calipers to measure tumour dimensions and using the formula width² x length x 0.52 to determine tumour volume). TGI (or %TGI values) may be calculated using the formula: %TGI = 1-(Tf-Ti) / (Cf-Ci) x100, where “i" is initial tumour volume, “f” is assessment date/final tumour volume, “T” is “treatment” (i.e. test antibody) and “C” is “control” (e.g. isotype control).

A method for determining tumour growth inhibition may be run for (i.e. performed over) any appropriate period of time after the first administration of the antibody being tested (and control) (e.g. it may be run for 13 days, or 30 days, or 35 days, or 60 days, with day 0 being the day of the first administration of the antibody (or control)). Thus, the results of a method for determining tumour growth inhibition in a mouse model may be determined after any appropriate time period (e.g. at 13 days, or 30 days, or 35 days or 60 days, with day 0 being the day of the first administration of the antibody (or control)).

In some embodiments, antibodies of the invention may inhibit tumour growth in an experimental mouse model of cancer to a greater extent than Pembrolizumab (Keytruda). Pembrolizumab (Keytruda) is a clinically approved anti-PD1 antibody. The ability of Pembrolizumab (Keytruda) to inhibit tumour growth may be determined (or be as determined), mutatis mutandis, using an experimental mouse model of cancer as described above. In some embodiments, in an experimental mouse model of cancer, the tumour growth inhibition value (%TGI) of (or exhibited by or measured for) an antibody of the invention is at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 10%, at least 15% or at least 20% higher than the tumour growth inhibition value (%TGI) of (or exhibited by or measured for) Pembrolizumab. Preferred administration routes and schedules for Pembrolizumab may be as described in Example 3 herein.

A particularly preferred experimental mouse model of cancer is as described in Example 3 herein (or is substantially as described in Example 3). A particularly preferred method of determining whether or not an antibody inhibits tumour growth in an experimental mouse model of cancer (or model of a tumour) is described in Example 3 herein (or is substantially as described in Example 3). Thus, features of the mouse model and method as described in Example 3 are preferred. In some preferred embodiments, antibodies of the invention may inhibit tumour growth (or be capable of inhibiting tumour growth) in an experimental mouse model of cancer, wherein said inhibition of tumour growth is determined using (or is as determined using, or has been determined using) the model and method as described in Example 3 herein.

Nucleic acid molecules comprising nucleotide sequences that encode the antibodies of the present invention as defined herein or parts or fragments thereof, or nucleic acid molecules substantially homologous thereto, form yet further aspects of the invention.

The term "nucleic acid sequence" or "nucleic acid molecule" as used herein refers to a sequence of nucleoside or nucleotide monomers composed of naturally occurring bases, sugars and intersugar (backbone) linkages. The term also includes modified or substituted sequences comprising non-naturally occurring monomers or portions thereof. The nucleic acid sequences of the present invention may be deoxyribonucleic acid sequences (DNA) or ribonucleic acid sequences (RNA) and may include naturally occurring bases including adenine, guanine, cytosine, thymidine and uracil. The sequences may also contain modified bases. Examples of such modified bases include aza and deaza adenine, guanine, cytosine, thymidine and uracil; and xanthine and hypoxanthine. The nucleic acid molecules may be double stranded or single stranded. The nucleic acid molecules may be wholly or partially synthetic or recombinant.

Preferred nucleic acid molecules are those encoding a VH region of an antibody of the present invention (e.g., those encoding SEQ ID NOs:4 or 22 or 40 or 58, such as SEQ ID NOs:2 or 20 or 38 or 56, respectively). Other preferred nucleic acid molecules are those encoding a VL region of an antibody of the present invention (e.g., those encoding SEQ ID NOs:5 or 23 or 41 or 59, such as SEQ ID NOs:3 or 21 or 39 or 57, respectively).

Thus, preferred nucleic acid molecules comprise sequences which encode a heavy chain variable region (VH) that has the amino acid sequence of SEQ ID NO: 4 or 22 or 40 or 58 (which is preferably encoded by SEQ ID NO: 2 or 20 or 38 or 56) and/or comprise sequences which encode a light chain variable region (VL) which has the amino acid sequence of SEQ ID NO: 5 or 23 or 41 or 59 (which is preferably encoded by SEQ ID NO: 3 or 21 or 39 or 57).

Also preferred are nucleic acids which encode the following combinations: SEQ ID NOs: 4 and 5; or SEQ ID NOs: 22 and 23; or SEQ ID NOs: 40 and 41; or SEQ ID NOs: 58 and 59. Also preferred are nucleic acid molecules which comprise the following combinations: SEQ ID NOs: 2 and 3; or SEQ ID NOs: 20 and 21; or SEQ ID NOs: 38 and 39; or SEQ ID NOs: 56 and 57).

Nucleic acid molecules comprising nucleotide sequences that are substantially homologous to the specific nucleotide sequences described herein form further aspects and embodiments of the invention. The term "substantially homologous" as used herein in connection with nucleic acid sequences includes sequences having at least 65%, 70% or 75%, preferably at least 80%, and even more preferably at least 85%, 90%, 95%, 96%, 97%, 98% or 99%, sequence identity to the amino acid or nucleic acid sequence disclosed.

Other preferred nucleic acid molecules comprise sequences that encode IgG forms of the antibodies of the invention.

In another aspect, the present invention provides a set (or plurality) of nucleic acid molecules each comprising a nucleotide sequence, wherein said set of nucleic acid molecules together (or collectively) encode an antibody in accordance with the invention. Such a set of nucleic acid molecules may be characterised in that when the set is expressed (i.e. expressed together) (e.g. in a host cell) an entire antibody of the present invention is expressed and preferably assembled.

In the following descriptions of the compositions, immunoconjugates, pharmaceuticals, combinations, cocktails, kits, first and second medical uses and all methods in accordance with this invention, the terms "antibody" and "immunoconjugate", or an antigen-binding region or fragment thereof, unless otherwise specifically stated or made clear from the scientific terminology, refer to a range of anti-Thioredoxin 1 antibodies as well as to the specific antibodies described in the Example section herein.

The terms "antibody" and "immunoglobulin", as used herein, refer broadly to any immunological binding agent that comprises an antigen binding domain, including polyclonal and monoclonal antibodies.

Thus, the term “antibody” includes immunological binding agents that comprise an antigen binding domain obtained from or derived from an antibody (or based on an antigen binding domain of an antibody), e.g. obtained from or derived from an Ig (e.g. IgG) antibody (or based on an antigen binding domain of an Ig (e.g. IgG) antibody).

In some embodiments, monoclonal antibodies are preferred (e.g. mouse monoclonal or human monoclonal antibodies or humanized monoclonal antibodies or rabbit monoclonal antibodies). Preferred monoclonal antibodies include those based on the 7C8, 1B7, 1F5 and 9B6 antibodies of the invention (e.g. those having the CDR sequences and/or VH domain and/or VL domain sequences thereof, or sequences substantially homologous thereto).

Depending on the type of constant domain in the heavy chains, whole antibodies are assigned to one of five major classes: IgA, IgD, IgE, IgG, and IgM and the antibodies of the invention may be in any one of these classes. Several of these are further divided into subclasses or isotypes, such as lgG1 , lgG2, lgG3, lgG4, and the like. The heavy-chain constant domains that correspond to the difference classes of immunoglobulins are termed a, 8, s, y and p., respectively. The subunit structures and three-dimensional configurations of different classes of immunoglobulins are well known.

Generally, where whole antibodies rather than antigen binding regions are used in the invention, IgG (e.g. IgGi, lgG2 or lgG4) and/or IgM are preferred because they are the most common antibodies in the physiological situation and because they are most easily made in a laboratory setting. In some embodiments, IgG antibodies are preferred. In some embodiments, IgGi or lgG2b antibodies are preferred.

The "light chains" of mammalian antibodies are assigned to one of two clearly distinct types: kappa (K) and lambda ( ), based on the amino acid sequences of their constant domains and some amino acids in the framework regions of their variable domains.

As will be understood by those in the art, the immunological binding reagents encompassed by the term "antibody" includes or extends to all antibodies and antigen binding fragments thereof, including whole antibodies, dimeric, trimeric and multimeric antibodies; bispecific antibodies; chimeric antibodies; recombinant and engineered antibodies, and fragments thereof.

The term "antibody" is thus used to refer to any antibody-like molecule that has an antigen binding region, and this term includes antibody fragments that comprise an antigen binding domain such as Fab', Fab, F(ab')2, single domain antibodies (DABs), TandAbs dimer, Fv, scFv (single chain Fv), dsFv, ds-scFv, Fd, linear antibodies, minibodies, diabodies, bispecific antibody fragments, bibody, tribody (scFv-Fab fusions, bispecific or trispecific, respectively); sc-diabody; kappa(lamda) bodies (scFv-CL fusions); BiTE (Bispecific T-cell Engager, scFv-scFv tandems to attract T cells); DVD-lg (dual variable domain antibody, bispecific format); SIP (small immunoprotein, a kind of minibody); SMIP ("small modular immunopharmaceutical" scFv-Fc dimer; DART (ds-stabilized diabody "Dual Affinity ReTargeting"); small antibody mimetics comprising one or more CDRs and the like.

The techniques for preparing and using various antibody-based constructs and fragments are well known in the art. Diabodies, in particular, are further described in EP 404 097 and WO 93/11161; whereas linear antibodies are further described in the art. In some embodiments, the antibodies of the invention are non-human antibodies (e.g. rabbit or rat or mouse antibodies). In some embodiments, the antibodies of the invention are mouse antibodies (e.g. mouse monoclonal antibodies).

In some embodiments, the antibodies of the invention are human antibodies, more preferably fully human antibodies. In this regard, human antibodies generally have at least two potential advantages for use in human therapy. First, the human immune system should not recognize the antibody as foreign. Second, the half-life in the human circulation will be similar to naturally occurring human antibodies, allowing smaller and less frequent doses to be given.

The term "human" as used herein in connection with antibody molecules and binding proteins first refers to antibodies and binding proteins having variable regions {e.g., VH, VL, CDR or FR regions) and, optionally, constant antibody regions, isolated or derived from a human repertoire or derived from or corresponding to sequences found in humans or a human repertoire, e.g., in the human germline or somatic cells.

"Human" antibodies and binding proteins further include amino acid residues not encoded by human sequences, e.g., mutations introduced by random or site directed mutations in vitro, for example mutations introduced by in vitro cloning or PCR. Particular examples of such mutations are mutations that involve conservative substitutions or other mutations in a small number of residues of the antibody or binding protein, e.g., in up to 5, 4, 3, 2 or 1 of the residues of the antibody or binding protein, preferably e.g., in up to 5, 4, 3, 2 or 1 of the residues making up one or more of the CDRs of the antibody or binding protein. Certain examples of such "human" antibodies include antibodies and variable regions that have been subjected to standard modification techniques to reduce the amount of potentially immunogenic sites.

Thus, "human" antibodies include sequences derived from and related to sequences found in humans, but which may not naturally exist within the human antibody germline repertoire in vivo. In addition, human antibodies and binding proteins include proteins comprising human consensus sequences identified from human sequences, or sequences substantially homologous to human sequences.

In addition, human antibodies and binding proteins are not limited to combinations of VH, L, CDR or FR regions that are themselves found in combination in human antibody molecules. Thus, human antibodies and binding proteins can include or correspond to combinations of such regions that do not necessarily exist naturally in humans (e.g. are not naturally occurring antibodies).

In some embodiments, human antibodies will be fully human antibodies. "Fully human" antibodies, as used herein, are antibodies comprising "human" variable region domains and/or CDRs, without substantial non-human antibody sequences or without any non-human antibody sequences. For example, antibodies comprising human variable region domains and/or CDRs "without substantial non-human antibody sequences" are antibodies, domains and/or CDRs in which only up to 5, 4, 3, 2 or 1 amino acids are amino acids that are not encoded by human antibody sequences. Thus, "fully human" antibodies are distinguished from "humanized" antibodies, which are based on substantially non-human variable region domains, e.g., mouse variable region domains, in which certain amino acids have been changed to better correspond with the amino acids typically present in human antibodies.

The "fully human" antibodies of the invention may be human variable region domains and/or CDRs without any other substantial antibody sequences, such as being single chain antibodies. Alternatively, the "fully human" antibodies of the invention may be human variable region domains and/or CDRs integral with or operatively attached to one or more human antibody constant regions. Certain preferred fully human antibodies are IgG antibodies with the full complement of IgG constant regions.

In other embodiments, "human" antibodies of the invention will be part-human chimeric antibodies. "Part-human chimeric" antibodies, as used herein, are antibodies comprising "human" variable region domains and/or CDRs operatively attached to, or grafted onto, a constant region of a non-human species, such as rat or mouse. Such part-human chimeric antibodies may be used, for example, in pre-clinical studies, wherein the constant region will preferably be of the same species of animal used in the pre-clinical testing.

These part-human chimeric antibodies may also be used, for example, in ex vivo diagnostics, wherein the constant region of the non-human species may provide additional options for antibody detection.

In some embodiments, the antibodies of the invention will be humanized antibodies. “Humanized" antibodies, which are based on substantially non-human variable region domains are antibodies in which certain amino acids have been changed to better correspond with the amino acids typically present in human antibodies. Methods for generating humanized antibodies are well known in the art. For example, humanized antibodies can be accomplished by inserting the appropriate CDRs (e.g. murine CDRs) into a human antibody "scaffold". In some cases, one or more CDR residues may be changed to better correspond with the amino acids typically present in human antibodies.

In some embodiments, antibodies of the invention may be chimeric antibodies. Such chimeric antibodies may comprise non-human (e.g. mouse) variable region domains and/or CDRs operatively attached to, or grafted onto, a constant region of human antibody.

In some embodiments, antibodies of the invention may comprise a heavy chain variable region and a light chain variable region in accordance with the present invention and a heavy chain constant region of a human antibody (e.g. an IgG (for example IgG 1 ) heavy chain constant region of a human antibody).

The term "heavy chain complementarity determining region" ("heavy chain CDR") as used herein refers to regions of hypervariability within the heavy chain variable region (VH domain) of an antibody molecule. The heavy chain variable region has three CDRs termed heavy chain CDR1 , heavy chain CDR2 and heavy chain CDR3 from the amino terminus to carboxy terminus. The heavy chain variable region also has four framework regions (FR1 , FR2, FR3 and FR4 from the amino terminus to carboxy terminus). These framework regions separate the CDRs.

The term "heavy chain variable region" (VH domain) as used herein refers to the variable region of a heavy chain of an antibody molecule.

The term "light chain complementarity determining region" ("light chain CDR") as used herein refers to regions of hypervariability within the light chain variable region (VL domain) of an antibody molecule. Light chain variable regions have three CDRs termed light chain CDR1 , light chain CDR2 and light chain CDR3 from the amino terminus to the carboxy terminus. The light chain variable region also has four framework regions (FR1, FR2, FR3 and FR4 from the amino terminus to carboxy terminus). These framework regions separate the CDRs.

The term "light chain variable region" ( L domain) as used herein refers to the variable region of a light chain of an antibody molecule.

CDR sequences of certain antibodies of the invention are set forth herein in Tables A, B, C and D. In some other embodiments, CDR sequences of antibodies of the invention may be CDR sequences in the VH domains and VL domains of antibodies of the invention as identified using any suitable method (or tool), for example as identified according to the well-known methods of Kabat (e.g. Kabat, et al., "Sequences of Proteins of Immunological Interest", 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD, 647- 669, 1991) or Chothia (e.g. Chothia C, et al. (1989) Nature, 342:877-883, or Al-Lazikani et al., (1997) JMB 273,927-948). In some embodiments, CDR sequences of antibodies of the invention may be CDR sequences in the VH domains and VL domains of antibodies of the invention as identified using the IMGT numbering scheme (e.g. Lefranc, M.-P., The Immunologist, 7, 132-136 (1999); www.imgt.org)).

Antibodies can be fragmented using conventional techniques. For example, F(ab')2 fragments can be generated by treating the antibody with pepsin. The resulting F(ab')2 fragment can be treated to reduce disulfide bridges to produce Fab' fragments. Papain digestion can lead to the formation of Fab fragments. Fab, Fab' and F(ab')2, scFv, Fv, dsFv, Fd, dAbs, TandAbs, ds-scFv, dimers, minibodies, diabodies, bispecific antibody fragments and other fragments can also be synthesized by recombinant techniques or can be chemically synthesized. Techniques for producing antibody fragments are well known and described in the art.

In certain embodiments, the antibody or antibody fragment of the present invention comprises all or a portion of a heavy chain constant region, such as an lgG1, lgG2, lgG3, lgG4, lgA1, lgA2, IgE, IgM or IgD constant region. Preferably, the heavy chain constant region is an IgG heavy chain constant region, e.g. an IgG 1 or an lgG2 or an lgG4 heavy chain constant region, or a portion thereof. In some embodiments, a constant region may be a human IgG heavy chain constant region (or a portion thereof), e.g. a human IgG 1 heavy chain constant region (or a portion thereof). Furthermore, the antibody or antibody fragment can comprise all or a portion of a kappa light chain constant region or a lambda light chain constant region, or a portion thereof. All or part of such constant regions may be produced naturally or may be wholly or partially synthetic. Appropriate sequences for such constant regions are well known and documented in the art. When a full complement of constant regions from the heavy and light chains are included in the antibodies of the invention, such antibodies are typically referred to herein as "full length" antibodies or "whole" antibodies. Thus, in some embodiments, the antibodies of the invention are Ig (e.g. IgG) antibodies.

The antibodies or antibody fragments can be produced naturally or can be wholly or partially synthetically produced. Thus the antibody may be from any appropriate source, for example recombinant sources and/or produced in transgenic animals or transgenic plants, or in eggs using the IgY technology. Thus, the antibody molecules can be produced in vitro or in vivo. The antibody may be a recombinant antibody.

Preferably, the antibody or antibody fragment comprises an antibody light chain variable region (VL) that comprises three CDR domains and an antibody heavy chain variable region (VH) that comprises three CDR domains. Said VL and VH generally form the antigen binding site.

An "Fv" fragment is the minimum antibody fragment that contains a complete antigen-recognition and binding site. This region has a dimer of one heavy chain and one light chain variable domain in tight, non-covalent association. It is in this configuration that the three hypervariable regions (CDRs) of each variable domain interact to define an antigen-binding site on the surface of the H- L dimer. Collectively, the six hypervariable regions (CDRs) confer antigen-binding specificity to the antibody.

However, it is well documented in the art that the presence of three CDRs from the light chain variable domain and three CDRs from the heavy chain variable domain of an antibody is not always necessary for antigen binding. Thus, constructs smaller than the above classical antibody fragment are known to be effective. For example, camelid antibodies have an extensive antigen binding repertoire but are devoid of light chains. Also, results with single domain antibodies comprising VH domains alone or VL domains alone show that these domains can bind to antigen with acceptably high affinities. Thus, three CDRs can effectively bind antigen.

Thus, although preferred antibodies of the invention might comprise six CDR regions (three from a light chain and three from a heavy chain), antibodies with fewer than six CDR regions (e.g. 3 CDR regions) are encompassed by the invention. Antibodies with CDRs from only the heavy chain or light chain are also contemplated.

Preferred light chain CDR regions for use in conjunction with the specified heavy chain CDR regions are described elsewhere herein. However, other light chain variable regions that comprise three CDRs for use in conjunction with the heavy chain variable regions of the invention are also contemplated. Appropriate light chain variable regions which can be used in combination with the heavy chain variable regions of the invention and which give rise to an antibody which binds Thioredoxin 1 in accordance with the invention can be readily identified by a person skilled in the art.

A yet further aspect of the invention provides an antibody, preferably an isolated antibody, which binds to or specifically recognizes Thioredoxin 1 and which has the ability to compete with (i.e. bind to the same or substantially the same epitope as) an antibody of the invention for binding to Thioredoxin 1. Other features and properties of other aspects of the invention apply, mutatis mutandis, to this aspect of the invention.

In some embodiments, the invention provides an antibody, preferably an isolated antibody, which binds to or specifically recognizes Thioredoxin 1 and which has the ability to compete with (i.e. bind to the same or substantially the same epitope as) the 7C8, 1 B7, 1 F5 or 9B6 monoclonal antibodies of the invention (i.e. compete with an antibody comprising VL and VH sequences of these monoclonal antibodies as set out elsewhere herein) as described herein for binding to Thioredoxin 1.

In other embodiments, the invention provides an antibody, preferably an isolated antibody, which binds to or specifically recognizes Thioredoxin 1 and which has the ability to compete with an antibody comprising the same CDRs as the 7C8, 1 B7, 1 F5 or 9B6 monoclonal antibodies of the invention (the CDR sequences of these antibodies are set out elsewhere herein) for binding to Thioredoxin 1 .

Binding to the same epitope/antigen can be readily tested by methods well known and described in the art, e.g. using binding assays such as a competition assay, e.g. as described elsewhere herein.

Preferably, the above described abilities and properties are observed at a measurable or significant level and more preferably at a statistically significant level, when compared to appropriate control levels. Appropriate significance levels are discussed elsewhere herein. More preferably, one or more of the above described abilities and properties are observed at a level which is measurably better, or more preferably significantly better, when compared to the abilities observed for prior art antibodies.

In any statistical analysis referred to herein, preferably the statistically significant difference over a relevant control or other comparative entity or measurement has a probability value of < 0.1, preferably < 0.05. Appropriate methods of determining statistical significance are well known and documented in the art and any of these may be used.

The present invention provides an antibody, for example an isolated antibody, that binds to (or specifically binds to) Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises:

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:6 or a sequence substantially homologous thereto,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:7 or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:8 or a sequence substantially homologous thereto; and/or (preferably “and”) wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:9 or a sequence substantially homologous thereto,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO: 10 or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:11 or a sequence substantially homologous thereto; preferably said substantially homologous sequence is a sequence containing 1, 2 or 3 amino acid substitutions compared to the given CDR sequence, or wherein said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

Preferred embodiments of this aspect of the invention include antibodies comprising one or more of the antibody sequences (e.g. CDR sequences and/or VH domain and/or VL domain sequences) that are described elsewhere herein in connection with other aspects of the present invention. Thus, discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention. In some preferred embodiments of this aspect of the invention, the invention provides an antibody comprising a VH domain that has the amino acid sequence of SEQ ID NO:4 or a sequence substantially homologous thereto, and/or (preferably “and”) a VL domain that has the amino acid sequence of SEQ ID NO:5 or a sequence substantially homologous thereto.

In another aspect, and in some embodiments, the present invention provides an antibody, for example an isolated antibody, that binds to (or specifically binds to) Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region has the amino acid sequence of SEQ ID NO:4 or a sequence substantially homologous thereto (e.g. a sequence having at least 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% sequence identity thereto), and/or (preferably “and”) said light chain variable region has the amino acid sequence of SEQ ID NO:5 or a sequence substantially homologous thereto (e.g. a sequence having at least 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% sequence identity thereto). Preferred embodiments of this aspect of the invention include antibodies comprising one or more of the antibody sequences (e.g. CDR sequences and/or VH domain and/or VL domain sequences) that are described elsewhere herein in connection with other aspects of the present invention. Thus, discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention.

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:24 or a sequence substantially homologous thereto,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:25 or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:26 or a sequence substantially homologous thereto; and/or (preferably “and”) wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:27 or a sequence substantially homologous thereto, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or a sequence substantially homologous thereto; preferably said substantially homologous sequence is a sequence containing 1, 2 or 3 amino acid substitutions compared to the given CDR sequence, or wherein said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

Preferred embodiments of this aspect of the invention include antibodies comprising one or more of the antibody sequences (e.g. CDR sequences and/or VH domain and/or VL domain sequences) that are described elsewhere herein in connection with other aspects of the present invention. Thus, discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention. In some preferred embodiments of this aspect of the invention, the invention provides an antibody comprising a VH domain that has the amino acid sequence of SEQ ID NO:22 or a sequence substantially homologous thereto, and/or (preferably “and”) a VL domain that has the amino acid sequence of SEQ ID NO:23 or a sequence substantially homologous thereto.

In another aspect, and in some embodiments, the present invention provides an antibody, for example an isolated antibody, that binds to (or specifically binds to) Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region has the amino acid sequence of SEQ ID NO:22 or a sequence substantially homologous thereto (e.g. a sequence having at least 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% sequence identity thereto), and/or (preferably “and”) said light chain variable region has the amino acid sequence of SEQ ID NO:23 or a sequence substantially homologous thereto (e.g. a sequence having at least 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% sequence identity thereto). Preferred embodiments of this aspect of the invention include antibodies comprising one or more of the antibody sequences (e.g. CDR sequences and/or VH domain and/or VL domain sequences) that are described elsewhere herein in connection with other aspects of the present invention. Thus, discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention.

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:42 or a sequence substantially homologous thereto,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:43 or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or a sequence substantially homologous thereto; and/or (preferably “and”) wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:45 or a sequence substantially homologous thereto,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:46 or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:47 or a sequence substantially homologous thereto; preferably said substantially homologous sequence is a sequence containing 1, 2 or 3 amino acid substitutions compared to the given CDR sequence, or wherein said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

Preferred embodiments of this aspect of the invention include antibodies comprising one or more of the antibody sequences (e.g. CDR sequences and/or VH domain and/or VL domain sequences) that are described elsewhere herein in connection with other aspects of the present invention. Thus, discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention. In some preferred embodiments of this aspect of the invention, the invention provides an antibody comprising a VH domain that has the amino acid sequence of SEQ ID NQ:40 or a sequence substantially homologous thereto, and/or (preferably “and”) a VL domain that has the amino acid sequence of SEQ ID NO:41 or a sequence substantially homologous thereto.

In another aspect, and in some embodiments, the present invention provides an antibody, for example an isolated antibody, that binds to (or specifically binds to) Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region has the amino acid sequence of SEQ ID NO:40 or a sequence substantially homologous thereto (e.g. a sequence having at least 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% sequence identity thereto), and/or (preferably “and”) said light chain variable region has the amino acid sequence of SEQ ID NO:41 or a sequence substantially homologous thereto (e.g. a sequence having at least 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% sequence identity thereto). Preferred embodiments of this aspect of the invention include antibodies comprising one or more of the antibody sequences (e.g. CDR sequences and/or VH domain and/or VL domain sequences) that are described elsewhere herein in connection with other aspects of the present invention. Thus, discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention.

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NQ:60 or a sequence substantially homologous thereto,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:61 or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:62 or a sequence substantially homologous thereto; and/or (preferably “and”) wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:63 or a sequence substantially homologous thereto,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:64 or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:65 or a sequence substantially homologous thereto; preferably said substantially homologous sequence is a sequence containing 1, 2 or 3 amino acid substitutions compared to the given CDR sequence, or wherein said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence. Preferred embodiments of this aspect of the invention include antibodies comprising one or more of the antibody sequences (e.g. CDR sequences and/or VH domain and/or VL domain sequences) that are described elsewhere herein in connection with other aspects of the present invention. Thus, discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention. In some preferred embodiments of this aspect of the invention, the invention provides an antibody comprising a VH domain that has the amino acid sequence of SEQ ID NO:58 or a sequence substantially homologous thereto, and/or (preferably “and”) a VL domain that has the amino acid sequence of SEQ ID NO:59 or a sequence substantially homologous thereto.

In another aspect, and in some embodiments, the present invention provides an antibody, for example an isolated antibody, that binds to (or specifically binds to) Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region has the amino acid sequence of SEQ ID NO:58 or a sequence substantially homologous thereto (e.g. a sequence having at least 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% sequence identity thereto), and/or (preferably “and”) said light chain variable region has the amino acid sequence of SEQ ID NO:59 or a sequence substantially homologous thereto (e.g. a sequence having at least 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% sequence identity thereto). Preferred embodiments of this aspect of the invention include antibodies comprising one or more of the antibody sequences (e.g. CDR sequences and/or VH domain and/or VL domain sequences) that are described elsewhere herein in connection with other aspects of the present invention. Thus, discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention.

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:78 or a sequence substantially homologous thereto,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:79 or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NQ:80 or a sequence substantially homologous thereto; and/or (preferably “and”) wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:81 or a sequence substantially homologous thereto,

(e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:82 or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:83 or a sequence substantially homologous thereto; preferably said substantially homologous sequence is a sequence containing 1, 2 or 3 amino acid substitutions compared to the given CDR sequence, or wherein said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

Preferred embodiments of this aspect of the invention include antibodies comprising one or more of the antibody sequences (e.g. CDR sequences and/or VH domain and/or VL domain sequences) that are described elsewhere herein in connection with other aspects of the present invention. Thus, discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention. In some preferred embodiments of this aspect of the invention, the invention provides an antibody comprising a VH domain that has the amino acid sequence of SEQ ID NO:76 or a sequence substantially homologous thereto, and/or (preferably “and”) a VL domain that has the amino acid sequence of SEQ ID NO:77 or a sequence substantially homologous thereto.

In another aspect, and in some embodiments, the present invention provides an antibody, for example an isolated antibody, that binds to (or specifically binds to) Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region has the amino acid sequence of SEQ ID NO:76 or a sequence substantially homologous thereto (e.g. a sequence having at least 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% sequence identity thereto), and/or (preferably “and”) said light chain variable region has the amino acid sequence of SEQ ID NO:77 or a sequence substantially homologous thereto (e.g. a sequence having at least 65%, 70%, 75%, 80%, 85%, 90%, 95% or 98% sequence identity thereto). Preferred embodiments of this aspect of the invention include antibodies comprising one or more of the antibody sequences (e.g. CDR sequences and/or VH domain and/or VL domain sequences) that are described elsewhere herein in connection with other aspects of the present invention. Thus, discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention.

In another aspect, the present invention provides an antibody that binds to (or specifically binds to) Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a variable heavy (VH) CDR1, a VH CDR2 and a VH CDR3 of (or from or from within) the heavy chain variable region that has the sequence of SEQ ID NO:4 (or VH CDR1 , VH CDR2 and VH CDR3 sequences substantially homologous thereto), and/or (preferably “and”) wherein said light chain variable region comprises a variable light (VL) CDR1 , a VL CDR2 and a VL CDR3 of (or from or from within) the light chain variable region that has the sequence of SEQ ID NO:5 (or VL CDR1, VL CDR2 and VL CDR3 sequences substantially homologous thereto). Discussion of various features of the antibodies of other aspects of the invention and preferred embodiments may be applied mutatis mutandis to this aspect of the invention.

In another aspect, the present invention provides an antibody that binds to (or specifically binds to) Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a variable heavy (VH) CDR1, a VH CDR2 and a VH CDR3 of (or from or from within) the heavy chain variable region that has the sequence of SEQ ID NO:22 (or VH CDR1, VH CDR2 and VH CDR3 sequences substantially homologous thereto), and/or (preferably “and”) wherein said light chain variable region comprises a variable light (VL) CDR1 , a VL CDR2 and a VL CDR3 of (or from or from within) the light chain variable region that has the sequence of SEQ ID NO:23 (or VL CDR1 , VL CDR2 and VL CDR3 sequences substantially homologous thereto). Discussion of various features of the antibodies of other aspects of the invention and preferred embodiments may be applied mutatis mutandis to this aspect of the invention.

In another aspect, the present invention provides an antibody that binds to (or specifically binds to) Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a variable heavy (VH) CDR1, a VH CDR2 and a VH CDR3 of (or from or from within) the heavy chain variable region that has the sequence of SEQ ID NQ:40 (or VH CDR1, VH CDR2 and VH CDR3 sequences substantially homologous thereto), and/or (preferably “and”) wherein said light chain variable region comprises a variable light (VL) CDR1 , a VL CDR2 and a VL CDR3 of (or from or from within) the light chain variable region that has the sequence of SEQ ID NO:41 (or VL CDR1 , VL CDR2 and VL CDR3 sequences substantially homologous thereto). Discussion of various features of the antibodies of other aspects of the invention and preferred embodiments may be applied mutatis mutandis to this aspect of the invention.

In another aspect, the present invention provides an antibody that binds to (or specifically binds to) Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a variable heavy (VH) CDR1, a VH CDR2 and a VH CDR3 of (or from or from within) the heavy chain variable region that has the sequence of SEQ ID NO:58 (or VH CDR1, VH CDR2 and VH CDR3 sequences substantially homologous thereto), and/or (preferably “and”) wherein said light chain variable region comprises a variable light (VL) CDR1 , a VL CDR2 and a VL CDR3 of (or from or from within) the light chain variable region that has the sequence of SEQ ID NO:59 (or VL CDR1 , VL CDR2 and VL CDR3 sequences substantially homologous thereto). Discussion of various features of the antibodies of other aspects of the invention and preferred embodiments may be applied mutatis mutandis to this aspect of the invention.

In another aspect, the present invention provides an antibody that binds to (or specifically binds to) Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein said heavy chain variable region comprises a variable heavy (VH) CDR1, a VH CDR2 and a VH CDR3 of (or from or from within) the heavy chain variable region that has the sequence of SEQ ID NO:76 (or VH CDR1, VH CDR2 and VH CDR3 sequences substantially homologous thereto), and/or (preferably “and”) wherein said light chain variable region comprises a variable light (VL) CDR1 , a VL CDR2 and a VL CDR3 of (or from or from within) the light chain variable region that has the sequence of SEQ ID NO:77 (or VL CDR1 , VL CDR2 and VL CDR3 sequences substantially homologous thereto). Discussion of various features of the antibodies of other aspects of the invention and preferred embodiments may be applied mutatis mutandis to this aspect of the invention.

In some embodiments, the CDR sequences of (or from or from within) a heavy chain variable domain or a light chain variable domain are CDR sequences as set forth in Tables A, B, C, D or E herein. In some other embodiments, CDR sequences of (or from or from within) a heavy chain variable domain or a light chain variable domain are CDR sequences as identified using any suitable method (or tool), for example as identified according to the well-known methods of Kabat (e.g. Kabat, et al., "Sequences of Proteins of Immunological Interest", 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD, 647- 669, 1991) or Chothia (e.g. Chothia C, et al. (1989) Nature, 342:877-883, or Al-Lazikani et al., (1997) JMB 273,927-948). CDR sequences of (or from or from within) a heavy chain variable domain or a light chain variable domain may be CDR sequences as identified using the IMGT numbering scheme (e.g. Lefranc, M.-P., The Immunologist, 7, 132-136 (1999); www.imgt.org)).

In another aspect, the present invention provides an antibody, for example an isolated antibody, which binds to (or specifically recognises or specifically binds to) Thioredoxin 1 , wherein said antibody is capable of reducing (or inhibiting or decreasing) the differentiation (or polarization or production) and/or survival and/or activation of Tregs. Discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention.

In another aspect, the present invention provides an antibody, for example an isolated antibody, which binds to (or specifically recognises or specifically binds to) Thioredoxin 1 , wherein said antibody is capable of reducing (or inhibiting or decreasing) the differentiation of naive CD4+ T-cells into Tregs. Discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention.

In another aspect, the present invention provides an antibody, for example an isolated antibody, which binds to (or specifically recognises or specifically binds to) Thioredoxin 1 , wherein said antibody is capable of reducing (or inhibiting or decreasing) the expression (or expression level) of FOXP3 in live CD4+ CD25+ cells (within a live CD4+ CD25+ population). Discussion of various features of the antibodies of other aspects of the invention and preferred embodiments apply mutatis mutandis to this aspect of the invention.

The antibodies, proteins, binding proteins and nucleic acid molecules in accordance with the invention are generally "isolated" or "purified" molecules insofar as they are distinguished from any such components that may be present in situ within a human or animal body or a tissue sample derived from a human or animal body. The sequences may, however, correspond to or be substantially homologous to sequences as found in a human or animal body. Thus, the term "isolated" or "purified" as used herein in reference to nucleic acid molecules or sequences and proteins, or polypeptides, e.g. antibodies, refers to such molecules when isolated from, purified from, or substantially free of their natural environment, e.g. isolated from or purified from the human or animal body (if indeed they occur naturally), or refers to such molecules when produced by a technical process, i.e. includes recombinant and synthetically produced molecules.

Thus, when used in connection with a protein or polypeptide molecule such as, light chain CDRs 1 , 2 and 3, heavy chain CDRs 1 , 2 and 3, light chain variable regions, heavy chain variable regions, and binding proteins or antibodies of the invention, including full length antibodies, the term "isolated" or "purified" typically refers to a protein substantially free of cellular material or other proteins from the source from which it is derived. In some embodiments, particularly where the protein is to be administered to humans or animals, such isolated or purified proteins are substantially free of culture medium when produced by recombinant techniques, or chemical precursors or other chemicals when chemically synthesized.

The term "fragment" as used herein refers to fragments of biological relevance, e.g. fragments that contribute to antigen binding, e.g. form part of the antigen binding site, and/or contribute to the functional properties of the Thioredoxin 1 antibody. Certain preferred fragments comprise a heavy chain variable region (VH domain) and/or a light chain variable region (VL domain) of the antibodies of the invention.

A person skilled in the art will appreciate that the antibodies, antibody fragments, and immunoconjugates of the invention may be prepared in any of several ways well known and described in the art. For example, antibodies may be prepared by hybridoma technology. In other embodiments, antibodies, antibody fragments, and immunoconjugates of the invention may be prepared by recombinant methods.

Nucleic acid fragments encoding the light and heavy chain variable regions of the antibodies of the invention can be derived or produced by any appropriate method, e.g. by cloning or synthesis.

Once nucleic acid fragments encoding the light and heavy chain variable regions of the antibodies of the invention have been obtained, these fragments can be further manipulated by standard recombinant DNA techniques, for example to convert the variable region fragments into full length antibody molecules with appropriate constant region domains, or into particular formats of antibody fragment discussed elsewhere herein, e.g. Fab fragments, scFv fragments, etc. Typically, or as part of this further manipulation procedure, the nucleic acid fragments encoding antibody molecules of the invention are generally incorporated into one or more appropriate expression vectors in order to facilitate production of the antibodies of the invention.

Possible expression vectors include but are not limited to cosmids, plasmids, or modified viruses (e.g. replication defective retroviruses, adenoviruses and adeno-associated viruses), so long as the vector is compatible with the host cell used. The expression vectors are "suitable for transformation of a host cell", which means that the expression vectors contain a nucleic acid molecule of the invention and regulatory sequences selected on the basis of the host cells to be used for expression, which are operatively linked to the nucleic acid molecule. Operatively linked is intended to mean that the nucleic acid is linked to regulatory sequences in a manner that allows expression of the nucleic acid.

The invention therefore contemplates a recombinant expression vector containing a nucleic acid molecule of the invention, or a fragment thereof, and the necessary regulatory sequences for the transcription and translation of the protein sequence encoded by the nucleic acid molecule of the invention.

Suitable regulatory sequences may be derived from a variety of sources, including bacterial, fungal, viral, mammalian, or insect genes and are well known in the art. Selection of appropriate regulatory sequences is dependent on the host cell chosen as discussed below, and may be readily accomplished by one of ordinary skill in the art. Examples of such regulatory sequences include: a transcriptional promoter and enhancer or RNA polymerase binding sequence, a ribosomal binding sequence, including a translation initiation signal. Additionally, depending on the host cell chosen and the vector employed, other sequences, such as an origin of replication, additional DNA restriction sites, enhancers, and sequences conferring inducibility of transcription may be incorporated into the expression vector.

The recombinant expression vectors of the invention may also contain a selectable marker gene that facilitates the selection of host cells transformed or transfected with a recombinant molecule of the invention.

The recombinant expression vectors may also contain genes that encode a fusion moiety that provides increased expression of the recombinant protein; increased solubility of the recombinant protein; and aid in the purification of the target recombinant protein by acting as a ligand in affinity purification (for example appropriate "tags" to enable purification and/or identification may be present, e.g., His tags or myc tags).

Recombinant expression vectors can be introduced into host cells to produce a transformed host cell. The terms "transformed with", "transfected with", "transformation" and "transfection" are intended to encompass introduction of nucleic acid e.g., a vector) into a cell by one of many possible techniques known in the art. Suitable methods for transforming and transfecting host cells can be found in Sambrook et al., 1989 (Sambrook, Fritsch and Maniatis, Molecular Cloning: A Laboratory Manual, 2nd Ed., Cold Spring Harbor Press, Cold Spring Harbor, NY, 1989) and other laboratory textbooks.

Suitable host cells include a wide variety of eukaryotic host cells and prokaryotic cells. For example, the proteins (e.g. antibodies) of the invention may be expressed in yeast cells or mammalian cells. In addition, the proteins of the invention may be expressed in prokaryotic cells, such as Escherichia coli.

Given the teachings provided herein, promoters, terminators, and methods for introducing expression vectors of an appropriate type into plant, avian, and insect cells may also be readily accomplished.

Alternatively, the proteins (e.g. antibodies) of the invention may also be expressed in non-human transgenic animals such as, rats, rabbits, sheep and pigs. The proteins of the invention may also be prepared by chemical synthesis using techniques well known in the chemistry of proteins such as solid phase synthesis.

N-terminal or C-terminal fusion proteins comprising the antibodies and proteins of the invention conjugated to other molecules, such as proteins, may be prepared by fusing through recombinant techniques. The resultant fusion proteins contain an antibody or protein of the invention fused to the selected protein or marker protein, or tag protein as described herein. The antibodies and proteins of the invention may also be conjugated to other proteins by known techniques. For example, the proteins may be coupled using heterobifunctional thiol-containing linkers as described in WO 90/10457, N-succinimidyl-3-(2- pyridyldithio-proprionate) or N-succinimidyl-5 thioacetate.

A yet further aspect provides an expression construct or expression vector comprising one or more of the nucleic acid molecules or fragments or segments of the invention. Preferably, the expression constructs or vectors are recombinant. Also provided is a set of expression vectors (or a set of expression constructs) which, together (collectively), encode an antibody of the invention. Such a set of expression vectors may be characterised in that when the set is expressed (i.e. expressed together) (e.g. in a host cell) an antibody (an entire antibody) of the present invention is expressed and preferably assembled.

Preferably said constructs or vectors further comprise the necessary regulatory sequences for the transcription and translation of the protein sequence encoded by the nucleic acid molecule(s) of the invention.

A yet further aspect provides a host cell or virus comprising one or more expression constructs or expression vectors of the invention. Also provided are host cells or viruses comprising one or more of the nucleic acid molecules of the invention. A host cell (e.g. a mammalian host cell) or virus expressing an antibody of the invention forms a yet further aspect.

A yet further aspect of the invention provides a method of producing (or manufacturing) an antibody of the present invention comprising a step of culturing the host cells of the invention. Preferred methods comprise the steps of (i) culturing a host cell comprising one or more of the recombinant expression vectors (or a set of expression vectors) or one or more of the nucleic acid sequences (or a set of nucleic acid molecules) of the invention under conditions suitable for the expression of the encoded antibody; and optionally (ii) isolating or obtaining the antibody from the host cell or from the growth medium/supernatant.

In embodiments when the antibody or protein of the invention is made up of more than one polypeptide chain (e.g. certain fragments such as Fab fragments or whole antibodies), then all the polypeptides are preferably expressed in the host cell, either from the same or a different expression vector, so that the complete proteins, e.g. antibody proteins of the invention, can assemble in the host cell and be isolated or purified therefrom.

In some embodiments, methods of producing (or manufacturing or isolating or identifying or generating) an antibody in accordance with the invention may also comprise a step of purification of the antibody or protein product and/or formulating the antibody or product into a composition including at least one additional component, such as a pharmaceutically acceptable carrier or excipient.

In another aspect, the invention provides a method of binding Thioredoxin 1 , comprising contacting a composition comprising Thioredoxin 1 with an antibody of the invention, or an immunoconjugate thereof.

In yet another aspect, the invention provides a method of detecting Thioredoxin 1, comprising contacting a composition suspected of containing Thioredoxin 1 with an antibody of the invention, or an immunoconjugate thereof, under conditions effective to allow the formation of Thioredoxin 1/antibody complexes and detecting the complexes so formed.

The antibodies of the invention may also be used to produce further antibodies that bind to Thioredoxin 1. Such uses involve for example the addition, deletion, substitution or insertion of one or more amino acids in the amino acid sequence of a parent antibody to form a new antibody, wherein said parent antibody is one of the antibodies of the invention as defined elsewhere herein, and testing the resulting new antibody to identify antibodies that bind to Thioredoxin 1 in accordance with the invention. Such methods can be used to form multiple new antibodies that can all be tested for their ability to bind Thioredoxin 1. Said addition, deletion, substitution or insertion of one or more amino acids may take place in one or more of the CDR domains.

Such modification or mutation to a parent antibody can be carried out in any appropriate manner using techniques well known and documented in the art, for example by carrying out methods of random or directed mutagenesis. If directed mutagenesis is to be used then one strategy to identify appropriate residues for mutagenesis utilizes the resolution of the crystal structure of the binding protein-antigen complex, e.g., the Ab-Ag complex, to identify the key residues involved in the antigen binding. Alanine scanning mutagenesis is also a routine method which can be used to identify the key residues involved in the antigen binding. Subsequently, those residues can be mutated to enhance the interaction. Alternatively, one or more amino acid residues can simply be targeted for directed mutagenesis and the effect on binding to Thioredoxin 1 assessed.

Random mutagenesis can be carried out in any appropriate way, e.g., by error-prone PCR, chain shuffling or mutator E. coli strains. Thus, one or more of the VH domains of the invention can be combined with a single VL domain or a repertoire of VL domains from any appropriate source and the resulting new antibodies tested to identify antibodies which bind to Thioredoxin 1. Conversely, one or more of the VL domains of the invention can be combined with a single VH domain or repertoire of VH domains from any appropriate source and the resulting new antibodies tested to identify antibodies that bind to Thioredoxin 1.

Similarly, one or more, or preferably all three CDRs of the VH and/or VL domains of the invention can be grafted into a single VH and/or VL domain or a repertoire of VH and/or VL domains, as appropriate, and the resulting new antibodies tested to identify antibodies that bind to Thioredoxin 1.

Methods of carrying out the above described manipulation of amino acids and protein domains are well known to a person skilled in the art. For example, said manipulations could conveniently be carried out by genetic engineering at the nucleic acid level wherein nucleic acid molecules encoding appropriate binding proteins and domains thereof are modified such that the amino acid sequence of the resulting expressed protein is in turn modified in the appropriate way.

Testing the ability of one or more antibodies to bind to Thioredoxin 1 can be carried out by any appropriate method, which are well known and described in the art. Suitable methods are also described in the Examples section.

The invention also provides a range of conjugated antibodies and fragments thereof in which the anti-Thioredoxin 1 antibody is operatively attached to at least one other agent (e.g. a diagnostic or therapeutic agent). In some embodiments, the at least one other agent may be a diagnostic agent. The term "immunoconjugate" is broadly used to define the operative association of the antibody with another effective agent (e.g. diagnostic agent or therapeutic agent) and is not intended to refer solely to any type of operative association, and is particularly not limited to chemical "conjugation". Recombinant fusion proteins are particularly contemplated. So long as the delivery or targeting agent is able to bind to the target and the therapeutic or diagnostic agent is sufficiently functional upon delivery, the mode of attachment will be suitable.

In some embodiments, antibodies of the invention are used (e.g. used therapeutically) in their "naked" unconjugated form.

Compositions comprising at least a first antibody of the invention or an immunoconjugate thereof constitute a further aspect of the present invention. Formulations (compositions) comprising one or more antibodies of the invention in admixture with a suitable diluent, carrier or excipient constitute a preferred embodiment of the present invention. Such formulations may be for pharmaceutical use and thus compositions of the invention are preferably pharmaceutically acceptable. Suitable diluents, excipients and carriers are known to the skilled man.

The compositions according to the invention may be presented, for example, in a form suitable for oral, nasal, parenteral, intraperitoneal, intravenal, intratumoral, topical or rectal administration. In some embodiments, a form suitable for intravenous administration is preferred.

The active compounds defined herein may be presented in the conventional pharmacological forms of administration, such as tablets, coated tablets, nasal sprays, solutions, emulsions, liposomes, powders, capsules or sustained release forms. Conventional pharmaceutical excipients as well as the usual methods of production may be employed for the preparation of these forms.

Injection solutions may, for example, be produced in the conventional manner, such as by the addition of preservation agents, such as p-hydroxybenzoates, or stabilizers, such as EDTA. The solutions may then be filled into injection vials or ampoules.

Nasal sprays may be formulated similarly in aqueous solution and packed into spray containers, either with an aerosol propellant or provided with means for manual compression.

The pharmaceutical compositions (formulations) of the present invention may be administered parenterally. Intravenous administration is preferred in some embodiments. Parenteral administration may be performed by subcutaneous, intramuscular or intravenous injection by means of a syringe. Alternatively, parenteral administration can be performed by means of an infusion pump. A further option is a composition which may be a powder or a liquid for the administration of the antibody in the form of a nasal or pulmonal spray. As a still further option, the antibodies of the invention may also be administered transdermally, e.g. from a patch, optionally an iontophoretic patch, or transmucosally, e.g. bucally. As a still further option, the antibodies of the invention may also be administered by intratumoral administration (e.g. intratumoral injection).

Suitable dosage units can be determined by a person skilled in the art.

The pharmaceutical compositions may additionally comprise further active ingredients in the context of co-administration regimens or combined regimens.

A further aspect of the present invention provides the anti-Thioredoxin 1 antibodies of the invention for use in therapy.

In some embodiments, the disease or condition to be treated (or prevented) is a disease or condition that is characterized by Tregs (or characterized by the presence of T regs). The presence of T regs may be an overabundance or aberrant abundance of T regs or a high level (or prevalence) of Tregs (for example a higher or increased level or amount or number of Tregs as compared to in the non-disease state or in corresponding non-diseased tissue (e.g. surrounding tissue) and/or for example in healthy or normal subjects or a corresponding heathy or normal tissue of a healthy or normal subject). In some such embodiments the disease or condition is cancer.

In some embodiments, the therapy is therapy for a disease or condition that associated with (or exacerbated by) Tregs (e.g. an over or aberrant abundance of Tregs or high (or higher) levels of T regs). In some such embodiments the disease or condition is cancer.

In some embodiments, the disease or condition to be treated (or prevented) is a disease or condition that is characterized by the differentiation (or production) and/or activity and/or survival of Tregs. In some such embodiments the disease or condition is cancer.

In some embodiments, the therapy is therapy for a disease or condition that associated with (or exacerbated by) Tregs (e.g. an overabundance or aberrant abundance of Tregs or high (or higher) levels of Tregs, or increased Treg activity). In some such embodiments the disease or condition is cancer.

In some embodiments, the disease or condition to be treated (or prevented) is a disease or condition that is characterized by differentiation of naive CD4+ T-cells into Tregs. There may be an increased or high (or higher) level of naive CD4+ T-cell to Treg differentiation (for example a higher or increased level or amount of naive CD4+ T-cell to Treg differentiation as compared to in the non-disease state or in a corresponding nondiseased tissue (e.g. surrounding tissue) and/or as compared to in healthy or normal subjects or a corresponding healthy or normal tissue of a healthy or normal subject). In some such embodiments the disease or condition is cancer.

In some embodiments, the therapy is therapy for a disease or condition that associated with (or exacerbated by) the differentiation of naive CD4+ T-cells into Tregs (e.g. an increased or high (or higher) level of naive CD4+ T-cell to Treg differentiation). In some such embodiments the disease or condition is cancer.

In one aspect, and in preferred embodiments, the present invention provides the antiThioredoxin 1 antibodies of the invention for use in cancer therapy. Thus, the present invention provides the anti-Thioredoxin 1 antibodies of the invention for use in the treatment or prevention of cancer. Typically, the cancer is in the form of a tumour (e.g. a solid tumour). In some embodiments, the cancer is breast cancer (for example triple negative breast cancer). In some other embodiments the cancer may be a haematological cancer (or a haematological malignancy), for example a T-cell leukaemia or a B-cell leukaemia.

In some embodiments, the cancer (or tumour) is an immune cell infiltrated cancer (or tumour) or a cancer (or tumour) that is capable of being (or is susceptible to being) infiltrated by immune cells. Typically, said immune cells are T-cells, e.g. naive CD4+ T-cells and/or Tregs. Thus, in some embodiments the cancer (or tumour) is an T-cell infiltrated cancer (or tumour), e.g. a cancer (or tumour) that is infiltrated with naive CD4+ T-cells and/or Tregs, or is a cancer (or tumour) that is capable of being (or is susceptible to being) infiltrated by T- cells (e.g. naive CD4+ T-cells and/or Tregs).

In some cancers to be treated in accordance with the invention there may be high (or increased) levels of naive CD4+ T-cells and/or Tregs. High (or increased) levels of naive CD4+ T-cells and/or Tregs typically means that that the frequency (or number or prevalence) of CD4+ T-cells and/or Tregs in the tumour microenvironment is higher (e.g. significantly higher) than that in tumour-surrounding tissue (in non-tumour tissue).

Typically, the cancer (or tumour) is characterized by the presence of (e.g. secretion of) Thioredoxin 1. Thus, typically the cancer (or tumour) is characterized by (or has) the presence of (e.g. secretion of) Thioredoxin 1 in the tumour microenvironment, e.g. in the extracellular space or extracellular matrix of the tumour microenvironment. In some embodiments, the level of Trx1 in the tumour microenvironment may higher than in tumoursurrounding tissue (in non-tumour tissue) or other suitable control tissue.

Treg cells are involved in tumour development and progression by suppressing anticancer immune responses. Tregs (e.g. high levels of Tregs) in the tumour microenvironment have been associated with worsened disease outcomes in many cancer types. Thus, depleting Treg populations or inhibiting Treg activity in particular within the tumour microenvironment is desirable. Without wishing to be bound by theory, it is believed that treatments in accordance with the invention reduce the Treg cell population size (and/or activity). Without wishing to be bound by theory, it is believed this would be therapeutically beneficial as there would be more anti-cancer immune cell activity in the tumour microenvironment.

In some embodiments, the present invention provides anti-Thioredoxin 1 antibodies of the invention for use in the therapy of a disease or condition against which eliciting (or enhancing or elevating) an immune response in the subject would be desirable (or be beneficial or necessary). In some such embodiments, the disease or condition is cancer (e.g. enhancing an anti-cancer immune response may be desirable/beneficial). In other embodiments, the disease and/or condition may be an infectious disease. In another aspect, the present invention provides the anti-Thioredoxin 1 antibodies of the invention for use in reducing the level (or amount) of Tregs. In some embodiments, antibodies are for use in reducing the level (or amount) of Tregs in a tumour (or cancer) microenvironment. Embodiments of other therapeutic aspects of the invention described herein may be applied, mutatis mutandis, to this aspect of the invention.

In another aspect, the present invention provides the anti-Thioredoxin 1 antibodies of the invention for use in reducing (or inhibiting) the differentiation (or production or generation) and/or activity and/or survival of Tregs. In some embodiments, antibodies are for use in reducing the differentiation (or production or generation) and/or activity and/or surival of Tregs in a tumour (or cancer) microenvironment. Embodiments of other therapeutic aspects of the invention described herein may be applied, mutatis mutandis, to this aspect of the invention.

In another aspect, the present invention provides the anti-Thioredoxin 1 antibodies of the invention for use in reducing (or inhibiting) differentiation of naive CD4+ T-cells into Tregs. In some embodiments, antibodies are for use in reducing (or inhibiting) differentiation of naive CD4+ T-cells into Tregs in a tumour (or cancer) microenvironment. Embodiments of other therapeutic aspects of the invention described herein may be applied, mutatis mutandis, to this aspect of the invention.

“Therapy” includes treatment and prophylaxis, i.e. in includes both treatment and preventative uses. For example, “cancer therapy” thus includes the treatment of cancer and the prevention of cancer.

Thus, in some embodiments, the present invention provides the anti-Thioredoxin 1 antibodies of the invention for use in the treatment of a disease or condition as described elsewhere herein. Thus, in some embodiments, the present invention provides the anti- Thioredoxin 1 antibodies of the invention for use in the prevention of a disease or condition as described elsewhere herein.

In another aspect, the present invention provides the antibodies of the invention for use in diagnosis, e.g. diagnosis of a disease or condition as described elsewhere herein.

In another aspect, the present invention provides immunoconjugates of the invention for use in therapy or diagnosis, in particular for use in the treatment or diagnosis of a disease or condition as described elsewhere herein.

The in vivo methods and uses as described herein are generally carried out in a mammal. Any mammal may be treated, for example humans and any livestock, domestic or laboratory animal. Specific examples include mice, rats, pigs, cats, dogs, sheep, rabbits, cows and monkey. Preferably, however, the mammal is a human.

Thus, the term "animal" or "patient" as used herein includes any mammal, for example humans and any livestock, domestic or laboratory animal. Specific examples include mice, rats, pigs, cats, dogs, sheep, rabbits, cows and monkey. Preferably, however, the animal or patient is a human subject. Thus, subjects or patients treated in accordance with the present invention will preferably be humans.

In some embodiments, subjects or patients will be those having a disease or condition described herein (or suffering from or experiencing such a disease/condition), or those at risk of having such a disease or condition, or at risk of developing such a disease or condition, or suspected of having such a disease or condition.

Alternatively viewed, the present invention provides a method of treating a disease or condition as described herein which method comprises administering to a patient in need thereof a therapeutically effective amount of an antibody of the invention as defined herein. Embodiments of the therapeutic uses of the invention described herein apply, mutatis mutandis, to this aspect of the invention.

In another aspect the invention provides a method for reducing (or inhibiting) the differentiation (or production or generation) and/or activity and/or survival of Tregs which method comprises administering to a patient in need thereof a therapeutically effective amount of an antibody of the invention as defined herein. Embodiments of other therapeutic aspects of the invention described herein may be applied, mutatis mutandis, to this aspect of the invention.

In another aspect the invention provides a method for reducing (or inhibiting) differentiation of naive CD4+ T-cells into Tregs which method comprises administering to a patient in need thereof a therapeutically effective amount of an antibody of the invention as defined herein. Embodiments of other therapeutic aspects of the invention described herein may be applied, mutatis mutandis, to this aspect of the invention.

A therapeutically effective amount will be determined based on the clinical assessment and can be readily monitored.

Further alternatively viewed, the present invention provides the use of an antibody of the invention as defined herein in the manufacture of a medicament for use in therapy. Preferred therapy is of a disease or condition as described elsewhere herein. Embodiments of other therapeutic aspects of the invention described herein apply, mutatis mutandis, to this aspect of the invention. In another aspect, the present invention provides the use of an antibody of the invention as defined herein in the manufacture of a medicament for use in reducing (or inhibiting) the differentiation (or production or generation) and/or activity and/or survival of T regs. Embodiments of other therapeutic aspects of the invention described herein may be applied, mutatis mutandis, to this aspect of the invention.

In another aspect, the present invention provides the use of an antibody of the invention as defined herein in the manufacture of a medicament for use in reducing (or inhibiting) differentiation of naive CD4+ T-cells into Tregs. Embodiments of other therapeutic aspects of the invention described herein may be applied, mutatis mutandis, to this aspect of the invention.

Further alternatively viewed, the present invention provides the use of an antibody of the invention as defined herein for the treatment of a disease or condition as described elsewhere herein. Embodiments of other therapeutic uses of the invention described herein apply, mutatis mutandis, to this aspect of the invention.

In another aspect, the present invention provides the use of an antibody of the invention as defined herein for reducing (or inhibiting) the differentiation (or production or generation) and/or activity and/or survival of Tregs. Embodiments of other therapeutic uses of the invention described herein apply, mutatis mutandis, to this aspect of the invention.

In another aspect, the present invention provides the use of an antibody of the invention as defined herein for reducing (or inhibiting) differentiation of naive CD4+ T-cells into Tregs. Embodiments of other therapeutic uses of the invention described herein apply, mutatis mutandis, to this aspect of the invention.

In another aspect, the invention provides a method of diagnosing a disease or condition as described herein elsewhere herein in a mammal comprising the steps of:

(a) contacting a test sample of said mammal with one or more of the antibodies of the invention or an immunoconjugate thereof;

(b) measuring the presence and/or amount and/or location of antibody-antigen complex in the test sample; and, optionally

(c) comparing the presence and/or amount of antibody-antigen complex in the test sample to a control.

In some embodiments of a diagnostic method of the invention, the test sample is isolated from the mammal and contacted with the antibody (or immunoconjugate) in vitro. In some embodiments of a diagnostic method of the invention the antibody (or immunoconjugate) is administered to said mammal, thereby contacting said test sample in vivo. In the above methods, said contacting step is carried out under conditions that permit the formation of an antibody-antigen complex. Appropriate conditions can readily be determined by a person skilled in the art.

In the above methods any appropriate test sample may be used, for example cells, tissues or organs (e.g. biopsy cells, tissues or organs) suspected of being affected by disease, or histological sections.

In some embodiments of methods of the invention, the mammal (e.g. a human) is a subject at risk of developing a disease or condition as described herein, e.g. a healthy subject or a subject not displaying any symptoms of disease. In other embodiments the mammal may be a mammal having, or suspected of having (or developing), or potentially having (or developing) a disease or condition as described herein.

In certain of the above diagnostic methods, the presence of any amount of antibodyantigen complex in the test sample would be indicative of the presence of disease. Preferably, for a positive diagnosis to be made, the amount of antibody-antigen complex in the test sample is greater than, preferably significantly greater than, the amount found in an appropriate control sample or an appropriate control level. More preferably, the significantly greater levels are statistically significant, preferably with a probability value of <0.05. Appropriate methods of determining statistical significance are well known and documented in the art and any of these may be used.

Appropriate control samples or control amounts (or control levels) could be readily chosen by a person skilled in the art, for example, in the case of diagnosis of a particular disease, an appropriate control could be a sample from (or amount in or level in) a subject that did not have that disease. Appropriate control values (or levels or amounts) could also be readily determined without running a control "sample" in every test, e.g., by reference to the range for normal subjects known in the art.

A control amount (or level) may be the amount (or level) of antibody-antigen complex measured in a control subject or population (e.g. in a sample that has been obtained from a control subject or population). Appropriate control subjects or samples for use in the methods of the invention would be readily identified by a person skilled in the art. Control subjects might also be referred to as "normal" subjects or as a reference population. Examples of appropriate control subjects and appropriate populations of control subjects would include healthy subjects, for example, individuals who have no history of any form of the disease to be diagnosed in accordance with the invention and preferably no other concurrent disease. Other preferred control subjects would include individuals who are not suffering from, and preferably have no history of, the disease or condition to be diagnosed (e.g. not suffering from, and preferably have no history of, any of the types of diseases or conditions described herein). In some embodiments, control subjects are not regular users of any medication. In a preferred embodiment, control subjects are healthy subjects.

A control amount (or level) may correspond to the level in appropriate control subjects or samples, e.g. may correspond to a cut-off or threshold level or range found in a control or reference population. Alternatively, a control amount (or level) may correspond to the amount or level in the same individual subject, or a sample from said subject, measured at an earlier time point (e.g. comparison with a "baseline" level in that subject). In this regard, an appropriate control level may be the individual's own baseline, stable, nil, previous or dry value (as appropriate) as opposed to a control or cut-off amount (or level) found in the general control population. Control amounts (or levels) may also be referred to as "normal" amounts or "reference" amounts. The control amount may be a discrete figure or a range.

Although a control amount (or level) for comparison could be derived by testing an appropriate control sample (or set of samples) or control subject (or set of subjects), diagnostic methods of the invention would not necessarily involve carrying out active tests on control samples or subjects as part of methods of the present invention but could involve a comparison with a control amount (or level) which had been determined previously from control subjects or samples and was known to the person carrying out a diagnostic method of the invention.

For use in the diagnostic or imaging applications, the antibodies of the invention may be labeled with a detectable marker (e.g. a marker as described elsewhere herein). Methods of attaching a label to a binding protein, such as an antibody or antibody fragment, are known in the art. Such detectable markers allow the presence, amount or location of antibody-antigen complexes in the test sample to be examined.

The invention also includes diagnostic or imaging agents comprising the antibodies of the invention attached to a label that produces a detectable signal, directly or indirectly. Appropriate labels are described elsewhere herein.

The antibodies and compositions and methods and uses of the present invention may be used in combination with other therapeutics and diagnostics. In terms of biological agents, preferably diagnostic or therapeutic agents, for use "in combination" with an antiThioredoxin 1 antibody in accordance with the present invention, the term "in combination" is succinctly used to cover a range of embodiments. The "in combination" terminology, unless otherwise specifically stated or made clear from the scientific terminology, thus applies to various formats of combined compositions, pharmaceuticals, cocktails, kits, methods, and first and second medical uses. The "combined" embodiments of the invention thus include, for example, where an anti-Thioredoxin 1 antibody of the invention is a naked antibody and is used in combination with an agent or therapeutic agent that is not operatively attached thereto. In other "combined" embodiments of the invention, an anti-Thioredoxin 1 antibody of the invention is an immunoconjugate wherein the antibody is itself operatively associated or combined with the agent. The operative attachment includes all forms of direct and indirect attachment as described herein and known in the art.

The "combined" uses, particularly in terms of an anti-Thioredoxin 1 antibody of the invention in combination with therapeutic agents, also include combined compositions, pharmaceuticals, cocktails, kits, methods, and first and second medical uses wherein the therapeutic agent is in the form of a prodrug. In such embodiments, the activating component able to convert the prodrug to the functional form of the drug may again be operatively associated with the anti-Thioredoxin 1 antibodies of the present invention.

Thus, where combined compositions, pharmaceuticals, cocktails, kits, methods, and first and second medical uses are described, preferably in terms of diagnostic agents or therapeutic agents, the combinations include anti-Thioredoxin 1 antibodies that are naked antibodies and immunoconjugates, and wherein practice of the in vivo embodiments of the invention involves the prior, simultaneous or subsequent administration of the naked antibodies or immunoconjugate and the biological, diagnostic or therapeutic agent; so long as, in some conjugated or unconjugated form, the overall provision of some form of the antibody and some form of the biological, diagnostic or therapeutic agent is achieved.

The foregoing and other explanations of the effects of the present invention are made for simplicity to explain the combined mode of operation, type of attached agent(s) and such like. This descriptive approach should not be interpreted as either an understatement or an oversimplification of the beneficial properties of the anti-Thioredoxin 1 antibodies of the invention. It will therefore be understood that such antibodies themselves have anti- Thioredoxin 1 properties and that immunoconjugates of such antibodies will maintain these properties and combine them with the properties of the attached agent.

The invention therefore provides compositions, pharmaceutical compositions, therapeutic kits and medicinal cocktails comprising, optionally in at least a first composition or container, a biologically effective amount of at least a first anti-Thioredoxin 1 antibody of the invention, or an antigen-binding fragment or immunoconjugate of such an anti-Thioredoxin 1 antibody; and a biologically effective amount of at least a second biological agent, component or system.

The "at least a second biological agent, component or system" will often be a therapeutic or diagnostic agent, component or system, but it need not be. For example, the at least a second biological agent, component or system may comprise components for modification of the antibody and/or for attaching other agents to the antibody.

Where therapeutic or diagnostic agents are included as the at least a second biological agent, component or system, such therapeutics and/or diagnostics will typically be those for use in connection with the treatment or diagnosis of one or more of the diseases or conditions defined above.

Thus, in certain embodiments "at least a second therapeutic agent" will be included in the therapeutic kit or cocktail. The term is chosen in reference to the anti-Thioredoxin 1 antibody of the invention being the first therapeutic agent.

In certain embodiments of the present invention, the second therapeutic agent may be a further agent for the therapy of a disease or condition described herein.

In terms of compositions, kits and/or medicaments of the invention, the combined effective amounts of the therapeutic agents may be comprised within a single container or container means, or comprised within distinct containers or container means. The cocktails may be admixed together for combined use. Imaging components may also be included. The kits may also comprise instructions for using the at least a first antibody and the one or more other biological agents included.

Speaking generally, the at least a second therapeutic agent may be administered to the animal or patient substantially simultaneously with the anti-Thioredoxin 1 antibody of the invention; such as from a single pharmaceutical composition or from two pharmaceutical compositions administered closely together.

Alternatively, the at least a second therapeutic agent may be administered to the animal or patient at a time sequential to the administration of the anti-Thioredoxin 1 antibody of the invention. "At a time sequential", as used herein, means "staggered", such that the at least a second therapeutic agent is administered to the animal or patient at a time distinct to the administration of the anti-Thioredoxin 1 antibody of the invention. Generally, the two agents are administered at times effectively spaced apart to allow the two agents to exert their respective therapeutic effects, i.e. , they are administered at "biologically effective time intervals". The at least a second therapeutic agent may be administered to the animal or patient at a biologically effective time prior to the anti-Thioredoxin 1 antibody of the invention, or at a biologically effective time subsequent to that therapeutic.

A yet further aspect is a method of imaging of a subject or sample comprising the administration of an appropriate amount of an antibody or other protein of the invention as defined herein to the subject or sample and detecting the presence and/or amount and/or the location of the antibody or other protein of the invention in the subject or sample. For use in the imaging applications, the antibodies of the invention may be labeled with a detectable marker such as a radio-opaque or radioisotope, such as ³H, ¹⁴C, ³²P, ³⁵S, 123|, ¹²⁵|, ¹³¹1; a radioactive emitter (e.g. a, p or y emitters); a fluorescent (fluorophore) or chemiluminescent (chromophore) compound, such as fluorescein isothiocyanate, rhodamine or luciferin; an enzyme, such as alkaline phosphatase, beta-galactosidase or horseradish peroxidase; an imaging agent; or a metal ion; or a chemical moiety such as biotin which may be detected by binding to a specific cognate detectable moiety, e.g. labelled avidin/streptavidin. Methods of attaching a label to a binding protein, such as an antibody or antibody fragment, are known in the art. Such detectable markers allow the presence, amount or location of binding protein-antigen complexes in the test sample to be examined.

The invention also includes imaging agents comprising an antibody of the invention attached to a label that produces a detectable signal, directly or indirectly. Appropriate labels are described elsewhere herein.

The invention further includes kits comprising one or more of the antibodies, immunoconjugates or compositions of the invention, or one or more of the nucleic acid molecules encoding the antibodies of the invention, or one or more recombinant expression vectors comprising the nucleic acid sequences of the invention, or one or more host cells or viruses comprising the recombinant expression vectors or nucleic acid sequences of the invention. Preferably said kits are for use in the methods and uses as described herein, e.g. the therapeutic, methods as described herein, or are for use in the in vitro assays or methods as described herein. The antibody in such kits may be a “naked” antibody or may be an antibody conjugate as described elsewhere herein, e.g. may be an immunoconjugate. Preferably said kits comprise instructions for use of the kit components. Preferably said kits are for treating or diagnosing diseases or conditions as described elsewhere herein, and optionally comprise instructions for use of the kit components to treat such diseases or conditions.

The antibodies of the invention as defined herein may also be used as molecular tools for in vitro or in vivo applications and assays. As the antibodies have an antigen binding site, these can function as members of specific binding pairs and these molecules can be used in any assay where the particular binding pair member is required.

Thus, yet further aspects of the invention provide a reagent that comprises an antibody of the invention as defined herein and the use of such antibodies as molecular tools, for example in in vitro or in vivo assays.

As used throughout the entire application, the terms "a" and "an" are used in the sense that they mean "at least one", "at least a first", "one or more" or "a plurality" of the referenced components or steps, except in instances wherein an upper limit is thereafter specifically stated. Therefore, an "antibody", as used herein, means "at least a first antibody". The operable limits and parameters of combinations, as with the amounts of any single agent, will be known to those of ordinary skill in the art in light of the present disclosure. In addition, where the terms “comprise”, “comprises”, “has” or “having”, or other equivalent terms are used herein, then in some more specific embodiments these terms include the term “consists of” or “consists essentially of”, or other equivalent terms. LIST AND TABLES OF NUCLEOTIDE (nt) AND AMINO ACID (a.a.) SEQUENCES DISCLOSED HEREIN AND THEIR SEQUENCE IDENTIFIERS (SEQ ID NOs)

All nucleotide sequences are recited herein 5' to 3' in line with convention in this technical field. Amino acid sequence of full length 105 residue human Thioredoxin 1 protein (SEQ ID NO:1)

MVKQIESKTAFQEALDAAGDKLVWDFSATWCGPCKMIKPFFHSLSEKYSNVIFLEVDVDDC

QDVASECEVKCMPTFQFFKKGQKVGEFSGANKEKLEATINELV

Table A - Sequences of antibody 7C8

Table B - Sequences of antibody 1 B7

Table C - Sequences of antibody 1 F5

Table D - Sequences of antibody 9B6

Table E - Sequences of antibody 15G8

Table F - Consensus amino acid sequences

The VH (i.e. heavy) CDR1 and VH CDR2 amino acid sequences of the 1 B7 and 1 F5 antibodies of the invention each fall within the heavy CDR1 and heavy CDR2 consensus sequences of the above T able F.

The VL (i.e. light) CDR3 amino acid sequences of the 1 F5 and 9B6 antibodies of the invention each fall within the light CDR3 consensus sequences of the above Table F.

The invention will now be further described in the following non-limiting Examples with reference to the following drawings:

Figure 1: Monoclonal antibody binding to hTrxl as determined by ELISA. Serial dilutions of antibody were incubated for 2 hr in ELISA plates coated with hTrxl protein (SEQ ID NO:1). Plates were washed and bound antibody was detected using anti-mouse IgG conjugated to horse radish peroxidase with absorbance measured at 450 nm. Half maximal binding occurred at antibody concentrations of 0.06, 0.16, 0.09, 0.05 and 0.04 pg/mL of 1 B7, 1 F5, 7C8, 9B6 and 15G8 antibody, respectively.

Figure 2: Effect of anti-Trx1 antibodies on the viability of CD4+ cells in the T-regulatory polarization assay. CD4+ naive T cells were isolated by negative selection from PBMCs recovered from buffy coats of healthy donors (n=3). Cells were differentiated into iTreg (induced Treg) with IL-2 and TGF-p and simultaneously treated with human thioredoxin 1 (TRX; SEQ ID NO:1) on day 0 in the presence of anti-CD3/CD28 bead stimulation and 10 pg/mL of anti-TRX1 antibodies, Isotype control or vehicle (PBS). Cells were recovered on day 3 and stained for viability and surface expression of CD4, CD25 and intracellular expression of FOXP3 for analysis by flow cytometry. The figure shows the mean (n=3 +/- SEM), as well as individual values for each donor, live cell frequency in the culture after three days. * p<0.05, **** p<0.0001 as determined using a repeated-measure one-way ANOVA with Sidak’s multiple comparison test between cultures treated with anti-TRX1 antibodies with the appropriate isotype control-treated cultures (MOPC-21) are shown.

Figure 3: Effect of anti-Trx1 antibodies on the levels of CD4+CD25+ cells in the T-regulatory polarization assay. CD4+ naive T cells were isolated by negative selection from PBMCs recovered from buffy coats of healthy donors (n=4). Cells were differentiated into iTreg (induced Treg) with IL-2 and TGF-p and simultaneously treated with human thioredoxin 1 (TRX; SEQ ID NO:1) on day 0 in the presence of anti-CD3/CD28 bead stimulation and 10 pg/mL of anti-TRX1 antibodies, Isotype control or vehicle (PBS). Cells were recovered on day 3 and stained for viability and surface expression of CD4, CD25 and intracellular expression of FOXP3 for analysis by flow cytometry. The figure shows the mean (n=3 +/- SEM), as well as individual values for each donor, frequency of CD4+CD25+ within the live cell population. * p<0.05, **** p<0.0001 as determined using a repeated-measure one-way ANOVA with Sidak’s multiple comparison test between cultures treated with anti-TRX1 antibodies with the appropriate isotype control-treated cultures (MOPC-21) are shown. Figure 4: Effect of anti-Trx1 antibodies on the level of expression of CD25 within CD4+ cell population in the T-regulatory polarization assay. CD4+ naive T cells were isolated by negative selection from PBMCs recovered from buffy coats of healthy donors (n=4). Cells were differentiated into iTreg (induced Treg) with IL-2 and TGF-p and simultaneously treated with human thioredoxin (TRX; SEQ ID NO:1) on day 0 in the presence of anti-CD3/CD28 bead stimulation and 10 pg/mL of anti-TRX1 antibodies, Isotype control or vehicle (PBS). Cells were recovered on day 3 and stained for viability and surface expression of CD4, CD25 and intracellular expression of FOXP3 for analysis by flow cytometry. The figure shows the mean (n=3 +/-SEM), as well as individual values for each donor, level of expression (MFI) of CD25 within live (viable) CD4+ cell population. *** p< 0.001 , **** p<0.0001 as determined using a repeated-measure one-way ANOVA with Sidak’s multiple comparison test between cultures treated with anti-TRX1 antibodies with the appropriate isotype control-treated cultures (MOPC-21) are shown.

Figure 5: Effect of anti-Trx1 antibodies on the levels of FOXP3+ cells within CD4+CD25+ cell population in the T-regulatory polarization assay. CD4+ naive T cells were isolated by negative selection from PBMCs recovered from buffy coats of healthy donors (n=4). Cells were differentiated into iTreg (induced Treg) with IL-2 and TGF-p and simultaneously treated with human thioredoxin (TRX; SEQ ID NO:1) on day 0 in the presence of anti-CD3/CD28 bead stimulation and 10 pg/mL of anti-TRX1 antibodies, Isotype control or vehicle (PBS). Cells were recovered on day 3 and stained for viability and surface expression of CD4, CD25 and intracellular expression of FOXP3 for analysis by flow cytometry. The figure shows the mean (n=3 +/-SEM), as well as individual values for each donor, frequency of FOXP3+ cells within live (viable) CD4+CD25+ cell population. **** p<0.0001 as determined using a repeated-measure one-way ANOVA with Sidak’s multiple comparison test between cultures treated with anti-TRX1 antibodies with the appropriate isotype control-treated cultures (MOPC-21) are shown.

Figure 6: Effect of anti-Trx1 antibodies on the level of expression of FOXP3 within CD4+CD25+ cell population in the T-regulatory polarization assay. CD4+ naive T cells were isolated by negative selection from PBMCs recovered from buffy coats of healthy donors (n=4). Cells were differentiated into iTreg (induced Treg) with IL-2 and TGF-p and simultaneously treated with human thioredoxin (TRX; SEQ ID NO:1) on day 0 in the presence of anti-CD3/CD28 bead stimulation and 10 pg/mL of anti-TRX1 antibodies, Isotype control or vehicle (PBS). Cells were recovered on day 3 and stained for viability and surface expression of CD4, CD25 and intracellular expression of FOXP3 for analysis by flow cytometry. The figure shows the mean (n=3 +/-SEM), as well as individual values for each donor, level of expression (MFI) of FOXP3 within live (viable) CD4+CD25+ cell population. ** p< 0.01 , *** p< 0.001 , **** p<0.0001 as determined using a repeated-measure one-way ANOVA with Sidak’s multiple comparison test between cultures treated with anti-TRX1 antibodies with the appropriate isotype control-treated cultures (MOPC-21) are shown.

Figure 7: Effect of anti-TRX1 mAb 1 F5 on survival of mice bearing 4T1 mouse breast tumors. Survival was measured as either death or reaching a mean tumor volume of 1500mm³ in each group whichever happens earlier. Survival of mice treated either with a control mlgG1 antibody or anti-TRX1 mAb 1 F5 are shown. Median survival and the hazard ratio are shown below the survival plot. KM = Kaplan Meier.

Figure 8: Effect of anti-Trx1 mAb 9B6 on growth of a human breast cancer cell line MDA- MB-231 in humanized immune system mice. Mean (left panel) and Median (right panel) tumor volume of mice treated either with a control hl gG 1 antibody or anti-TRX1 mAb 9B6 are shown. Statistical test and the p value are shown below the graphs.

Figure 9: Effect of an anti-PD-1 antibody Keytruda (used as a positive control antibody in the study) on growth of a human breast cancer cell line MDA-MB-231 in humanized immune system mice. Mean (left panel) and Median (right panel) tumor volume of mice treated either with a control hlgG 1 antibody or Keytruda are shown. Statistical test and the p value are shown below the graphs.

Example 1 :

Materials and Methods

Antibody development

Production of monoclonal antibodies (mouse IgG) using the hybridoma technology

In brief, monoclonal antibodies were produced through immunizing BALB/c mice (Mus musculus) with human Thioredoxin 1 (Trx1 , Cayman Chemicals, catalogue # 11518 (SEQ ID NO:1)). For selection of hybridoma clones Elisa analysis of binding to the antigen was used. Monoclonal antibodies were affinity purified against Protein A from hybridoma supernatant.

In more detail, mice were immunized with full length recombinant human Trx1 (SEQ ID NO:1). Immune responses were evaluated with ELISA. After the immunization process mice were selected based on ELISA screening of serum, and spleen cells from mouse were extracted and fused with myeloma cells to produce hybridoma cells. Hybridomas were screened by ELISA to obtain positive clones (i.e. that produce antibody that binds to the target). After this screening, sub-cloning of the selected hybridomas was performed and a further round of screening was performed using ELISA. Sub-cloned hybridomas were then used to produce monoclonal antibodies. The binding properties of antibodies in the supernatant were tested using ELISA. Five monoclonal antibodies, 1 B7, 1F5, 7C8, 9B6 and 15G8 were identified. Monoclonal antibodies were affinity purified against Protein A from hybridoma supernatant.

Cloning and Sequencing of Mouse Hybridoma IgG

From mouse hybridomas, RNA was prepared from which cDNA was synthesized. Variable Light (VL) and Variable Heavy (VH) regions of cDNA were amplified and cloned into standard cloning vector separately. Identification of positive clones was done by colony PCR followed by gel electrophoresis. VL and VH DNA and amino acid sequences were obtained from positive clones.

Sequencing of the cDNAs encoding the VH and VL domains identified one VH region (domain) sequence and one VL region (domain) sequence per antibody (i.e. per hybridoma). Sequences of the antibodies are set out in Tables A, B, C, D and E herein.

ELISA

Maxisorp, Nunc-lmmuno Plates, (Thermo Scientific) were coated with hTrxl (SEQ ID NO:1) (5 pg/mL) in 0.58M carbonate-bicarbonate buffer pH9.5 100pl/well and incubated 2h at 37°C. Plates were washed with PBS containing 0.1 % Tween and incubated O/N at 4°C in the presence of blocking buffer (PBS, 3% BSA, pH 7.4). A serial dilution of antibodies was added in blocking buffer and incubated for 1h at 37°C. Plates were washed with PBS containing 0.1% Tween and a secondary antibody (goat anti-mouse IgG conjugated to HRP (Jackson Labs, catalogue #115-035-071)), 0.5 pg/mL in PBS was added and incubated for 0.5h at 37°C. Plates were washed with PBS containing 0.1% Tween followed by addition of TMB substrate, 100pl/well and incubated for 5 min at 37°C. Reaction was stopped by adding 50pl/well of 2M HCI. Absorbance was measured at 450 nm.

T regulatory polarization assay

PBMC were recovered from fresh healthy human donor buffy coats (n=3) and naive CD4+ T cells isolated by negative selection using magnetic beads (StemCell EasySep™ Human Naive CD4+ Isolation Kit II, Cat. No. 17555) and resuspended at 1 x 10⁶ cells/mL in RPMI- 10 (RPMI-1640, 10 % heat inactivated FBS, 100 U/rnL penicillin, 100 pg/mL streptomycin, 2 mM L-glutamine and 50 pM p-mercaptoethanol). A 50 pL aliquot was added to the wells of a 96-well flat bottom plate (5 x 10⁴ cells/well). On day 0, cultures were treated with 5 ng/mL recombinant human TGF-pi (R&D Systems, Cat. No. 240-B) and 100 U/rnL recombinant human IL-2 (Peprotech, Cat. No. 200-02) in the presence of 10 pg/mL (final concentration) of the affinity purified anti-Trx1 1 B7, 1 F5, 7C8, 9B6 or 15G8 antibody, or mouse lgG1 isotype control. Human Trx1 (SEQ ID NO:1) (final concentration 100 ng/mL) was added to the culture and cells stimulated with Dynabeads human T-Activator CD3/CD28 (ThermoFisher, Cat. No. 11132D) at a ratio of 1 :2 (cells:beads). The final volume in all wells was 200 pL. Cells were cultured in a humidified atmosphere at approximately 37°C, 5 % CO2 for 3 days. On day 3, cultures were agitated by gentle pipetting and were transferred to a round bottom plate for flow cytometry staining.

Flow Staining: Cells were washed with 200 pL PBS, centrifuged 5 minutes at 300 x g, supernatant discarded and cells were re-suspended in a 1 :1000 dilution of e-fluor 780 fixable viability dye (ThermoFisher, Cat. No. 65-0865-18) in PBS for 20 minutes at 2-8°C. Cultures were topped up with 100 pL PBS, centrifuged at 300 x g, supernatant discarded and then washed in 200 pL FACS buffer (PBS supplemented with 2 % FCS and 0.1 % sodium azide), centrifuged at 300 x g, then supernatant discarded. Cells were resuspended in 25 plantibody staining cocktail containing anti-CD4 and anti-CD25 antibodies (see Table 1) for 30 minutes at 2-8°C in the dark then washed twice in 200 pL FACS buffer (PBS supplemented with 2 % FCS and 0.1 % sodium azide). For intracellular staining, cells were then permeabilised with eBioscience™ FOXP3 / Transcription Factor Staining Buffer (ThermoFisher, Cat. No. 00-5523-00) then incubated with anti-FOXP3 antibody (see Table 1) for 30 minutes at room temperature protected from light. Plates were stored at 2-8°C and protected from light for up to three days until acquisition on an Attune NXT flow cytometer.

Table 1: Antibodies used for flow staining

Data Analysis: The frequency and Mean Fluorescence Intensity (MFI) of CD25 in live (viable) CD4+ population and the frequency and Mean Fluorescence Intensity (MFI) of Foxp3 in live (viable) CD4+CD25+ population were determined. Gating of positive populations were based on Fluorescence Minus One (FMO) controls. Statistical analysis with one-way ANOVA with Sidak’s multiple comparison test was used to compare the difference between various treatment groups.

Results and Discussion

The monoclonal antibodies (1 B7, 1 F5, 7C8, 9B6 and 15G8) were affinity purified and subjected to ELISA tests. ELISA tests showed that the antibodies were able to bind to full length hTrxl with high affinity (Figure 1). The five antibodies show slightly different affinities to hTrxl but all of them have an EC50 of <0.16 ug/mL or <1.06nM.

Effect of anti-Trx1 mAbs on T-regulatory cells (Tregs) was evaluated in an in vitro Treg polarization assay. Naive CD4+ cells isolated from PBMCs (peripheral blood mononuclear cells) differentiate into FOXP3 expressing CD4+CD25+ Treg cells upon stimulation with anti- CD3 + anti-CD28 antibodies in the presence of TGFbl , IL-2 and Trx1. These regulatory T cells express high levels of CD25 which is the receptor for IL-2, a survival factor for these T cells. FOXP3 is a key transcription factor that is specifically expressed in these Tregs and is very critical for their suppressive activity. Treatment of CD4+ cells in the Treg polarization assay for 3 days with mAb clones 1 F5, 7C8, 9B6 and 15G8 result in reduced viability of these cells (Figure 2). Clone 7C8 has the maximal effect and along with clone 9B6 show statistically significant reduction in % live cells.

Clones 1 B7, 1F5, 7C8 and 9B6 show a statistically significant reduction in % of CD4+CD25+ cells; again clone 7C8 has the maximal effect. (Figure 3). Clone 15G8 does not show an effect at all. In addition, the level of expression of CD25 in these cells is reduced by the treatment with 1B7, 1F5, 7C8 and 9B6 but not 15G8 clones (Figure 4).

CD4+CD25+FOXP3+ cells which are classified as typical T regulatory cells (Tregs) are highly affected by the treatment with 1 B7, 1 F5, 7C8 and 9B6 but not with 15G8; a decrease in Tregs is observed with the 1 B7, 1 F5, 7C8 and 9B6 antibodies (Figure 5). Moreover, the expression level of FOXP3 (a marker of Tregs) is similarly reduced by 1 B7, 1 F5, 7C8 and 9B6 but not 15G8 (Figure 6).

Tregs have been implicated in cancer and inflammatory diseases. In the context of cancer, Treg cells are involved in tumour development and progression by suppressing anti-cancer immune responses. Inhibiting/reducing levels of Treg cells can thus be therapeutically beneficial, e.g. in cancer. The present study indicates that Trx1 is an important factor in the differentiation of naive CD4+ T-cells into Tregs and has identified monoclonal anti-Trx1 antibodies which are able to reduce levels of Tregs. These antibodies are promising candidates for therapies in which reducing Tregs would be beneficial, e.g. in cancer therapies.

Example 2

In Vivo Evaluation of anti-TRX1 mAb 1F5 in a Syngeneic Model (4T1) of Breast Cancer

Aim

To evaluate the activity of anti-TRX1 mAb 1F5 in a Syngeneic Model (4T1) of Breast Cancer.

Materials and Methods Test substances

Anti-TRX1 mAb - 1 F5 mouse lgG1 Isotype control antibody (BioXcell cat # BE0083)

T est System

Species: Mouse

Strain: Balb/c (Immunocompetent)

Source: Jax (The Jackson Laboratory)

Gender: Female

Target age at initiation of dosing: At least 6-8 weeks of age

Target weight at initiation of dosing: At least 18 grams

Acclimation period: 3 days

Cages: Individual HEPA ventilated cages

Bedding: Irradiated corncob (Teklad 7902, CS)

Enrichment: 100% virgin kraft nesting enrichment sheets (Innorichment™)

Food: Sterilized test rodent diet (Teklad 2019), 19% protein, 9% fat and 4% fiber

Water: ad libitum

Environmental Conditions:

Temperature: 68-74°F (20-23°C)

Humidity: 30-70%

Light cycle: 14-10hour light-dark cycle

Experimental Design

Pre-study animals were injected with 0.1 mL containing 300,000 4T 1 cells in PBS, subcutaneously in the left flank of immunocompetent Balb/c mice.

Pre-study tumor volumes were recorded for each experiment beginning four to five days after injection. When tumors reached an average tumor volume of 50-120 mm³, animals were matched by tumor volume into treatment or control groups to be used for dosing. Each group consisted of ten tumor bearing animals. Dosing was initiated on Day 0, the day after randomization. Dosing: anti-TRX mAb 1F5 or mouse lgG1 isotype control antibody in PBS were administered at 10 mg/kg in the dosing volume of 10 mL/kg intravenously, twice a week for three weeks.

In-Life Measurements

Tumor Volume: Tumor volumes were measured three times weekly. A final tumor volume was taken on the day study reaches endpoint. If possible, a final tumor volume was taken if an animal was found moribund.

Animal Weights: Animals were weighed three times weekly. A final weight was taken on the day the study reached end point or if animal is found moribund, if possible. Animals exhibiting >10% weight loss when compared to Day 0 were provided DietGel® ad libitum. Any animal exhibiting >20% net weight loss for a period lasting 7 days or if mice display >30% net weight loss when compared to Day 0 was considered moribund and euthanized.

Study Termination

Efficacy: The study endpoint of survival was death (due to any cause) or mean tumor volume of 1500mm³ in each group whichever happened earlier.

Necropsy: At the end of the study, gross necropsy was performed and any gross observations in the lung and spleen such as metastasis were recorded. Wherever possible, gross necropsy and observations in the lung and spleen were recorded from dead and moribund animals before the study was terminated.

Data Analysis

Beginning Day 0, tumor dimensions were measured twice weekly by digital caliper and data including individual and mean estimated tumor volumes (Mean TV ± SEM) recorded for each group; tumor volume was calculated using the formula (1): TV= width² x length x 0.52.

Data was plotted as Kaplan-Meier survival curves using Graphpad Prism 9.2.0 software. Results and Discussion

The monoclonal antibody 1F5 was chosen to test the effects of neutralizing Trx1 in a mouse model of cancer. 1 F5 has the ability to bind mouse T rx1. An ELISA test showed that the 1 F5 mAb is able to bind to mouse Trx1 (data not shown). 4T 1 mouse breast cancer model was chosen since it represents triple negative breast cancer and has the ability to metastasize to lungs and spleen. There was a profound and statistically highly significant effect on survival of mice treated with anti-Trx1 mAb 1 F5 compared to control lgG1, with median survival time “not reached” and 13 days, respectively (Figure 7).

In conclusion, there is potential for the anti-Trx1 mAb 1 F5 (and other antibodies described herein) to be developed as a therapeutic agent for treating cancer.

Example 3

In Vivo Evaluation of The Efficacy ofanti-Trx1 mAb 9B6 in a Subcutaneous, Triple Negative Breast Cancer Model (MDA-MB-231) in Humanized Immune System mice.

Aim

To evaluate the antitumor activity of anti-TRX1 mAb 9B6 in a subcutaneous, Triple Negative Breast Cancer Model (MDA-MB-231) in humanized immune system mice.

Materials and Methods

Test substances

Anti-TRX1 mAb - 9B6 (in this Example a recombinant chimeric version of the 9B6 mAb was used which contained the variable region of the mouse 9B6 mAb described elsewhere herein and a human lgG1 constant region) Keytruda/Pembrolizumab (anti-PD-1 mAb, Merck) Human lgG1 control (BioXcell cat # BP0297)

T est System

Species: Mouse Strain: CD34+ humanized NCG

Source: Charles River

Gender: Female

Target age at initiation of dosing: At least 16 weeks of age Target weight at initiation of dosing: At least 25-28 grams Acclimation period: 7 days

Cages: Individual ventilated cages (type II 16x19x35 cm, floor area = 500 cm²)) Bedding: TEK-Fresh Laboratory Animal Bedding (Envigo, Gannat, France) Enrichment: A cardboard house (safe Hut; Safe, France) and a chew stick Food & Water: Ref. 2018, Harlan France; available ad libitum Environmental Conditions:

Temperature: 22±2°C Humidity: 55±10%

Light cycle: 12:12-hour light-dark cycle 7am:7pm

CD34+ Cord Blood Cell Engraftment Protocol

Experiments were carried out with the female NOD/Shi-scid/IL-2Rynull immunodeficient mouse strain (NCG, Charles River). Four-week-old immunodeficient NCG mice were engrafted intravenously with human cord blood-derived CD34+ hematopoietic stem and progenitor cells (French Blood Bank) two days after chemical myeloablative treatment (Busulphan). CD34+ cord blood cells (i.v. injection of 50,000-100,000 cells) from at least 5 different human donors were used for engraftment and randomized across all groups. Fourteen weeks after cell injection, engraftment level was monitored with the analysis of human CD45+ cells among total blood leukocytes (mouse and human) by flow cytometry. Only mice with a humanization rate (hCD45/Total CD45) above 25% were used.

Experimental Design

PreAnimals Pre-study animals (CD34+humanized NCG mice) were implanted in the mammary fat pad (inguinal region) with 5x10⁶ MDA-MB-231 cells, re-suspended in 100pL 1 :1 Matrigel™: PBS.

Animals Pre-study tumor volumes were recorded for each experiment beginning 2-3 days after implantation. When tumors reached an average tumor volume of 80-150mm³, animals were matched by tumor volume, donor and humanization rate into treatment or control groups to be used for dosing (Day -1). Each group consisted of nine tumor bearing animals. Dosing was initiated on Day 0, the day after randomization.

Dosing: anti-TRX1 mAb 9B6 or human IgG 1 isotype control antibody in PBS were administered at 10 mg/kg at the dosing volume of 10 ml_/kg intravenously, twice a week for five weeks. Keytruda was administered at 10 mg/kg at the dosing volume of 10 mL/kg intraperitonially once every five days for five weeks.

In-Life Measurements

Tumor Volume: Tumor volumes were taken twice weekly. A final tumor volume was taken on the day study reaches endpoint. If possible, a final tumor volume was taken if an animal is found moribund.

Study Termination

The study endpoint is when the mean tumor volume of the control group (uncensored) reached 1200mm³. If this occurred before Day 28, treatment groups and individual mice were dosed and measured up to Day 28. If the mean tumor volume of the control group (uncensored) did not reach 1200mm³ by Day 28, then the endpoint for all animals was the day when the mean tumor volume of the control group (uncensored) reached 1200mm³ up to a maximum of Day 60.

Any mouse bearing a tumor that exceeds terminal size (1 ,500mm³) was euthanized.

Data Analysis

Agent Efficacy: Tumor Growth Inhibition - Beginning Day 0, tumor dimensions were measured twice weekly by digital caliper and data including individual and mean estimated tumor volumes (Mean TV ± SEM) recorded for each group; tumor volume was calculated using the formula (1): TV= width² x length x 0.52. At study completion, percent tumor growth inhibition (%TGI) values were calculated and reported for each treatment group (T) versus control (C) using initial (i) and assessment date/final (f) tumor measurements by the formula (2): %TGI = 1 - (Tf-Ti) / (Cf-Ci) x100.

Plotting and statistical analysis of the data was done using Graphpad Prism 9.2.0 software. Results and Discussion

The monoclonal antibody 9B6 was tested for its ability to inhibit growth of a human tumor in a humanized mouse model. MDA-MB-231 is a human triple negative breast cancer cell line. When grown in a mouse where human immune system is grafted using human CD34+ cells, this model mimics some aspects of human triple negative breast cancer. 9B6 showed a statistically highly significant 20% - 35% tumor growth inhibition between days 13 and 30 after the start of the treatment (Figure 8). In comparison, the clinically approved anti-PD-1 mAb Keytruda showed a statistically significant (but lower than 9B6) 15 - 25% tumor growth inhibition between days 13 and 30 after the start of the treatment (Figure 9).

In conclusion, there is potential for the anti-Trx1 mAb 9B6 (and other antibodies described herein) to be developed as a therapeutic agent for treating cancer.

Claims

1. An antibody that binds to Thioredoxin 1 and that comprises at least one heavy chain variable region that comprises three CDRs and at least one light chain variable region that comprises three CDRs, wherein

(i) said heavy chain variable region comprises: (a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:6 or a sequence substantially homologous thereto, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:7 or a sequence substantially homologous thereto, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:8 or a sequence substantially homologous thereto; and/or said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:9 or a sequence substantially homologous thereto, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO: 10 or a sequence substantially homologous thereto, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:11 or a sequence substantially homologous thereto; or

(ii) said heavy chain variable region comprises: (a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:24 or a sequence substantially homologous thereto, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:25 or a sequence substantially homologous thereto, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:26 or a sequence substantially homologous thereto; and/or said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:27 or a sequence substantially homologous thereto, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 or a sequence substantially homologous thereto, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:29 or a sequence substantially homologous thereto; or

(iii) said heavy chain variable region comprises: (a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:42 or a sequence substantially homologous thereto, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:43 or a sequence substantially homologous thereto, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:44 or a sequence substantially homologous thereto; and/or said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:45 or a sequence substantially homologous thereto, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:46 or a sequence substantially homologous thereto, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:47 or a sequence substantially homologous thereto; or

(iv) said heavy chain variable region comprises: (a) a variable heavy (VH)

CDR1 that has the amino acid sequence of SEQ ID NQ:60 or a sequence substantially homologous thereto, (b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:61 or a sequence substantially homologous thereto, and (c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:62 or a sequence substantially homologous thereto; and/or said light chain variable region comprises: (d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:63 or a sequence substantially homologous thereto, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:64 or a sequence substantially homologous thereto, and (f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:65 or a sequence substantially homologous thereto; wherein said substantially homologous sequence is a sequence containing 1 , 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

2. The antibody of claim 1 , wherein said heavy chain variable region comprises:

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:6, or a sequence substantially homologous thereto,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:7, or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:8, or a sequence substantially homologous thereto; and wherein said light chain variable region comprises:

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:11, or a sequence substantially homologous thereto, wherein said substantially homologous sequence is a sequence containing 1, 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

3. The antibody of claim 1 or claim 2, wherein said heavy chain variable region comprises a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:6, a VH CDR2 that has the amino acid sequence of SEQ ID NO:7 and a VH CDR3 that has the amino acid sequence of SEQ ID NO:8, and wherein said light chain variable region comprises a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:9, a VL CDR2 that has the amino acid sequence of SEQ ID NO: 10 and a VL CDR3 that has the amino acid sequence of SEQ ID NO:11.

4. The antibody of claim 1 , wherein said heavy chain variable region comprises:

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:26, or a sequence substantially homologous thereto; and wherein said light chain variable region comprises:

(d) a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:27, or a sequence substantially homologous thereto, (e) a VL CDR2 that has the amino acid sequence of SEQ ID NO:28, or a sequence substantially homologous thereto, and

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:29, or a sequence substantially homologous thereto, wherein said substantially homologous sequence is a sequence containing 1, 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

5. The antibody of claim 1 or claim 4, wherein said heavy chain variable region comprises a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:24, a VH CDR2 that has the amino acid sequence of SEQ ID NO:25 and a VH CDR3 that has the amino acid sequence of SEQ ID NO:26, and wherein said light chain variable region comprises a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:27, a VL CDR2 that has the amino acid sequence of SEQ ID NO:28 and a VL CDR3 that has the amino acid sequence of SEQ ID NO:29.

6. The antibody of claim 1 , wherein said heavy chain variable region comprises:

(a) a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:42, or a sequence substantially homologous thereto,

(b) a VH CDR2 that has the amino acid sequence of SEQ ID NO:43, or a sequence substantially homologous thereto, and

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:44, or a sequence substantially homologous thereto; and wherein said light chain variable region comprises:

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:47, or a sequence substantially homologous thereto, wherein said substantially homologous sequence is a sequence containing 1, 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

7. The antibody of claim 1 or claim 6, wherein said heavy chain variable region comprises a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:42, a VH CDR2 that has the amino acid sequence of SEQ ID NO:43 and a VH CDR3 that has the amino acid sequence of SEQ ID NO:44, and wherein said light chain variable region comprises a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:45, a VL CDR2 that has the amino acid sequence of SEQ ID NO:46 and a VL CDR3 that has the amino acid sequence of SEQ ID NO:47.

8. The antibody of claim 1 , wherein said heavy chain variable region comprises:

(c) a VH CDR3 that has the amino acid sequence of SEQ ID NO:62, or a sequence substantially homologous thereto; and wherein said light chain variable region comprises:

(f) a VL CDR3 that has the amino acid sequence of SEQ ID NO:65, or a sequence substantially homologous thereto, wherein said substantially homologous sequence is a sequence containing 1, 2 or 3 amino acid substitutions compared to the given CDR sequence, or said substantially homologous sequence is a sequence containing conservative amino acid substitutions of the given CDR sequence.

9. The antibody of claim 1 or claim 8, wherein said heavy chain variable region comprises a variable heavy (VH) CDR1 that has the amino acid sequence of SEQ ID NO:60, a VH CDR2 that has the amino acid sequence of SEQ ID NO:61 and a VH CDR3 that has the amino acid sequence of SEQ ID NO:62, and wherein said light chain variable region comprises a variable light (VL) CDR1 that has the amino acid sequence of SEQ ID NO:63, a VL CDR2 that has the amino acid sequence of SEQ ID NO:64 and a VL CDR3 that has the amino acid sequence of SEQ ID NO:65.

10. The antibody of any one of claims 1 to 3, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:5 or a sequence having at least 80% sequence identity thereto and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:4, or a sequence having at least 80% sequence identity thereto.

11. The antibody of any one of claims 1 to 3 or 10, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:5 and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:4.

12. The antibody of any one of claims 1 , 4 or 5, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:23 or a sequence having at least 80% sequence identity thereto and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:22, or a sequence having at least 80% sequence identity thereto.

13. The antibody of any one of claims 1 , 4, 5 or 12, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:23 and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:22.

14. The antibody of any one of claims 1 , 6 or 7, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:41 or a sequence having at least 80% sequence identity thereto and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NQ:40, or a sequence having at least 80% sequence identity thereto.

15. The antibody of any one of claims 1 , 6, 7 or 14, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:41 and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:40.

16. The antibody of any one of claims 1 , 8 or 9, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:59 or a sequence having at least 80% sequence identity thereto and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:58, or a sequence having at least 80% sequence identity thereto.

17. The antibody of any one of claims 1 , 8, 9 or 16, wherein the light chain variable region has the amino acid sequence of SEQ ID NO:59 and wherein the heavy chain variable region has the amino acid sequence of SEQ ID NO:58.

18. The antibody of any one of claims 1 to 17, wherein said antibody is a whole antibody comprising an antibody constant region, preferably said antibody is an IgG antibody.

19. The antibody of any one of claims 1 to 17, wherein said antibody is an antigen binding fragment of an antibody.

20. The antibody of any one of claims 1 to 19, wherein said antibody reduces the differentiation of naive CD4+ T-cells into Tregs.

21. A composition comprising an antibody of any one of claims 1 to 20 and a diluent, carrier or excipient, preferably a pharmaceutically acceptable diluent, carrier or excipient.

22. A nucleic acid molecule comprising a nucleotide sequence that encodes an antibody of any one of claims 1 to 20, or a set of nucleic acid molecules each comprising a nucleotide sequence, wherein said set of nucleic acid molecules together encode an antibody of any one of claims 1 to 20.

23. A method of producing an antibody according to any one of claims 1 to 20, comprising the steps of: (i) culturing a host cell comprising (i) one or more nucleic acid molecules encoding an antibody according to any one of claims 1 to 20 or (ii) a set of nucleic acid molecules each comprising a nucleotide sequence, wherein said set of nucleic acid molecules together encode an antibody of any one of claims 1 to 20, or (iii) one or more recombinant expression vectors comprising one or more of said nucleic acid molecules, under conditions suitable for the expression of the encoded antibody; and

(ii) isolating or obtaining the antibody from the host cell or from the growth medium/supernatant.

24. An antibody as defined in any one of claims 1 to 20 for use in therapy.

25. An antibody as defined in any one of claims 1 to 20 for use in the treatment of a disease or condition that is associated with Tregs.

26. An antibody as defined in any one of claims 1 to 20 for use in the treatment or prevention of cancer.

27. A method of treating or preventing a disease or condition that is associated with Tregs, said method comprising administering to a patient in need thereof a therapeutically effective amount of an antibody as defined in any one of claims 1 to 20.

28. A method of treating or preventing cancer, said method comprising administering to a patient in need thereof a therapeutically effective amount of an antibody as defined in any one of claims 1 to 20.

29. Use of an antibody as defined in any one of claims 1 to 20 in the manufacture of a medicament for use in therapy.

30. The use according to claim 29, wherein said therapy is the treatment or prevention of a disease or condition that is associated with Tregs.

31. The use according to claim 29 or claim 30, wherein said therapy is the treatment or prevention of cancer.