WO2020030571A1

WO2020030571A1 - Combinations of a pd-1 antibody and a tlr4 modulator and uses thereof

Info

Publication number: WO2020030571A1
Application number: PCT/EP2019/070979
Authority: WO
Inventors: Bruce A HUG; Christopher J MATHENY
Original assignee: Glaxosmithkline Intellectual Property Development Limited
Priority date: 2018-08-06
Filing date: 2019-08-05
Publication date: 2020-02-13

Abstract

Disclosed herein are combinations of a PD-1 binding protein, and a TLR4 modulator, such as a TLR4 agonist, pharmaceutical compositions thereof, uses thereof, and methods of treatment comprising administering said combination, including uses in cancer.

Description

COMBINATIONS OF A PD-1 ANTIBODY AND A TLR4 MODULATOR

AND USES THEREOF

FIELD OF THE INVENTION

The present invention relates to a method of treating cancer in a mammal and to combinations useful in such treatment. In particular, the present invention relates to combinations of a PD-l binding protein and one or more TLR4 agonist.

BACKGROUND OF THE INVENTION

Effective treatment of hyperproliferative disorders, including cancer, is a continuing goal in the oncology field. Generally, cancer results from the deregulation of the normal processes that control cell division, differentiation and apoptotic cell death and is characterized by the proliferation of malignant cells which have the potential for unlimited growth, local expansion and systemic metastasis. Deregulation of normal processes includes abnormalities in signal transduction pathways and response to factors that differ from those found in normal cells.

Immunotherapies are one approach to treat hyperproliferative disorders. A major hurdle that scientists and clinicians have encountered in the development of various types of cancer immunotherapies has been to break tolerance to self-antigen (cancer) in order to mount a robust anti-tumor response leading to tumor regression. Unlike traditional development of small and large molecule agents that target the tumor, cancer immunotherapies target cells of the immune system that have the potential to generate a memory pool of effector cells to induce more durable effects and minimize recurrences.

Binding of the PD-l ligands, PD-L1 and PD-L2, to the PD-l receptor found on T cells, inhibits T cell proliferation and cytokine production. Upregulation of PD-l ligands occurs in some tumors and signaling through this pathway can contribute to inhibition of active T-cell immune surveillance of tumors. Antigen binding proteins such as antibodies that bind to the PD-l receptor and block its interaction with PD-L1 and PD-L2 may release PD-l pathway- mediated inhibition of the immune response, including the anti-tumor immune response. Enhancing anti-tumor T cell function and inducing T cell proliferation is a powerful and new approach for cancer treatment. Three immune-oncology antibodies ( e.g ., immuno- modulators) are presently marketed. Anti-CTLA-4 (YERVOY/ipilimumab) is thought to augment immune responses at the point of T cell priming and anti-PD-l antibodies (OPDIVO/nivolumab and KEYTRUDA/pembrolizumab) are thought to act in the local tumor microenvironment, by relieving an inhibitory checkpoint in tumor specific T cells that have already been primed and activated.

Aminoalkyl glucosaminide phosphates (AGPs) are synthetic ligands of Toll-like

Receptor 4 (TLR4). AGPs are known to be useful as vaccine adjuvants and for stimulating cytokine production, activating macrophages, promoting innate immune response, and augmenting antibody production in immunized animals.

Though there have been many recent advances in the treatment of cancer, there remains a need for more effective and/or enhanced treatment of an individual suffering the effects of cancer. The combinations and methods herein that relate to combining therapeutic approaches for enhancing anti-tumor immunity address this need.

SUMMARY OF THE INVENTION

Provided herein are combinations of a PD- 1 binding protein and one or more TLR4 modulators. Also provided are methods of treating cancer in a human with the compositions of the invention, and uses of the combinations for therapy, such as therapy for cancer. Further provided are methods for modulating the immune response of a subject in need of cancer treatment, such as a human, comprising administering to said subject an effective amount of the combination, e.g., in one or more pharmaceutical compositions.

In some aspects, the disclosure is drawn to a combination of a PD-l binding protein and a TLR4 agonist, wherein the PD-l binding protein comprises (a) a heavy chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO:5; (b) a heavy chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:6; (c) a heavy chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO:7; (d) a light chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO: 8; (e) a light chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:9; and (f) a light chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO: 10.

In some embodiments, the PD-l binding protein comprises a VH region comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO:3 and a VL region comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO:4.

In some embodiments, the PD-l binding protein comprises a VH region comprising the amino acid sequence as set forth in SEQ ID NO:3 and a VL region comprising the amino acid sequence as set forth in SEQ ID NO:4.

In some embodiments, the PD-l binding protein comprises a heavy chain comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO: 1 and a light chain comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO:2.

In some embodiments, the PD-l binding protein comprises a heavy chain comprising the amino acid sequence as set forth in SEQ ID NO: 1 and a light chain comprising the amino acid sequence as set forth in SEQ ID NO:2.

In some embodiments, the TLR4 agonist is an aminoalkyl glucosaminide phosphate (AGP).

In some embodiments, the TLR4 agonist is a compound of Formula I.

In some embodiments, the TLR4 agonist is a compound of Formula la.

In some embodiments, the TLR4 agonist is CRX-601 ; CRX-547; CRX-602; or CRX-527. In some embodiments, the TLR4 agonist is CRX-601 and has the formula:

In some aspects, the disclosure is drawn to a method of treating cancer in a subject in need thereof, the method comprising administering to the subject a combination described herein. In some aspects, the disclosure is drawn to a pharmaceutical combination of a first pharmaceutical composition comprising a therapeutically effective amount of a PD-l binding protein and a second pharmaceutical composition comprising a therapeutically effective amount of a TLR4 agonist, wherein the PD-l binding protein comprises (a) a heavy chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO:5; (b) a heavy chain variable region CDR2 comprising the amino acid sequence of SEQ ID

NO:6; (c) a heavy chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO:7; (d) a light chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO: 8; (e) a light chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:9; and (f) a light chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO: 10.

In some embodiments, the PD-l binding protein comprises a heavy chain comprising the amino acid sequence as set forth in SEQ ID NO: 1 and a light chain comprising the amino acid sequence as set forth in SEQ ID NO:2. In some embodiments, the TLR4 agonist is an aminoalkyl glucosaminide phosphate (AGP).

In some embodiments, the TLR4 agonist is a compound of Formula I.

In some embodiments, the TLR4 agonist is a compound of Formula la.

In some embodiments, the TLR-4 agonist is 0-((2R,3R,4R,5S,6R)-3-((R)-3- (decyloxy)tetradecanamido)-4-(((R)-3-(decyloxy)tetradecanoyl)oxy)-6-(hydroxymethyl)- 5-(phosphonooxy)tetrahydro-2H-pyran-2-yl)-N-((R)-3-(decyloxy)tetradecanoyl)-L- serine.

In some aspects, the disclosure is drawn to a method of treating cancer in a subject in need thereof, the method comprising administering to the subject a pharmaceutical combination described herein.

In some embodiments, the first pharmaceutical composition and the second

pharmaceutical composition are administered to the subject simultaneously or sequentially, in any order, by a route selected from the group consisting of: systemically; intravenously; subcutaneously; and, intratumorally.

In some embodiments, the first pharmaceutical composition is administered

intravenously, and second pharmaceutical composition is administered intravenously. In some embodiments, first pharmaceutical composition is administered intravenously, and the second pharmaceutical composition is administered intratumorally. In some embodiments, the cancer is selected from the group consisting of: melanoma; lung cancer; non-small cell lung cancer (NSCLC); kidney cancer; renal cell carcinoma (RCC) breast cancer; metastatic breast cancer; triple-negative breast cancer (TNBC); head and neck cancer; colon cancer; colorectal cancer (CRC); ovarian cancer; pancreatic cancer; liver cancer; hepatocellular carcinoma (HCC); prostate cancer; bladder cancer; gastric cancer; a liquid tumor; solid tumors; a hematopoietic tumor; leukemia; non- Hodgkin’s lymphoma (NHL); lymphoma; and chronic lymphocytic leukemia (CLL).

In some embodiments, the cancer comprises squamous cell carcinoma of head and neck (SCCHN). In some embodiments, the SCCHN is recurrent, locally advanced, or metastatic.

In some embodiments, the subject has more than one solid tumor, and wherein the TLR4 agonist is administered intratumorally to a single tumor of the subject, the tumor size of at least one solid tumor into which the TLR4 was not administered is reduced. In some aspects, the disclosure provides a method of treatment of a subject with cancer, the method comprising: administering to the subject a PD-l binding protein and a TLR4 agonist.

In some aspects, the disclosure provides a PD-l binding protein and a TLR4 agonist for simultaneous or sequential use in treating cancer.

In some aspects, the disclosure provides a PD-l binding protein for use in treating cancer, wherein the PD-l binding protein is to be administered simultaneously or sequentially with a TLR4 agonist.

In some aspects, the disclosure provides a TLR4 agonist for use in treating cancer, wherein the TLR4 agonist is to be administered simultaneously or sequentially with a PD-l binding protein.

In some aspects, the disclosure provides use of a PD-l binding protein in the manufacture of a medicament for treating cancer, wherein the PD-l binding protein is to be administered simultaneously or sequentially with a TLR4 agonist. In some aspects, the disclosure provides use of a TLR4 agonist in the manufacture of a medicament for treating cancer, wherein the TLR4 agonist is to be administered simultaneously or sequentially with a PD-l binding protein.

In some aspects, the disclosure provides a pharmaceutical kit comprising a PD-l binding protein and a TLR4 agonist.

In some embodiments of the method, binding protein, agonist, use, or kit, the PD-l binding protein is administered intravenously ( e.g ., intravenous infusion).

In some embodiments of the method, binding protein, agonist, use, or kit, the TLR4 agonist is administered intravenously (e.g., intravenous injection).

In some embodiments of the method, binding protein, agonist, use, or kit, the TLR4 agonist is administered intratumorally (e.g., by intratumoral injection).

In some embodiments of the method, binding protein, agonist, use, or kit, the PD-l binding protein is administered intravenously (e.g. , intravenous infusion) and the TLR4 agonist is administered intravenously (e.g., intravenous injection).

In some embodiments of the method, binding protein, agonist, use, or kit, the PD-l binding protein is a humanized monoclonal antibody.

In some embodiments of the method, binding protein, agonist, use, or kit, the PD-l binding protein comprises (a) a heavy chain variable region CDR1 comprising the amino acid sequence set forth in SEQ ID NO:5; (b) a heavy chain variable region CDR2 comprising the amino acid sequence set forth in SEQ ID NO:6; (c) a heavy chain variable region CDR3 comprising the amino acid sequence set forth in SEQ ID NO:7; (d) a light chain variable region CDR1 comprising the amino acid sequence set forth in SEQ ID NO:8; (e) a light chain variable region CDR2 comprising the amino acid sequence set forth in SEQ ID NO:9; and (f) a light chain variable region CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 10.

In some embodiments of the method, binding protein, agonist, use, or kit, the PD-l binding protein comprises a heavy chain variable region comprising the amino acid sequence as set forth in SEQ ID NO:3; and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO:4.

In some embodiments of the method, binding protein, agonist, use, or kit, the PD-l binding protein comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 1 and a light chain comprising the amino acid sequence set forth in SEQ ID NO:2.

In some embodiments of the method, binding protein, agonist, use, or kit, the TLR4 agonist is selected from the group consisting of: CRX-601; CRX-547; CRX-602; and, CRX-527.

In some embodiments of the method, binding protein, agonist, use, or kit, the TLR4 agonist is CRX-527.

In some embodiments of the method, binding protein, agonist, use, or kit, the TLR4 agonist is CRX-601.

In some embodiments of the method, binding protein, agonist, use, or kit, the cancer comprises a solid tumor.

In some embodiments of the method, binding protein, agonist, use, or kit, the cancer comprises squamous cell carcinoma of head and neck (SCCHN).

In some embodiments of the method, binding protein, agonist, use, or kit, the SCCHN is recurrent, locally advanced, or metastatic.

In some embodiments of the method, binding protein, agonist, use, or kit, the TLR4 agonist ( e.g ., CRX-601) and the PD-l binding protein ( e.g ., a PD-l binding protein comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 1 and a light chain comprising the amino acid sequence set forth in SEQ ID NO:2) are both administered to the subject every three weeks.

In some embodiments of the method, binding protein, agonist, use, or kit, the TLR4 agonist (e.g., CRX-601) is administered for a two-week run in period (e.g., the TLR4 agonist is administered on day 1 and 8) prior to commencing administering the PD-l binding protein (e.g. , a PD- 1 binding protein comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: l and a light chain comprising the amino acid sequence set forth in SEQ ID NO:2 is administered on day 15).

In some embodiments of the method, binding protein, agonist, use, or kit, after the run in period, the TLR4 agonist ( e.g ., CRX-601) and the PD-l binding protein ( e.g ., a PD-l binding protein comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 1 and a light chain comprising the amino acid sequence set forth in SEQ ID NO:2) are both administered to the subject every three weeks.

In some aspects, the disclosure is drawn to a method of treatment of a subject with cancer, the method comprising: administering to the subject a PD-l binding protein and a TLR4 agonist, wherein the PD-l binding protein is administered at a dose of about 200 mg and the TLR4 agonist is administered at a dose of about 5 ng to about 1000 ng. In an embodiment, the TLR4 agonist is administered at a dose of about 50 ng to about 250 ng.

In some aspects, the disclosure is drawn to a PD-l binding protein and a TLR4 agonist for simultaneous or sequential use in treating cancer, wherein the PD- 1 binding protein is to be administered at a dose of about 200 mg and the TLR4 agonist is to be administered at a dose of about 5 ng to about 1000 ng. In an embodiment, the TLR4 agonist is to be administered at a dose of about 50 ng to about 250 ng.

In some aspects, the disclosure is drawn to a PD-l binding protein for use in treating cancer, wherein the PD-l binding protein is to be administered at a dose of about 200 mg and is to be administered simultaneously or sequentially with a TLR4 agonist at a dose of about 5 ng to about 1000 ng. In an embodiment, the TLR4 agonist is to be administered at a dose of about 50 ng to about 250 ng.

In some aspects, the disclosure is drawn to a TLR4 agonist for use in treating cancer, wherein the TLR4 agonist is to be administered at a dose of about 5 ng to about 1000 ng and is to be administered simultaneously or sequentially with a PD- 1 binding protein at a dose of about 200 mg. In an embodiment, the TLR4 agonist is to be administered at a dose of about 50 ng to about 250 ng.

In some aspects, the disclosure is drawn to use of a PD-l binding protein in the manufacture of a medicament for treating cancer, wherein the PD-l binding protein is to be administered at a dose of about 200 mg and is to be administered simultaneously or sequentially with a TLR4 agonist at a dose of about 5 ng to about 1000 ng. In an embodiment, the TLR4 agonist is to be administered at a dose of about 50 ng to about 250 ng.

In some aspects, the disclosure is drawn to use of a TLR4 agonist in the manufacture of a medicament for treating cancer, wherein the TLR4 agonist is to be administered at a dose of about 5 ng to about 1000 ng and is to be administered simultaneously or sequentially with a PD-l binding protein at a dose of about 200 mg. In an embodiment, the TLR4 agonist is to be administered at a dose of about 50 ng to about 250 ng.

In some aspects, the disclosure is drawn to a pharmaceutical kit comprising about 200 mg of a PD-l binding protein and about 5 ng to 1000 ng of a TLR4 agonist. In an

embodiment, the kit comprises about 50 ng to about 250 ng of a TLR4 agonist.

In some embodiments, the PD-l binding protein is administered intravenously ( e.g ., intravenous infusion, e.g., over a period of 30 minutes).

In some embodiments, the TLR4 agonist is administered intravenously (e.g., intravenous injection).

In some embodiments, the TLR4 agonist is administered intratumorally (e.g., by intratumoral injection).

In some embodiments, the PD-l binding protein is administered intravenously (e.g., intravenous infusion) and the TLR4 agonist is administered intravenously (e.g. , intravenous injection).

In some embodiments, the TLR4 agonist is administered at a dose of about 5 ng to about 1000 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 50 ng to about 250 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 50 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 100 ng. In some embodiments, the TLR4 agonist is administered at a dose of about 150 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 200 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 250 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 300 ng. In some embodiments, the TLR4 agonist is administered at a dose of about 350 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 400 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 450 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 500 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 550 ng. In some embodiments, the TLR4 agonist is administered at a dose of about 600 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 600 ng to about 1000 ng.

In some embodiments, the PD-l binding protein is a monoclonal antibody, optionally a humanized monoclonal antibody or human monoclonal antibody. In an embodiment, the monoclonal antibody is of a human IgG4 antibody isotype. In an embodiment, the monoclonal antibody is of a human IgGl antibody isotype with an inactivated Fc region.

In some embodiments, the PD-l binding protein comprises (a) a heavy chain variable region CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 5; (b) a heavy chain variable region CDR2 comprising the amino acid sequence set forth in SEQ ID NO:6; (c) a heavy chain variable region CDR3 comprising the amino acid sequence set forth in SEQ ID NO:7; (d) a light chain variable region CDR1 comprising the amino acid sequence set forth in SEQ ID NO: 8; (e) a light chain variable region CDR2 comprising the amino acid sequence set forth in SEQ ID NO:9; and (f) a light chain variable region CDR3 comprising the amino acid sequence set forth in SEQ ID NO: 10. In some embodiments, the PD-l binding protein comprises a heavy chain variable region comprising the amino acid sequence as set forth in SEQ ID NO:3; and a light chain variable region comprising the amino acid sequence set forth in SEQ ID NO:4.

In some embodiments, the PD-l binding protein comprises a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: l and a light chain comprising the amino acid sequence set forth in SEQ ID NO:2.

In some embodiments, the TLR4 agonist is selected from the group consisting of: CRX- 601 ; CRX-547; CRX-602; and, CRX-527.

In some embodiments, the TLR4 agonist is CRX-527.

In some embodiments, the TLR4 agonist is CRX-601.

In some embodiments, the cancer comprises a solid tumor.

In some embodiments, the TLR4 agonist ( e.g ., CRX-601) and the PD-l binding protein (e.g. , a PD- 1 binding protein comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 1 and a light chain comprising the amino acid sequence set forth in SEQ ID NO:2) are both administered to the subject every three weeks.

In some embodiments, the TLR4 agonist (e.g., CRX-601) is administered for a two-week run in period (e.g., the TLR4 agonist is administered on day 1 and 8) prior to

administering the PD-l binding protein (e.g., a PD-l binding protein comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: l and a light chain comprising the amino acid sequence set forth in SEQ ID NO:2 administered on day 15).

In some embodiments, the TLR4 agonist is administered for a two-week run in period, and following the run in period, the TLR4 agonist and the PD-l binding protein are both administered to the subject, e.g., every three weeks. In some embodiments, the PD-l binding protein is a PD-l antagonist. In some embodiments, the PD-l antagonist is a monoclonal antibody. In some embodiments, the PD-l antagonist is selected from the group consisting of nivolumab, pembrolizumab, and cemiplimab.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a graph showing EMT-6 tumor growth in Balb/c mice treated with CRX-601 (TLR4 agonist) and/or PD-l antibody (RMPI-14, mouse surrogate for pembrolizumab).

Figure 2 is a graph showing survival of Balb/c mice implanted with EMT-6 tumors and treated with CRX-601 (TLR4 agonist) and/or PD-l antibody (RMPI-14, mouse surrogate for pembrolizumab).

DETAILED DESCRIPTION OF THE INVENTION Compositions and Combinations

Improved function of the immune system is a goal of immunotherapy for cancer. While not being bound by theory, it is thought that for the immune system to be activated and effectively cause regression or eliminate tumors, there must be efficient cross-talk among the various compartments of the immune system as well as at the tumor bed. The tumoricidal effect is dependent on one or more steps, e.g., the uptake of antigen by immature dendritic cells and presentation of processed antigen via MHC I and II by mature dendritic cells to naive CD8 (cytotoxic) and CD4 (helper) lymphocytes, respectively, in the draining lymph nodes. Naive T cells express molecules, such as CTLA-4 and CD28, that engage with co-stimulatory molecules of the B7 family on antigen presenting cells (APCs) such as dendritic cells. In order to keep T cells in check during immune surveillance, B7 on APCs preferentially binds to CTLA-4, an inhibitory molecule on T lymphocytes. However, upon engagement of the T cell receptor (TCR) with MHC Class I or II receptors via cognate peptide presentation on APCs, the co stimulatory molecule disengages from CTLA-4 and instead binds to the lower affinity stimulatory molecule CD28, causing T cell activation and proliferation. This expanded population of primed T lymphocytes retains memory of the antigen that was presented to them as they traffic to distant tumor sites. Upon encountering a tumor cell bearing the cognate antigen, they eliminate the tumor via cytolytic mediators such as granzyme B and perforins. This apparently simplistic sequence of events is highly dependent on several cytokines, co-stimulatory molecules and check point modulators to activate and differentiate these primed T lymphocytes to a memory pool of cells that can eliminate the tumor.

“Modulate” as used herein, for example, with regard to a receptor or other target, means to change any natural or existing function of the receptor, for example, it means affecting binding of natural or artificial ligands to the receptor or target; it includes initiating any partial or full conformational changes or signaling through the receptor or target, and also includes preventing partial or full binding of the receptor or target with its natural or artificial ligands. Also included in the case of membrane bound receptors or targets are any changes in the way the receptor or target interacts with other proteins or molecules in the membrane or change in any localization (or co-localization with other molecules) within membrane compartments as compared to its natural or unchanged state.

Modulators are, therefore, compounds or ligands or molecules that modulate a target or receptor.“Modulate” includes agonizing, e.g., signaling, as well as antagonizing, or blocking signaling or interactions with a ligand or compound or molecule that happen in the unchanged or unmodulated state. Thus, modulators may be agonists or antagonists. Further, one of skill in the art will recognize that not all modulators will have absolute selectivity for one target or receptor, but are still considered a modulator for that target or receptor; for example, a TLR4 modulator may also engage another TLR, but still be considered a TLR4 modulator. Other modulators are known to have multiple

specificities, such as TLR7/8 modulators that modulate both TLR7 and TLR8. Molecules with such known double or multiple specificities are considered a modulator of each of its target; that is, a TLR7/8 modulator is a TLR7 modulator as used herein and likewise a TLR7/8 modulator is a TLR8 modulator as used herein.

As used herein the term“agonist” refers to an antigen binding protein, including but not limited to an antibody, which upon contact with a co-signalling receptor causes one or more of the following (1) stimulates or activates the receptor, (2) enhances, increases or promotes, induces or prolongs an activity, function or presence of the receptor (3) mimics one or more functions of a natural ligand or molecule that interacts with a target or receptor and includes initiating one or more signaling events through the receptor, mimicking one or more functions of a natural ligand, or initiating one or more partial or full conformational changes that are seen in known functioning or signaling through the receptor and/or (4) enhances, increases, promotes or induces the expression of the receptor. Agonist activity can be measured in vitro by various assays known in the art such as, but not limited to, measurement of cell signalling, cell proliferation, immune cell activation markers, cytokine production. Agonist activity can also be measured in vivo by various assays that measure surrogate end points such as, but not limited to the measurement of T cell proliferation or cytokine production.

Thus, as used herein the term“combination of the invention” refers to a combination comprising a PD-l binding protein, such as an antibody, and a TLR4 modulator, such as an aminoalkyl glucosaminide phosphate compound (AGP), each of which may be administered separately or simultaneously as described herein.

As used herein, the terms“cancer”,“neoplasm”, and“tumor”, are used interchangeably and in either the singular or plural form, refer to cells that have undergone a malignant transformation or undergone cellular changes that result in aberrant or unregulated growth or hyperproliferation. Such changes or malignant transformations usually make such cells pathological to the host organism, thus precancers or pre-cancerous cells that are or could become pathological and require or could benefit from intervention are also intended to be included. Primary cancer cells (that is, cells obtained from near the site of malignant transformation) can be readily distinguished from non-cancerous cells by well- established techniques, such as histological examination. The definition of a cancer cell, as used herein, includes not only a primary cancer cell, but any cell derived from a cancer cell ancestor. This includes metastasized cancer cells, and in vitro cultures and cell lines derived from cancer cells. When referring to a type of cancer that normally manifests as a solid tumor, a“clinically detectable” tumor is one that is detectable on the basis of tumor mass; e.g., by procedures such as CAT scan, MR imaging, X-ray, ultrasound or palpation, and/or which is detectable because of the expression of one or more cancer- specific antigens in a sample obtainable from a patient. In other words, the terms herein include cells, neoplasms, cancers, and tumors of any stage, including what a clinician refers to as precancer, tumors, in situ growths, as well as late stage metastatic growths. Tumors may be hematopoietic tumor, for example, tumors of blood cells or the like, meaning liquid tumors. Specific examples of clinical conditions based on such a tumor include leukemia such as chronic myelocytic leukemia or acute myelocytic leukemia; myeloma such as multiple myeloma; lymphoma, and the like.

As used herein, the term“agent” means a substance that produces a desired effect in a tissue, system, animal, mammal, human, or other subject. Accordingly, the term“anti neoplastic agent” means a substance producing an anti-neoplastic effect in a tissue, system, animal, mammal, human, or other subject. The term“agent” may be a single compound or a combination or composition of two or more compounds.

By the term“treating” and derivatives thereof as used herein, is meant therapeutic therapy. In reference to a particular condition, treating means: (1) to ameliorate the condition or one or more of the biological manifestations of the condition (2) to interfere with (a) one or more points in the biological cascade that leads to or is responsible for the condition or (b) one or more of the biological manifestations of the condition; (3) to alleviate one or more of the symptoms, effects or side effects associated with the condition or one or more of the symptoms, effects or side effects associated with the condition or treatment thereof; or (4) to slow the progression of the condition or one or more of the biological manifestations of the condition.

As used herein,“prevention” means the prophylactic administration of a drug, such as an agent, to substantially diminish the likelihood or severity of a condition or biological manifestation thereof, or to delay the onset of such condition or biological manifestation thereof. The skilled artisan will appreciate that“prevention” is not an absolute term. Prophylactic therapy is appropriate, for example, when a subject is considered at high risk for developing cancer, such as when a subject has a strong family history of cancer or when a subject has been exposed to a carcinogen.

As used herein, the term“effective amount” means that amount of a drug or agent that will elicit the biological or medical response of a tissue, system, animal or human that is being sought, for instance, by a researcher or clinician. Furthermore, the term

“therapeutically effective amount” means any amount that, as compared to a corresponding subject who has not received such amount, results in improved treatment, healing, prevention, or amelioration of a disease, disorder, or side effect, or a decrease in the rate of advancement of a disease or disorder. The term also includes within its scope amounts effective to enhance normal physiological function. One or both of a PD-l binding protein and/or a TLR4 modulator can be administered to a subject or used in an effective amount (such as a therapeutically effective amount), e.g., in the methods and uses described herein.

By the term“combination” and grammatical variations thereof, as used herein, means either simultaneous administration or any manner of separate sequential administration of a therapeutically effective amount of Compound A (a PD-l ABP) and Compound B (a TLR4 agonist) or a pharmaceutically acceptable salt thereof. Furthermore, it does not matter if the compounds are administered in the same dosage form, e.g., one compound may be administered intravenously, and the other compound may be administered intratumorally.

The term“combination kit”, as used herein, means the pharmaceutical composition or compositions that are used to administer Compound A, or a pharmaceutically acceptable salt thereof, and Compound B, or a pharmaceutically acceptable salt thereof, according to the invention. When both compounds are administered simultaneously, the combination kit can contain Compound A, or a pharmaceutically acceptable salt thereof, and

Compound B, or a pharmaceutically acceptable salt thereof, in a single pharmaceutical composition, such as a tablet, or in separate pharmaceutical compositions. When the compounds are not administered simultaneously, the combination kit will contain Compound A, or a pharmaceutically acceptable salt thereof, and Compound B, or a pharmaceutically acceptable salt thereof, in separate pharmaceutical compositions. The combination kit can comprise Compound A, or a pharmaceutically acceptable salt thereof, and Compound B, or a pharmaceutically acceptable salt thereof, in separate pharmaceutical compositions in a single package or in separate pharmaceutical compositions in separate packages.

In one embodiment, the invention provides a combination kit comprising the

components: Compound A ( e.g ., a PD-l binding protein, e.g., at a dose of about 200 mg), or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier; and

Compound B (e.g., a TLR4 agonist, e.g., at a dose of about 50 ng to about 250 ng), or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier.

In another embodiment, the combination kit comprises the following components:

Compound A (e.g., a PD-l binding protein, e.g., at a dose of about 200 mg), or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier; and

Compound B (e.g., a TLR4 agonist, e.g., at a dose of about 50 ng to about 250 ng), or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier, wherein the components are provided in a form which is suitable for sequential, separate and/or simultaneous administration.

In yet another embodiment, the combination kit comprises: a first container comprising Compound A (e.g., a PD-l binding protein, e.g., at a dose of about 200 mg), or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier; and a second container comprising Compound B (e.g., a TLR4 agonist, e.g., at a dose of about 50 ng to about 250 ng), or a pharmaceutically acceptable salt thereof, in association with a pharmaceutically acceptable carrier, and a container means for containing said first and second containers.

The“combination kit” can also be provided by instruction, such as dosage and administration instructions. Such dosage and administration instructions can be of the kind that is provided to a doctor, for example by a drug product label, or they can be of the kind that is provided by a doctor, such as instructions to a patient. As used herein, the term“Compound A²” means a monoclonal antibody to human PD- 1 or the antigen binding portion thereof. Suitably Compound A² means a humanized monoclonal antibody having a heavy chain variable region as set forth in SEQ ID NO:3 and a light chain variable region as set forth in SEQ ID NO:4. Suitably, Compound A² can mean a monoclonal antibody having a heavy chain as set forth in SEQ ID NO: 1 and a light chain as set forth in SEQ ID NO:2.

As used herein, the term“Compound B²” means a TLR4 agonist of Formula I or Formula la. Suitably, Compound B² means the TLR4 agonist CRX-601.

Suitably, the combinations of this invention are administered within a“specified period”.

The term“specified period” and grammatical variations thereof, as used herein, means the interval of time between the administration of one of Compound A² and Compound B² and the other of Compound A² and Compound B². ETnless otherwise defined, the specified period can include simultaneous administration. ETnless otherwise defined, the specified period refers to administration of Compound A² and Compound B² during a single day.

Suitably, if the compounds are administered within a specified period and not administered simultaneously, they are both administered within about 24 hours of each other - in this case, the specified period will be about 24 hours; suitably they will both be administered within about 12 hours of each other - in this case, the specified period will be about 12 hours; suitably they will both be administered within about 1 1 hours of each other - in this case, the specified period will be about 11 hours; suitably they will both be administered within about 10 hours of each other - in this case, the specified period will be about 10 hours; suitably they will both be administered within about 9 hours of each other - in this case, the specified period will be about 9 hours; suitably they will both be administered within about 8 hours of each other - in this case, the specified period will be about 8 hours; suitably they will both be administered within about 7 hours of each other - in this case, the specified period will be about 7 hours; suitably they will both be administered within about 6 hours of each other - in this case, the specified period will be about 6 hours; suitably they will both be administered within about 5 hours of each other - in this case, the specified period will be about 5 hours; suitably they will both be administered within about 4 hours of each other - in this case, the specified period will be about 4 hours; suitably they will both be administered within about 3 hours of each other

- in this case, the specified period will be about 3 hours; suitably they will be

administered within about 2 hours of each other - in this case, the specified period will be about 2 hours; suitably they will both be administered within about 1 hour of each other - in this case, the specified period will be about 1 hour. As used herein, the administration of Compound A² and Compound B² in less than about 45 minutes apart is considered simultaneous administration.

Suitably, when the combination of the invention is administered for a“specified period”, the compounds will be co-administered for a“duration of time”.

The term“duration of time” and grammatical variations thereof, as used herein means that both compounds of the invention are administered for an indicated number of consecutive days. Unless otherwise defined, the number of consecutive days does not have to commence with the start of treatment or terminate with the end of treatment, it is only required that the number of consecutive days occur at some point during the course of treatment.

Regarding specified period administration: suitably, both compounds will be

administered within a specified period for at least one day - in this case, the duration of time will be at least one day; suitably, during the course to treatment, both compounds will be administered within a specified period for at least 3 consecutive days - in this case, the duration of time will be at least 3 days; suitably, during the course to treatment, both compounds will be administered within a specified period for at least 5 consecutive days - in this case, the duration of time will be at least 5 days; suitably, during the course to treatment, both compounds will be administered within a specified period for at least 7 consecutive days - in this case, the duration of time will be at least 7 days; suitably, during the course to treatment, both compounds will be administered within a specified period for at least 14 consecutive days - in this case, the duration of time will be at least 14 days; suitably, during the course to treatment, both compounds will be administered within a specified period for at least 30 consecutive days - in this case, the duration of time will be at least 30 days. In embodiments provided herein, both compounds are administered within a specified period ( e.g ., within one day, e.g., at least an hour between administration of the two compounds) which specified period occurs every three weeks.

Suitably, if the compounds are not administered during a specified period, they are administered sequentially. By the term“sequential administration”, and grammatical derivates thereof, as used herein is meant that one of Compound A² and Compound B² is administered once a day for two or more consecutive days and the other of Compound A² and Compound B² is subsequently administered once a day for two or more consecutive days. Also, contemplated herein is a drug holiday utilized between the sequential administration of one of Compound A² and Compound B² and the other of Compound A² and Compound B². As used herein, a drug holiday is a period of days after the sequential administration of one of Compound A² and Compound B² and before the administration of the other of Compound A² and Compound B² where neither Compound A² nor Compound B² is administered. Suitably the drug holiday will be a period of days selected from: 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days and 14 days.

Regarding sequential administration: suitably, one of Compound A² and Compound B² is administered for from 1 to 30 consecutive days, followed by an optional drug holiday, followed by administration of the other of Compound A² and Compound B² for from 1 to 30 consecutive days. Suitably, one of Compound A² and Compound B² is administered for from 1 to 21 consecutive days, followed by an optional drug holiday, followed by administration of the other of Compound A² and Compound B² for from 1 to 21 consecutive days. Suitably, one of Compound A² and Compound B² is administered for from 1 to 14 consecutive days, followed by a drug holiday of from 1 to 14 days, followed by administration of the other of Compound A² and Compound B² for from 1 to 14 consecutive days. Suitably, one of Compound A² and Compound B² is administered for from 1 to 7 consecutive days, followed by a drug holiday of from 1 to 10 days, followed by administration of the other of Compound A² and Compound B² for from 1 to 7 consecutive days.

Suitably, Compound B² will be administered first in the sequence, followed by an optional drug holiday, followed by administration of Compound A². Suitably, Compound B² is administered for from 3 to 21 consecutive days, followed by an optional drug holiday, followed by administration of Compound A² for from 3 to 21 consecutive days. Suitably, Compound B² is administered for from 3 to 21 consecutive days, followed by a drug holiday of from 1 to 14 days, followed by administration of

Compound A² for from 3 to 21 consecutive days. Suitably, Compound B² is

administered for from 3 to 21 consecutive days, followed by a drug holiday of from 3 to 14 days, followed by administration of Compound A² for from 3 to 21 consecutive days. Suitably, Compound B² is administered for 21 consecutive days, followed by an optional drug holiday, followed by administration of Compound A² for 14 consecutive days. Suitably, Compound B² is administered for 14 consecutive days, followed by a drug holiday of from 1 to 14 days, followed by administration of Compound A² for 14 consecutive days. Suitably, Compound B² is administered for 7 consecutive days, followed by a drug holiday of from 3 to 10 days, followed by administration of

Compound A² for 7 consecutive days. Suitably, Compound B² is administered for 3 consecutive days, followed by a drug holiday of from 3 to 14 days, followed by administration of Compound A² for 7 consecutive days. Suitably, Compound B² is administered for 3 consecutive days, followed by a drug holiday of from 3 to 10 days, followed by administration of Compound A² for 3 consecutive days.

It is understood that a“specified period” administration and a“sequential” administration can be followed by repeat dosing or can be followed by an alternate dosing protocol, and a drug holiday may precede the repeat dosing or alternate dosing protocol.

The methods of the present invention may also be employed with other therapeutic methods of cancer treatment.

While it is possible that, for use in therapy, therapeutically effective amounts of the combinations of the present invention may be administered as the raw chemical, it is preferable to present the combinations as a pharmaceutical composition or

compositions. Accordingly, the invention further provides pharmaceutical compositions, which include Compound A² and/or Compound B², and one or more pharmaceutically acceptable carriers. The combinations of the present invention are as described above. The carrier(s) must be acceptable in the sense of being compatible with the other ingredients of the formulation, capable of pharmaceutical formulation, and not deleterious to the recipient thereof. In accordance with another aspect of the invention there is also provided a process for the preparation of a pharmaceutical formulation including admixing Compound A² and/or Compound B² with one or more

pharmaceutically acceptable carriers. As indicated above, such elements of the pharmaceutical combination utilized may be presented in separate pharmaceutical compositions or formulated together in one pharmaceutical formulation.

Pharmaceutical formulations may be presented in unit dose forms containing a predetermined amount of active ingredient per unit dose. As is known to those skilled in the art, the amount of active ingredient per dose will depend on the condition being treated, the route of administration and the age, weight and condition of the

patient. Preferred unit dosage formulations are those containing a daily dose or sub-dose, or an appropriate fraction thereof, of an active ingredient. Furthermore, such

pharmaceutical formulations may be prepared by any of the methods well known in the pharmacy art.

Compound A² and Compound B² may be administered by any appropriate

route. Suitable routes include oral, rectal, nasal, topical (including buccal and

sublingual), intratumorally, vaginal, and parenteral (including subcutaneous,

intramuscular, intravenous, intradermal, intrathecal, and epidural). It will be appreciated that the preferred route may vary with, for example, the condition of the recipient of the combination and the cancer to be treated. It will also be appreciated that each of the agents administered may be administered by the same or different routes and that Compound A² and Compound B² may be compounded together in a pharmaceutical composition/formulation.

The administration of a therapeutically effective amount of the combinations of the invention (or therapeutically effective amounts of each of the components of the combination) are advantageous over the individual component compounds in that the combinations provide one or more of the following improved properties when compared to the individual administration of a therapeutically effective amount of a component compound: i) a greater anti-cancer effect than the most active single agent; ii) synergistic or highly synergistic anti-cancer activity; iii) a dosing protocol that provides enhanced anti-cancer activity with reduced side effect profile; iv) a reduction in the toxic effect profile, v) an increase in the therapeutic window; or vi) an increase in the bioavailability of one or both of the component compounds.

The invention further provides pharmaceutical compositions, which include one or more of the components herein, and one or more pharmaceutically acceptable carriers, diluents, or excipients. The combination of the invention may comprise two pharmaceutical compositions, one comprising an ABP or antibody of the invention, and the other comprising a TLR4 modulator, each of which may have the same or different carriers, diluents or excipients. The carrier(s), diluent(s) or excipient(s) must be acceptable in the sense of being compatible with the other ingredients of the formulation, capable of pharmaceutical formulation, and not deleterious to the recipient thereof. In one embodiment of the invention, the formulation may be aqueous or liposomal. In one embodiment, the liposomal formulation may be a DOPC/CHOL Liposome formulation.

The components of the combination of the invention, and pharmaceutical compositions comprising such components may be administered in any order, and in different routes; the components and pharmaceutical compositions comprising the same may be administered simultaneously.

In accordance with another aspect of the invention there is also provided a process for the preparation of a pharmaceutical composition including admixing a component of the combination of the invention and one or more pharmaceutically acceptable carriers, diluents or excipients.

The components of the invention may be administered by any appropriate route. For some components, suitable routes include oral, rectal, nasal, topical (including buccal and sublingual), vaginal, and parenteral (including subcutaneous, intramuscular, intravenous, intradermal, intrathecal, and epidural). The preferred route may vary with, for example, the condition of the recipient of the combination and the cancer to be treated. Each of the agents administered may be administered by the same or different routes, and the components may be compounded together or in separate pharmaceutical compositions. In one embodiment, one or more components of a combination of the invention are administered intravenously. In another embodiment, one or more components of a combination of the invention are administered intratumorally. In another embodiment, one or more components of a combination of the invention are administered systemically, e.g., intravenously, and one or more other components of a combination of the invention are administered intratumorally. In another embodiment, all of the components of a combination of the invention are administered systemically, e.g., intravenously. In an alternative embodiment, all of the components of the combination of the invention are administered intratumorally. In any of the embodiments, e.g., in this paragraph, the components of the invention are administered as one or more pharmaceutical

compositions.

In some embodiments, the two compounds are administered intravenously. In some embodiments, the PD-l ABP is administered by intravenous infusion. In some embodiments, the TLR4 agonist is administered by intravenous injection. In some embodiments, the PD-l ABP is administered by intravenous infusion and the TLR4 agonist is administered by intravenous injection. In some embodiments, the TLR4 agonist is administered by intratumoral injection.

Antigen Binding Proteins that bind PD-l

“Antigen Binding Protein (ABP)” means a protein that binds an antigen and includes antibodies or engineered molecules that function in similar ways to antibodies. Such alternative antibody formats include triabody, tetrabody, miniantibody, and a minibody, Also included are alternative scaffolds in which the one or more CDRs of any molecules in accordance with the disclosure can be arranged onto a suitable non-immunoglobulin protein scaffold or skeleton, such as an affibody, a SpA scaffold, an LDL receptor class A domain, an avimer (see, e.g., U.S. Patent Application Publication Nos. 2005/0053973, 2005/0089932, 2005/0164301) or an EGF domain. An ABP also includes antigen binding fragments of such antibodies or other molecules. Further, an ABP may comprise the VH regions of the invention formatted into a full-length antibody, a (Fab')2 fragment, a Fab fragment, a bi-specific or biparatopic molecule or equivalent thereof (such as scFV, bi- tri- or tetra-bodies, Tandabs, etc.), when paired with an appropriate light chain. The ABP may comprise an antibody that is an IgGl, IgG2, IgG3, or IgG4; or IgM; IgA, IgE or IgD or a modified variant thereof. The constant domain of the antibody heavy chain may be selected accordingly. The light chain constant domain may be a kappa or lambda constant domain. The ABP may also be a chimeric antibody of the type described in WO86/01533, which comprises an antigen binding region and a non-immunoglobulin region.

The term“antibody” as used herein refers to molecules with an antigen binding domain, and optionally an immunoglobulin-like domain or fragment thereof and includes monoclonal (for example IgG, IgM, IgA, IgD or IgE and modified variants thereof), recombinant, polyclonal, chimeric, humanized, biparatopic, bispecific and

heteroconjugate antibodies, or a closed conformation multispecific antibody. An “antibody” included xenogeneic, allogeneic, syngeneic, or other modified forms thereof. An antibody may be isolated or purified. An antibody may also be recombinant, i.e., produced by recombinant means; for example, an antibody that is 90% identical to a reference antibody may be generated by mutagenesis of certain residues using recombinant molecular biology techniques known in the art. Thus, the antibodies of the present invention may comprise heavy chain variable regions and light chain variable regions of the invention which may be formatted into the structure of a natural antibody or formatted into a full length recombinant antibody, a (Fab')2 fragment, a Fab fragment, a bi-specific or biparatopic molecule or equivalent thereof (such as scFV, bi- tri- or tetra- bodies, Tandabs etc.), when paired with an appropriate light chain. The antibody may be an IgGl, IgG2, IgG3, or IgG4 or a modified variant thereof. The constant domain of the antibody heavy chain may be selected accordingly. The light chain constant domain may be a kappa or lambda constant domain. The antibody may also be a chimeric antibody of the type described in WO86/01533 which comprises an antigen binding region and a non- immunoglobulin region.

One of skill in the art will recognize that Fc regions of an antibody, a bi-specific or other Fc region containing recombinant antigen binding protein, require post-translational modification for Fc receptor-mediated activity; modification of glycosylation target sequences in the Fc region will reduce or eliminate Fc receptor-mediated activity. See, for example, Peipp et ah, (2008),“Antibody fucosylation differentially impacts cytotoxicity mediated by NK and PMN effector cells”. Blood. 1 12 (6): 2390-2399.

Stadlmann et ah, survey antibody glycosylation in their publication,“Analysis of immunoglobulin glycosylation by LC-ESI-MS of glycopeptides and oligosaccharides”. Proteomics. 8 (14): 2858-2871 (2008).“Inactivated Fc Regions” refers to Fc regions that have been modified to reduce or eliminate Fc receptor-mediated activity.

One of skill in the art will recognize that the ABPs, such as antibodies, of the invention bind an epitope of PD-l . The epitope of an ABP is the region of its antigen to which the ABP binds. Two ABPs bind to the same or overlapping epitope if each competitively inhibits (blocks) binding of the other to the antigen. That is, a lx, 5x, lOx, 20x or lOOx excess of one antibody inhibits binding of the other by at least 50%, 75%, 90% or even 99% as measured in a competitive binding assay compared to a control lacking the competing antibody (see, e.g., Junghans, et ah, Cancer Res . 50: 1495, 1990.

Alternatively, two antibodies have the same epitope if essentially all amino acid mutations in the antigen that reduce or eliminate binding of one antibody reduce or eliminate binding of the other. In addition, the same epitope may include“overlapping epitopes”, e.g., if some amino acid mutations that reduce or eliminate binding of one antibody reduce or eliminate binding of the other.

The strength of binding may be important in dosing and administration of an ABP of the invention. In one embodiment, the ABP of the invention binds to PD-l, preferably human PD-l , with high affinity. For example, when measured by surface plasmon resonance, for example with a BIACORE instrument, the ABP binds to PD- 1 , preferably human PD-l , with an affinity of 1-1000 nM or 500 nM or less or an affinity of 200 nM or less or an affinity of 100 nM or less or an affinity of 50 nM or less or an affinity of 500 pM or less or an affinity of 400 pM or less, or 300 pM or less. In a further aspect the ABP binds to PD-l, preferably human PD-l , when measured by BIACORE of between about 50 nM and about 200 nM or between about 50 nM and about 150 nM. In one aspect of the present invention the ABP binds PD-l, preferably human PD-l, with an affinity of less than lOOnM.

In a further embodiment, binding is measured by BIACORE. Affinity is the strength of binding of one molecule, e.g., an ABP of the invention, to another, e.g., its target antigen, at a single binding site. The binding affinity of an ABP to its target may be determined by equilibrium methods ( e.g . , enzyme-linked immunoabsorbent assay (ELISA) or radioimmunoassay (RIA)), or kinetics (e.g., BIACORE analysis). For example, the BIACORE methods known in the art may be used to measure binding affinity.

Avidity is the sum total of the strength of binding of two molecules to one another at multiple sites, e.g., taking into account the valency of the interaction.

In an aspect, the equilibrium dissociation constant (K_D) of the ABP of the invention and PD-l, preferably human PD-l , interaction is 100 nM or less, 10 nM or less, 2 nM or less or 1 nM or less. Alternatively, the KD may be between 5 and 10 nM; or between 1 and 2 nM. The K_D may be between 1 pM and 500 pM; or between 500 pM and 1 nM. A skilled person will appreciate that the smaller the K_D numerical value, the stronger the binding. The reciprocal of K_D (i.e., 1 /K_D) is the equilibrium association constant (K_A) having units M ¹. A skilled person will appreciate that the larger the K_A numerical value, the stronger the binding.

The dissociation rate constant (k_d) or“off-rate” describes the stability of the complex of an ABP on one hand and PD- 1 , preferably human PD- 1 on the other hand, i. e. , the fraction of complexes that decay per second. For example, a k_d of 0.01 s^-1 equates to 1% of the complexes decaying per second. In one embodiment, the dissociation rate constant (k_d) is 1x10^-3 s^-1 or less, 1x10^-4 s^-1 or less, 1x10^-5 s^-1 or less, or 1x10^-6 s^-1 or less. The k_d may be between 1x10^-5 s^-1 and lxlO ⁴ s^-1; or between 1x10^-4 s^-1 and 1x10^-3 s^-1.

Competition between an ABP (e.g., a PD-l binding protein of the invention) and a reference antibody, e.g., for binding PD-l, an epitope of PD-l , or a fragment of the PD-l, may be determined by competition ELISA, FMAT or BIACORE. In one aspect, the competition assay is carried out by BIACORE. There are several possible reasons for this competition: the two proteins may bind to the same or overlapping epitopes, there may be steric inhibition of binding, or binding of the first protein may induce a conformational change in the antigen that prevents or reduces binding of the second protein.

“Binding fragments” as used herein means a portion or fragment of the ABPs of the invention that include the antigen-binding site and are capable of binding PD-l as defined herein, e.g., but not limited to capable of binding to the same epitope of the parent or full- length antibody.

Functional fragments of the ABPs of the invention are contemplated herein.

Thus,“binding fragments” and“functional fragments” may be Fab and F(ab')2 fragments that lack the Fc fragment of an intact antibody, clear more rapidly from the circulation, and may have less non-specific tissue binding than an intact antibody (Wahl, et ah, J. Nuc. Med. 24:316-325 (1983)). Also included are Fv fragments (Hochman, et ah, Biochemistry 12: 1 130-1135 (1973); Sharon, et ah, Biochemistry 15: 1591-1594 (1976)). These various fragments are produced using conventional techniques such as protease cleavage or chemical cleavage (see, e.g., Rousseaux, et ah, Meth. Enzymoh, 121 :663-69 (1986)).

“Functional fragments”, as used herein, means a portion or fragment of the ABPs of the invention that include the antigen-binding site and are capable of binding the same target as the parent ABP, e.g., but not limited to, binding the same epitope, and that also retain one or more modulating or other functions described herein or known in the art.

As the ABPs of the present invention may comprise heavy chain variable regions and light chain variable regions of the invention which may be formatted into the structure of a natural antibody, a functional fragment is one that retains binding or one or more functions of the full length ABP as described herein. A binding fragment of an ABP of the invention may therefore comprise the VL or VH regions, a (Fab')2 fragment, a Fab fragment, a fragment of a bi-specific or biparatopic molecule or equivalent thereof (such as scFV, bi- tri- or tetra-bodies, Tandabs etc.), when paired with an appropriate light chain.

The term,“CDR”, as used herein, refers to the complementarity determining region amino acid sequences of an antigen binding protein (ABP). These are the hypervariable regions of immunoglobulin heavy and light chains. There are three heavy chain and three light chain CDRs (or CDR regions) in the variable portion of an immunoglobulin.

It will be apparent to those skilled in the art that there are various numbering conventions for CDR sequences; Chothia (Chothia et ah (1989) Nature 342: 877-883), Kabat (Kabat et al, Sequences of Proteins of Immunological Interest, 4th Ed., U.S. Department of Health and Human Services, National Institutes of Health (1987)), AbM (University of Bath) and Contact (University College London). The minimum overlapping region using at least two of the Kabat, Chothia, AbM and contact methods can be determined to provide the“minimum binding unit”. The minimum binding unit may be a subportion of a CDR. The structure and protein folding of the antibody may mean that other residues are considered part of the CDR sequence and would be understood to be so by a skilled person. It is noted that some of the CDR definitions may vary depending on the individual publication used. Unless otherwise stated and/or in absence of a specifically identified sequence, references herein to“CDR”,“CDRL1”,“CDRL2”,“CDRL3”,“CDRH1”,“CDRH2”,“CDRH3” refer to amino acid sequences numbered according to any of the known conventions; alternatively, the CDRs are referred to as“CDR1 ,”“CDR2,”“CDR3” of the variable light chain and“CDR1 ,”“CDR2,” and“CDR3” of the variable heavy chain. In some embodiments, the numbering convention is the Kabat convention.

The term,“CDR variant”, as used herein, refers to a CDR that has been modified by at least one, for example 1, 2 or 3, amino acid substitution(s), deletion(s) or addition(s), wherein the modified antigen binding protein comprising the CDR variant substantially retains the biological characteristics of the antigen binding protein pre-modification. It will be appreciated that each CDR that can be modified may be modified alone or in combination with another CDR. In one aspect, the modification is a substitution, particularly a conservative substitution, for example as shown in Table 1.

Table 1

For example, in a variant CDR, the amino acid residues of the minimum binding unit may remain the same, but the flanking residues that comprise the CDR as part of the Rabat or Chothia definition(s) may be substituted with a conservative amino acid residue.

Such antigen binding proteins comprising modified CDRs or minimum binding units as described above may be referred to herein as“functional CDR variants” or“functional binding unit variants”.

The antigen binding protein may be of any species, or modified to be suitable to administer to a cross species. For example, the CDRs from a mouse antibody may be humanized for administration to humans. In any embodiment, the antigen binding protein is optionally a humanized antibody.

A“humanized antibody” refers to a type of engineered antibody having its CDRs derived from a non-human donor immunoglobulin, the remaining immunoglobulin-derived parts of the molecule being derived from one (or more) human immunoglobulin(s). In addition, framework support residues may be altered to preserve binding affinity (see, e.g., Queen, et al, Proc. Natl Acad Sci USA, 86: 10029-10032 (1989), Hodgson, et al., Bio/Technology, 9:421 (1991)). A suitable human acceptor antibody may be one selected from a conventional database, e.g., the RABAT database, Los Alamos database, and Swiss Protein database, by homology to the nucleotide and amino acid sequences of the donor antibody. A human antibody characterized by a homology to the framework regions of the donor antibody (on an amino acid basis) may be suitable to provide a heavy chain constant region and/or a heavy chain variable framework region for insertion of the donor CDRs. A suitable acceptor antibody capable of donating light chain constant or variable framework regions may be selected in a similar manner. It should be noted that the acceptor antibody heavy and light chains are not required to originate from the same acceptor antibody. The prior art describes several ways of producing such humanised antibodies - see, for example, EP-A-0239400 and EP-A-054951. In yet a further embodiment, the humanized antibody has a human antibody constant region that is an IgG. In another embodiment, the IgG is a sequence as disclosed in any of the above references or patent publications.

For nucleotide and amino acid sequences, the term“identical" or“identity” indicates the degree of identity between two nucleic acid or two amino acid sequences when optimally aligned and compared with appropriate insertions or deletions.

The percent identity between two sequences is a function of the number of identical positions shared by the sequences: i.e.% identity = number of identical positions/total number of positions multiplied by 100, taking into account the number of gaps, and the length of each gap, which need to be introduced for optimal alignment of the two sequences. The comparison of sequences and determination of percent identity between two sequences can be accomplished using a mathematical algorithm, as described below.

Percent identity between a query nucleic acid sequence and a subject nucleic acid sequence is the“Identities” value, expressed as a percentage, which is calculated by the BLASTN algorithm when a subject nucleic acid sequence has 100% query coverage with a query nucleic acid sequence after a pair-wise BLASTN alignment is performed. Such pair-wise BLASTN alignments between a query nucleic acid sequence and a subject nucleic acid sequence are performed by using the default settings of the BLASTN algorithm available on the National Center for Biotechnology Institute’s website with the filter for low complexity regions turned off. Importantly, a query nucleic acid sequence may be described by a nucleic acid sequence identified in one or more claims herein.

Percent identity between a query amino acid sequence and a subject amino acid sequence is the“Identities” value, expressed as a percentage, which is calculated by the BLASTP algorithm when a subject amino acid sequence has 100% query coverage with a query amino acid sequence after a pair-wise BLASTP alignment is performed. Such pair-wise BLASTP alignments between a query amino acid sequence and a subject amino acid sequence are performed by using the default settings of the BLASTP algorithm available on the National Center for Biotechnology Institute’s website with the filter for low complexity regions turned off. Importantly, a query amino acid sequence may be described by an amino acid sequence identified in one or more claims herein. In any embodiment of the invention herein, the ABP may have any one or all CDRs, VH, VL, with 100, 99, 98, 97, 96, 95, 94, 93, 92, 91, or 90 percent identity to the sequence shown or referenced, e.g., as defined by a SEQ ID NO disclosed herein.

ABPs that bind human PD-l are provided herein (e.g., a PD-l ABP, or PD-l binding protein, or PD-l antigen binding protein, sometimes referred to herein as an“anti- PD-l ABP” or“an anti-PD-l antibody” and/or other variations of the same). These antigen binding proteins are useful in the treatment or prevention of acute or chronic diseases or conditions whose pathology involves PD-l signaling. In one aspect, an antigen binding protein, such as an isolated human antibody or functional fragment of such protein or antibody, that binds to human PD- 1 and is effective as a cancer treatment or treatment against disease is described, for example in combination with another compound such as a TLR4 modulator or TLR4 agonist. Any of the PD-l antigen binding proteins such as anti-PD-l antibodies disclosed herein may be used as a medicament. Any one or more of the PD-l antigen binding proteins such as anti-PD-l antibodies may be used in the methods or compositions to treat cancer, e.g., those disclosed herein.

The isolated antigen binding proteins, such as antibodies, as described herein bind to human PD- 1 (“hPD- 1”), and may bind to human PD- 1 encoded by the gene Pdcdl , or genes or cDNA sequences having 90 percent homology or 90 percent identity thereto.

The complete hPD-l mRNA sequence can be found under GenBank Accession No. U64863. The protein sequence for human PD-l can be found at GenBank Accession No. AAC51773.

Antigen binding proteins, such as antibodies, that bind and/or modulate PD-l are known in the art. Exemplary PD-l ABPs of a combination of the invention, or a method or use thereof, are disclosed, for example in U.S. Patent Nos. 8,354,509; 8,900,587; 8008,449, each of which is incorporated by reference in its entirety herein (To the extent any definitions conflict, this instant application controls). PD-l antibodies and methods of using in treatment of disease are described in US Patent Nos.: US 7,595,048; US 8,168,179; US 8,728,474; US 7,722,868; US 8,008,449; US 7,488,802; US 7,521,051;

US 8,088,905; US 8,168,757; US 8,354,509; and US Publication Nos. US201 10171220; US201 10171215; and US201 10271358. Combinations of CTLA-4 and PD-l antibodies are described in US Patent No. 9,084,776.

In another embodiment, any mouse or chimeric sequences of a PD-l ABP of a combination of the invention, or a method or use thereof, are engineered to make a humanized antibody.

In another embodiment, the PD-l ABP of a combination of the invention, or a method or use thereof, comprises one or more ( e.g . all) of the CDRs or VH or VL or HC (heavy chain) or LC (light chain) sequences of pembrolizumab, or sequences with at least 90% (e.g., 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, or 100%) sequence identity thereto.

The HC and LC CDRs of pembrolizumab are provided below. In one embodiment, the PD-l ABP of a combination of the invention, or a method or use thereof, comprises: (a) a heavy chain variable region CDR1 of pembrolizumab (e.g., SEQ ID NO:5); (b) a heavy chain variable region CDR2 of pembrolizumab (e.g., SEQ ID NO:6); (c) a heavy chain variable region CDR3 of pembrolizumab (e.g., SEQ ID NO:7); (d) a light chain variable region CDR1 of pembrolizumab (e.g., SEQ ID NO: 8); (e) a light chain variable region CDR2 of pembrolizumab (e.g., SEQ ID NO:9); and (f) a light chain variable region CDR3 of pembrolizumab (e.g., SEQ ID NO: 10).

In another embodiment, the PD-l of a combination of the invention, or a method or use thereof, comprises: a heavy chain variable region CDR1 of pembrolizumab; a heavy chain variable region CDR2 of pembrolizumab and/or a heavy chain variable region CDR3 of pembrolizumab.

In another embodiment, the PD-l of a combination of the invention, or a method or use thereof, comprises: a light chain variable region CDR1 of pembrolizumab; a light chain variable region CDR2 of pembrolizumab and/or a light chain variable region CDR3 of pembrolizumab.

In another embodiment, the PD-l ABP of a combination of the invention, or a method or use thereof, comprises: a light chain variable region (“VL”) of pembrolizumab, or an amino acid sequence with at least 90% (e.g., 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, or 100%) sequence identity to the amino acid sequence of the VL of pembrolizumab ( e.g ., SEQ ID NO:4).

In another embodiment, the PD- 1 ABP of a combination of the invention, or a method or use thereof, comprises a heavy chain variable region (“VH”) of pembrolizumab, or an amino acid sequence with at least 90% (e.g., 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, or 100%) sequence identity to the amino acid sequence of the VH of pembrolizumab (e.g., SEQ ID NO:3).

In another embodiment, the PD- 1 ABP of a combination of the invention, or a method or use thereof, comprises: a light chain variable region (“VL”) of pembrolizumab, or an amino acid sequence with at least 90% (e.g., 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, or 100%) sequence identity to the amino acid sequence of the VL of pembrolizumab (e.g., SEQ ID NO:4) and the PD-l ABP of a combination of the invention, or a method or use thereof, comprises a heavy chain variable region (“VH”) of pembrolizumab (e.g., SEQ ID NO:3), or an amino acid sequence with at least 90% (e.g., 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, or 100%) sequence identity to the amino acid sequence of the VH of pembrolizumab.

In another embodiment, the PD-l ABP of a combination of the invention, or a method or use thereof, comprises: a light chain (“LC”) of pembrolizumab, or an amino acid sequence with at least 90% (e.g., 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, or 100%) sequence identity to the amino acid sequence of the LC of

pembrolizumab (e.g., SEQ ID NO:2).

In another embodiment, the PD-l ABP of a combination of the invention, or a method or use thereof, comprises a heavy chain (“HC”) of pembrolizumab, or an amino acid sequence with at least 90% (e.g., 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, or 100%) sequence identity to the amino acid sequence of the HC of

pembrolizumab (e.g., SEQ ID NO: l).

In another embodiment, the PD-l ABP of a combination of the invention, or a method or use thereof, comprises: a light chain (“LC”) of pembrolizumab (e.g., SEQ ID NO:2), or an amino acid sequence with at least 90% (e.g., 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, or 100%) sequence identity to the amino acid sequence of the LC of pembrolizumab and the PD-l ABP of a combination of the invention, or a method or use thereof, comprises a heavy chain (“HC”) of pembrolizumab, or an amino acid sequence with at least 90% (e.g., 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, or 100%) sequence identity to the amino acid sequence of the HC of pembrolizumab (e.g., SEQ ID NO: l).

While in development, pembrolizumab (KEYTRUDA) was known as MK3475 and as lambrolizumab. Pembrolizumab (KEYTRETDA) is a human programmed death receptor- 1 (PD-l)-blocking antibody indicated for the treatment of patients with unresectable or metastatic melanoma and disease progression following ipilimumab and, if BRAF V600 mutation positive, a BRAF inhibitor. The recommended dose of pembrolizumab is 2 mg/kg administered as an intravenous infusion over 30 minutes every 3 weeks until disease progression or unacceptable toxicity.

Pembrolizumab is a humanized monoclonal antibody that blocks the interaction between PD-l and its ligands, PD-L1 and PD-L2. Pembrolizumab is an IgG4 kappa

immunoglobulin with an approximate molecular weight of 149 kDa.

Pembrolizumab for injection is a sterile, preservative-free, white to off-white lyophilized powder in single-use vials. Each vial is reconstituted and diluted for intravenous infusion. Each 2 mL of reconstituted solution contains 50 mg of pembrolizumab and is formulated in L-histidine (3.1 mg), polysorbate-80 (0.4 mg), sucrose (140 mg). May contain hydrochloric acid/sodium hydroxide to adjust pH to 5.5.

Pembrolizumab injection is a sterile, preservative-free, clear to slightly opalescent, colorless to slightly yellow solution that requires dilution for intravenous infusion. Each vial contains 100 mg of pembrolizumab in 4 mL of solution. Each 1 mL of solution contains 25 mg of pembrolizumab and is formulated in: L-histidine (1.55 mg), polysorbate 80 (0.2 mg), sucrose (70 mg), and Water for Injection, ETSP.

Binding of the PD-l ligands, PD-L1 and PD-L2, to the PD-l receptor found on T cells, inhibits T cell proliferation and cytokine production. Upregulation of PD-l ligands occurs in some tumors and signaling through this pathway can contribute to inhibition of active T-cell immune surveillance of tumors. Pembrolizumab is a monoclonal antibody that binds to the PD-l receptor and blocks its interaction with PD-L1 and PD-L2, releasing PD-l pathway- mediated inhibition of the immune response, including the anti-tumor immune response. In syngeneic mouse tumor models, blocking PD-l activity resulted in decreased tumor growth.

Pembrolizumab is described, e.g. in U.S. Patent Nos. 8,354,509 and 8,900,587.

The approved product is pembrolizumab (KEYTRUDA) for injection, for intravenous infusion of the active ingredient pembrolizumab, available as a 50 mg lyophilized powder in a single-use vial for reconstitution. Pembrolizumab has been approved for the treatment of patients with unresectable or metastatic melanoma and disease progression following ipilimumab and, if BRAF V600 mutation positive, a BRAF inhibitor.

Pembrolizumab (KEYTRUDA) is a humanized monoclonal antibody that blocks the interaction between PD-l and its ligands, PD-L1 and PD-L2. Pembrolizumab is an IgG4 kappa immunoglobulin with an approximate molecular weight of 149 kDa. The amino acid sequence for pembrolizumab is as follows, and is set forth using the same one-letter amino acid code nomenclature provided in the table at column 15 of the U.S. Pat.

No. 8,354,509:

Heavy Chain of pembrolizumab:

QVQLVQSGVE VKKPGASVKV SCKASGYTFT NYYMYWVRQA PGQGLEWMGG 50

INPSNGGTNF NEKFKNRVTL TTDSSTTTAY MELKSLQFDD TAVYYCARRD 100

YRFDMGFDYW GQGTTVTVSS ASTKGPSVFP LAPCSRSTSE STAALGCLVK · 150

DYFPEPVTVS WNSGALTSGV HTFPAVLQSS GLYSLSSWT VPSSSLGTKT 200

YTCNVDHKPS NTKVDKRVES KYGPPCPPCP APEFLGGPSV FLFPPKPKDT 250

LMISRTPEVT CVWDVSQED PEVQFNWYVD GVEVHNAKTK PREEQFNSTY 300

WSVLTVLH QDWLNGKEYK CKVSNKGLPS S IEKTISKAK GQPREPQVYT 350

LPPSQEEMTK NQVSLTCLVK GFYPSDIAVE WESNGQPENN YKTTPPVLDS 400

DGSFFLYSRL TVDKSRWQEG NVFSCSVMHE ALHNHYTQKS LSLSLGK (SEQ ID NO : 1 )

Light Chain of pembrolizumab:

EIVLTQSPAT LSLSPGERAT LSCRASKGVS TSGYSYLHWY QQKPGQAPRL 50

LIYLASYLES GVPARFSGSG SGTDFTLTIS SLEPEDFAVY YCQHSRDLPL 100

TFGGGTKVE I KRTVAAPSVF IFPPSDEQLK SGTASVVCLL NNFYPREAKV 150

QWKVDNALQS GNSQESVTEQ DSKDSTYSLS STLTLSKADY EKHKVYACEV 200 THQGLSSPVT KSFNRGEC (SEQ ID NO : 2 )

Heavy Chain Variable Region of pembrolizumab:

QVQLVQSGVE VKKPGASVKV SCKASGYTFT NYYMYWVRQA PGQGLEWMGG 50

INPSNGGTNF NEKFKNRVTL TTDSSTTTAY MELKSLQFDD TAVYYCARRD 100

YRFDMGFDYW GQGTTVTVSS (SEQ ID NO : 3 )

Light Chain Variable Region of pembrolizumab:

EIVLTQSPAT LSLSPGERAT LSCRASKGVS TSGYSYLHWY QQKPGQAPRL 50

LIYLASYLES GVPARFSGSG SGTDFTLTIS SLEPEDFAVY YCQHSRDLPL 100

TFGGGTKVE I K (SEQ ID NO : 4 )

CDR sequences of pembrolizumab:

HC CDR1 : Asn Tyr Tyr Met Tyr (SEQ ID NO : 5 )

HC CDR2 : Gly lie Asn Pro Ser Asn Gly Gly Thr Asn Phe Asn Glu Lys Phe Lys Asn (SEQ ID NO: 6)

HC CDR3 : Arg Asp Tyr Arg Phe Asp Met Gly Phe Asp Tyr (SEQ ID NO: 7)

LC CDR1 : Arg Ala Ser Lys Gly Val Ser Thr Ser Gly Tyr Ser Tyr Leu His

(SEQ ID NO : 8 )

LC CDR2 : Leu Ala Ser Tyr Leu Glu Ser (SEQ ID NO: 9)

LC CDR3 : Gin His Ser Arg Asp Leu Pro Leu Thr (SEQ ID NO: 10)

TLR4 modulators

The combinations of the invention comprise TLR4“modulators”, that is, molecules that modulate TLR4, for example, by binding and initiating conformational changes or signaling by engaging TLR4, molecules that block binding with a TLR4 ligand. The TLR4 modulator can be a TLR4 agonist.

In one embodiment, TLR4 modulators are aminoalkyl glucosaminide phosphate compounds (AGPs). TLR4 recognizes bacterial LPS (lipopolysaccharide) and when activated initiates an innate immune response. AGPs are a monosaccharide mimetic of the lipid A protein of bacterial LPS and have been developed with ether and ester linkages on the“acyl chains” of the compound. Processes for making these compounds are known and disclosed, for example, in WO 2006/016997, U.S. Patent Nos. 7,288,640 and 6,113,918, and WO 01/90129. Other AGPs and related processes are disclosed in U.S. Patent No. 7,129,219, U.S. Patent No. 6,525,028 and U.S. Patent No 6,911,434. AGPs with ether linkages on the acyl chains employed in the composition of the invention are known and disclosed in WO 2006/016997. The AGP compounds set forth and described according to Formula (III) at paragraphs [0019] through [0021] in WO 2006/016997 may be employed in the presently claimed methods and combinations.

AGP compounds employed in the present invention have the structure set forth in Formula 1 as follows:

wherein

m is 0 to 6

n is 0 to 4;

X is O or S, preferably O;

Y is O or NH;

Z is O or H;

each Ri, R₂, R₃ is selected independently from the group consisting of a Cl -20 acyl and a Cl -20 alkyl;

R₄ is H or Me;

R5 is selected independently from the group consisting of -H, -OH, -(C1-C4) alkoxy, -PO3R8R9, -OPO3R8R9, -SO3R8, -OSO3R8, -NR8R9, -SRs, -CN, -NO2, -

CHO, -CO2R8, and -CONR8R9, wherein Rs and R9 are each independently selected from H and (C1-C4) alkyl; and

each R₆ and R₇ is independently H or PO3H2. In Formula 1 the configuration of the 3' stereogenic centers to which the normal fatty acyl residues (that is, the secondary acyloxy or alkoxy residues, e.g., RiO, R₂0, and R₃0) are attached is R or S, preferably R (as designated by Cahn- Ingold-Prelog priority rules). Configuration of aglycon stereogenic centers to which R₄ and R5 are attached can be R or S. All stereoisomers, both enantiomers and diastereomers, and mixtures thereof, are considered to fall within the scope of the present invention.

The number of carbon atoms between heteroatom X and the aglycon nitrogen atom is determined by the variable“n”, which can be an integer from 0 to 4, or an integer from 0 to 2.

The chain length of normal fatty acids Ri, R₂, and R3 can be from about 6 to about 16 carbons, or from about 9 to about 14 carbons. The chain lengths can be the same or different. Some embodiments include chain lengths where Ri, R₂ and R3 are 6 or 10 or 12 or 14. Formula 1 encompasses L/D-seryl, -threonyl, -cysteinyl ether and ester lipid AGPs, both agonists and antagonists and their homologs (n=l-4), as well as various carboxylic acid bioisosteres (i.e., R5 is an acidic group capable of salt formation; the phosphate can be either on 4- or 6- position of the glucosamine unit, preferably, is in the 4-position).

In a one embodiment of the invention employing an AGP compound of Formula 1 , n is 0, R5 is C0₂H, R₆ is PCfiFb, and R₇ is H. This AGP compound is set forth as the structure in Formula la as follows:

wherein X is O or S; Y is O or NH; Z is O or H; each Ri, R₂, R3 is selected independently from the group consisting of a Cl -20 acyl and a Cl -20 alkyl; and R₄ is H or methyl. In Formula la the configuration of the 3' stereogenic centers to which the normal fatty acyl residues (that is, the secondary acyloxy or alkoxy residues, e.g., RiO, R₂0, and R3O) are attached as R or S, preferably R (as designated by Cahn- Ingold-Prelog priority rules). Configuration of aglycon stereogenic centers to which R₄ and CO2H are attached can be R or S. All stereoisomers, both enantiomers and diastereomers, and mixtures thereof, are considered to fall within the scope of the present invention.

Formula la encompasses L/D-seryl, -threonyl, -cysteinyl ether or ester lipid AGPs, both agonists and antagonists.

In both Formula 1 and Formula la, Z is O attached by a double bond or two hydrogen atoms which are each attached by a single bond. That is, the compound is ester-linked when Z=Y=0; amide-linked when Z =0 and Y=NH; and ether-linked when Z=H/H and Y=0.

CRX-601 and CRX-527 are compounds of Formula 1. Their structures are set forth as follows:

Additionally, another preferred embodiment employs CRX-547 having the structure shown. CRX-547

CRX-547

Still other embodiments include AGPs, such as CRX-602 or CRX-526 providing increased stability to AGPs having shorter secondary acyl or alkyl chains.

CRX-526

In a further embodiment of the invention, the TLR4 modulator is an agonist. In a further embodiment, the TLR4 modulator that is an agonist is selected from the group consisting of: CRX-601, CRX-547, and CRX-527.

AGP Buffers

In one embodiment of the present invention, the composition comprising a TLR4 modulator, such as an AGP, is buffered using a zwitterionic buffer. In one embodiment of the invention, the zwitterionic buffer is an aminoalkanesulfonic acid or suitable salt. Examples of amninoalkanesulfonic buffers include, but are not limited, to HEPES, HEPPS/EPPS, MOPS, MOBS and PIPES. In one embodiment of the invention, the buffer is a pharmaceutically acceptable buffer, suitable for use in humans, such as in for use in a commercial injection product. In one embodiment of the invention, the buffer is HEPES. Dosing Regimens

In some aspects, the disclosure is drawn to a method of treatment of a subject with cancer, wherein a PD- 1 binding protein and a TLR4 agonist are administered to the subject, wherein the PD-l binding protein is administered at a dose of about 200 mg and the TLR4 agonist is administered at a dose of about 50 ng to about 250 ng.

In some aspects, the disclosure is drawn to a PD-l binding protein and a TLR4 agonist for simultaneous or sequential use in treating cancer, wherein the PD- 1 binding protein is to be administered at a dose of about 200 mg and the TLR4 agonist is to be administered at a dose of about 50 ng to about 250 ng.

In some aspects, the disclosure is drawn to a PD-l binding protein for use in treating cancer, wherein the PD-l binding protein is to be administered at a dose of about 200 mg and is to be administered simultaneously or sequentially with a TLR4 agonist at a dose of about 50 ng to about 250 ng.

In some aspects, the disclosure is drawn to a TLR4 agonist for use in treating cancer, wherein the TLR4 agonist is to be administered at a dose of about 50 ng to about 250 ng and is to be administered simultaneously or sequentially with a PD- 1 binding protein at a dose of about 200 mg.

In some aspects, the disclosure is drawn to use of a PD-l binding protein in the manufacture of a medicament for treating cancer, wherein the PD-l binding protein is to be administered at a dose of about 200 mg and is to be administered simultaneously or sequentially with a TLR4 agonist at a dose of about 50 ng to about 250 ng.

In some aspects, the disclosure is drawn to use of a TLR4 agonist in the manufacture of a medicament for treating cancer, wherein the TLR4 agonist is to be administered at a dose of about 50 ng to about 250 ng and is to be administered simultaneously or sequentially with a PD-l binding protein at a dose of about 200 mg.

In some aspects, the disclosure is drawn to a pharmaceutical kit comprising about 200 mg of a PD-l binding protein and about 50 ng to 250 ng of a TLR4 agonist. In some embodiments, the PD-l binding protein is administered intravenously ( e.g ., intravenous infusion).

In some embodiments, the TLR4 agonist is administered intratumo rally (e.g., by intratumoral injection).

In some embodiments, the PD-l binding protein is administered at a dose of about 200 mg.

In some embodiments, the TLR4 agonist is administered at a dose of about 50 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 100 ng.

In some embodiments, the TLR4 agonist is administered at a dose of about 150 ng.

In some embodiments, the PD-l binding protein is a humanized monoclonal antibody.

In some embodiments, the TLR4 agonist is selected from the group consisting of: CRX- 601 ; CRX-547; CRX-602; and CRX-527.

In some embodiments, the TLR4 agonist is CRX-527.

In some embodiments, the TLR4 agonist is CRX-601.

In some embodiments, the cancer comprises a solid tumor.

In some embodiments, the TLR4 agonist (e.g., CRX-601) is administered for a two-week run in period (e.g., the TLR4 agonist is administered on day 1 and 8 of the run in period) prior to administering the PD-l binding protein (e.g., a PD-l binding protein comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 1 and a light chain comprising the amino acid sequence set forth in SEQ ID NO:2).

In some embodiments, after the run in period, the TLR4 agonist (e.g., CRX-601) and the PD-l binding protein (e.g., a PD-l binding protein comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 1 and a light chain comprising the amino acid sequence set forth in SEQ ID NO:2) are both administered to the subject every three weeks. In some embodiments, the TLR4 agonist ( e.g ., CRX-601) is administered for a two-week run in period (e.g., the TLR4 agonist is administered on day 1 and day 8 of the two-week run in period), and following the run in period, the TLR4 agonist and the PD-l binding protein (e.g. , a PD- 1 binding protein comprising a heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 1 and a light chain comprising the amino acid sequence set forth in SEQ ID NO:2) are both administered to the subject, e.g., every three weeks.

Kits

In some aspects, the disclosure is drawn to a kit comprising: a first pharmaceutical composition comprising a therapeutically effective amount of a PD- 1 binding protein and a second pharmaceutical composition comprising a therapeutically effective amount of a TLR4 agonist, wherein the PD-l binding protein comprises (a) a heavy chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO:5; (b) a heavy chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:6; (c) a heavy chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO:7; (d) a light chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO: 8; (e) a light chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:9; and (f) a light chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO: 10.

In some embodiments, the PD-l binding protein of the kit comprises a VH region comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO:3 and a VL region comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO:4. In some embodiments, the PD-l binding protein of the kit comprises a VH region comprising the amino acid sequence as set forth in SEQ ID NO:3 and a VL region comprising the amino acid sequence as set forth in SEQ ID NO:4.

In some embodiments, the PD-l binding protein of the kit comprises a heavy chain comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO: 1 and a light chain comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO:2.

In some embodiments, the PD-l binding protein of the kit comprises a heavy chain comprising the amino acid sequence as set forth in SEQ ID NO: 1 and a light chain comprising the amino acid sequence as set forth in SEQ ID NO:2.

In some embodiments, the TLR4 agonist of the kit is an aminoalkyl glucosaminide phosphate (AGP). In some embodiments, the TLR4 agonist of the kit is a compound of Formula I. In some embodiments, the TLR4 agonist of the kit is a compound of Formula la. In some embodiments, the TLR4 agonist is CRX-601; CRX-547; CRX-602; or CRX- 527.

Methods of Treatment

The combinations of the invention are believed to have utility in disorders wherein the engagement of TLR4 and/or blocking the engagement between PD-l and PD-L1 or PD- L2 is beneficial.

The present invention thus also provides a combination of the invention, for use in therapy, particularly, in the treatment of disorders wherein the engagement of TLR4 and/or blocking the engagement between PD-l and PD-L1 or PD-L2 is beneficial, particularly cancer.

In one embodiment, the present invention provides methods of treating cancer in a patient with the combination of a TLR4 agonist, such as CRX-601, with a humanized monoclonal PD-l antibody, such as pembrolizumab, wherein the humanized PD-l antibody is administered intravenously, and the TLR4 agonist is administered

intratumorally, resulting in an abscopal effect in the tumor(s) in the patient.

As used herein, the term“abscopal effect”, means a phenomenon in which local treatment causes tumor regression at not only the treated site, but also at distant tumor sites. Postow, et ah, N Engl J Med 366 (10): 925-31 (2012). A further aspect of the invention provides a method of treatment of a disorder wherein engagement of TLR4 and/or blocking the engagement between PD-l and PD-L1 or PD- L2 is beneficial, comprising administering a combination of the invention.

A further aspect of the present invention provides the use of a combination of the invention, e.g. in the manufacture of a medicament, for the treatment of a disorder wherein engagement of TLR4 and/or blocking the engagement between PD-l and PD-L1 or PD-L2 is beneficial. In some embodiments, the disorder is cancer. Suitably, the present invention provides the use of the combinations of the present invention for the treatment of cancer.

The cancer can comprise a solid cancer, e.g., solid tumor.

Examples of cancers that are suitable for treatment with combination of the invention include, but are limited to, both primary and metastatic forms of head and neck, breast, lung, colon, ovary, and prostate cancers. Suitably the cancer is selected from: brain (gliomas), glioblastomas, astrocytomas, glioblastoma multiforme, Bannayan-Zonana syndrome, Cowden disease, Lhermitte-Duclos disease, breast, inflammatory breast cancer, Wilm's tumor, Ewing's sarcoma, Rhabdomyosarcoma, ependymoma, medulloblastoma, colon, head and neck, kidney, lung, liver, melanoma, ovarian, pancreatic, prostate, sarcoma, osteosarcoma, giant cell tumor of bone, thyroid, lymphoblastic T cell leukemia, Chronic myelogenous leukemia, Chronic lymphocytic leukemia, Hairy-cell leukemia, acute lymphoblastic leukemia, acute myelogenous leukemia, AML, Chronic neutrophilic leukemia, Acute lymphoblastic T cell leukemia, plasmacytoma, Immunoblastic large cell leukemia, Mantle cell leukemia, Multiple myeloma Megakaryoblastic leukemia, multiple myeloma, acute megakaryocytic leukemia, promyelocytic leukemia, Erythroleukemia, malignant lymphoma, hodgkins lymphoma, non-hodgkins lymphoma, lymphoblastic T cell lymphoma, Burkitt’s lymphoma, follicular lymphoma, neuroblastoma, bladder cancer, urothelial cancer, lung cancer, vulval cancer, cervical cancer, endometrial cancer, renal cancer, mesothelioma, esophageal cancer, salivary gland cancer, hepatocellular cancer, gastric cancer, nasopharangeal cancer, buccal cancer, cancer of the mouth, GIST (gastrointestinal stromal tumor); and testicular cancer. Additionally, examples of a cancer to be treated include Barret’s adenocarcinoma; biliary tract carcinomas; breast cancer; cervical cancer; cholangiocarcinoma; central nervous system tumors including primary CNS tumors such as glioblastomas, astrocytomas ( e.g ., glioblastoma multiforme) and ependymomas, and secondary CNS tumors (i.e., metastases to the central nervous system of tumors originating outside of the central nervous system); colorectal cancer including large intestinal colon carcinoma; gastric cancer; carcinoma of the head and neck including squamous cell carcinoma of the head and neck; hematologic cancers including leukemias and lymphomas such as acute lymphoblastic leukemia, acute myelogenous leukemia (AML), myelodysplastic syndromes, chronic myelogenous leukemia, Hodgkin’s lymphoma, non-Hodgkin’s lymphoma, megakaryoblastic leukemia, multiple myeloma and erythroleukemia;

hepatocellular carcinoma; lung cancer including small cell lung cancer and non-small cell lung cancer; ovarian cancer; endometrial cancer; pancreatic cancer; pituitary adenoma; prostate cancer; renal cancer; sarcoma; skin cancers including melanomas; and thyroid cancers.

Suitably, the present invention relates to a method for treating or lessening the severity of a cancer selected from: brain (gliomas), glioblastomas, astrocytomas, glioblastoma multiforme, Bannayan-Zonana syndrome, Cowden disease, Lhermitte-Duclos disease, breast, colon, head and neck, kidney, lung, liver, melanoma, ovarian, pancreatic, prostate, sarcoma and thyroid.

In one embodiment, the present invention relates to a method for treating or lessening the severity of a cancer selected from ovarian, breast, pancreatic and prostate.

In another embodiment, the present invention relates to a method for treating or lessening the severity of pre-cancerous syndromes in a mammal, including a human, wherein the pre-cancerous syndrome is selected from: cervical intraepithelial neoplasia, monoclonal gammapathy of unknown significance (MGUS), myelodysplastic syndrome, aplastic anemia, cervical lesions, skin nevi (pre-melanoma), prostatic intraepithelial (intraductal) neoplasia (PIN), Ductal Carcinoma in situ (DCIS), colon polyps and severe hepatitis or cirrhosis. The combination of the invention may be used alone, or in combination with, one or more other therapeutic agents. The invention thus provides in a further aspect a further combination comprising a combination of the invention with a further therapeutic agent or agents, compositions and medicaments comprising the combination and use of the further combination, compositions and medicaments in therapy, in particular, in the treatment of diseases susceptible to engagement of TLR4 and/or blocking the

engagement between PD- 1 and PD-Ll or PD-L2.

In the embodiment, the combination of the invention may be employed with other therapeutic methods of cancer treatment. In particular in anti-neoplastic therapy, combination therapy with other chemotherapeutic, hormonal, antibody agents as well as surgical and/or radiation treatments other than those mentioned above are envisaged. Combination therapies according to the present invention thus include the administration of a PD-l binding protein of the invention and/or a TLR4 modulator as well as optional use of other therapeutic agents including other anti-neoplastic agents. Such combination of agents may be administered together or separately and, when administered separately this may occur simultaneously or sequentially in any order, both close and remote in time. In one embodiment, the pharmaceutical combination includes a PD-l binding protein of the invention and a TLR4 modulator, and optionally at least one additional anti-neoplastic agent.

In one embodiment, the further anti-cancer therapy is surgical and/or radiotherapy.

In one embodiment, the further anti-cancer therapy is at least one additional anti neoplastic agent.

Any anti-neoplastic agent that has activity versus a susceptible tumor being treated may be utilized in the combination. Typical anti-neoplastic agents useful include, but are not limited to, anti-microtubule agents such as diterpenoids and vinca alkaloids; platinum coordination complexes; alkylating agents such as nitrogen mustards, oxazaphosphorines, alkylsulfonates, nitrosoureas, and triazenes; antibiotic agents such as anthracyclins, actinomycins and bleomycins; topoisomerase II inhibitors such as epipodophyllotoxins; antimetabolites such as purine and pyrimidine analogues and anti-folate compounds; topoisomerase I inhibitors such as camptothecins; hormones and hormonal analogues; signal transduction pathway inhibitors; non-receptor tyrosine angiogenesis inhibitors; immunotherapeutic agents; proapoptotic agents; and cell cycle signaling inhibitors.

Anti-microtubule or anti-mitotic agents: Anti-microtubule or anti-mitotic agents are phase specific agents active against the microtubules of tumor cells during M or the mitosis phase of the cell cycle. Examples of anti-microtubule agents include, but are not limited to, diterpenoids and vinca alkaloids.

Diterpenoids, which are derived from natural sources, are phase specific anti -cancer agents that operate at the G₂/M phases of the cell cycle. It is believed that the

diterpenoids stabilize the b-tubulin subunit of the microtubules, by binding with this protein. Disassembly of the protein appears then to be inhibited with mitosis being arrested and cell death following. Examples of diterpenoids include, but are not limited to, paclitaxel and its analog, docetaxel.

Paclitaxel, 5p,20-epoxy-l,2a,4,7p,l0p,l3a-hexa-hydroxytax-l l-en-9-one 4,10-diacetate 2-benzoate l3-ester with (2R,3S)-N-benzoyl-3-phenylisoserine; is a natural diterpene product isolated from the Pacific yew tree Taxus brevifolia and is commercially available as an injectable solution TAXOL. It is a member of the taxane family of terpenes.

Paclitaxel has been approved for clinical use in the treatment of refractory ovarian cancer in the United States (Markman, el ah, Yale Journal of Biology and Medicine , 64:583 (1991); McGuire, et ah, Ann. Intern, Med., 1 11 :273 (989), and for the treatment of breast cancer (Holmes, et ah, J. Nat. Cancer Inst., 83: 1797 (1991)). Paclitaxel is a potential candidate for treatment of neoplasms in the skin (Einzig, et ah, Proc. Am. Soc. Clin. Oncol., 20:46 (2001) and head and neck carcinomas (Forastire, et ah, Sem. Oncol., 20:56, (1990)). The compound also shows potential for the treatment of polycystic kidney disease (Woo, et. ah, Nature, 368:750 (1994)), lung cancer and malaria. Treatment of patients with paclitaxel results in bone marrow suppression (multiple cell lineages,

Ignoff, et al, Cancer Chemotherapy Pocket Guide, 1998) related to the duration of dosing above a threshold concentration (50 nM) (Kearns, et ah, Seminars in Oncology, 3(6) p.16-23 (1995)).

Docetaxel, (2R,3S)- N-carboxy-3-phenylisoserine,N-/er/-butyl ester, l3-ester with 5b-20- cpoxy- 1 ,2a,4,7b, 10b, 13a-hcxahydroxytax- 1 l-en-9-one 4-acetate 2-benzoate, trihydrate; is commercially available as an injectable solution as TAXOTERE. Docetaxel is indicated for the treatment of breast cancer. Docetaxel is a semisynthetic derivative of paclitaxel q.v., prepared using a natural precursor, lO-deacetyl-baccatin III, extracted from the needle of the European Yew tree.

Vinca alkaloids are phase specific anti-neoplastic agents derived from the periwinkle plant. Vinca alkaloids act at the M phase (mitosis) of the cell cycle by binding specifically to tubulin. Consequently, the bound tubulin molecule is unable to polymerize into microtubules. Mitosis is believed to be arrested in metaphase with cell death following. Examples of vinca alkaloids include, but are not limited to, vinblastine, vincristine, and vinorelbine.

Vinblastine, vincaleukoblastine sulfate, is commercially available as VELBAN as an injectable solution. Although, it has possible indication as a second line therapy of various solid tumors, it is primarily indicated in the treatment of testicular cancer and various lymphomas including Hodgkin’s Disease; and lymphocytic and histiocytic lymphomas. Myelosuppression is the dose-limiting side effect of vinblastine.

Vincristine, vincaleukoblastine, 22-oxo-, sulfate, is commercially available as ONCOVIN as an injectable solution. Vincristine is indicated for the treatment of acute leukemias and has also found use in treatment regimens for Hodgkin’s and non-Hodgkin’s malignant lymphomas. Alopecia and neurologic effects are the most common side effect of vincristine and to a lesser extent myelosupression and gastrointestinal mucositis effects occur.

Vinorelbine, 3 ',4'-di dehydro -4'-deoxy-C'-norvincaleukoblastine [R-(R*,R*)-2,3- dihydroxybutanedioate (l :2)(salt)], commercially available as an injectable solution of vinorelbine tartrate (NAVELBINE), is a semi-synthetic vinca alkaloid. Vinorelbine is indicated as a single agent or in combination with other chemotherapeutic agents, such as cisplatin, in the treatment of various solid tumors, such as non-small cell lung, advanced breast, and hormone refractory prostate cancers. Myelosuppression is the most common dose-limiting side effect of vinorelbine. Platinum coordination complexes: Platinum coordination complexes are non-phase specific anti-cancer agents, which are interactive with DNA. The platinum complexes enter tumor cells, undergo, aquation and form intra- and interstrand cross-links with DNA causing adverse biological effects to the tumor. Examples of platinum coordination complexes include, but are not limited to, oxaliplatin, cisplatin and carboplatin.

Cisplatin, cis-diamminedichloroplatinum, is commercially available as PLATINOL as an injectable solution. Cisplatin is primarily indicated in the treatment of metastatic testicular and ovarian cancer and advanced bladder cancer.

Carboplatin, platinum, diammine [l,l-cyclobutane-dicarboxylate(2-)-0,0'], is commercially available as PARAPLATIN as an injectable solution. Carboplatin is primarily indicated in the first- and second-line treatment of advanced ovarian carcinoma.

Alkylating agents: Alkylating agents are non-phase anti-cancer specific agents and strong electrophiles. Typically, alkylating agents form covalent linkages, by alkylation, to DNA through nucleophilic moieties of the DNA molecule such as phosphate, amino, sulfhydryl, hydroxyl, carboxyl, and imidazole groups. Such alkylation disrupts nucleic acid function leading to cell death. Examples of alkylating agents include, but are not limited to, nitrogen mustards such as cyclophosphamide, melphalan, and chlorambucil; alkyl sulfonates such as busulfan; nitrosoureas such as carmustine; and triazenes such as dacarbazine.

Cyclophosphamide, 2-[bis(2-chloroethyl)amino]tetrahydro-2H-l,3,2-oxazaphosphorine 2-oxide monohydrate, is commercially available as an injectable solution or tablets as CYTOXAN. Cyclophosphamide is indicated as a single agent, or in combination with other chemotherapeutic agents, in the treatment of malignant lymphomas, multiple myeloma, and leukemias.

Melphalan, 4-[bis(2-chloroethyl)amino]-L-phenylalanine, is commercially available as an injectable solution or tablets as ALKERAN. Melphalan is indicated for the palliative treatment of multiple myeloma and non-resectable epithelial carcinoma of the ovary.

Bone marrow suppression is the most common dose-limiting side effect of melphalan. Chlorambucil, 4-[bis(2-chloroethyl)amino]benzenebutanoic acid, is commercially available as LEUKERAN tablets. Chlorambucil is indicated for the palliative treatment of chronic lymphatic leukemia, and malignant lymphomas such as lymphosarcoma, giant follicular lymphoma, and Hodgkin’s disease.

Busulfan, 1 ,4-butanediol dimethanesulfonate, is commercially available as MYLERAN TABLETS. Busulfan is indicated for the palliative treatment of chronic myelogenous leukemia.

Carmustine, 1 , 3- [bis(2-chloroethyl)-l -nitrosourea, is commercially available as single vials of lyophilized material as BiCNET. Carmustine is indicated for the palliative treatment as a single agent or in combination with other agents for brain tumors, multiple myeloma, Hodgkin’s disease, and non-Hodgkin’s lymphomas.

Dacarbazine, 5-(3,3-dimethyl-l-triazeno)-imidazole-4-carboxamide, is commercially available as single vials of material as DTIC-Dome. Dacarbazine is indicated for the treatment of metastatic malignant melanoma and in combination with other agents for the second line treatment of Hodgkin’s Disease.

Antibiotic anti-neoplastics: Antibiotic anti-neoplastics are non-phase specific agents, which bind or intercalate with DNA. Typically, such action results in stable DNA complexes or strand breakage, which disrupts ordinary function of the nucleic acids leading to cell death. Examples of antibiotic anti-neoplastic agents include, but are not limited to, actinomycins such as dactinomycin, anthrocyclins such as daunorubicin and doxorubicin; and bleomycins.

Dactinomycin, also known as Actinomycin D, is commercially available in injectable form as COSMEGEN. Dactinomycin is indicated for the treatment of Wilm’s tumor and rhabdomyosarcoma.

Daunorubicin, (8S-cis-)-8-acetyl-l0-[(3-amino-2,3,6-trideoxy-a-L-lyxo- hexopyranosyl)oxy]-7,8,9, 10-tetrahydro-6,8, 1 1 -trihydroxy- 1 -methoxy-5, 12 naphthacenedione hydrochloride, is commercially available as a liposomal injectable form as DAUNOXOME or as an injectable as CERUBIDINE. Daunorubicin is indicated for remission induction in the treatment of acute nonlymphocytic leukemia and advanced HIV associated Kaposi’s sarcoma.

Doxorubicin, (8S, lOS)-lO-[(3-amino-2,3,6-trideoxy-a-L-lyxo-hexopyranosyl)oxy]-8- glycoloyl, 7,8,9, lO-tetrahydro-6, 8,1 1 -trihydro xy-l-methoxy-5, 12 naphthacenedione hydrochloride, is commercially available as an injectable form as RUBEX or

ADRIAMYCIN RDF. Doxorubicin is primarily indicated for the treatment of acute lymphoblastic leukemia and acute myeloblastic leukemia but is also a useful component in the treatment of some solid tumors and lymphomas.

Bleomycin, a mixture of cytotoxic glycopeptide antibiotics isolated from a strain of Streptomyces verticillus, is commercially available as BLENOXANE. Bleomycin is indicated as a palliative treatment, as a single agent or in combination with other agents, of squamous cell carcinoma, lymphomas, and testicular carcinomas.

Topoisomerase II inhibitors: Topoisomerase II inhibitors include, but are not limited to, epipodophyllotoxins.

Epipodophyllotoxins are phase specific anti-neoplastic agents derived from the mandrake plant. Epipodophyllotoxins typically affect cells in the S and G₂ phases of the cell cycle by forming a ternary complex with topoisomerase II and DNA causing DNA strand breaks. The strand breaks accumulate, and cell death follows. Examples of

epipodophyllotoxins include, but are not limited to, etoposide and teniposide.

Etoposide, 4'-demethyl-epipodophyllotoxin 9[4,6-0-(R)-ethylidene-P-D- glucopyranoside], is commercially available as an injectable solution or capsules as VePESID and is commonly known as VP- 16. Etoposide is indicated as a single agent, or in combination with, other chemotherapy agents in the treatment of testicular and non small cell lung cancers. Teniposide, 4'-demethyl-epipodophyllotoxin 9[4,6-0-(R )-thenylidene-P-D- glucopyranoside], is commercially available as an injectable solution as VUMON and is commonly known as VM-26. Teniposide is indicated as a single agent or in combination with other chemotherapy agents in the treatment of acute leukemia in children.

Antimetabolite neoplastic agents: Antimetabolite neoplastic agents are phase specific anti-neoplastic agents that act at S phase (DNA synthesis) of the cell cycle by inhibiting DNA synthesis or by inhibiting purine or pyrimidine base synthesis and thereby limiting DNA synthesis. Consequently, S phase does not proceed, and cell death follows.

Examples of antimetabolite anti-neoplastic agents include, but are not limited to, fluorouracil, methotrexate, cytarabine, mecaptopurine, thioguanine, and gemcitabine.

5-fluorouracil, 5-fluoro-2,4- (lH,3H) pyrimidinedione, is commercially available as fluorouracil. Administration of 5-fluorouracil leads to inhibition of thymidylate synthesis and is also incorporated into both RNA and DNA. The result typically is cell death. 5- fluorouracil is indicated as a single agent or in combination with other chemotherapy agents in the treatment of carcinomas of the breast, colon, rectum, stomach and pancreas. Other fluoropyrimidine analogs include 5-fluoro deoxyuridine (floxuridine) and 5- fluorodeoxyuridine monophosphate.

Cytarabine, 4-amino- l-P-D-arabinofuranosyl-2 (lH)-pyrimidinone, is commercially available as CYTOSAR-U^® and is commonly known as Ara-C. It is believed that cytarabine exhibits cell phase specificity at S-phase by inhibiting DNA chain elongation by terminal incorporation of cytarabine into the growing DNA chain. Cytarabine is indicated as a single agent or in combination with other chemotherapy agents in the treatment of acute leukemia. Other cytidine analogs include 5-azacytidine and 2', 2'- difluorodeoxycytidine (gemcitabine).

Mercaptopurine, l,7-dihydro-6H-purine-6-thione monohydrate, is commercially available as PURINETHOL^®. Mercaptopurine exhibits cell phase specificity at S-phase by inhibiting DNA synthesis by an as of yet unspecified mechanism. Mercaptopurine is indicated as a single agent or in combination with other chemotherapy agents in the treatment of acute leukemia. A useful mercaptopurine analog is azathioprine.

Thioguanine, 2-amino- l ,7-dihydro-6H-purine-6-thione, is commercially available as TABLOID^®. Thioguanine exhibits cell phase specificity at S-phase by inhibiting DNA synthesis by an as of yet unspecified mechanism. Thioguanine is indicated as a single agent or in combination with other chemotherapy agents in the treatment of acute leukemia. Other purine analogs include pentostatin, erythrohydroxynonyladenine, fludarabine phosphate, and cladribine.

Gemcitabine, 2'-deoxy-2', 2'-difluorocytidine monohydrochloride (b-isomer), is commercially available as GEMZAR^®. Gemcitabine exhibits cell phase specificity at S- phase and by blocking progression of cells through the Gl/S boundary. Gemcitabine is indicated in combination with cisplatin in the treatment of locally advanced non-small cell lung cancer and alone in the treatment of locally advanced pancreatic cancer.

Methotrexate, N-[4[[(2,4-diamino-6-pteridinyl) methyl] methylamino] benzoyl]-L- glutamic acid, is commercially available as methotrexate sodium. Methotrexate exhibits cell phase effects specifically at S-phase by inhibiting DNA synthesis, repair and/or replication through the inhibition of dyhydro folic acid reductase which is required for synthesis of purine nucleotides and thymidylate. Methotrexate is indicated as a single agent or in combination with other chemotherapy agents in the treatment of

choriocarcinoma, meningeal leukemia, non-Hodgkin’s lymphoma, and carcinomas of the breast, head, neck, ovary and bladder.

Topoisomerase I inhibitors: Camptothecins, including, camptothecin and camptothecin derivatives are available or under development as Topoisomerase I inhibitors.

Camptothecins cytotoxic activity is believed to be related to its Topoisomerase I inhibitory activity. Examples of camptothecins include, but are not limited to, irinotecan, topotecan, and the various optical forms of 7-(4-methylpiperazino-methylene)-l0,l 1- ethylenedioxy-20-camptothecin described below. Irinotecan HC1, (4S)-4,l l-diethyl-4-hydroxy-9-[(4-piperidinopiperidino) carbonyloxy]- lH-pyrano[3',4',6,7]indolizino[l ,2-b]quinoline-3,l4(4H,l2H)-dione hydrochloride, is commercially available as the injectable solution CAMPTOSAR^®. Irinotecan is a derivative of camptothecin which binds, along with its active metabolite SN-38, to the topoisomerase I - DNA complex. It is believed that cytotoxicity occurs as a result of irreparable double strand breaks caused by interaction of the topoisomerase I : DNA : irinotecan or SN-38 ternary complex with replication enzymes. Irinotecan is indicated for treatment of metastatic cancer of the colon or rectum.

Topotecan HC1, (S)- 10-[(dimethylamino)methyl]-4-ethyl-4, 9-dihydroxy- 1 H- pyrano[3',4',6,7]indolizino[l,2-b]quinoline-3,l4-(4H,l2H)-dione monohydrochloride, is commercially available as the injectable solution HYCAMTIN^®. Topotecan is a derivative of camptothecin which binds to the topoisomerase I - DNA complex and prevents religation of singles strand breaks caused by Topoisomerase I in response to torsional strain of the DNA molecule. Topotecan is indicated for second line treatment of metastatic carcinoma of the ovary and small cell lung cancer.

Hormones and hormonal analogues: Hormones and hormonal analogues are useful compounds for treating cancers in which there is a relationship between the hormone(s) and growth and/or lack of growth of the cancer. Examples of hormones and hormonal analogues useful in cancer treatment include, but are not limited to, adrenocorticosteroids such as prednisone and prednisolone which are useful in the treatment of malignant lymphoma and acute leukemia in children ; aminoglutethimide and other aromatase inhibitors such as anastrozole, letrazole, vorazole, and exemestane useful in the treatment of adrenocortical carcinoma and hormone dependent breast carcinoma containing estrogen receptors; progestrins such as megestrol acetate useful in the treatment of hormone dependent breast cancer and endometrial carcinoma; estrogens, androgens, and anti-androgens such as flutamide, nilutamide, bicalutamide, cyproterone acetate and 5a- reductases such as finasteride and dutasteride, useful in the treatment of prostatic carcinoma and benign prostatic hypertrophy; anti-estrogens such as tamoxifen, toremifene, raloxifene, droloxifene, iodoxyfene, as well as selective estrogen receptor modulators (SERMS) such those described in U.S. Patent Nos. 5,681,835, 5,877,219, and 6,207,716, useful in the treatment of hormone dependent breast carcinoma and other susceptible cancers; and gonadotropin-releasing hormone (GnRH) and analogues thereof which stimulate the release of leutinizing hormone (LH) and/or follicle stimulating hormone (FSH) for the treatment prostatic carcinoma, for instance, LHRH agonists and antagonists such as goserelin acetate and luprolide.

Signal transduction pathway inhibitors: Signal transduction pathway inhibitors are those inhibitors, which block or inhibit a chemical process which evokes an intracellular change. As used herein this change is cell proliferation or differentiation. Signal transduction inhibitors useful in the present invention include, but are not limited to, inhibitors of receptor tyrosine kinases, non-receptor tyrosine kinases, SH2/SH3 domain blockers, serine/threonine kinases, phosphotidyl inositol-3 kinases, myo-inositol signaling, and Ras oncogenes.

Several protein tyrosine kinases catalyse the phosphorylation of specific tyrosyl residues in various proteins involved in the regulation of cell growth. Such protein tyrosine kinases can be broadly classified as receptor or non-receptor kinases.

Receptor tyrosine kinases are transmembrane proteins having an extracellular ligand binding domain, a transmembrane domain, and a tyrosine kinase domain. Receptor tyrosine kinases are involved in the regulation of cell growth and are generally termed growth factor receptors. Inappropriate or uncontrolled activation of many of these kinases, i.e., aberrant kinase growth factor receptor activity, for example by over expression or mutation, has been shown to result in uncontrolled cell growth.

Accordingly, the aberrant activity of such kinases has been linked to malignant tissue growth. Consequently, inhibitors of such kinases could provide cancer treatment methods. Growth factor receptors include, for example, epidermal growth factor receptor (EGFr), platelet derived growth factor receptor (PDGFr), erbB2, erbB4, ret, vascular endothelial growth factor receptor (VEGFr), tyrosine kinase with immunoglobulin-like and epidermal growth factor identity domains (TIE-2), insulin growth factor -I (IGFI) receptor, macrophage colony stimulating factor (cfms), BTK, ckit, cmet, fibroblast growth factor (FGF) receptors, Trk receptors (TrkA, TrkB, and TrkC), ephrin (eph) receptors, and the RET protooncogene. Several inhibitors of growth receptors are under development and include ligand antagonists, antibodies, tyrosine kinase inhibitors and anti-sense oligonucleotides. Growth factor receptors and agents that inhibit growth factor receptor function are described, for instance, in Kath, John C., Exp. Opin. Ther. Patents (2000) 10(6):803-818; Shawver, et al DDT, Vol 2, No. 2 (February 1997); and Lofts, F.

J., el al, GROWTH FACTOR RECEPTORS AS TARGETS”, NEW MOLECULAR TARGETS FOR CANCER CHEMOTHERAPY (Workman, Paul and Kerr, David, CRC press 1994, London).

Tyrosine kinases, which are not growth factor receptor kinases are termed non-receptor tyrosine kinases. Non-receptor tyrosine kinases useful in the present invention, which are targets or potential targets of anti-cancer drugs, include cSrc, Lck, Fyn, Yes, Jak, cAbl, FAK (Focal adhesion kinase), Brutons tyrosine kinase, and Bcr-Abl. Such non-receptor kinases and agents which inhibit non-receptor tyrosine kinase function are described in Sinh, et al, Journal of Hematotherapy and Stem Cell Research, 8 (5): 465-80 (1999); and Bolen, et al, Annual review of Immunology, 15: 371-404 (1997).

SH2/SH3 domain blockers are agents that disrupt SH2 or SH3 domain binding in a variety of enzymes or adaptor proteins including, PI3-K p85 subunit, Src family kinases, adaptor molecules (She, Crk, Nek, Grb2) and Ras-GAP. SH2/SH3 domains as targets for anti-cancer drugs are discussed in Smithgall, T.E., Journal of Pharmacological and Toxicological Methods, 34(3) 125-32 (1995).

Inhibitors of Serine/Threonine Kinases including MAP kinase cascade blockers which include blockers of Raf kinases (rafk), Mitogen or Extracellular Regulated Kinase (MEKs), and Extracellular Regulated Kinases (ERKs); and Protein kinase C family member blockers including blockers of PKCs (alpha, beta, gamma, epsilon, mu, lambda, iota, zeta). IkB kinase family (IKKa, IKKb), PKB family kinases, akt kinase family members, and TGF beta receptor kinases. Such Serine/Threonine kinases and inhibitors thereof are described in Yamamoto, et al, Journal of Biochemistry, 126 (5) 799-803 (1999); Brodt, et al, Biochemical Pharmacology, 60. 1 101-1107 (2000); Massague, et al, Cancer Surveys, 27:41-64 (1996); Philip, et al, Cancer Treatment and Research, 78: 3-27 (1995), Lackey, et al, Bioorganic and Medicinal Chemistry Letters , (10) 223-226 (2000); U.S. Patent No. 6,268,391; and Martinez-Iacaci, et al, Int. J. Cancer, 88(1), 44-52 (2000). Inhibitors of Phosphotidyl inositol-3 Kinase family members including blockers of PI3- kinase, ATM, DNA-PK, and Ku are also useful in the present invention. Such kinases are discussed in Abraham, R.T. (1996), Current Opinion in Immunology. 8 (3) 412-8;

Canman, C.E., Lim, D.S. (1998), Oncogene 17 (25) 3301-3308; Jackson, S.P. (1997), International Journal of Biochemistry and Cell Biology. 29 (7):935-8; and Zhong, H., el al, Cancer Res., (2000) 60(6), 1541-1545.

Also useful in the present invention are myo-inositol signaling inhibitors, such as phospholipase C blockers and Myoinositol analogues. Such signal inhibitors are described in Powis, G., and Kozikowski A., (1994) NEW MOLECULAR TARGETS FOR CANCER CHEMOTHERAPY ED. (Paul Workman and David Kerr, CRC press 1994,

London).

Another group of signal transduction pathway inhibitor are inhibitors of Ras Oncogene. Such inhibitors include inhibitors of famesyltransferase, geranyl-geranyl transferase, and CAAX proteases as well as anti-sense oligonucleotides, ribozymes and immunotherapy. Such inhibitors have been shown to block ras activation in cells containing wild-type mutant ras, thereby acting as antiproliferation agents. Ras oncogene inhibition is discussed in Scharovsky, et al. (2000), Journal of Biomedical Science. 7(4) 292-8;

Ashby, M.N. (1998), Current Opinion in Lipidology. 9 (2) 99 - 102; and BioChim.

Biophys. Acta, (1989) 1423(3): 19-30.

As mentioned above, antibody antagonists to receptor kinase ligand binding may also serve as signal transduction inhibitors. This group of signal transduction pathway inhibitors includes the use of humanized antibodies to the extracellular ligand binding domain of receptor tyrosine kinases. For example, Imclone C225 EGFR specific antibody (see Green, et al, Monoclonal Antibody Therapy for Solid Tumors, Cancer Treat. Rev., (2000), 26(4), 269-286); Herceptin^® erbB2 antibody (see“Tyrosine Kinase Signalling in Breast cancer: erbB Family Receptor Tyrosine Kinases”, Breast Cancer Res ., 2000, 2(3), 176-183); and 2CB VEGFR2 specific antibody (see Brekken, et al.,“Selective Inhibition of VEGFR2 Activity by a monoclonal Anti-VEGF antibody blocks tumor growth in mice”, Cancer Res. (2000) 60, 5117-5124). Anti-angiogenic agents: Anti-angiogenic agents including non-receptor MEK

angiogenesis inhibitors may also be useful. Anti-angiogenic agents such as those which inhibit the effects of vascular endothelial growth factor, (for example the anti-vascular endothelial cell growth factor antibody bevacizumab [AVASTIN], and compounds that work by other mechanisms (for example linomide, inhibitors of integrin anb3 function, endostatin and angiostatin);

Immuno therapeutic agents: Agents used in immunotherapeutic regimens may also be useful in combination with the compounds of formula (I). Immunotherapy approaches, including for example ex-vivo and in-vivo approaches to increase the immunogenicity of patient tumor cells, such as transfection with cytokines such as interleukin 2, interleukin 4 or granulocyte-macrophage colony stimulating factor, approaches to decrease T-cell anergy, approaches using transfected immune cells such as cytokine -transfected dendritic cells, approaches using cytokine -transfected tumor cell lines and approaches using anti- idiotypic antibodies

Proapoptotic agents: Agents used in proapoptotic regimens (e.g., bcl-2 antisense oligonucleotides) may also be used in the combination of the present invention.

Cell cycle signaling inhibitors: Cell cycle signaling inhibitors inhibit molecules involved in the control of the cell cycle. A family of protein kinases called cyclin dependent kinases (CDKs) and their interaction with a family of proteins termed cyclins controls progression through the eukaryotic cell cycle. The coordinate activation and inactivation of different cyclin/CDK complexes is necessary for normal progression through the cell cycle. Several inhibitors of cell cycle signaling are under development. For instance, examples of cyclin dependent kinases, including CDK2, CDK4, and CDK6 and inhibitors for the same are described in, for instance, Rosania, el ah, Exp. Opin. Ther. Patents (2000) 10(2):215-230.

In one embodiment, the combination of the present invention comprises a PD-l binding protein and a TLR4 modulator and at least one anti-neoplastic agent selected from anti microtubule agents, platinum coordination complexes, alkylating agents, antibiotic agents, topoisomerase II inhibitors, antimetabolites, topoisomerase I inhibitors, hormones and hormonal analogues, signal transduction pathway inhibitors, non-receptor tyrosine MEK angiogenesis inhibitors, immunotherapeutic agents, proapoptotic agents, and cell cycle signaling inhibitors.

In one embodiment, the combination of the present invention comprises a PD- 1 binding protein and a TLR4 modulator and at least one anti-neoplastic agent which is an anti microtubule agent selected from diterpenoids and vinca alkaloids.

In a further embodiment, the anti-neoplastic agent is a diterpenoid.

In a further embodiment, the anti-neoplastic agent is a vinca alkaloid.

In one embodiment, the combination of the present invention comprises a PD- 1 binding protein and a TLR4 modulator and at least one anti-neoplastic agent, which is a platinum coordination complex.

In a further embodiment, the anti-neoplastic agent is paclitaxel, carboplatin, or vinorelbine.

In one embodiment, the combination of the present invention comprises a PD- 1 binding protein and a TLR4 modulator and at least one anti-neoplastic agent which is a signal transduction pathway inhibitor.

In a further embodiment, the signal transduction pathway inhibitor is an inhibitor of a growth factor receptor kinase, VEGFR2, TIE2, PDGFR, BTK, erbB2, EGFr, IGFR-l, TrkA, TrkB, TrkC, or c-fms.

In a further embodiment, the signal transduction pathway inhibitor is an inhibitor of a serine/threonine kinase rafk, akt, or PKC-zeta.

In a further embodiment, the signal transduction pathway inhibitor is an inhibitor of a non- receptor tyrosine kinase selected from the src family of kinases.

In a further embodiment, the signal transduction pathway inhibitor is an inhibitor of c-src

In a further embodiment, the signal transduction pathway inhibitor is an inhibitor of Ras oncogene selected from inhibitors of famesyl transferase and geranylgeranyl transferase. In a further embodiment, the signal transduction pathway inhibitor is an inhibitor of a serine/threonine kinase selected from the group consisting of PI3K.

In a further embodiment, the signal transduction pathway inhibitor is a dual EGFr/erbB2 inhibitor, for example N-{3-Chloro-4-[(3-fluorobenzyl) oxy]phenyl}-6-[5-({[2- (methanesulphonyl) ethyl]amino}methyl)-2-furyl]-4-quinazolinamine (structure below):

In one embodiment, the combination of the present invention comprises a compound of formula I or a salt or solvate thereof and at least one anti-neoplastic agent which is a cell cycle signaling inhibitor. In further embodiment, cell cycle signaling inhibitor is an inhibitor of CDK2, CDK4, or CDK6.

In one embodiment the mammal in the methods and uses of the present invention is a human.

The invention thus provides in a further aspect a method for treating metastatic solid tumors, the method comprising: (i) systemically administering CRX-601; and, (ii) systemically administering a PD-l antagonist. In some embodiments, the CRX-601 is systemically administered in a dose from about 50 ng to about 250 ng. In some embodiments, the PD-l antagonist is selected from the group consisting of nivolumab, pembrolizumab, and cemiplimab. In some embodiments, a method for treating metastatic solid tumors comprises: (i) intravenously administering from about 50 ng to about 250 ng of CRX-601; and (ii) intravenously administering about 200 mg of pembrolizumab.

In some embodiments, a method for treating metastatic solid tumors, comprises: (i) systemically administering from about 50 ng to about 250 ng of CRX-601 ; and (ii) systemically administering about 2 mg/kg of pembrolizumab. In various embodiments, the CRX-601 is periodically dosed. In various embodiments, the PD-l antagonist is periodically dosed.

As indicated, therapeutically effective amounts of the combinations of the invention (a PD- 1 binding protein and a TLR4 modulator) are administered to a human. Typically, the therapeutically effective amount of the administered agents of the present invention will depend upon a number of factors including, for example, the age and weight of the subject, the precise condition requiring treatment, the severity of the condition, the nature of the formulation, and the route of administration. Ultimately, the therapeutically effective amount will be at the discretion of the attendant physician.

All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In the case of conflict, the present

specification, including definitions, controls. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. The following examples are intended for illustration only and are not intended to limit the scope of the invention in any way.

EXAMPLES

Example 1: A Phase I, Open-Label Study of CRX-601 in Combination with

Immunotherapies in Participants with Selected Advanced Solid Tumors

1. Synopsis

Protocol Title: A Phase I, Open-Label Study of CRX-601 in Combination with Immunotherapies in Participants with Selected Advanced Solid Tumors

Short Title: Study of combinations of CRX-601 and immunotherapies in participants with advanced solid tumors

Rationale: The combination of two or more immunotherapies holds promise in treating patients with cancer. One model of a“cancer-immune cycle” describes a series of feed forward steps by which the immune system recognizes and kills tumor cells, a cycle which is counterbalanced by tumor and host derived factors which suppress anti-tumor immune activation [Chen, 2013; Chen, 2017] These steps include:

Release of cancer cell antigens

Cancer antigen presentation

Priming and activation

Trafficking of T-cells to tumors

Infiltration of T-cells into tumors

Recognition of cancer cells by T-cells

Killing of cancer cells

Rational combination strategies, such as immunotherapies acting at different steps in the immune cycle, could produce meaningful and synergistic activity compared to monotherapies [Hoos, 2016] Combining a TLR4 agonist with a checkpoint modulator targets two complementary steps in the cancer-immunity cycle; TLR engagement results in the production of various inflammatory cytokines/chemokines such as tumor necrosis factor (TNF)a, interleukin (IL) 6, granulocyte colony-stimulating factor (G-CSF), and type I interferons (i.e., IFNa, IFNP) and enhanced uptake, processing, and presentation of antigens. Based on nonclinical data, the combinations of CRX-601 (a TLR4 agonist) and pembrolizumab (a PD- 1 inhibitor) is anticipated to have antitumor activity greater than either of the monotherapies.

Objectives and Endpoints:

Overall Design: This is a Phase I, open-label, non-randomized, multicenter and multi-country study designed to evaluate the safety, tolerability, PK, pharmacodynamic, and preliminary clinical activity of CRX-601 administered in combination with other immunotherapies to participants with advanced solid tumors.

In Part 1, the safety and tolerability of escalating doses of CRX-601 and a single dose level of a monoclonal antibody (mAh) combination partner (pembrolizumab) will be evaluated in separate cohorts of participants with advanced solid tumor cancers according to an Neuenschwander-Continual Reassessment Method (N-CRM) design to identify doses for evaluation in Part 2 [Neuenschwander, 2008] Part 1 will include a CRX-601 run-in period of 2 weeks (i.e., CRX-601 administration on Days 1 and 8) prior to administration of the combination partner beginning at Day 15. Approximately 5 dose levels of CRX-601 in combination with a single fixed dose level of the combination partner are planned to be evaluated in Part 1. Following protocol amendment, CRX-601 may also be further evaluated by additional routes of administration.

In Part 2, expansion cohorts of approximately 6 to 15 participants with squamous cell carcinoma of the head and neck (SCCHN) will be enrolled in the combination treatment arm to further evaluate the safety and activity of dose(s) identified in Part 1. The dose(s) of CRX-601 administered in combination with 200 mg pembrolizumab will be determined based on data from Part 1. Following protocol amendment, additional expansion cohorts in other tumor types may be enrolled, based on emerging nonclinical and clinical data.

In addition, PK/Pharmacodynamic cohorts for the combination will be opened to enrollment during Part 1 to obtain additional PK and pharmacodynamic data, with an emphasis to obtain insight on the potential impact of the combination treatments on the immune cells and status of the tumor microenvironment, in conjunction with PK and pharmacodynamic markers obtained from blood. Tumor biopsies are required for enrollment to the PK/Pharmacodynamic cohorts, whereas biopsies are strongly encouraged but not mandatory for Part 1 dose escalation cohorts. For the combination, participants in the PK/Pharmacodynamic cohorts may be enrolled to any dose level which has already been completed and supported by adequate safety and tolerability from dose escalation for the combination. Up to a maximum of 45 participants may be enrolled into the PK/Pharmacodynamic cohorts with up to approximately 6 per dose level for each combination.

Treatment Groups and Duration:

Participants will receive the combination of CRX-601 with pembrolizumab. In Part 1, escalating doses of CRX-601 will be evaluated as guided by the N-CRM approach. In Part 2, participants will receive a single dose level of CRX-601 as identified based on data from Part 1 , in combination with pembrolizumab.

The study includes a screening period, a treatment period, and a follow-up period.

Participants will be screened for eligibility beginning 4 weeks before the start of treatment. The duration of study treatment is expected to be up to 2 years. For participants that discontinue study treatment prior to a determination of progressive disease (PD), the follow-up period will include disease assessments every 12 weeks until documented PD occurs (PFS Follow Up [FU]). Following PD or for participants that discontinue study treatment for PD, participants will be contacted every 12 weeks to assess survival status (Survival FU [SFU]) for up to 2 years from the start of the study treatment.

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3. Introduction

3.1. Study Rationale

The model of a“cancer-immune cycle” describes a series of feed-forward steps by which the immune system recognizes and kills tumor cells, a cycle which is counterbalanced by tumor and host derived factors which suppress anti-tumor immune activation [Chen,

2013; Chen, 2017] The steps of tumor immune recognition and killing include release of cancer cell antigens, cancer antigen presentation, priming and activation, trafficking of T- cells to tumors, recognition of cancer cells by T-cells, and killing of cancer cells. Immune suppressive factors which may be operative in tumor microenvironment include checkpoint pathways ( e.g ., programmed death receptor- 1 [PD-l], cytotoxic T- lymphocyte-associated antigen 4 [CTLA-4]) and a range of immunosuppressive factors (e.g., IDO, TGF-b), as well as immune inhibitory cell populations including T regulatory (Treg) cells, myeloid derived suppressor cells, and immune suppressive macrophages (M2-macrophages). Thus, cancer persistence and growth results from aberrant cell replication together with a relative imbalance in favor of immune suppressive factors as compared to anti -tumor immune activating responses.

The therapeutic benefit of blocking the immuno-inhibitory checkpoint pathways PD-l and CTLA-4 recently has been demonstrated across multiple tumor types, yielding durable responses in some patients. However, a majority of patients do not respond to monotherapy with checkpoint inhibitors, and strategies to increase their activity by combination approaches are being actively explored. It is also possible that

immunotherapies acting at different steps in the cycle and on different cells and pathways could have improved therapeutic indices over currently available monotherapies.

Furthermore, engaging novel pathways and combinations may provide therapeutic options for patients wherein the pre-existing host and tumor microenvironment factors do not favor response to PD-l or CTLA-4.

Toll-like receptors (TLRs) are a family of‘sensor’ proteins primarily expressed on certain immune and epithelial cells that function as activators of innate immunity in response to microbial-related molecules known as Pathogen- Associated Molecular Patterns (PAMPs). PAMPs include molecules such as nucleic acids, flagellar proteins, and lipopolysaccharide (LPS), the prototypical ligand for TLR4. Ligand-driven activation of TLRs results in the production of various inflammatory cytokines and chemokines such as tumor necrosis factor (TNF)a, IL-6, IL-8, IP- 10, G-CSF, interferons (IFNs), and enhanced uptake, processing, and presentation of antigens by antigen presenting cells. Further effects of TLR4 agonism observed in animal models of cancer include reduction of Treg cells and promotion of macrophage phenotypic switching from an immunosuppressive M2 phenotype to an immune active Ml phenotype. CRX-601 is a synthetic TLR4 agonist that is being developed by GlaxoSmithKline as an immunological adjuvant to be administered in combination with other immune system modulators for the treatment of cancers. CRX-601 is not being developed as a

monotherapy given the lack of robust anti-tumor activity that has been reported for the drug class in participants with advanced malignancies [Guha, 2012; Weihrauch, 2015; Pashenkov, 2006] Therefore, the first-time in human (FTIH) study of CRX-601 was performed in healthy participants to evaluate preliminary safety, PK, pharmacodynamics, and to identify a pharmacologically active starting dose to initiate studies in cancer patients.

The adverse event (AE) profile in the CRX-601 FTIH study was characterized by cytokine-related effects such as flu-like symptoms and changes in temperature and heart rate (see below). One (1) study participant experienced an elevation in transaminases (see below). Overall, the clinical profile of CRX-601 as evaluated in healthy participants was consistent with that anticipated by the repeat dose GLP toxicology studies in rats and monkeys and with the profiles of other TLR agonists reported in both healthy participants and cancer patients [Kanzler, 2007; Astiz ME, Rackow EC, Still JG, Howell ST, Cato A, Von Eschen KB, et al. Pretreatment of normal humans with monophosphoryl lipid A induces tolerance to endotoxin: a prospective, double -blind, randomized, controlled trial. Crit Care Med. 1995 Jan;23(l):9-l7.

Bahador, 2007; Schmoll, 2014; Northfelt, 2014; Isambert, 2013] Data from the FTIH study was used to support the starting dose and dose rationale in the present study (see below).

Pembrolizumab is a humanized IgG4 kappa monoclonal antibody that blocks the interaction between the PD-l receptor found on T cells and its ligands, PD-L1 and PD- L2. Upregulation of PD-l ligands occurs in some tumors and signaling through this pathway can contribute to inhibition of active T-cell immune surveillance of tumors. Pembrolizumab releases the PD-l pathway-mediated inhibition of the immune response, including the anti-tumor immune response. Pembrolizumab is in clinical development as an IV immunotherapy for advanced malignancies and indicated for the treatment of patients across a number of conditions. For more details on specific indications refer to pembrolizumab IB [KEYTRUDA SPC, 2018] and approved labelling.

This study will assess the safety, PK, pharmacodynamics, and preliminary clinical activity of CRX-601 administered in combination with other immunotherapies to participants with advanced solid tumors. Pembrolizumab is well-suited for combination with CRX-601 based on mechanisms of action targeting complementary nodes of the cancer-immunity cycle and compelling antitumor activity observed in preclinical models. Subsequent combination partners and/or additional routes of administration may be evaluated (following protocol amendment/s) based on biologic rationale, nonclinical data, and/or emerging clinical data. 3.2. Brief Background

3.2.1. CRX-601 Background

An overview of CRX-601 is provided below.

CRX-601 was initially developed in the course of structure-activity studies on LPS (also known as‘endotoxin’), the naturally occurring ligand of TLR4. CRX-601 is a monosaccharide from the aminoalkyl glucosaminide 4-phosphate class of compounds intended for use as a vaccine adjuvant or an immune modulator. CRX-601 is an agonist of TLR4 that induces immunologic responses in vitro and in vivo. CRX-601 , as a single agent, stimulates cytokine production (in vitro and in vivo), changes in immune cell populations (in vivo) and generates fever response (in vivo).

3.2.1.1. CRX-601 Nonclinical Activity

CRX-601 has shown immunomodulatory activity in multiple in vitro and in vivo models. CRX-601 added to whole blood ex vivo induces cytokine production, and when administered to BALB/c mice, induces phenotypic trends in peripheral blood leukocytes including decreased regulatory T-cells (Tregs), increased T-cell activation, and expansion of myeloid cells and monocyte/macrophages. CRX-601 administered to CT-26 tumor bearing BALB/c mice resulted in an increase in survival compared to control groups.

The in vitro and in vivo pharmacology of CRX-601 is consistent with other TLR agonists [Kanzler, 2007] In vitro cytokine induction (IL-l b, IL-6, IP-10 and TNFa) by CRX-601 is similar to that of LPS. In rabbits, a species used for assessing endotoxin contamination of parenteral formulations due to their high sensitivity, CRX-601 produced a transient increase in body temperature similar to that which occurs following LPS administration. In the repeat dose intravenous toxicity studies in rats and monkeys, CRX-601 was associated with the expected pro-inflammatory actions of a TLR4 agonist. The primary systemic effect seen with weekly dosing of CRX-601 in rat (dosing up to 4 weeks) and monkey (dosing up to 6 weeks) studies was increased levels of specific cytokines; all other findings were transient and considered secondary to this primary response.

Adverse findings were only noted in rat and include microscopic changes in the heart valves and lymphocytic inflammatory cell infiltrates in the liver.

The no-observed-adverse-effect-level (NOAEL) is 15 pg/kg/dosc and 200 pg/kg/dose, in the rat and monkey, respectively. Based on the predicted human exposure at the highest planned clinical dose of 250 ng (predicted maximum concentration [C max] IS

approximately 0.036 ng/mL, and predicted area under the plasma concentration-time curve [AUC] is approximately 1.21 ng-h/mL), the margin to the NOAEL dose in rat is approximately 206 IX for Cmax and 214X for AUC and in monkey is approximately 40,000X for C_max and 24,l32X for AUC. 3.2.1.2. CRX-601 Development Plan and Clinical Experience

This protocol describes a study evaluating the combination of CRX-601 with other immunotherapies. The study will be the second evaluation of CRX-601 in humans and the first in participants with cancer.

CRX-601 is not planned for development as a monotherapy in cancer participants given that the TLR agonist drug class has not produced robust monotherapy antitumor activity in multiple prior clinical trials of participants with advanced malignancies. However, the safety, PK, and pharmacodynamics results from the FTIH study support the design and conduct of a clinical trial in cancer participants where the benefits of CRX-601 are more likely to be realized as an adjuvant in combination with other immune therapies with complementary modes of action. Should the combination(s) demonstrate robust anti tumor activity and a favorable safety profile, monotherapy study arms could be added by future amendment to explore the relative contributions of the study treatments.

Like CRX-601 , other TLR agonists including the prototypical TLR4 agonist, LPS, have been evaluated in both healthy participants and cancer patients for experimental and therapeutic purposes. Administration causes dose-dependent increases in cytokines including TNFa, IL-6, and IL-8, which peak within 2 to 4 hours and return to normal within 24 hours. In cases where the same TLR agonist has been administered to both healthy participants and to cancer participants, the PK and pharmacodynamic profiles have been similar for the two populations [Riella, L.V., S. Dada, L. Chabtini, B. Smith,

L. Huang, P. Dakle, B. Mfarrej, F. D'Addio, L.-T. Adams, N. Kochupurakkal, A.

Vergani, P. Fiorina, A.L. Mellor, A.H. Sharpe, H. Yagita, and I. Guleria. 2013. B7h (ICOS-L) Maintains Tolerance at the Fetomaternal Interface. The American Journal of Pathology 182:2204-2213.

Schmidt, 2015; Dietsch, 2014] Clinical safety data for the drug class is characterized by a predictable tolerability profile of transient fever and flu-like symptoms ( e.g ., chills, nausea, malaise, etc.) attributable to cytokine production [Astiz ME, Rackow EC, Still JG, Howell ST, Cato A, Von Eschen KB, et al. Pretreatment of normal humans with monophosphoryl lipid A induces tolerance to endotoxin: a prospective, double-blind, randomized, controlled trial. Crit Care Med. 1995 Jan;23(l):9-l7.

Bahador, 2007] A review of studies comprising thousands of healthy participants that have been administered LPS notes that long-term toxicities have not been described [Astiz ME, Rackow EC, Still JG, Howell ST, Cato A, Von Eschen KB, et al.

Pretreatment of normal humans with monophosphoryl lipid A induces tolerance to endotoxin: a prospective, double-blind, randomized, controlled trial. Crit Care Med. 1995 Jan;23(l):9-l7.

Bahador, 2007] Although elderly participants have greater decreases in blood pressure as compared to young participants administered 2 ng/kg doses of LPS [Krabbe, 2001], the difference in sensitivity has not prevented administration of even higher doses (5 ng/kg) to cancer participants [Engelhardt, 1991] At these doses, peak TNFa and IL-6 levels can exceed 5000 pg/mL, and further dose escalation has been limited by rising transaminase levels [Engelhardt, 1991] In other trials of TLR4 agonists in participants with advanced malignancies, cytokine-associated SAEs such as bronchospasm and hypotension have been reported [Vosika, 1984; de Bono, 2000] Overall, the cytokine- associated adverse events associated with TLR agonists overlaps minimally with the profiles of checkpoint modulators. Thus, the safety profile of TLR agonists is well suited for administration in combination with other immune therapies such as checkpoint modulators.

The FTIH study of CRX-601 was a randomized, double-blind (sponsor unblinded), placebo-controlled, ascending dose and parallel group study in healthy participants. In Part 1, single IV bolus doses of placebo or CRX-601 at 7, 21, 60, or 100 ng were administered (n=6 CRX-601, n=2 placebo per dose level, except the 60 ng cohort which was repeated, i.e., n=l2 CRX-601 , n=4 placebo). Dose escalation was stopped, per protocol, following the 100 ng cohort, in which 3 of 6 participants experienced AEs of moderate intensity. In Part 2, participants were to receive repeat doses of CRX-601. However, Part 2 was not started following an elevation in transaminases on study day 30 for 1 participant in cohort 4 (60 ng) of Part 1 (see details herein).

Preliminary PK assessments of CRX-601 were performed based on available data. No quantifiable concentrations were observed at the 7 ng dose (assay lower limit of quantification [LLOQ] = 2 pg/mL), and insufficient PK concentrations were above the LLOQ at the 21 ng dose to enable calculation of AUC. Median peak concentrations (C_max) at doses 21 (n=6), 60 (n=l2) and 100 ng (n=6) doses were 3.90, 10.02 and 23.26 pg/mL, respectively. The C_max values from these three single doses were evaluated for dose-proportionality using the power model loge (PK parameter) = a + b * loge (dose) where“a” is the intercept and“b” is the slope and was fitted by restricted maximum likelihood using SAS Proc Mixed. An estimate of the slope with corresponding 90% confidence interval (Cl) was obtained from the power model to assess the degree of dose- proportionality, wherein a slope equal to 1.0 is indicative of dose-proportionality. The 90% confidence interval for the slope was (0.84, 1.20) and (0.96, 1.24) with inclusion and without inclusion, respectively, of a participant from the 100 ng dose cohort who showed an approximately 3-fold lower C_max compared to other participants from this cohort.

These intervals were contained within the interval (0.8, 1.25) indicating that slope is around unity implying that dose-proportionality is observed for C_max within this dose range. Half-life could not be reliably estimated for lower dose groups due to limited data above the assay LLOQ. The median half-life calculated from the 100 ng dose is ~72 h, which is in agreement with expectations based on extrapolation of preclinical data.

The safety profile of CRX-601 in the FTIH study, included AEs consistent with cytokine production and was generally qualitatively similar to profiles of other TLR agonists. Based on preliminary, unblinded safety data, as of 7 days after completing dosing in the 100 ng cohort, the most common clinical findings were influenza-like illness (10 participants), body temperature increased (4 participants), abdominal pain, back pain, dizziness, headache, oropharyngeal pain, presyncope, (2 participants). No other AEs were observed in more than 1 participant. The frequency of safety observations increased with dose as described below.

• Following administration of 7 or 21 ng CRX-601 (6 participants in each group), the reported AEs and changes in vital signs resembled the placebo group.

• Following administration of 60 ng CRX-601 (12 participants), mild influenza- like symptoms or headache were reported for 7 participants. One (1) participant had moderate abdominal cramps considered possibly related to study treatment. One (1) participant experienced a 58 bpm increase in heart rate to a maximum of

125 bpm. One (1) participant experienced a 12-fold increase in alanine aminotransferase (ALT) (as described herein).

• Following administration of 100 ng CRX-601 (6 participants), influenza-like symptoms were reported for 5 participants. Three (3) participants experienced moderate AEs considered at least possibly related to study treatment by the investigator, including orthostatic presyncope, muscle tremor, back pain, nausea, dizziness, influenza-like symptoms. Because 3 of 6 participants experienced AEs of moderate intensity dose escalation was stopped, per protocol.

3.2.1.2.1. Transaminase elevation

One participant received a single 60 ng IV dose of CRX-601 and experienced a 12-fold increase in ALT. The time course of the increase was notable in that the participant had a slightly elevated ALT immediately prior to dosing (53 U/L; upper limit of normal [ULN] = 50 U/L), and the value remained of low grade but trended upward to 89.6 U/L on day 7 post-dose and 122.5 U/L on day 21. On day 32, the ALT increased to 563.4 U/L, and it peaked on day 34 (626.7 U/L) before declining. Beginning with day 35, total bilirubin was elevated (29.9 pmol/L; ULN = 21 pmol/L). Day 35 aspartate aminotransferase (AST), indirect bilirubin, and direct bilirubin were 254.5 U/L (ULN = 50 U/L), 25.8 pmol/L (ULN = 17.6 pmol/L), and 4.1 pmol/L (ULN = 3.4 pmol/L), respectively. The participant experienced no other AEs on the trial and only had mild increases in body temperature (0.6°C) and heart rate (14 bpm) relative to predose values. A thorough evaluation by a hepatologist including comprehensive laboratory studies and liver ultrasound provided no additional insight into the elevations in hepatic laboratory values. Of note, the participant had multiple elevations in transaminases and total bilirubin before or during other clinical trials at the investigative site, although all were of low grade (maximum ALT <4-fold ULN; maximum total bilirubin < 1.5-fold ULN).

The elevation in transaminases and total bilirubin was considered possibly related to CRX-601 by the investigator. In addition, the sponsor, in consultation with external hepatolo gists, considered an undefined, underlying, low-grade hepatic pathology to possibly have contributed to the elevation in transaminases, given the participant’s history. A potential role for CRX-601 as contributing to the observed increases cannot be ruled out based on the available information.

Transaminases were routinely measured in all participants in the study, and no other participant experienced an increase.

3.2.2. Pembrolizumab Background

Pembrolizumab, a humanized monoclonal antibody against the PD-l protein, has been developed by Merck & Co for the treatment of patients with cancer and has been approved for treatment of patients with multiple advanced malignancies. Refer to the pembrolizumab approved labelling for detailed background information [KEYTRETDA SPC, 2018; KEYTRUDA PI, 2018]

Pembrolizumab has been administered in combination with TLR agonists in clinical trials [Flowers, 2017; Milhem, 2018] In these clinical trials, a higher frequency of cytokine- associated AEs was observed than has been observed at the 60 ng dose level of CRX-601 in the FTIH trial. Nevertheless, the combinations have been well-tolerated and their AE profiles not markedly changed from that described in the KEYTRETDA PI. For example, SD-101 administered by intratumoral injection with standard doses of pembrolizumab in subjects with metastatic melanoma experienced frequent AEs characteristic of TLR agonists, e.g. chills (17/22 subjects; 77.3%); headache (16/22 subjects; 72.7%); myalgia (15/22 subjects; 68.2%); nausea (7/22 subjects; 31.8%); and pyrexia (7/22 subjects; 31.8%); influenza like illness (6/22 subjects; 27.3%). Grade > 3 AEs were observed in 59.1% pts (most common: myalgia 13.6% and injection site pain 13.6%). Immune- related AEs occurred in 2 pts. [Leung, 2017] When SD-101 was administered to subjects with metastatic SCCHN in combination with pembrolizumab, potential irAEs were reported at a frequency of 3/22 subjects (14%) [Cohen, 2018] The TLR4 agonist G100, administered 5 pg intratumorally, with and without radiation, is associated with a 50% incidence of flu-like symptoms [Flowers, 2017] When administered in

combination with pembrolizumab, the frequency of AEs was 69% for G100 alone vs.

85% for G100 + pembrolizumab. One (1) of 13 subjects experienced Grade 3 adrenal insufficiency. No other Grade 3 or greater events were described [Flowers, 2017] In an ongoing phase lb trial evaluating intratumoral TLR9 agonist CMP-001 in combination with pembrolizumab in 63 subjects with advanced melanoma, 15 Grade 3/4 related AEs were reported, including hypotension (n=7), anemia (n=2), chills (n=2), hypertension (n=2) and fever (n=2) [Milhem, 2018] No maximum tolerated dose was identified during the dose escalation phase of the study. While acknowledging direct comparisons to these studies are problematic, other TLR agonists administered at doses associated with systemic, cytokine-associated AEs have been well-tolerated in combination with pembrolizumab.

3.2.3. CRX-601 Combination Background

3.2.3.1. CRX-601 In Vivo Studies

Efficacy Studies

CRX-601 and a PD-l antibody in combination were evaluated in B ALB/c mice implanted with syngeneic EMT-6 tumors. Four groups of 10 B ALB/c mice with intact immune systems were implanted with EMT-6 tumors. The mice received one of the following treatments: placebo, CRX-601 (TLR4 agonist), RMP1-14 (mouse surrogate PD-l antibody), or the combination of CRX-601 and RMP1-14. While the

monotherapies exhibited tumor growth inhibition (Figure 1), the combination treatment of CRX-601 and RMPI-14 resulted in greater tumor growth inhibition. CRX-601 and RMPI-14 monotherapies resulted in 40% tumor free mice that survived more than 100 days, while the combination therapy resulted in 90% tumor free mice that survived more than 100 days (Figure 2).

These preclinical efficacy results for CRX-601 have been reproducible across a range of studies ( e.g ., testing of different doses, dose frequencies, and routes of administration), and together with in vitro and in vivo pharmacologic data, provide rationale for evaluating the combination of CRX-601 with pembrolizumab in a clinical trial for the treatment of cancer.

Safety Studies

A review of the data from the nonclinical combination efficacy studies of CRX-601 and anti-PDl as well as the nonclinical toxicology findings and clinical (pembrolizumab only) safety information for both CRX-601 and pembrolizumab used as single agents was conducted and adequately provide support for their use in combination in the target patient population. Additionally, the nonclinical toxicology findings for both CRX-601 and pembrolizumab given as single agents indicate that a combination toxicology study in monkeys would not likely provide additional relevant clinical risk assessment data.

3.3. Benefit/Risk Assessment

Information for pembrolizumab is found in the KEYTRLTDA Prescribing Information. The following section outlines the risk assessment and mitigation strategy for this protocol.

3.3.1. Risk Assessment

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3.3.2. Overall Benefit: Risk Conclusion

This is an open-label, dose escalation study and the first study of the combination of CRX- 601 with pembrolizumab conducted in humans; this study will enroll participants with advanced solid tumors. There is biologic rationale to study the combination for the treatment of cancer based on complementary modes of action on the immune system, and antitumor activity of the combination that exceeds activity of the monotherapies in preclinical models. However, it is unknown if the combination will have clinical activity for patients with cancer.

Based on nonclinical in vivo and ex vivo combination evaluations and clinical experience to date, and the conservative starting dose of CRX-601, the safety profiles of the combination is not expected to exceed that of the monotherapies. As a checkpoint inhibitor, rather than a direct immune-stimulator, pembrolizumab is not expected to substantially increase the potential for DLTs, but specific synergies cannot be excluded a priori.

Consistent with other Phase 1 trials for the treatment of cancer, a target DLT frequency has been set as 16-33%, and a Bayesian adaptive dose escalation design for CRX-601 is employed to efficiently determine the dose(s) associated with this DLT frequency. In addition, it is possible that infrequent events unrelated to CRX-601 dose, such as increases in hepatic laboratory values, might be observed. This risk will, in part, be mitigated by a run-in period for CRX-601 prior to the initiation of combination study treatment. The run- in provides an evaluation of monotherapy CRX-601 safety and tolerability in participants with cancer and prevents the administration of combination therapy to participants that experience, with CRX-601 alone, a DLT, unacceptable tolerability, or an increase in ALT to 1 5x ULN and 1 5x baseline. Overall, the benefit: risk is typical of a Phase I study of participants with advanced cancer.

. Objectives and Endpoints

5. Study Design

5.1. Overall Design

This is a Phase I, open-label, non-randomized, multicentre, multi-country study designed to evaluate the safety, tolerability, PK, pharmacodynamic, and preliminary clinical activity of CRX-601 administered in combination with other immunotherapies to participants with advanced solid tumors.

The study will be conducted in two parts. Part 1 is a treatment arm based on the CRX-601 combination partner. The treatment arm may have up to 5 dose escalation cohorts to investigate the safety and tolerability of escalating doses of CRX-60lwith a single dose level of the combination partner. CRX-601 combination partners is:

• Pembrolizumab: 200 mg (Part lc, Part 2c)

Part 1 will include a CRX-601 run-in period of 2 weeks (i.e., CRX-601 administration on days 1 and 8) prior to administration of the combinations beginning on day 15 (Week 3). Following protocol amendment, CRX-601 may also be evaluated by additional routes of administration. Safety data will be evaluated according to a Neuenschwander-Continual Reassessment Method (N-CRM) design [Neuenschwander, 2008] to help identify a dose for investigation in Part 2.

Part 2c is also a treatment arm for the expansion cohorts. Expansion cohorts of

approximately 6 to 15 participants with SCCHN will be enrolled to each combination to further evaluate safety and activity of the dose regimen(s) identified in Part lc. The dose(s) of CRX-601 administered with 200 mg pembrolizumab will be determined based on data from Part 1. Following protocol amendment, additional expansion cohorts in other tumor types may be enrolled based on emerging nonclinical and/or clinical data.

For the combination of CRX-601 in Part lc, PK/Pharmacodynamic cohorts will be opened at cleared dose levels for that combination (i.e. the most recent investigated dose level that supported dose escalation) to explore the potential relationships between dose, biological effects in the tumor microenvironment, and tumor response. A particular emphasis in the PK/Pharmacodynamic cohort is placed on evaluating the possible effects of the

combination on the immune cells and immune status within the tumor microenvironment. Thus, to be eligible for the PK/Pharmacodynamic cohort, participants must consent to mandatory fresh biopsy collection at baseline and on treatment (see above, SoA). An additional radiographic disease assessment (see above, SoA) will support exploratory investigation of tumor growth kinetics in this cohort. Note that while consent to fresh tumor biopsy is not required for participation in the dose escalation cohorts in Part lc, it is strongly encouraged. Up to 6 participants per dose level may be enrolled into the

PK/Pharmacodynamic cohort for each combination. The study includes a screening period, a treatment period, and a follow-up period.

Participants will be screened for eligibility beginning 4 weeks before the start of treatment. The duration of study treatment will be up to 2 years. For participants that discontinue study treatment prior to a determination of PD, the follow-up period includes disease assessments every 12 weeks until documented PD. Following PD or for participants that discontinue study treatment for PD, participants will be contacted every 12 weeks to assess survival status for 2 years from the start of the study.

Participants with confirmed PR or CR will be followed for response duration and may be eligible (outside of Canada) for continued study treatment at the time of

relapse/progression. The decision whether a participant will receive additional treatment will be discussed and agreed upon by the treating investigator and the Sponsor/Medical Monitor on a case-by-case basis.

Following protocol amendment(s), additional participants may be enrolled to evaluate additional routes of study treatment administration (e.g., intratumoral administration), additional agents to be used in combination with CRX-601, or additional indications, based on emerging nonclinical and/or clinical data.

5.1.1. Part 1: Dose Escalation of CRX-601 administered in combination with pembrolizumab

In Part 1, dose escalation will be performed to identify combination dose levels comprising CRX-601 with 200 mg pembrolizumab (Part lc). One (1) dose level of pembrolizumab with up to 5 dose levels of CRX-601 are planned for evaluation, pending emerging safety and tolerability information as dose escalation proceeds.

Part 1 will include a run-in period of 2 weeks in which CRX-601 is administered once- weekly [/. e. , administration on day 1 (Week 1) and day 8 (Week 2)] prior to initiation of combination treatment with pembrolizumab beginning on day 15 (Week 3). During the run-in period, participants that experience a DLT, unacceptable toxicity, or an increase in ALT (l.5x ULN and l.5x baseline) and not attributable to another cause will be discontinued from the study and will not receive CRX-601 in combination. (See herein).

Guidance for the management of toxicity, including dose modification algorithms, is provided below.

The starting schedule for CRX-601 will be at every l-week intervals (Ql W) from Week 1 through Week 12 including the 2-week monotherapy run in period (Week 1 and Week 2) (see SoA Table 1). Subsequently, CRX-601 will be administered at every 3 -week intervals (Q3W) to coincide with pembrolizumab dosing. Thus, beginning with Week 12 for Part 1 and Week 13 for Part 2, both CRX-601 and combination partners will be administered on the same study day at a frequency of Q3W. Cohorts will be opened beginning with 50 ng CRX-601 administered in combination with 200 mg pembrolizumab. Three (3) or more participants will be enrolled in each cohort.

The total number of participants enrolled into each cohort and dose assignments will be guided by safety information (as described herein) from participants receiving the study treatment combinations according to N-CRM modelling (as described herein,

[Neuenschwander, 2008]).

Sequential cohorts will be enrolled and dose escalation (or de-escalation) will proceed guided by an N-CRM design. Dose escalation for each cohort will proceed independently of the other cohorts. The first 3 participants at each dose level will receive study treatment at least 3 days apart ( e.g ., if the first participant in a cohort were dosed on Monday, the earliest the next participant could be dosed is Thursday). Once the 6-week DLT evaluation period has been completed (as described herein), N-CRM analysis will be performed to guide the dose level to which the next 3 participants will be assigned based on DLT frequency (as described herein). The number of participants allocated to any cohort is an estimate; participants may also be allocated to PK/Pharmacodynamic cohorts at a previous dose level that supported dose escalation.

No dose reductions for pembrolizumab will be implemented.

5.1.1.1. Description of the Continual Reassessment Method

The N-CRM model-based design is a Bayesian adaptive dose escalation scheme that assumes a 2-parameter logistic model for the toxicity rate as a function of dose. It is a modified version of the original Continual Reassessment Method proposed by [O’ Quigley, 1990] The N-CRM method is fully adaptive and makes use of all DLT information, therefore is expected to locate the target dose level efficiently. In this case, the model will be applied to the dose escalation decision for CRX-601, which will be performed independently for each combination.

Dose escalation decisions will be held after participants within any given cohort have been observed for at least 6 weeks after starting the study treatment (as described herein). At the time of each dose escalation decision, the Fixed and Adaptive Clinical Trial Simulator (FACTS [Tessella, Abington, United Kingdom]) will be used to obtain the posterior probabilities for the DLT rate. The N-CRM estimates for each potential dose will provide the posterior probabilities that the DLT rate lies in each of four toxicity ranges:

• [0%, 16%] Underdosing

• [16%, 33%] Target toxicity

• [33%, 60%] Excessive toxicity

• [60%, 100%] Unacceptable toxicity

The recommended dose for dose escalation, based on the N-CRM model, will be the dose with the highest posterior probability of lying in the target toxicity interval with the additional requirement that the sum of the posterior probabilities of the DLT rate lying in the excessive toxicity or unacceptable toxicity range is less than 25%. An updated estimate of the toxicity curve will be provided at the time of each dose escalation meeting. Note that de-escalation as well as escalation is possible using this method. Dose escalation will continue until conditions for either scenario (i) or (ii) are met:

i) Six participants have been treated at the current target dose

AND

For the current dose level, the posterior probabilities of the DLT rate lying within the excessive toxicity interval or within the unacceptable toxicity interval sum to less than 25%

AND

For the next higher dose, the posterior probabilities of the DLT rate lying within the excessive toxicity interval or within the unacceptable toxicity interval sum to greater than 25%. ii) No doses are usable (i.e., for all doses, the posterior probabilities of the DLT rate lying within the excessive toxicity interval or within the unacceptable toxicity interval sum to more than 25%)

AND

At least 2 DLTs have been observed.

Dose recommendations based on the N-CRM analysis will be used as guidance. To ensure safety of participants, additional participants may be enrolled at a current dose level at the discretion of the study investigators and sponsor, even though a higher dose is

recommended by N-CRM analysis.

5.1.1.2. Logistic Model for N-CRM

A two-parameter logistic model will be used for N-CRM analysis for dose level selection during the dose escalation phase. This model will estimate the probability of observing a DLT at each dose level in the study as DLT information becomes available.

The logistic model that used for describing the dose-toxicity relationship is:

where p_d is the probability of DLT at dose d, and d_m is a reference dose, and a and b are Bayesian priors.

5.1.2. PK/Pharmacodynamic Cohort(s) Characterizing the effects of treatment on the tumor microenvironment is essential to the understanding the mechanism of action of CRX-601 and its combination partners at the site of action. Thus, for each combination of CRX-601 in Part 1, PK/Pharmacodynamic cohorts will be opened to characterize the biological effects in the tumor microenvironment and explore the potential relationships between dose and tumor response.

PK/Pharmacodynamic cohorts, with up to 6 participants per dose level, will be opened for CRX-601 dose levels previously cleared for dose escalation.

Pre- and on-treatment tumor biopsies are required for enrollment to this cohort. PK, pharmacodynamic markers, and safety samples will be drawn according as described herein to obtain additional PK and pharmacodynamic data. Participants in the

PK/Pharmacodynamic cohort may have the dose escalated to a higher completed dose level (not exceeding the target toxicity level) after Week 9 once the necessary

PK/Pharmacodynamic procedures and tissue biopsies have been completed. See herein for further instructions on intra-participant dose escalation.

5.1.3. Part 2: Expansion Cohort

Part 2 of the study will further characterize the safety and tolerability of CRX-601 administered in combination with pembrolizumab (Part 2c) in participants with recurrent, locally advanced, or metastatic SCCHN as determined by safety and tolerability results from the respective cohorts in Part 1. Part 2 will also characterize antitumor activity, PK, and pharmacodynamics effects, including effects measured from tumor biopsy. Part 2 may be opened for a given combination before Part 1 has been completed provided a tolerable dose level within or below the target toxicity range has been identified for that

combination. The dose of CRX-601 to be administered in the expansion cohort will be based on all available data and may have a DLT frequency within or below the target toxicity range.

Fifteen participants with SCCHN will be enrolled in the Part 2c expansion cohort. No more than 6 participants will be enrolled in an expansion cohort without meeting eligibility requirements for mandatory biopsy requirement.

5.1.4. Tumor Types Enrolled During Parts 1 and 2

In Part 1, participants with advanced solid tumors will be enrolled. In Part 2, only participants with SCCHN will be enrolled.

5.1.5. Intra-Participant Dose Escalation

Following the selection of a recommended combination dose for Part 2 (as described herein), participants in respective cohorts in Part 1 may be considered for escalation to the Part 2 dose level. Intra-participant dose escalation will be considered on a case-by-case basis provided the participant has completed at least 6 weeks of study treatment without the occurrence of a SAE or >Grade 2 drug-related toxicity. Approval by the Sponsor is required for intra-participant dose escalation.

5.2. Scientific Rationale for Study Design

The combination of CRX-601 with pembrolizumab was selected based on complementary mechanisms of action and robust antitumor activity in preclinical models.

Eligibility criteria require that participants have progressed after standard therapies or are otherwise unsuitable for standard therapies, and the criteria are intended to minimize the risk of adverse reactions to treatment with immunotherapies.

In Part 1, dose escalation of CRX-601, with a fixed dose of the combination partners, will be performed using an N-CRM model to optimize the allocation of participants to dose levels with a 16-33% DLT frequency. The DLT criteria are based on typical oncology rules with additional modifications for toxicities expected for the study treatments.

In Part 1, a 2-week run-in period for CRX-601 precedes the administration of the combination therapy. The run-in provides an evaluation of monotherapy CRX-601 safety and tolerability in participants with cancer and prevents the administration of combination therapy to participants that experience, with CRX-601 alone, a DLT, unacceptable tolerability, or an increase in ALT to l.5x ULN and l.5x baseline.

In Part 2, expansion cohorts will be opened to evaluate safety and tolerability of the combinations as well as preliminary activity in participants with SCCHN (as described herein). SCCHN was chosen for further study based on observations of responses to other immunotherapies and recognition of the considerable unmet need for this indication.

Additionally, since TLR agonists are being developed by different routes of administration, including intratumoral injection, SCCHN is a possible indication for future exploration of alternative approaches to dosing.

5.3. Dose Justification

5.3.1. Overview

CRX-601 has been previously administered as a monotherapy.

The selection of starting combination doses has taken into consideration all available data, including the safety, tolerability, and pharmacology data of monotherapy CRX-601, observed in the respective LTIH studies and for pembrolizumab as summarized in the Prescribing Information [KEYTRUDA PI, 2018], together with pharmacology and safety data from animal models and human ex vivo (peripheral blood mononuclear cell [PBMC]) assays, conducted under monotherapy and combination conditions.

5.3.1.1. Starting dose for TLR4 agonist CRX-601

The starting dose of CRX-601 is 50 ng administered once-weekly IV. Previously CRX- 601 was administered at doses up to 100 ng IV to healthy participants in the FTIH Study. Based on data from the FTIH study, the starting dose in the current study (50 ng) is expected to produce low level pharmacological effects consistent with TLR4 agonism based on data from the FTIH study (as described herein).

Because robust TLR receptor saturation assays are not available, target engagement by CRX-601 in the FTIH study was monitored using representative inflammatory cytokine biomarkers. Based on review of available preliminary data (dose levels up to 100 ng), post-dose elevations of cytokines following administration of CRX-601 in the FTIH study were of a low magnitude compared to historical clinical studies of TLR agonists administered to cancer patients. For example, the peak levels of inflammatory cytokines at 2h, such as TNFa (median: 12 pg/mL; min: 6 pg/mL; max: 23 pg/mL) and IL-6 (median: 132 pg/mL; min: 81 pg/mL; max: 184 pg/mL pg/mL, respectively), associated with administration of 100 ng CRX-601 are below levels reported in previous studies of TLR agonists in cancer patients (>1000 pg/mL) [Chow, 2017; Engelhardt, 1991] These differences are likely not a function of differences in study populations, given that prior comparisons of TLR agonists in healthy participants and cancer participants have shown similar cytokine responses between populations [Riella, L.V., S. Dada, L. Chabtini, B. Smith, L. Huang, P. Dakle, B. Mfarrej, F. D'Addio, L.-T. Adams, N. Kochupurakkal, A. Vergani, P. Fiorina, A.L. Mellor, A.H. Sharpe, H. Yagita, and I. Guleria. 2013. B7h (ICOS- L) Maintains Tolerance at the Fetomatemal Interface. The American Journal of Pathology 182:2204-2213.

Schmidt, 2015; Dietsch, 2014] Even acknowledging possible differences in

pharmacodynamic assay performance, the greater than 10-100 fold margin between cytokine concentrations associated with 100 ng doses of CRX-601 versus concentrations reported in other studies of cancer patients provides reassurance that a significant margin separates the starting dose of CRX-601 and maximum tolerated dose of other TLR agonists.

Consistent with the mechanism of action of CRX-601, body temperature and heart rate increased with dose in an earlier study. Mean maximum change with 95% Cl in body temperature in the participants that received placebo was 0.4 ± 0.2°C. For CRX-601 dose levels, 7 ng, 21 ng, 60 ng, and 100 ng, mean maximum change with 95% Cl in body temperature was 0.5 ± 0.3, 0.6 ± 0.4, 0.8+.5, and 1.3 ± 0.3 °C, respectively. Mean maximum change with 95% Cl in heart rate in the participants that received placebo was 6 ± 5 beats per minute. For CRX-601 dose levels, 7 ng, 21 ng, 60 ng, and 100 ng, mean maximum change with 95% Cl in heart rate was 8 + 9, 10 + 18, 18 + 15, 21 ± 5 beats per minute, respectively. Thus, a 50 ng starting dose is expected to be associated with modest changes in body temperature and heart rate.

Based on preliminary, unblinded safety data (as described herein), the most common clinical findings were influenza-like symptoms and increased body temperature.

Predominantly mild AEs were reported when doses up to 60 ng were administered. Three (3) participants experienced moderate AEs following administration of 100 ng CRX-601.

In addition to the aforementioned dose-related AEs, 1 out of the 12 participants that received a 60 ng dose of CRX-601 experienced a 12-fold ULN increase in ALT, 5 -fold ULN increase in AST, and 1 4-fold ULN increase in total bilirubin on day 35. As only 1 event was observed and the dose administered was below the maximum administered, 100 ng, the data are too limited to relate elevations in hepatic laboratories to dose. Because of the possible risk of infrequent or idiosyncratic transaminase elevations, a 2-week CRX-601 run-in period will be performed in Part 1 , including monitoring and study treatment discontinuation criteria for ALT elevations, before CRX-601 and combination partners are administered.

In summary, at the CRX-601 starting dose of 50 ng, minimal pharmacodynamic effects and dose-related cytokine-associated clinical effects are expected. The risk of infrequent events of uncertain relationship to CRX-601 dose will be mitigated by a 2-week monotherapy run- in period.

5.3.1.2. Pembrolizumab dose

The dose regimen for pembrolizumab, 200 mg IV Q3W, is the approved dosing scheme as described in the Prescribing Information [KEYTRUDA PI, 2018] No reduction in dose is planned given that pembrolizumab has been administered in combination with other TLR agonists to subjects with advanced cancers without causing a notable change in the safety and tolerability profile. Moreover, the safety and efficacy profile of the approved dose regimen for pembrolizumab is well established, whereas the efficacy of lower doses is not fully characterized.

5.3.1.3. Combination considerations

At the 50 ng starting dose of CRX-601, only minimal clinical and pharmacodynamic effects are expected. Therefore, CRX-601 is not expected to significantly alter the safety and tolerability profile of pembrolizumab.

Pembrolizumab has been administered with TLR agonists in patients with several tumor types, and the treatments are associated with mild to moderate systemic cytokine- associated side effects. Nevertheless, the safety profile of pembrolizumab is not markedly changed from the profile described in the Prescribing Information [KEYTRUDA PI, 2018] Overall, the clinical and nonclinical data for CRX-601 and pembrolizumab administered as monotherapies and in combination support the starting combination of low doses of CRX- 601 with pembrolizumab.

5.3.2. Dose Escalation and Top Dose

Based on available clinical data, the tolerability of CRX-601 approximates that of LPS. Therefore, the top dose of CRX-601 for study participants with cancer is expected to be similar to doses of LPS studied in similar populations, namely 2 to 4 ng/kg (i.e., 160 to 320 ng). The top dose of CRX-601 will not exceed approximately 250 ng, which would represent a less than 3-fold escalation beyond the 100 ng dose which has been studied in the FTIH healthy volunteer study. The dose escalation step size of 50 ng increments results in a dose escalation scheme with progressively more conservative relative increases ( e.g . ,

50 ng to 100 ng = 100% increase; 100 to 150 ng = 50% increase; 150 ng to 200 ng = 33% increase; 200 ng to 250 ng = 25% increase).

6. Study Population

Prospective approval of protocol deviations to recruitment and enrollment criteria, also known as protocol waivers or exemptions, is not permitted.

Specific information regarding warnings, precautions, contraindications, AEs, and other pertinent information on the GSK investigational product or other study treatment that may impact participant eligibility is provided in the IBs/IB supplements. Deviations from inclusion and exclusion criteria are not allowed because they can potentially jeopardize the scientific integrity of the study, regulatory acceptability, or participant safety. Therefore, adherence to the criteria as specified in the protocol is essential.

6.1. Inclusion Criteria

Participants are eligible to be included in the study only if all of the following criteria apply:

Age

1. Participant must be >18 years of at the time of signing the informed consent.

Type of Participant and Disease Characteristics

2. Histological documentation of advanced solid tumor.

3. Archival tumor tissue obtained at any time from the initial diagnosis to study entry. Although a fresh biopsy obtained during screening is preferred, archival tumor specimen is acceptable if it is not feasible to obtain a fresh biopsy.

Note: Participants enrolled in a PK/Pharmacodynamic Cohort must provide a fresh biopsy of a tumour lesion not previously irradiated during the screening period and must agree to provide at least one additional on-treatment biopsy.

4. Disease that has progressed after standard therapies or for which standard

therapy is otherwise unsuitable ( e.g ., intolerance).

5. Measurable disease, i.e., presenting with at least 1 measurable lesion per

Response Evaluation Criteria in Solid Tumors (RECIST version 1.1). See D Appendix 9 for definition of a measurable lesion.

6. Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-1.

7. Life expectancy of at least 12 weeks.

8. Adequate organ function (see Table 5):

9. In France, a participant will be eligible for inclusion in this study only if either affiliated to or a beneficiary of a social security category.

Sex

10. Male or female

a. Female participants:

A female participant is eligible to participate if she is not pregnant, not breastfeeding, and at least 1 of the following conditions applies:

i. Not a woman of childbearing potential (WOCBP)

OR

ii. A WOCBP who agrees to follow the contraceptive guidance during the treatment period and for at least 120 days after the last dose of study treatment.

Informed Consent

11. Capable of giving signed informed consent a which includes compliance with the requirements and restrictions listed in the ICF and in this protocol.

Additional Inclusion Criteria for Patients in Part 2c (pembrolizumab expansion)

12. Histological or cytological documentation of SCCHN (oral cavity, oropharynx, hypopharynx, or larynx) that is recurrent, locally advanced, or metastatic and is not amenable to curative treatment options, surgery or definitive chemoradiation therapy.

13. Received or ineligible for platinum-based therapy.

14. Received no more than 2 prior lines of systemic therapy for metastatic disease.

6.2. Exclusion Criteria

Participants are excluded from the study if any of the following criteria apply:

Medical Conditions

1. Malignancy other than disease under study with the exception of those from which the participant has been disease-free for more than 2 years and not expected to affect the safety of the participant or the endpoints of the trial.

2. Symptomatic central nervous system (CNS) metastases or asymptomatic CNS metastases that have required steroids within 2 weeks prior to first dose of study treatment.

3. Active autoimmune disease that has required systemic disease modifying or immunosuppressive treatment within the last 2 years.

Note: Replacement therapy ( e.g ., thyroxine or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is permitted.

4. Concurrent medical condition requiring the use of systemic immunosuppressive treatment within 28 days before the first dose of study treatment.

5. Known human immunodeficiency virus infection.

6. Current unstable liver or biliary disease per investigator assessment defined by the presence of ascites, encephalopathy, coagulopathy, hypoalbuminaemia, oesophageal or gastric varices, persistent jaundice, or cirrhosis.

NOTE: Stable chronic liver disease (including Gilbert’s syndrome or

asymptomatic gallstones) or hepatobiliary involvement of malignancy is acceptable if participant otherwise meets entry criteria.

7. Presence of Hepatitis B surface antigen (HBsAg) at screening or within 3

months prior to first dose of study treatment

8. Positive Hepatitis C test result at screening or within 3 months prior to first dose of study treatment.

NOTE: Participants with positive Hepatitis C antibody due to prior resolved disease can be enrolled, only if a confirmatory negative Hepatitis C RNA test is obtained.

Participants with negative Hepatitis C antibody test are not required to also undergo

Hepatitis C RNA testing

9. QTcF >450 msec or QTcF >480 msec for participants with bundle branch block

The QTcF is the QT interval corrected for heart rate according to Fridericia’s formula, machine -read or manually over-read. 10. Recent history (within the past 6 months) of acute diverticulitis, inflammatory bowel disease, intra-abdominal abscess, or gastrointestinal obstruction.

11. Recent history of allergen desensitization therapy within 4 weeks of starting study treatment.

12. History of severe hypersensitivity to mAbs.

13. History or evidence of cardiovascular (CV) risk including any of the following:

• Recent (within the past 6 months) history of serious uncontrolled cardiac

arrhythmia or clinically significant ECG abnormalities including second degree (Type II) or third degree atrioventricular block.

• Cardiomyopathy, myocardial infarction, acute coronary syndromes (including unstable angina pectoris), coronary angioplasty, stenting, or bypass grafting within the past 6 months before enrollment.

• Congestive heart failure (Class II, III, or IV) as defined by the New York Heart Association functional classification system [NYHA, 1994]

• Recent (within the past 6 months) history of symptomatic pericarditis.

14. History of idiopathic pulmonary fibrosis, pneumonitis, interstitial lung disease, or organizing pneumonia, or evidence of active, non-infectious pneumonitis. Note: post-radiation changes in the lung related to prior radiotherapy and/or asymptomatic radiation-induced pneumonitis not requiring treatment may be permitted if agreed by the investigator and Sponsor.

15. Recent history (within 6 months) of uncontrolled symptomatic ascites or pleural effusions.

16. Any serious and/or unstable pre-existing medical, psychiatric disorder, or other condition that could interfere with the participant’s safety, obtaining informed consent, or compliance to the study procedures.

17. Is or has an immediate family member (e.g., spouse, parent/legal guardian, sibling or child) who is investigational site or sponsor staff directly involved with this trial, unless prospective Institutional Review Board (IRB) approval (by chair or designee) is given allowing exception to this criterion for a specific participant.

Prior/Concomitant Therapy

18. Prior treatment with the following agents :

• Tumor necrosis factor receptor (TNFR) agonists, including 0X40, CD27,

CD 137 (4-1BB), CD357 (glucocorticoid-induced TNFR family-related gene) at any time.

• Prior systemic or intratumoral therapy with TFR agonist.

• Anticancer therapy or investigational therapy within 30 days or 5 half-lives of the drug, whichever is shorter.

• Prior radiation therapy: permissible if at least 1 non-irradiated measurable lesion is available for assessment according to RECIST version 1.1 or if a solitary measurable lesion was irradiated, objective progression is documented. A wash out of at least 14 days before start of study treatment for radiation of any intended use to the extremities for bone metastases and 28 days for radiation to the chest, brain, or visceral organs is required.

19. Prior allogeneic or autologous bone marrow transplantation or another solid organ transplantation.

20. Toxicity from previous treatment including:

• Toxicity Grade >3 related to prior immunotherapy and that lead to study

treatment discontinuation.

• Toxicity related to prior treatment has not resolved to Grade <1 (except

alopecia, or endocrinopathy managed with replacement therapy).

21. Received transfusion of blood products (including platelets or red blood cells) or administration of colony stimulating factors (including G-CSF, granulocyte- macrophage colony-stimulating factor, and recombinant erythropoietin) within 2 weeks before the first dose of study treatment.

Other Exclusions

22. Major surgery <4 weeks before the first dose of study treatment. Participants must have also fully recovered from any surgery (major or minor) and/or its complications before initiating study treatment.

23. Known drug or alcohol abuse.

24. Receipt of any live vaccine within 4 weeks.

Additional Exclusion Criteria for Patients in Part 2c

25. Received prior PD- 1 /PD -Ll therapy.

6.3. Lifestyle Restrictions

6.3.1. Meals and Dietary Restrictions

No dietary restrictions are required. Note that participants should be well-hydrated before receiving study treatment (see below)

6.3.2. Caffeine, Alcohol, and Tobacco

Participants who use products containing caffeine, alcohol, or tobacco are not required to change their habits of using these products during the study treatment.

6.3.3. Activity

Participants may experience orthostatic dizziness following administration of CRX-601. Precautions should be taken to avoid falls after rising from a lying or seated position for several hours after administration of study treatment. In addition, participants will abstain from strenuous exercise for 8 hours before each blood collection for clinical laboratory tests. Participants may participate in light recreational activities during studies ( e.g ., watching television, reading). 6.4. Screen Failures

Screen failures are defined as participants who consent to participate in the clinical study but are not subsequently entered in the study. A minimal set of screen failure information is required to ensure transparent reporting of screen failure participants to meet the

Consolidated Standards of Reporting Trials publishing requirements and to respond to queries from regulatory authorities. Minimal information includes demography, screen failure details, eligibility criteria, and any SAEs.

Individuals who do not meet the criteria for participation in this study (screen failure) may be rescreened once. This includes retesting specific vital sign measurements, laboratory assessments, etc. that may not have met eligibility criteria.

7. Treatments

Study treatment is defined as any investigational treatment(s), marketed product(s), placebo, or medical device(s) intended to be administered to a study participant according to the study protocol. The term‘study treatment’ is used throughout the protocol to describe any combination of products received by the participant as per the protocol design.

7.1. Treatments Administered

Participants receiving study treatment should be well-hydrated (TLR agonists have rarely been associated with severe bradycardia or asystole in clinical trials, attributed to poor hydration and/or history of syncope) [van Eijk, 2004] Oral hydration should be encouraged in the days prior to study treatment and/or IV fluids ( e.g ., 1 L or as clinically indicated) administered before CRX-601. Participants with a history of syncope and/or uncertain compliance with hydration recommendations should receive additional pre-dose and/or post-dose fluids at the discretion of the investigator.

Following administration of CRX-601, assessments must be performed as noted in the SoA. Cytokine-related AEs including changes in vital signs commonly begin within several hours of administration of CRX-601. Participants must be monitored for 6 hours after administration of the first dose of CRX-601 or longer as clinically indicated. Similarly, participants must be monitored for 6 hours after administration of the first 2 study treatments of CRX-601 and combination partners. Participants that tolerate CRX-601 without adverse changes in heart rate or blood pressure may have the duration of observation with subsequent study treatment reduced to 2 hours, provided the dose and schedule has not been changed. Guidelines for monitoring cytokine-related AEs are described herein.

CRX-601 and mAh combination partner pembrolizumab will be administered to

participants at each study site under medical supervision of an investigator or designee. Pembrolizumab will be administered first, and CRX-601 will be administered at least 1 hour after the completion of the mAh infusion. The date and time of administration will be recorded in the source documents and reported in the eCRF.

If a participant experiences an infusion reaction with the administration of the mAh combination partner, associated AEs should resolve before CRX-601 is administered. If AEs associated with the mAh are slow to resolve, it is acceptable to administer CRX-601 on the following day. Should further delay be required, the participant will be discontinued from study treatment. Any participant who experiences an infusion reaction attributable to the mAh may receive CRX-601 on the following day for all subsequent study treatments.

The specific time of study treatment administration (e.g. , time of the week for first administration; time of the day for each administration) should take into consideration PK sampling time points and study visit procedures. See herein for dosing timepoints and visit windows and section below for additional details regarding dosing delays.

The Study Reference Manual (SRM) contains specific instructions for the preparation of CRX-601 and pembrolizumab.

7.2. Dose Modification

Safety management guidelines, including dose modification algorithms, are provided below. Please note, in cases where the investigator is directed to permanently discontinue study treatment, these instructions are mandatory as described herein.

An overview of the dose modification guidelines is presented in Table 7.

All AEs are to be graded according to NCI-CTCAE, version 4.0 (http://ctep.cancer.gov). All dose modifications and the reason(s) for the dose modification must be documented in the eCRF.

The major classes of toxicity described herein include“cytokine-related AEs and infusion reactions” and“immune-related AEs”. Even though both cytokine production and immune activity play roles in both categories of events, the nomenclature is intended to describe distinct classes of AEs, as described below.

Refer to the approved labelling for pembrolizumab-related background information and management of AEs [KEYTRUDA SPC, 2018; KEYTRUDA PI, 2018]

In case a dose reduction is necessary, the dose level of CRX-601 , the mAh or both may be changed as determined by the investigator and sponsor. Participants may not discontinue only 1 study treatment. If either study treatment is deemed intolerable and requires discontinuation despite optimal management, as described below, the participant must be discontinued from both study treatments. CRX-601 may be restarted at the next lower dose level. Pembrolizumab must always be administered at the fixed 200 mg dose level.

Table 7 General Dose Modification and Management Guidelines for Drug- Related Non-Hematologic Adverse Events Not Otherwise Specified

7.3. Efficacy Assessments

· Lesion assessment method and timing, evaluation of disease, disease progression and response criteria will be conducted according to Response Evaluation Criteria in Solid Tumors (RECIST 1.1) [Dillingh M, van Poelgeest E, Malone K, Kemper E, Stroes E, Moerland M, et al. Characterization of inflammation and immune cell modulation induced by low-dose LPS administration to healthy volunteers. Journal of

Inflammation. 2014; 11(1).

• Eisenhauer, 2009] as outlined below.

• Disease assessment modalities may include imaging ( e.g . , computed tomography [CT] scan, magnetic resonance imaging [MRI], bone scan, plain radiography) and physical examination (as indicated for palpable/superficial lesions). Scans will be collected centrally during the study and may be reviewed or analyzed by an independent central reviewer. Details will be provided in the SRM.

• The baseline disease assessment will be completed up to 28 days prior to the first dose of study treatment. See the Schedule of Activities Tables (above) for the schedule of assessments of anti-cancer activity subsequent to the baseline disease assessment.

• Assessments must be performed on a calendar schedule and should not be affected by dose interruptions/delays.

• For post-baseline assessments, a window of [+7 days] is permitted to allow for flexible scheduling. If the last radiographic assessment was 6 weeks or more prior to the participant’s withdrawal from study treatment and PD has not been documented, a disease assessment should be obtained at the time of withdrawal from study treatment.

• To ensure comparability between the baseline and subsequent assessments, the same method of assessment and the same technique will be used when assessing response.

7.3.1. Evaluation of Anti-Cancer Activity

• RECIST version 1.1 guidelines will be used to determine the overall tumor burden at baseline, select target and non-target lesions, and in the disease assessments throughout the duration of the study [Dillingh M, van Poelgeest E, Malone K, Kemper E, Stroes E, Moerland M, et al. Characterization of inflammation and immune cell modulation induced by low-dose LPS administration to healthy volunteers. Journal of Inflammation. 2014; 11(1).

• Eisenhauer, 2009] as further outlined in D Appendix 9 of this protocol. irRECIST assessments will be evaluated as well. Treatment decisions according to irRECIST are encouraged, including confirmatory disease assessments at least 4 weeks after the date disease progression was declared. Similarly, new lesions should be measured, as feasible, and may be incorporated into assessments of tumor burden according to irRECIST guidelines.

• Lymph nodes that have a short axis of <10 mm are considered non-pathological and should not be recorded or followed.

• Pathological lymph nodes with <15 mm and but >10 mm short axis are considered non-measurable.

• Pathological lymph nodes with >15 mm short axis are considered measurable and can be selected as target lesions, however lymph nodes should not be selected as target lesions when other suitable target lesions are available.

• Measurable lesions up to a maximum of 2 lesions per organ and 5 lesions in total, representative of all involved organs, should be identified as target lesions, and recorded and measured at baseline. These lesions should be selected on the basis of their size (lesions with the longest diameter) and their suitability for accurate repeated measurements (either by imaging techniques or clinically).

Note: Cystic lesions thought to represent cystic metastases should not be selected as target lesions when other suitable target lesions are available. Note: Measurable lesions that have been previously irradiated and have not been shown to be progressing following irradiation should not be considered as target lesions.

• Lytic bone lesions or mixed lytic-blastic lesions, with identifiable soft tissue

components, that can be evaluated by CT or MRI can be considered measurable.

Bone scans, fluorodeoxyglucose (FDG)-positron-emission tomography (PET) scans or X-rays are not considered adequate imaging techniques to measure bone lesions.

• All other lesions (or sites of disease) should be identified as non-target and should also be recorded at baseline. Non-target lesions will be grouped by organ. Measurements of these lesions are not required, but the presence or absence of each should be noted throughout follow-up.

• The following are required at baseline (up to 28 days before first dose, as described herein): CT scan with contrast of the chest, abdomen, and pelvis is required. For participants with SCCHN, a scan of the head and neck area is required. Other areas should be evaluated as indicated by the participant’s underlying disease prior to screening, including clinical disease assessment for palpable/visible lesions. Although CT scan is preferred, MRI may be used as an alternative method of baseline disease assessment, especially for those participants where a CT scan is contraindicated due to allergy to contrast, provided that the method used to document baseline status is used consistently throughout study treatment to facilitate direct comparison. At each post baseline assessment, evaluations of the sites of disease identified by these scans are required. Refer to RECIST version 1.1 guidelines for use of FDG-PET/CT [Dillingh M, van Poelgeest E, Malone K, Kemper E, Stroes E, Moerland M, et al.

Characterization of inflammation and immune cell modulation induced by low-dose LPS administration to healthy volunteers. Journal of Inflammation. 2014; 11(1).

• Eisenhauer, 2009]

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9. Appendices

9.1. Appendix 1 Abbreviations

Abbreviations

9.2. D Appendix 9 Guidelines for Assessment of Disease, Disease Progression and Response Criteria - adapted from RECIST version 1.1

Assessment Guidelines

Please note the following:

• The same diagnostic method, including use of contrast when applicable, must be used throughout the study to evaluate a lesion. Contrast agents must be used in accordance with the Image Acquisition Guidelines.

• All measurements should be taken and recorded in millimeters (mm), using a ruler or calipers.

• Ultrasound is not a suitable modality of disease assessment. If new lesions are

identified by ultrasound, confirmation by CT or MRI is required.

• Fluorodeoxyglucose (FDG)-PET is generally not suitable for ongoing assessments of disease. However, FDG-PET can be useful in confirming new sites of disease where a positive FDG-PET scans correlates with the new site of disease present on CT/MRI or when a baseline FDG-PET was previously negative for the site of the new lesion. FDG-PET may also be used in lieu of a standard bone scan providing coverage allows interrogation of all likely sites of bone disease and FDG-PET is performed at all assessments.

• If PET/CT is performed then the CT component can only be used for standard

response assessments if performed to diagnostic quality, which includes the required anatomical coverage and prescribed use of contrast. The method of assessment should be noted as CT on the CRF.

Clinical Examination: Clinically detected lesions will only be considered measurable when they are superficial ( e.g ., skin nodules). In the case of skin lesions, documentation by color photography, including a ruler/calipers to measure the size of the lesion, is required [Dillingh M, van Poelgeest E, Malone K, Kemper E, Stroes E, Moerland M, et al.

Eisenhauer, 2009]

CT and MRI: Contrast enhanced CT with 5mm contiguous slices is recommended.

Minimum size of a measurable baseline lesion should be twice the slice thickness, with a minimum lesion size of 10 mm when the slice thickness is 5 mm. MRI is acceptable, but when used, the technical specification of the scanning sequences should be optimized for the evaluation of the type and site of disease and lesions must be measured in the same anatomic plane by use of the same imaging examinations. Whenever possible the same scanner should be used [Dillingh M, van Poelgeest E, Malone K, Kemper E, Stroes E, Moerland M, et al. Characterization of inflammation and immune cell modulation induced by low-dose LPS administration to healthy volunteers. Journal of Inflammation.

2014;! 1(1). Eisenhauer, 2009]

X-ray: In general, X-ray should not be used for target lesion measurements owing to poor lesion definition. Lesions on chest X-ray may be considered measurable if they are clearly defined and surrounded by aerated lung; however, chest CT is preferred over chest X-ray [Dillingh M, van Poelgeest E, Malone K, Kemper E, Stroes E, Moerland M, et al.

Eisenhauer, 2009]

Guidelines for Evaluation of Disease

Measurable and Non-Measurable Definitions

Measurable lesion:

A non-nodal lesion that can be accurately measured in at least 1 dimension (longest dimension) of

• >10 mm with MRI or CT when the scan slice thickness is no greater than 5mm. If the slice thickness is greater than 5mm, the minimum size of a measurable lesion must be at least double the slice thickness ( e.g ., if the slice thickness is 10 mm, a measurable lesion must be >20 mm).

• >10 mm caliper/ruler measurement by clinical exam or medical photography.

• >20 mm by chest x-ray.

Additionally, lymph nodes can be considered pathologically enlarged and measurable if

• >l5mm in the short axis when assessed by CT or MRI (slice thickness recommended to be no more than 5mm). At baseline and follow-up, only the short axis will be measured [Dillingh M, van Poelgeest E, Malone K, Kemper E, Stroes E, Moerland M, et al. Characterization of inflammation and immune cell modulation induced by low- dose LPS administration to healthy volunteers. Journal of Inflammation. 2014; 11(1).

• Eisenhauer, 2009]

Non-measurable lesion:

All other lesions including lesions too small to be considered measurable (longest diameter <10 mm or pathological lymph nodes with > 10 mm and <15 mm short axis) as well as truly non-measurable lesions, which include: leptomeningeal disease, ascites, pleural or pericardial effusions, inflammatory breast disease, lymphangitic involvement of the skin or lung, abdominal masses/abdominal organomegaly identified by physical exam that is not measurable by reproducible imaging techniques [Dillingh M, van Poelgeest E, Malone K, Kemper E, Stroes E, Moerland M, et al. Characterization of inflammation and immune cell modulation induced by low-dose LPS administration to healthy volunteers. Journal of Inflammation. 2014; 11(1).

Eisenhauer, 2009]

Measurable disease: The presence of at least 1 measurable lesion. Palpable lesions that are not measurable by radiologic or photographic evaluations may not be utilized as the only measurable lesion.

Non-Measurable only disease: The presence of only non-measurable lesions. Note: non- measurable only disease is not allowed per protocol.

Immune-Related RECIST Response Criteria

Table 8 Evaluation of Target Lesions

a. Measurable according to RECIST version 1.1.

b. Treatment decisions may be based upon the immune-related RECIST guidelines.

Antitumor response based on total measurable tumor burden

For Modified RECIST based on RECIST version 1.1 and irRECIST [Wolchok, 2009; Nishino, 2013], the initial target (‘index”) and measurable new lesions are taken into account. At the baseline tumor assessment, the sum of the diameters in the plane of measurement of all target lesions (maximum of 5 lesions in total and a maximum of 2 lesions per organ representative of all involved organs) is calculated.

Note: If pathological lymph nodes are included in the sum of diameters, the short axis of the lymph node(s) is added into the sum. The short axis is the longest perpendicular diameter to the longest diameter of a lymph node or nodal mass. At each subsequent tumor assessment, the sum of diameters of the baseline target lesions and of new, measurable nodal and non-nodal lesions (>10 mm), up to 2 new lesions per organ are added together to provide the total tumor burden:

Tumor Burden = Sum of diameterstarget lesions + sum of diametersnew, measurable lesions

Time-point response assessment using the Immune-Related RECIST criteria

Percentage changes in tumor burden per assessment time point describe the size and growth kinetics of both conventional and new, measurable lesions as they appear. At each tumor assessment, the response in index and new, measurable lesions is defined based on the change in tumor burden (after ruling out irPD). Decreases in tumor burden must be assessed relative to baseline measurements (i.e., the sum of diameters of all target lesions at screening).

Response Criteria

Evaluation of target lesions

Definitions for assessment of response for target lesion(s) are as follows:

• CR: Disappearance of all target lesions. Any pathological lymph nodes must be

<l0mm in the short axis.

• PR: At least a 30% decrease in the sum of the diameters of target lesions, taking as a reference, the baseline sum of the diameters ( e.g ., percent change from baseline).

• SD: Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD.

• PD: At least a 20% increase in the sum of the diameters of target lesions, taking as a reference, the smallest sum of diameters recorded since the treatment started (e.g., percent change from nadir, where nadir is defined as the smallest sum of diameters recorded since treatment start). In addition, the sum must have an absolute increase from nadir of 5mm.

• Not Applicable (NA): No target lesions at baseline.

• Not Evaluable (NE): Cannot be classified by 1 of the 5 preceding definitions.

Note:

• If lymph nodes are documented as target lesions the short axis is added into the sum of the diameters (e.g., sum of diameters is the sum of the longest diameters for non-nodal lesions and the short axis for nodal lesions). When lymph nodes decrease to non- pathological size (short axis <l0mm) they should still have a measurement reported in order not to overstate progression.

• If at a given assessment time point all target lesions identified at baseline are not

assessed, sum of the diameters cannot be calculated for purposes of assessing CR, PR, or SD, or for use as the nadir for future assessments. However, the sum of the diameters of the assessed lesions and the percent change from nadir should be calculated to ensure that progression has not been documented. If an assessment of PD cannot be made, the response assessment should be NE.

• All lesions (nodal and non-nodal) should have their measurements recorded even when very small ( e.g ., 2 mm). If lesions are present but too small to measure, 5 mm should be recorded and should contribute to the sum of the diameters, unless it is likely that the lesion has disappeared in which case 0 mm should be reported.

• If a lesion disappears and reappears at a subsequent time point it should continue to be measured. The response at the time when the lesion reappears will depend upon the status of the other lesions. For example, if the disease had reached a CR status then PD would be documented at the time of reappearance. However, if the response status was PR or SD, the diameter of the reappearing lesion should be added to the remaining diameters and response determined based on percent change from baseline and percent change from nadir.

Evaluation of non-target lesions

Definitions for assessment of response for non-target lesions are as follows:

• Complete Response: The disappearance of all non-target lesions. All lymph nodes identified as a site of disease at baseline must be non-pathological (e.g., <10 mm short axis).

• Non-CR/Non-PD: The persistence of 1 or more non-target lesion(s) or lymph nodes identified as a site of disease at baseline > 10 mm short axis.

• Progressive Disease: Unequivocal progression of existing non-target lesions.

• Not Applicable (NA): No non-target lesions at baseline.

• Not Evaluable (NE): Cannot be classified by 1 of the 4 preceding definitions.

Note:

• In the presence of measurable disease, progression on the basis of solely non-target disease requires substantial worsening such that even in the presence of SD or PR in target disease, the overall tumor burden has increased sufficiently to merit

discontinuation of therapy.

• Sites of non-target lesions, which are not assessed at a particular timepoint based on the assessment schedule, should be excluded from the response determination (e.g., non-target response does not have to be "Not Evaluable").

New lesions

New malignancies denoting disease progression must be unequivocal. Lesions identified in follow-up in an anatomical location not scanned at baseline are considered new lesions.

Any equivocal new lesions should continue to be followed. Treatment can continue at the discretion of the investigator until the next scheduled assessment. If at the next assessment the new lesion is considered to be unequivocal, progression should be documented. Evaluation of overall response

Table 9 presents the overall response at an individual time point for all possible

combinations of tumor responses in target and non-target lesions with or without the appearance of new lesions for participants with measurable disease at baseline.

Table 9 Evaluation of Overall Response for Participants with Measurable

Disease at Baseline

Note:

• Participants with a global deterioration of health status requiring discontinuation of treatment without objective evidence of disease progression at that time should be classified as having "symptomatic deterioration." Objective response status is determined by evaluations of disease burden. Every effort should be made to document the objective progression even after discontinuation of treatment.

• In some circumstances, it may be difficult to distinguish residual disease from

normal tissue. When the evaluation of CR depends on this determination, it is recommended that the residual lesion be investigated (fine needle aspirate/biopsy) to confirm the CR.

Evaluation of best overall response

The best overall response is the best response recorded from the start of the treatment until disease progression/recurrence and will be determined programmatically by GSK based on the investigator’s assessment of response at each time point.

• To be assigned a status of SD, follow-up disease assessment must have met the SD criteria at least once after the first dose at a minimum interval of the first scheduled tumor evaluation.

• If the minimum time for SD is not met, best response will depend on the subsequent assessments. For example, if an assessment of PD follows the assessment of SD and SD does not meet the minimum time requirement the best response will be PD. Alternatively, participants lost to follow-up after an SD assessment not meeting the minimum time criteria will be considered not evaluable.

Confirmation Criteria:

To be assigned a status of PR or CR, a confirmatory disease assessment should be performed no less than 4 weeks (28 days) after the criteria for response are first met.

Claims

We claim:

1. A combination of a PD-l binding protein and a TLR4 agonist for simultaneous or sequential use in treating cancer, wherein the PD-l binding protein comprises (a) a heavy chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO:5; (b) a heavy chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:6; (c) a heavy chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO:7; (d) a light chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO:8; (e) a light chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:9; and (f) a light chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO: 10.

2. The combination of claim 1, wherein the PD-l binding protein comprises a VH region comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO:3 and a VL region comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO:4.

3. The combination of any of the preceding claims, wherein the TLR4 agonist is CRX- 601; CRX-547; CRX-602; or CRX-527.

4. The combination of any of the preceding claims, wherein the TLR4 agonist is CRX-601 and has the formula:

5. A method of treating cancer in a subject in need thereof, the method comprising administering to the subject a combination of any one of the preceding claims.

6. A kit comprising: a first pharmaceutical composition comprising a therapeutically effective amount of a PD-l binding protein and a second pharmaceutical composition comprising a therapeutically effective amount of a TLR4 agonist, wherein the PD-l binding protein comprises (a) a heavy chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO:5; (b) a heavy chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:6; (c) a heavy chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO:7; (d) a light chain variable region CDR1 comprising the amino acid sequence of SEQ ID NO:8; (e) a light chain variable region CDR2 comprising the amino acid sequence of SEQ ID NO:9; and (f) a light chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO: 10.

7. The kit of claim 6, wherein the PD-l binding protein comprises a V_H region comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%,

99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO:3 and a V_L region comprising an amino acid sequence with at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity to the amino acid sequence as set forth in SEQ ID NO:4.

8. The kit of any one of the claims 7-8, wherein the TLR4 agonist is CRX-601; CRX-547; CRX-602; or CRX-527.

9. The method of treatment of claim 5, wherein the first pharmaceutical composition and the second pharmaceutical composition are administered simultaneously or sequentially, in any order, to the subject by a route selected from the group consisting of: systemically; intravenously; subcutaneously; and, intratumorally.

10. The method of treatment of claim 9, wherein the first pharmaceutical composition is administered intravenously, and second pharmaceutical composition is administered intravenously.

11. The method of treatment of any one of claims 5, 9, or 10, wherein the cancer is selected from the group consisting of: melanoma; lung cancer; non-small cell lung cancer (NSCLC); kidney cancer; renal cell carcinoma (RCC) breast cancer; metastatic breast cancer; triple-negative breast cancer (TNBC); head and neck cancer; colon cancer;

colorectal cancer (CRC); ovarian cancer; pancreatic cancer; liver cancer; hepatocellular carcinoma (HCC); prostate cancer; bladder cancer; gastric cancer; a liquid tumor; solid tumors; a hematopoietic tumor; leukemia; non-Hodgkins lymphoma (NHL); lymphoma; and chronic lymphocytic leukemia (CLL).

12. A TLR4 agonist for use in treating cancer, wherein the TLR4 agonist is to be administered at a dose of about 5 ng to about 1000 ng, optionally about 50 ng to about 250 ng, and is to be administered simultaneously or sequentially with a PD-l binding protein at a dose of about 200 mg.

13. Use of a PD-l binding protein in the manufacture of a medicament for treating cancer, wherein the PD-l binding protein is to be administered at a dose of about 200 mg and is to be administered simultaneously or sequentially with a TLR4 agonist at a dose of about 5 ng to about 1000 ng, optionally about 50 ng to about 250 ng.

14. Use of a TLR4 agonist in the manufacture of a medicament for treating cancer, wherein the TLR4 agonist is to be administered at a dose of about 5 ng to about 1000 ng, optionally about 50 ng to about 250 ng, and is to be administered simultaneously or sequentially with a PD-l binding protein at a dose of about 200 mg.

15. The method, agonist, use, or kit of any one of the preceding claims, wherein the TLR4 agonist is administered intravenously.

16. The method, agonist, use, or kit of any one of claims 1 to 15, wherein the TLR4 agonist and the PD-l binding protein are both administered to the subject every three weeks.

17. The method, agonist, use, or kit of any one of claims 1 to 15, wherein the TLR4 agonist is administered for a two- week run in period ( e.g ., the TLR4 agonist is

administered on day 1 and 8) prior to administering the PD-l binding protein.

18. The method, agonist, use, or kit of any one of claims 1 to 15, wherein the TLR4 agonist is administered for a two-week run in period, and following the run in period, the TLR4 agonist and the PD-l binding protein are both administered to the subject every three weeks.

19. A method for treating metastatic solid tumors, the method comprising: (i) systemically administering CRX-601 in a dose from about 5 ng to about 1000 ng, optionally about 50 ng to about 250 ng; and, (ii) systemically administering a therapeutic amount of a PD-l antagonist.

20. The method according to claim 19, wherein the PD-l antagonist is pembrolizumab, and wherein the pembrolizumab is administered at a dose of about 2 mg/kg or a dose of about 200 mg.