WO2011146559A1

WO2011146559A1 - Combination therapy with ae37 peptide and an antibody that binds to her2/neu protein

Info

Publication number: WO2011146559A1
Application number: PCT/US2011/036916
Authority: WO
Inventors: George E. Peoples; Sathibalan Ponniah; Michael Papamichail; Sonia Perez
Original assignee: The Henry M. Jackson Foundation For The Advancement Of Military Medicine, Inc.
Priority date: 2010-05-19
Filing date: 2011-05-18
Publication date: 2011-11-24

Abstract

Provided are methods to induce and maintain a protective immunological response to a peptide of the HER2/neu oncogene, AE37, with the effect of inducing and maintaining protective or therapeutic immunity against cancer that is associated with expression of the HER2/neu protein, such as breast cancer, particularly in a patient in clinical remission. The methods comprise administering to the patient an effective amount of a vaccine composition comprising a pharmaceutically acceptable carrier, the AE37 peptide, and optionally an adjuvant, such as GM-CSF, in combination with an antibody that binds to the HER2/neu protein, such as trastuzumab. The methods may further comprise administering a periodic booster vaccine dose as needed due to declining AE37-specific immunity. Also provided are vaccine compositions for use in the methods.

Description

COMBINATION THERAPY WITH AE37 PEPTIDE

AND AN ANTIBODY THAT BINDS TO HER2/NEU PROTEIN

SEQUENCE LISTING

[001 ] Trie instant application contains a Sequence Listing, which has been submitted via EFS-Web and is hereby incorporated by reference in its entirety. The ASCII copy of the Sequence Listing, created on I i May 201 1 , is named HMJ121PCT.txt, and is 12 kilobytes in size.

GOVERNMENT INTEREST

[002] This invention was made in part with Government support. The Government may have certain rights in the invention.

CROSS REFERENCE TO RELATED APPLICATIONS

[003] This application claims the benefit of, and relies on the filing date of, U.S. provisional patent application number 61/346,125, filed 19 May 2010, the entire disclosure of which is incorporated herein by reference.

BACKGROUND

[004] Breast cancer (BCa) Is the most common cancer diagnosis in women and the second -leading cause of cancer-related death among women (Ries LAG, el al. (eds). SEER Cancer Statistics Review, 1975-2003, National Cancer- Institute, Bethesda, MD). Major advances in breast cancer treatment over the last 20 years have led to significant improvement in the rate of disease-free survival (DPS), For example, therapies utilizing antibodies reactive against tumor-related antigens have been used to block specific cellular processes in order to slow disease progress or prevent disease recurrence. Despite the recent advances in breast cancer treatment, a significant number of patients will ultimately die from recurrent disease.

[005] Vaccines are an attractive model for preventing, slowing, or prohibiting the development of recurrent disease due to their ease of administration, and because of their high rate of success observed for infectious diseases. The basic concept of constructing a cancer vaccine is straightforward in theory, The development of effective cancer vaccines for solid tumors in practice, however, has met with limited success. For example, one group attempting to administer a peptide vaccine directed against metastatic melanoma observed an objective response rate of only 2.6% (Rosenberg SA et al. (2004) Nat. Med. 10:909-15).

[006] There are many potential explanations for this low success rate (Campo!i M et al. (2005) Cancer Treat. Res. 123:61 -88). For example, even if an antigen is specifically associated with a particular type of tumor ceil, the tumor cells may express only low levels of the antigen, or it may be located in a cryptic site or otherwise shielded from immune detection, in addition, tumors often change their antigenic profile by shedding antigens as they develop. Also contributing to the low success rate is the fact that tumor cells may express very low levels of MHC proteins and other eo-stimuiatory proteins necessary to generate an immune response.

[007] Additional problems facing attempts at vaccination against tumors arise in patients with advanced-stage cancers. Such patients tend to have larger primary and metastatic tumors, and the ceils on the interior of the tumor may not be accessible due to poor blood flow. This is consistent with the observation that vaccine strategies have tended to be more successful for the treatment of hematologic malignancies (Radford J et al, (2005) Pathology37:534-50; and, MoJldrem JJ (2006) Biol. Bone Marrow Transplant. 12:13-8). In addition, as tumors become metastatic, they may develop the ability to release immunosuppressive factors into their microenvironment (Campoli, 2005; and, Kortyiewski M et al (2005) Nature Med. 1 1 :1314-21 ). Metastatic tumors have also been associated with a decrease in the number of peripheral blood lymphocytes, and dendritic cell dysfunction (Gillanders WE et al. (2006) Breast Diseases: A Year Book and Quarterly 17:26-8).

[008] While some or all of these factors may contribute to the difficulty in developing an effective preventative or therapeutic vaccine, the major underlying challenge is that most tumor antigens are self antigens or have a high degree of homology with self antigens, and are thus expected to be subject to stringent immune tolerance. Thus, it is clear that many peptide-based cancer vaccines, with or without immune- stimulating adjuncts, may be doomed to only limited success in clinical practice due to low immunogenicity and lack of specificity.

[009] Prototype breast cancer vaccines based on single antigens have been moderately successful in inducing a measurable immune response in animal experiments and in clinical tests with breast cancer patients. The observed immune response,

_ 7 _ however, has not translated into a clinically-significant protective immunity against recurrence of disease put in remission by standard therapy (e.g., surgery, radiation therapy, and chemotherapy).

[0010] HER2/«ew is a proto-oncogeae expressed in many epithelial malignancies (Siamon DJ et al. (1989) Science 244:707-12). }iEK2/ne is a member of the epidermal growth factor receptor family and encodes a 85-kd tyrosine kinase receptor involved in regulating cell growth and proliferation. (Popescu NC et al (1 89) Genomics 4:362- 366; Yarden Y et ai. (2001) Nat Rev Mol Cell Bio 2:127-137.) Over-expression and/or amplification of HERl/neu is found in 25-30% of invasive breast cancers (BCa) and is associated with more aggressive tumors and a poorer clinical outcome. (Siamon DI et al. Science (1987) 235:177- 382; Siamon DJ et ai. Science ( 1989) 244:707-12; Toikkanen S et al J Clin Oncol (1992) 10:1044-1048; Pritchard KI et al. (2006) N. Engl. J. Med. 354:2103-1 1.) HER2/H<?« overexpression and/or amplification have also been observed in ovarian cancer (Disis et a!., (1999) Clin Cancer Res. 5:1289-97), prostate cancer (Yan Shi et al, (2001) J. Urology 166:1514-19), colon cancer (Schuell et al., (2006) BMC Cancer 8(6):123), bladder cancer (Eltze et al (2005) Int J. Oncol. 26(6): 1525-31), gastric cancer (Gravalos et al. (2008) Annals of Oncology 19(9): 1523-29), pancreatic cancer (Safran et al. (200.1 ) Am. J. Clin. Oncol. 24(5):496-99), non-small cell lung cancer (Yoshino (1994) Cancer Res. 54:3387-90), endometrial cancer (Hetzel et al. (1992) Gynecol. Oncol. 47:179-85), uterine cervix cancer ( itra et al (1994) Cancer Res. 54:637-39), esophageal cancer (Reic elt et al. (2007) Med. Path. 20(1): 120- 129), and head and neck squamous cell carcinoma (Beckhardt et al. (1995) 121 (1 265-70).

[001 1 ] Determining HERl/neu status is performed predominately via two tests, immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), IHC detects over-expression of HER2/«ew protein and is reported on a semi-quantitative scale of 0 to 3-r (0~negative, Γ-low expression, 2^+:::intemiediate, and ^{1 :}=over-expression). FISH on the other hand detects amplification (excess copies) of the HERl/neu gene and is expressed as a ratio of HERl/neu gene copies to chromosome 17 gene copies and interpreted as "over-expression" if FISH is >2.0 copies. (Hicks DO et al. Hum Pathol (2005) 36:250-261.) Concurrence rate of IHC and FiSH is approximately 90%. (Jacobs et al J Clin Oncol (1999) 17:1533-1541.) FISH is considered the gold standard, as retrospective analysis reveals it is a better predictor of trastuzumab (Tz) response; it is more objective and reproducible, (Press F et al. J Clin Oncol (2002) 14:3095-3105; Bartlett J et al J Pathol (2003) 199:41 1 -417; Wolff AC et al J Clin Oncol (2007) 25:118-145.)

[0012] identification and quantification of HER2/«eu as a proto-oncogene has led to humoral or antibody-based passive immunotherapy, including the use of trastuzumab (Herceptin^¾ Genentech Inc., South San Francisco, CA). Trastuzumab is a recombinant, humanized monoclonal antibody that binds the extracellular juxtamembrane domain of RER2/neu protein. (Plosker GL et al Drugs (2006) 66:449-475.) Tz is indicated for HERl/neu over-expressing (IHC 3⁺ or FISH >2.0) node-positive (NP) and .metastatic BCa patients, (Vogel CL et al J Clin Oncol (2002) 20:719-726; Piccart-Gebhart Ml et al. N Engl J Med (2005) 353: 1659-1672) and shows very limited activity in patients with low to intermediate ^'HER2/neu expression. (Herceptin*^' (Trastuzumab), prescription product insert, Genentech Ine, South San Francisco_., CA: revised September 2000.)

[0013] Another form of immunotherapy being pursued is vaccination and active immunotherapy targeting a cellular immune response to epitopes on tumor associated antigens, such as HER2/«eti. HER2/« w is a source of several immunogenic peptides that cars stimulate the immune system to recognize and kill HER2 «e«-expressing cancer cells. (Fisk B et al J Exp Med (1995) 181 :2109-21 17.) Two such peptides are termed E75 and GP2. E75 and GP2 are both nine amino-acid peptides that are human leukocyte antigen (HLA)-A2-restricted and stimulate CTL to recognize and lyse HER2/ne«-expressmg cancer cells (Fisk B et al J Exp Med (1995) 181 :2109-21 17; Peoples GE et al. Proc atl Acad Sci USA (1995) 92:432-436). Cancer vaccines targeting "self tumor antigens, like FIER2/«ew, present unique challenges because of the immunologic tolerance characteristic of self proteins.

[0014] E75 is derived from the extracellular domain of the WERHneu protein and corresponds to amino acids 369-377 (KJFGSLAFL)(SEQ ID NO:2) of the HER2/weu amino acid sequence and is disclosed as SEQ ID NO: 1 1 in U.S. Pat. No. 6,514,942, which patent is hereby incorporated by reference in its entirety. The full length EER2/neu protein sequence is set forth below and is disclosed as SEQ ID NO:2 in U.S. Patent No. 5,869.445, which patent is hereby incorporated by reference in its entirety: MELAALC WGLLLALLPPGAASTQVCTGTDMKLRLPASPETHLD LRHLYQGCQVVQGNLELTYIi PTNASLSFLQDIQEVQGYVLIAHNOVRQVPLQRLRIVRGTQLFEDNYAIAVLDNGDPLNNTTPVT GASPGGLRELQLRSLTEILKGGVLIQR PQI YQDTILWKDIFH i©TQLALTLlDTNRSRAGHPC SP C GSRCWGESSEDCQSLTRTVCAGGCARCKGPLPTDCCHEQCAAGCTGPKKSDCIJiCLHFNH SGICELHCPALV YNTDTFESMPKPEGRYTFGASCVTACPYNYLSTDVGSCTLVCPLHKQEVTAE DGTQRCEKCSKPCARVCYGLGMEHL EVRAVTSANIQSFAGC KIFGSLAFLPESFDGDPASHTA PLQPEQLQVFETLEEITGYLYISAWPDSLPDLSVFQNLQVIRGRILHNGAYSLTLCJGLGIS IiGL RSI^EI^GSGIJAI^IHHWTHLCFVHTVPWDQLFRNPHQALLHTANRPEDECVGEGIACHQLCARGHC WGPGPTQCWCSQFLRGQSCVEECRVLQGLPREYVNARHCI.PCHPECQPQNGSVTCFGPEADQCV ACAHYKDPPFCVARCPSGVKPDLSYMPIW^' FPDEEGACQPCPINCTHSCVDLDDKGCPAEQRASP LTS 11 S AWG I LL V LG FG I L I RRQQK I R K Y MRRL LQETELVE PL PS GAM PNOAQMR I L KSTELRKVKVLGSGAFGTVYKG IWI PDGENVKI VAI VLREN S PKA KE I LDEAYVMAGVGS P YVSRLLGICLTSTVQLVTQI^PYGCLLDHVRENRGRI^SQDLIJNWCTIQIA GMSYLEDVRLVKRD LAARNVLVKS PNHVKITDFGLARLLD I DETE YHADGGKVP I KWMALES I LRRRFTHQSDV SYGV TV ELMT FGA PYDGI PAREI PDLLEKGERLPQPPI CT I DVYMIMVKCW I DSECRPRFRELVSE FSRMARBPQRF IQNEDLGPASPLDSTPYRSLLEDDDMGDLVDAEEYLVPQQGFFCPDPAPGAG G VHHRHR S S S RS GGGDLTLGLE P S EEEAPRS PLAPS EGAGSDVFDGDLG GAAKGLQ SLPTHD PSPLQRYSEDPTVPLPSETDGYVAPLTCSPQPEYVNQPDVRPQPPSPREGPLPAARPAGATLERP TLSPGKKGWKDVFAFGGAVENPEYLTPQGGAAPQPHPPPAFSPAPDNLYYWDQDPPERGAPPS TF GTPTAENPEYLGLDVPV

{SEQ ID O : l )

[0015] GP2, initially described by Peoples et L, Is a nine amino acid peptide derived from the transmembrane portion of the EERl/neu protein corresponding to amino acids 654-662 of the full length sequence (i.e., iiSAVVGIL: SEQ ID NO:3) (Peoples GE et αί, Proc Natl Acad Sci USA (1995) 92:432-436, which is hereby incorporated by reference in its entirety). The peptide was isolated using tumor-associated lymphocytes from patients with breast and ovarian cancer, and later found to be shared -amongst several epithelial malignancies including non-small cell lung cancer and pancreatic cancer (Lmehan DC et /., J Immunol (1995) 155:4486-4491 Peiper M et at. Surgery (1997) 122:235-242; YosMno I et al. Cancer Res (1994) 54:3387-3390; Peiper M et al._t Eur j Immunol (1997) 27:1 1 15-1 123).

[0016] E75 and GP2 are being used as clinical vaccines in patients with HER2/ ^' breast cancer (Peoples et at, j Clin Oncol (2005) 23:7536-7545; Mittendorf E et al, Cancer (2006) 106:2309-2317). Thus far, they have been shown to be safe and effective in stimulating antigen-specific immunity, and the immunity conferred by E75 appears to have clinical benefit in decreasing breast cancer recurrence (Peoples GE et al, Clin Cancer Res (in press)). Booster vaccinations help to sustain vaccine-induced immunity (Peoples GE et al., Clin Cancer Res (in press); Kiratson K et al, Clin Cancer Res (2002) 8: 1014-1018). WO 2007/03077! and WO 2009/1 12792 also disclose compositions comprising E75 or GP2 and an antibody, such as Trastuzumab, and methods of using those compositions to treat cancer patients,

[0017] AE37 is another HBR2,¾ M-derived immunogenic peptide, AE37 is derived from the AE36 peptide (HER2 neu: 776-790) (Disis ML et al, Clin Can Res (.1999) 4: 1289-1297) and corresponds to the amino acid sequence LRMKGVGSPYVSRLLGICL (SEQ ID NO:4). More specifically, AE37 is the AE36 peptide (GVGSPYVSRLLGICL) (SEQ ID NO:5) that has been modified by the addition of 4 amino acids (LRMK) (SEQ ID NO:6), also called the Ii-Key peptide. The LRMK amino acids, added to T helper peptides, facilitate direct antigenic epitope charging of MHC class Π molecules at the cell surface (Adams S et al, Eur J Immun ( 1995) 25:1693- 1702; Xu M et al, Scan J Immunol (2001) 54:39-44). This enhanced epitope charging and concomitant increase in antigen presentation can increase potency =250 times compared to the unmodified class O epitope in vitro (Humphreys RE et al. Vaccine (2000) 18:2693-2697; Gillogly ME et al, Cancer Immunol Immunother (2004) 53:490- 496). Animal models have shown li-Key hybrid methodology to be highly efficient using melanoma peptides. More recently, phase I trials in humans show that AE37 was safely tolerated while dieting HER2/neu~specifie immune responses, even without the use of an adjuvant (Jarrod P. Holmes et al, J. Clin. Oncon. (2008) 26(20): 3426-33),

[0018] Unlike E75 and GP2, AE37 does not associate with class i MHC molecules. Rather, AE37 associates with class II MHC molecules, in humans, AE37 is recognized in the context of human leukocyte antigen (HLA)-DR class 11 molecules. MHC class Ϊ and class II molecules deli er antigens from different cellular compartments to the cell surface, where they are used to activate the two major classes of T cells: CDS (class I) and CD4 (class II). MHC class I molecules are found on the surface of all nucleated cells and present peptides derived from proteins found in the cytoplasm of a cell, including endogenous proteins, as wells as proteins derived from intracellular pathogens. CDS T cells recognize peptides in the context of a class I MHC molecule when the peptide and class I molecule are presented together on the cell surface, leading to CDS T ceil activation. Activated CD8 cytotoxic T cells typically lyse the targeted cell. MHC class II molecules, on the other hand, usually recognize peptides derived from extracellular pathogens. MHC class ϊί molecules are found only on specialized ceils called antigen presenting cells, which internalize extracellular pathogens and generate peptides from those pathogens using vesicular proteases and present those peptides on their surface in the context of class Π MHC molecules. CD4 T cells recognize peptides in the context of class ίί MHC molecules and promote either cell mediated or humoral (antibody) immunity.

[0019] While the mechanism of action of trastuzumab is not completely elucidated, several mechanisms have been postulated to include immune activation of antibody-dependent cellular toxicity (Gennar R, et ., Clin Cancer Res (2004) 10:5650- 5655; Clynes RS, et ai, Nat Med (2000) 6:443-446). Pre-ciinicai studies relating to trastuzumab 's mechanism have found that treating patients with trastuzumab increases the amount of endogenous HER2/neu peptide compiexed and presented on MHC class I molecules. In the context of the class Ϊ MHC molecules, CD 8 cytotoxic T cells can recognize these HER2/neu peptides, resulting in tumor cells that are more susceptible to peptide vaccine induced killing (Mittendorf EA, el al, Ann Surg Oncol (2006) 13: 1085- 1098). While this mechanism of action may apply to class I-restricted peptides, like E75 and GP2, it would not be expected to apply to a class II-restricted peptide like AE37 because AE3? is not presented to CDS cytotoxic T cells in the context of MHC class I molecules.

SUMMARY

[0020] The present disclosure provides methods and compositions for treating a cancer characterized by the expression of the HERl/neu protein, such as breast cancer, ovarian cancer, prostate cancer, colon cancer, bladder cancer, gastric cancer, pancreatic cancer, non-small cell lung cancer, endometrial cancer, uterine cervix cancer, esophageal cancer, and head and neck squamous cell carcinoma. The methods comprise administering to a subject the AE37 peptide, with or without an adjuvant, and an antibody, such as trastuzumab, that binds to HER2/«e».

[0021] Thus, one embodimen is directed to a method of treating cancer in a subject who has HER2/new expressing cancer cells, the method comprising administering to the subject 1 ) a composition comprising an AE37 peptide and a pharmaceutically effective carrier and 2} an antibody, such as trastuzumab, thai binds to the BER2/«<?« protein. The composition may further comprise an adjuvant, such as granulocyte macrophage-colony stimulating factor (GM-CSF). In one embodiment, the method is directed to preventing cancer recurrence in a subject who is in remission following treatment with a standard course of therapy. I one embodiment, the standard course of therapy is treatment with an antibody, such as trastuzumab, that binds to HER2/O<?M, which treatment may continue concurrently with the methods described herein. In one embodiment, the cance is breast cancer. In other embodiments, the cancer is ovarian, prostate cancer, or any other cancer characterized by the expression of the HER2/«e« protein, such as those listed above. The composition comprising the AE37 peptide may be administered before, after, or concurrently with the antibody.

[0022] in one embodiment, other than the AE37 peptide, the composition does not contain any other HER2/¾ew~derived peptides, including, for example, the E75 or GP2 peptides. In another embodiment, the composition comprises AE37 and E75 or AE37 and GP2 or AE37, E75, and GP2. The administration of the AE37 peptide can be accomplished by any means suitable in the ait, such as inoculation or injection, and more particularly intradermal injection, which can occur with one or more separate doses. The AE37 peptide can be administered approximately three to six times or more on a regular basis (e.g., every 3 weeks or monthly) or until a protective immunity is established.

[0023] In some aspects, the composition further comprises an adjuvant such as GM-CSF and preferably recombinant human GM-CSF. Doses of the peptide and an adjuvant may comprise an equal concentration of the peptide and the adjuvant and may be administered substantially concurrently, and can be administered at one inoculation site or spaced apart from each other on the surface of the skin.

[0024] in some aspects, the methods further comprise- administering to the subject a booster vaccine dose, which comprises an effective amount of a composition comprising a pharmaceutically effective earner and an AE37 peptide. In some aspects, the composition of the booster further comprises an adjuvant such as GM-CSF and preferably recombinant human GM-CSF. The administration of a booster can be accomplished by any means suitable in the art, such as inoculation or injection, and more particularly intradermal injection, which can occur with one or more separate doses. Such doses may comprise an equal concentration of the peptide and the adjuvant, may be administered substantially concurrently, and can be administered at one inoculation site or spaced apart from each other on the surface of the skin. Typically the booster is administered after a primary immunization schedule has been completed, and preferably every six or 12 months alter the primary immunization, as needed.

[0025] The subject can be any mammal, and is preferably a human. In certain aspects, the human is positive for major histocompatibility antigen blood-typed as human leukocyte antigen DR. m other aspects, cancer cells from the human are positive for the expression of detectable levels of ER2/neu. In some aspects, the cancer cells exhibit low or intermediate expression of HER2/neu. For example, in some preferred aspects, the cancer cells from the human have an immunohistochemistry (IHC) rating of 1+ or 2÷ and/or a fluorescence in situ hybridization (FISH) rating of less than 2.0). in other aspects, the cancer cells from the human may have a IHC rating up to 3+. In other aspects, the cancer ceils from the human can exhibit over-expression of EEK2/ne . For example, in some preferred aspects, the cancer cells from the human have an immunohistochemistry (IHC) rating of 3+ and/or a fluorescence in situ hybridization (FISH) rating of greater than or equal to 2.0),

[0026] In another embodiment, the invention provides a composition comprising an AE37 peptide and an antibody that binds to the HER2//∑<?w protein, such as trastuzumab. The composition optionally comprises a pharmaceutically acceptable earner and/or an adjuvant, such as GM-CSF. The compositions are preferably administered .in an optimized immunization schedule. In one embodiment, the composition comprises 0.1-1 mg ml peptide and 0.125-0.5 mg/ml adjuvant, in some specific aspects, the preferred concentrations and schedules of the composition include: (1 ) 1 mg/ml peptide and 0.25 mg ml adjuvant, {2} 0.5 mg/ml peptide and 0.25 mg ml adjuvant, (3) 0.1 mg^/ml peptide and 0.25 mg/ml adjuvant, (4) 1 mg ml peptide and 0.125 mg ml adjuvant, and (5) 0.5 m /ml peptide and 0.125 mg/ml adjuvant, each with monthly (or every 3 weeks) inoculations for at least 6 consecutive inoculations followed by periodic booster inoculations (preferably semi-annually or annually) for 1 year, 2 years, or 3 or more years. These compositions, containing AE37 and an antibody that binds to the HBR2/»ew protein, such as trastuzumab, may be used for the treatment of cancer characterized by the expression of the ER2/neu protein, including breast cancer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate aspects of the invention and together with the description serve to explain the principles of the invention. In the drawings:

[0028] Figure 1 shows the number of IFNy spots per 10⁶ PBMC, as determined by an ELISPOT assay in scatter plot format in PBMCs from patients vaccinated with either AE37 + G -CSF or GM-CSF alone. The PBMCs were incubated with either AE36 or AE37. Patients were grouped as follows and measurements were made prior to the first vaccination ("pre"), after the third vaccination ("vac 3"), and after the sixth vaccination ("vac 6")'· A. AE37 + GM-CSF after completion of trastuzumab treatment, with PBMCs incubated with AE36 ("vac ns AE36"). B. AE37 + GM-CSF after completion of trastuzumab treatment, with PBMCs incubated with AE37 ("vac ns AE37"). C. AE37 - GM-CSF with simultaneous trastuzumab treatment, with PBMCs incubated with AE36 ("vac sim AE36"). D. AE37 + GM-CSF with simultaneous trastuzumab treatment with PBMCs incubated with AE37 ("vac sim AE37"), E, GM- CSF alone after completion of trastuzumab treatment, with PBMCs incubated with AE36 ("GM ns AE36"). F. GM-CSF alone after completion of trastuzumab treatment, with PBMCs incubated with AE37 ("GM ns AE37"). G. GM-CSF with simultaneous trastuzumab treatment, with PBMCs incubated with AE36 ("GM sim AE36"). H. GM- CSF with simultaneous trastuzumab treatment, with PBMCs incubated with AE37 ("GM sim AE37").

[0029] Figure 2 shows the proliferation of PBMCs incubated with either AE36 or AE37 as measured by H-thymidine incorporation, determined as counts per minute (cpm) in scatter plot format Patients were grouped as follows and measurements were made prior to the first vaccination ("pre''), after the third vaccination ("vac 3"}, after the sixth vaccination ("vac 6"), and 6 months after completing the vaccine series (" C6'"): A, AE37 + GM-CSF after completion of trastuzumab treatment, with PBMCs incubated with AE36 ("vac ns AE36"). B. AE37 + GM-CSF after completion of trastuzumab treatment, with PBMCs incubated with AE37 ("vac ns AE37"). C. AE37 + GM-CSF with simultaneous trastuzumab treatment, with PBMCs incubated with AE36 ("vac sim ΑΕ36")· I . AE37 + GM-CSF with simultaneous trastuzumab treatment, with PBMCs incubated with AE37 ("vac sim AE37"), 1, GM-CSF alone after completion of trastuzumab treatment, with PBMCs incubated with AE36 ("GM ns AE36"). F. GM- CSF alone after completion of trastuzumab treatment, with PBMCs incubated with AE37 ("GM ns AE37"). G. GM-CSF with simultaneous trastuzumab treatment, with PBMCs incubated with AE36 ("GM sim AE36"), H. GM-CSF with simultaneous trastuzumab treatment, with PBMCs incubated with AE37 ("GM sim AE37").

[0030] Figure 3 shows delayed type hypersensitivity (DTH) reactions in response to either AE36 or AE37, measured as induration .(mm) in scatter plot format. Patients were grouped as follows and measurements were made prior to the first vaccination ("pre"), after the sixth vaccination ("post"), and at 6-12 months after completing the vaccine series ("long,"): A, AE37 + GM-CSF after completion of trastuzumab treatment, with AE36-induced DTH ("vac ns AE36"). B. AE37 + GM-CSF after completion of trastuzumab treatment, with AE37-induced DTH ("vac ns AE37"). C. AE37 + GM-CSF with simultaneous trastuzumab treatment, with AE36-induced DTH ("vac sim ΑΕ36")· D. AE37 + GM-CSF with simultaneous trastuzumab treatment, with AE37-induced Dili ("vac sim AE37"). E. GM-CSF alone after completion of trastuzumab treatment, with AE36-induced DTH ("GM ns AE36"). F» GM-CSF alone after completion of trastuzumab treatment, with AE37-indueed DTH ("GM ns AE37"). G. GM-CSF alone with simultaneous trastuzumab treatment, with AE36-induced DTH ("GM sim ΑΕ36")· H. GM-CSF alone with simultaneous trasruzumab treatmen with AE37-induced DTH ("GM sim AE37").

- 1.1 - [0031] Figure 4 represents the same data as Figure 1 except that they are presented as average values using bar graphs.

[0032] Figure 5 represents the same dat as Figure 2 except that they are presented as average values using bar graphs.

[0033] Figure 6 represents the same data as Figure 3 except that they are presented as average values using bar graphs.

[0034] Figure 7 shows the frequency of CD ^'i"CD25⁺CDL27^" T regulatory cells ("TREGS") before the first inoculation ("pre") and after the sixth inoculation ("post") as measured by flow cytometry, with patients grouped as follows: A. AE37 + GM-CSF after completion of trastuzurnab treatment ("vac ns"), B. AE37 + GM-CSF with simultaneous trastuzumab treatment ("vac sim"). C. GM-CSF alone after completion of trastuzurnab treatment ("gm ns"). D. GM-CSF with simultaneous trastuzurnab treatment ("gm sim"),

[0035] Figure 8 shows cardiotoxicity responses, measured by echocardiography as the percentage ejection fraction with patients grouped as follows: A, AE37 ÷ GM-CSF after completion of trastuzurnab treatment ("vac ns"). B. AE37 + GM-CSF with simultaneous trastuzumab treatment ("vac sim"). C, GM-CSF alone after completion of trastuzurnab treatment ("gm ns"). D. GM-CSF with simultaneous trastuzumab treatment ("gm sim"),

[00.36] Figure 9 is a schematic depicting the HER2/neu protein that has an extracellular domain (ECD), transmembrane domain (TMD), and intracellular domain (ICD). AE37 is an li-Kcy hybrid of Her2/neu: 776-790 (AE36) generated by the addition of the li- ey peptide to the N-terminus of the HER2 AE36 peptide.

DETAILED DESCRIPTION

[0037] Various terms relating to the methods and other aspects of the present invention are used throughout the specification and claims. Such terms are to be given their ordinary meaning in the art unless otherwise indicated, Other specifically defined terms are to be construed in a manner consistent with the definition provided herein.

[0038] The term "AE37 peptide" refers to a polypeptide with the amino acid sequence LRM G V GSP YVS RLLGICL (SEQ ID NO:4).

[0039] The term "prevent" or "prevention" refers to any success or indicia of success In the forestalling or delay of cancer recurrence/relapse in patients in clinical remission, as measured fay any objective or subjective parameter, including the results of a radiological or physical examination.

[0040] "Effective amount" or "therapeutically effective amount" are used interchangeably herein, and refer to an. amount of a compound, material, or composition, as described herein effective to achieve a particular biological result such as, but not limited to, biological results disclosed, described, or exemplified herein. Such results may include, but are not limited to, the prevention of cancer, and more particularly, the prevention of recurrent cancer, e.g., the prevention of relapse in a subject, as determined by any means suitable in the art. Optimal therapeutic amount refers to the dose, schedule and the use of boosters to achieve the best therapeutic outcome.

[0041] "Pharmaceutically acceptable" refers to those properties and/or substances which are acceptable to the patient from a pharmacologieal/toxicological point of view and to the manufacturing pharmaceutical chemist from a physical/chemical point of view regarding composition, formulation, stability, patient acceptance and bioavailability. "Pharmaceutically acceptable carrier" refers to a medium that does not interfere with the effectiveness of the biological activity of the active ingredient(s) and is not toxic to the host to which it is administered,

[0042] "Protective immunity" o "protective immune response," means that the subject mounts an active immune response to an immunogenic component of an antigen such as the breast cancer antigens described and exemplified herein, such that upon subsequent exposure to the antigen, the subject's immune system is able to target and destroy cells expressing the antigen, thereby decreasing the incidence of morbidity and mortality from recurrence of cancer in the subject. Protecti ve immunity in the context of the present invention is preferably, but not exclusively, conferred by T lymphocytes.

[0043] The term "about" as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±20% or ±10%, more preferably ±5%, even more preferably ±1%, and still more preferably ±0.1 % from the specified value, as such variations are appropriate to perform the disclosed methods.

[0044] "Peptide" refers to any peptide comprising two or more amino acids joined to each other by peptide bonds or modified peptide bonds, i.e., peptide isosteres. Polypeptide refers to both short chains, commonly referred to as peptides, oligopeptides or oligomers, and to longer chains, generally referred to as proteins. Polypeptides may contain amino acids other than the 20 gene-encoded amino acids. Polypeptides include amino acid sequences modified either by natural processes, such as post-translational processing, or by chemical modification techniques which are well known in the art. Such modifications are well described in basic texts and in more detailed monographs, as well as in a voluminous research literature. Modifications can occur anywhere in a polypeptide, including the peptide backbone, the amino acid side-chains and the amino or carboxyl termini, it will be appreciated that the same type of modification may be present in the same or varying degrees at several sites in a given polypeptide. Also, a given polypeptide may contain many types of modifications. Polypeptides may be branched as a result of ubiquitination, and they may be cyclic, with or without branching. Cyclic, branched and branched cyclic polypeptides may result from natural posttxans!ational processes or may be made by synthetic methods. Modifications include acetylation, acylation, ADP-ribosylation, araidation, covalent attachment of flavin, covalent attachment of a heme moiety, covalent attachment of a nucleotide or nucleotide derivative, covalent attachment of a lipid or lipid derivative, covalent attachment of phosphatidyl inositol, cross-linking, cyclization, disulfide bond formation, demethylation, formation of covalent cross-links, formation of cystine, formation of pyroglutarnate, formylation, gamma-carboxy!ation, glycosylation, GP^'I anchor formation, hydroxy! ation, iodination, mefhylation, myristoylation, oxidation, proteolytic processing, phosphorylation, prenylation, racemizaiion, selenoyiation, sulfation, transfer-RNA mediated addition of amino acids to proteins such as arginyiation, and ubiquitination.

[0045] "Booster" refers to a dose of an im unogen administered to a patient to enhance, prolong, or maintain protective immunity and to overcome the down-regulation of T-cell responses mediated by regulatory T-cells.

[0046] "Free of cancer" or "disease free" or NED (No Evidence of Disease) means that the patient is in clinical remission induced by treatment with the current standard of care therapies. By "remission" or "clinical remission," which are used synonymously, it is meant that the clinical signs, radiological signs, and symptoms of cancer have been significantly diminished or have disappeared entirely based on clinical diagnostics, although cancerous cells may still exist in the body. Thus, it is contemplated that remission encompasses partial and complete remission. The presence of residual

- 1.4 - cancer cells can be enumerated by assays such as CTC (Circulating Tumor Cells) and may be predictive of recurrence.

[0047] "Relapse" or "recurrence" or "resurgence" are used interchangeably herein, and refer to the radiographic diagnosis of return, or signs and symptoms of return of cancer after a period of improvement or remission.

[0048] Peptide vaccines, and particularly those targeting the HER2/neii protein, that have been attempted to date have been limited in efficacy, particularl with respect to preventing relapse in patients who are in remission following a standard course of therapy. As discussed in this application, it has been determined that administering an AE37 peptide (SEQ ID NG:4) in combination with ait antibody that binds to the W£R2/neu protein, such as trastuzumab, can induce a potent in vivo immune response thai is known to correlate with a reduced rate of recurrence of cancer in disease-free patients,

[0049] Although trastuzumab has been combined with other class I-restricted peptides, like E75 and GP2, it has never been combined with a class Π-restricted peptide like AE37. Others have proposed that trastuzumab- induced cell surface turnover increases the number of tumor cells displaying endogenous HER2/ne« peptides in the context of class 1 MHC molecules and results in enhanced lysis of tumor targets by CDS cytotoxic T cells. (Mittendorf EA, ei al, Ann Surg Oncol (2006) 13 1085-1098). While this mechanism of action may help to explain how trastuzumab enhances peptide-induced killing of tumor cells for endogenous, class I-restricted peptides, it would not be expected to apply to class II-restricted peptides that are typically derived from exogenous pathogens and are not recognized by CDS cytotoxic T cells. Nevertheless, Applicants have unexpectedly discovered that combining the class 1.1 -restricted AE37 peptide with an antibody that binds to the V£&2ineu protein, such as trastuzumab, significantly increases the in vivo immune response (Dil ) to either AE36 or AE37, The DTH response provides a useful marker for clinical outcome and, in particular, for measuring predisposition to disease recurrence, with a higher DTH correlating with a lower predisposition to disease recurrence or a longer disease-free survival time and vice versa.

[0050] In addition to trastuzumabj the methods described in this application can be earned out with other antibodies that bind to the WERlineu protein, such as pertuzumab. Pertuzumab, also called 2C4 and Omnitarg™ (Genentech Inc., South San Francisco, CA), is a recombinant, humanized monoclonal antibody that binds to the HER2/«<?« protein and inhibits diinerization of HER2 with other HER receptors (De Bono et ai. (2007) J. Clin. Oncology 25(3}:257~62). Thus, pertuzumab can be substituted for trastuzumab in any of the methods or compositions described herein.

[0051] Accordingly, one embodiment of the present invention features vaccine compositions for inducing protective immunity against cancer relapse or recurrence, where the cancer is characterized by the expression of the HER2/nea protein, including, but not limited to breast cancer, ovarian cancer, or prostate cancer. Another embodiment provides methods for inducing and for maintaining protective immunity against cancer, and more particularly against recurrent cancer. In some aspects, the methods comprise administering to a subject an effective amount of 1 ) a composition comprising a pharmaceutically effective carrier, a polypeptide having the amino acid sequence of SEQ ID NO:4, and optionally an adjuvant, such as GM-CSF; and 2) an antibody, such as trastuzumab, that binds to HER2/neti,

[0052] The AE37 peptide can also be modified by a deletion or amino acid substitution at one or more residues of SEQ ID NO:4 and particularly at those amino acid residues that are not involved in binding to the MHC class 0 molecule. Such a modified AE37 peptide can be used in the compositions and methods disclosed herein.

[0053] The subject can be any animal, and preferably is a mammal such as a human, mouse, rat, hamster, guinea pig, rabbit, cat, dog, monkey, cow, horse, pig, and the like. Humans are most preferred. In certain aspects, the humans are positive for the HLA-DR haplotype. In other preferred aspects, the humans are positive for the expression of human H£R2/»eu, including preferentially humans with low and/or intermediate UERZ/neu expressing tumors, as well as humans that are overexpressors of llER2/nen.

[0054] The vaccine compositions can be formulated as freeze-dried or liquid preparations according to any means suitable in the art. Non-limiting examples of liquid form preparations include solutions, suspensions, syrups, slurries, and emulsions. Suitable liquid carriers include any suitable organic or inorganic solvent, for example, water, alcohol, saline solution, buffered saline solution, physiological saline solution, dextrose solution, water propylene glycol solutions, and the like, preferably in sterile form. [0055] The vaccine compositions can be formulated in either neutral or salt forms. Pharmaceutically acceptable salts include the acid addition salts (formed with the free amino groups of the active polypeptides) and which are formed with inorganic acids such as, for example, hydrochloric or phosphoric acids, or organic acids such as acetic, oxalic, tartaric, mandelie, and the like. Salts formed from free carboxyl groups can also be derived rom inorganic bases such as, for example, sodium, potassium, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropyl mine, trimethylamine, 2-ethylamino ethanol, histidine, procaine, and the like.

[0056] The vaccine compositions are preferably formulated for inoculation or injection into the subject. For injection, the vaccine compositions of the invention can be formulated in aqueous solutions such as water or alcohol, or in physiologically compatible buffers such as Hanks's solution, Ringer's solution, or physiological saline buffer. The solution may contain formulatory agents such as suspending, preserving, stabilizing and/or dispersing agents. Injection formulations may also be prepared as solid form preparations which are intended to be converted, shortly before use, to liquid form preparations suitable for injection, for example, by constitution with a suitable vehicle, such as sterile water, saline solution, or alcohol, before use.

[0057] The vaccine compositions can also be formulated in sustained release vehicles or depot preparations. Such long acting formulations may be administered by inoculation or implantation (for example subcutaneously or intramuscularly) or by injection. Thus, for example, the vaccine compositions may be formulated with suitable polymeric or hydrophobic materials (for example, as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt. Liposomes and emulsions are well-known examples of delivery vehicles suitable for use as carriers.

[0058] The vaccine compositions can comprise agents that enhance the protective efficacy of the vaccine, such as adjuvants. Adjuvants include any compound or compounds that act to increase a protective immune response to the AE37 or AE36 peptide antigen, thereby reducing the quantity of antigen necessary in the vaccine, and/or the frequency of administration necessary to generate a protective immune response. Adjuvants can include for example, emulsifiers. muramyl dipeptides, avridine, aqueous adjuvants such as aluminum hydroxide, chitosan-based adjuvants, and any of the various saponins, oils, and other substances known in the art, such as Ampfaigen, LPS, bacterial cell wall extracts, bacterial DNA, CpG sequences, synthetic oligonucleotides and combinations thereof (Schijns et al (2000) Curr. Opin. Immunol, 12:456), Mycohacterialplilei ( phlei) cell wall extract ( CWE) (U.S. Patent No. 4,744,984), M. phlei DNA (M-D A), and M-DNA-M phlei ceil wall complex (MCC). Compounds which can serve as emulsifiers include natural and synthetic emulsifying agents, as well as anionic, cationic and nonionic compounds. Among the synthetic compounds, anionic emulsifying agents include, for example, the potassium, sodium and ammonium sails of lauric and oleic acid, the calcium., magnesium and aluminum salts of fatty acids, and organic sulfonates such as sodium lauryl sulfate. Synthetic cationic agents include, for example, cetyltrhethylarnmonlum bromide, while synthetic nonionic agents are exemplified by glycerylesters (e.g., glyceryl monostearate), polyoxyethylene glycol esters and ethers, and the sorbitan fatty acid esters (e.g., sorbitan monopalmitate) and their polyoxyethylene derivatives (e.g., polyoxyethylene sorbitan. monopalmitate). Natural emulsifying agents include acacia, gelatin, lecithin and cholesterol.

[0059] Other suitable adjuvants can be formed with an oil component, such as a single oil, a mixture of oils, a water-in-oil emulsion, or an oil-in- water emulsion. The oil can be a mineral oil, a vegetable oil, or an animal oil. .Mineral oils are liquid hydrocarbons obtained from petrolatum via a distillation technique, and are also referred to in the art as liquid paraffin, liquid petrolatum,, or white mineral oil. Suitable animal oils include, for example, cod liver oil, halibut oii, menhaden oil, orange roughy oil and shark liver oil, ail of which are available commercially. Suitable vegetable oils, include, for example, canola oii, almond oil, cottonseed oil, com oil, olive oil, peanut oil, safHower oii, sesame oil, soybean oil, and the like. Freund's Complete Adjuvant (FCA) and Freund's incomplete Adjuvant (FIA) are two common adjuvants that are commonly used in vaccme preparations, and are also suitable for use in the present invention. Both FCA and FIA are water-in-mineral oil emulsions; however, FCA also contains a killed Mycobacterium sp.

[0060] immunomodulatory cytokines can also be used in the vaccine compositions to enhance vaccine efficacy, for example, a an adjuvant, Non-limiting examples of such cytokines include interferon alpha (IFN-a), interleukin-2 (IL-2), and granulocyte rnacrophage-colony stimulating factor (GM--CSF), or combinations thereof. GM-CSF is preferred.

[0061] Vaccine compositions comprising AE37 peptide antigens and further comprising adjuvants can be prepared using techniques well known to those skilled in the art including, but not limited to, mixing, sonication and microfluidation. The adjuvant can comprise from about 10% to about 50% (v/v) of the vaccine composition, more preferably about 20% to about 40% (v/v), and more preferably about 20% to about 30% (v/v), or any integer within these ranges. About 25% (v/v) is highly preferred.

[0062] Administration of the vaccine compositions cars be by infusion or injection (e.g., intravenously, intramuscularly, intracutaneousiy, subcutaneousiy, intrathecal, intraduodenaHy, mtraperitonealiy, and the like). The vaccine compositions can also be administered intranasal!}', vaginally, rectal ly, orally, or transderma!ly. Additionally, vaccine compositions can be admmistered by "needle-free" delivery systems. Preferably, the compositions are administered by intradermal injection. Administration can be at the direction of a physician or physician assistant.

[0063] The injections can be split into multiple injections, with such split inoculations administered preferably substantially concurrently. When administered as a split inoculation, the dose of the immunogen is preferably, but not necessarily, proportioned equally in each separate injection. If an adjuvant is present in the vaccine composition, the dose of the adjuvant is preferably, but not necessarily, proportioned equally in each separate injection. The separate injections for the split inoculation are preferably administered substantially proximal to each other on the patient's body. In some preferred aspects, the injections are administered at least about 1 cm apart from each other on the body. In some preferred aspects, the injections are administered at least about 2.5 cm apart from each other on the body. In highly preferred aspects, the injections are administered at least about 5 em apart from each other on the body, in some aspects, the injections are administered at least about 10 cm apart from each other on the body, in some aspects, the injections are administered more than 10 em apart from each other on the body, for example, at least about 12,5. 15, 17.5, 20, or more cm apart from each other on the body. Primary immunization injections and booster injections can be administered as a split inoculation as described and exemplified herein. [0064] Various alternative pharmaceutical delivery systems may be employed. Non-limiting examples of such systems include liposomes and emulsions. Certain organic solvents such as dimethylsulfoxide also may he employed. Additionally, the vaccine compositions may be delivered using a sustained-release system, such as semipermeable matrices of solid polymers containing the therapeutic agent. The various sustained-release materials available are well known by those skilled in the art. Sustained -release capsules may, depending on their chemical nature, release the vaccine compositions over a range of several days to several weeks to several months.

[0065] To prevent cancer recurrence in a patient who is in remission, a therapeutically effective amount of the vaccine composition is administered to the subject. A therapeutically effective amount will provide a clinically significant increase in AE36- or AE37~induced proliferation of peripheral blood mononuclear cells (PBMCs) as well as a clinically significant increase in delayed type hypersensitivit (DTK) reactions in response to either AE36 or AE37, as measured, for example, by the methods described in this application. In the patient on the whole, a therapeutically effective amount of the vaccine composition will destroy residual microscopic disease and significantly reduce or eliminate the risk of recurrence of cancer in the patient.

[0066] The effective amount of the vaccine composition may be dependent on any number of variables, including without limitation, the species, breed, size, height, weight, age, overall health of the patient, the type of formulation, the mode or manner or administration, or the presence or absence of risk factors thai significantly increase the likelihood that the breast cancer will recur in the patient. Such risk factors include, but are not limited to the type of surgery, status of lymph nodes and the number positive, the size of the tumor, the histologic grade of the tumor, the presence/absence of hormone receptors for certain cancers (e.g., estrogen and progesterone receptors), HER2/neu expression, iymphovascular invasion, and genetic predisposition (e.g., BRCA 1 and 2 for breast cancer). In some preferred aspects, the effective amount is dependent on whether the patient is lymph node positive of lymph node negative, and if the patient is lymph node positive, the number and extent of the positive nodes. In all cases, the appropriate effective amount can be routinely determined by those of skill in the art using routine optimization techniques and the skilled and informed judgment of the practitioner and other factors evident to those skilled in the art. Preferably, a therapeutically effective dose of the vaccine compositions described herein will provide the therapeutic preventive benefit without causing substantial toxicity to the subject.

[0067] Toxicity and therapeutic efficacy of the vaccine compositions can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., for determining the LD50 (the dose lethal to 50% of the population) and the ED50 (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio LD₅₀ ED₅₀. Vaccine compositions that exhibit large therapeutic indices are preferred. Data obtained from cell culture assays and animal studies can be used in formulating a range of dosage for use in patients. The dosage of such vaccine compositions lies preferably within a range of circulating concentrations that include the EDs_fj with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed and the route of administration utilized.

[0068] Toxicity information can be used to more accurately determine useful doses in a specified subject such as a human. The treating physician can terminate, interrupt, or adjust administration due to toxicity, or to organ dysfunctions, and. can adjust treatment as necessary if the clinical response is not adequate, to improve the response. The magnitude of an administrated dose in the prevention of recurrent breast cancer will vary with the severity of the patient's condition, relative risk for recurrence, or the route of administration, among other factors. The severity of the patient's condition may, for example, be evaluated, in part, by standard prognostic evaluation methods.

[0069] The vaccine compositions can be administered to a patient on any schedule appropriate to induce and/or sustain protective immunity against breast cancer relapse, and more specifically to induce and/or sustain a DTH response to either AE36 or AB37. For example, patients can be administered a. vaccine composition as primary immunization as described and exemplified herein, followed by administration of a booster to bolster and/or maintain the protective immunity.

[0070] In some aspects, patients can be administered the vaccine compositions 1 , 2 or more times per month. Once per three or four weeks for 18 or 24 consecutive weeks is preferred to establish the protective immune response, particularly with respect to the primary immunization schedule. In some aspects, boosters can be administered at regular intervals such as every 6 or more months after completion of the primary immunization t schedule. Administration of the booster is preferably every 6 months. Boosters can also be administered on an as-needed basis,

[0071] The vaccine administration schedule, including primary immunization and booster administration, can continue as long as needed for the patient, for example, over the course of several years, to over the lifetime of the patient. In some aspects, the vaccine schedule includes more frequent administration at the beginning of the vaccine regimen, and includes less frequent administration (e.g._t boosters) over time to maintain the protective immunity.

[0072] The vaccine can be administered at lower doses at the beginning of the vaccine regimen, with higher doses administered over time. The vaccines can also be administered at higher doses at the beginning of the vaccine regimen, with lo wer doses administered over time. The frequency of primary vaccine and booster administration and dose of AE37 administered can be tailored and/or adjusted to meet the particular needs of individual patients, as determined by the administering physician according to any means suitable in the art.

[0073] In some aspects, the vaccine compositions, including compositions for administration as a booster, comprise from about 0.1 mg to about 10 mg of AE37 peptide, in some preferred aspects, the compositions comprise about 0.1 mg of AE37. In some preferred aspects, the compositions comprise about 1 mg of AE37. n some most preferred aspects, the compositions comprise about 0.5 mg of AE37.

[0074] In some preferred aspects, the vaccine compositions comprising AE37, including compositions for administration as a booster, further comprise GM-CSF. Such compositions preferably comprise from about 0.01 mg to about 0.5 mg of GM-CSF. in some preferred aspects, the compositions comprise about 0.125 mg of GM-CSF. In some preferred aspects, the compositions comprise about 0.25 mg of GM-CSF.

[0075] In some particularly preferred aspects, the vaccine compositions comprise about 0.5 mg to I mg of AE37 peptide and from 0.125 to 0.250 mg of GM-CSF in a total volume of 1 mi, and are administered monthly as a split inoculation of 0.5 ml each, administered by injections about 5 cm apart on the patient's body, and administered concurrently or admixed. The administration schedule is preferably monthly (or every 3 weeks) for six inoculations. After a period of about 48 hours, the injection site can be assessed for local reaction of erythema and induration. If the reactions at both sites are confluent and the area of total induration measures >!00 mm (or the patient experiences any >grade 2 systemic toxicity), then the dose of GM-CSF may be reduced, for example, b half, though it is intended that the peptide dose remain the same. If the patient presents a robust reaction on subsequent doses, then further reduction of GM-CSF can occur, for example, reducing by half If the patient does not present with a robust reaction, then the patient, can continue with the higher GM-CSF dose. In some aspects, the administration schedule and dosing of the booster is similarly determined, with boosters beginning with administration of vaccine compositions comprising 1 mg of AE37 and 0.25 mg GM-CSF, administered about every six months following the conclusion of the primary immunization vaccine schedule.

[0076] The following examples are provided to describe the invention in greater detail. They are intended to illustrate, not to limit, the invention.

EXAMPLE 1: Phase I/II Trial of AE37 + Trastuzumab

Patient. Characteristics and Clinical Protocol

[0077] A phase I/O clinical trial of the HER2/«eH-derived AE37 peptide with trastuzuniab in disease-free breast cancer patients, AH patients were receiving adjuvant trastuzumab as standard of care treatment. The trial was Institutional Review Board- approved and conducted at Brooke Army Medical Center, San Antonio, TX and Saint Savas Hospital, Athens, Greece. All patients had histologically confirmed node-negative or node-positive breast cancer that over expressed KERlineu by standard immunohistochemistry (IHC 3+ or FISH - 2.0) and an ECOG performance status (PS) 0- 1.

[0078] Disease-free, high risk breast cancer patients who have completed standard adjuvant therapy were enrolled and randomized to receive six inoculations every 3 weeks of 500 meg of AE37 with 125 meg of GM-CSF or 125 meg of GM-CSF alone. Toxicity was assessed after each inoculation. Immunologic response was monitored by IF -γ ELISPOT assay, delayed type hypersensitivity reactions (DTH), and a PBMC proliferation assay.

[0079] Currently, 102 disease-free breast cancer patients that over expressed EERl/neii by standard immunohistochemistry (IHC 3+ or FISH ~ 2.0) have been enrolled and vaccinated, including 51 receiving trastuzumab as part of standard therapy. No patients withdrew from this study or were lost to follow up.

Vaccination and Clinical Protocol

[0080] In this trial, patients were randomized into arms receiving AE37 (500 xg) + GM-CSF (125 μg) or GM-CSF alone (325 g). The groups were further divided into patients who received the vaccine after completing trastuzumab treatment ("vac as" or "GM ns") and patients who received the vaccine simultaneously with trastuzumab ("vac sim" or "GM sim"). Patients in all groups received an injection every three weeks over a period of 1 S weeks, fo a total of six injections,

[0081] The injections were administered infradermally in 0.5 ml inoculums at two different sites within 5 cm of each other and within the same lymph node draining area (same arm or thigh). In patients receiving simultaneous trastuzumab treatment, the peptide inoculations were given 30 minutes after completion of trastuzumab treatment.

[0082] The immunologic response of the patients to the various treatment groups was measured using three different assays: 1) enzyme-linked immunospot (EL1SPOT) assays to measure IFN-γ release in response to the stimulating peptide; 2) H-thymidine incorporation assay to measure cell proliferation; and 3) delayed-type hypersensitivity (DTH) assay to measure in vivo cellular immune responses. Assays were performed at baseline, before the first inoculation ("pre"), after the third inoculation ("vac 3"), and after the sixth inoculation ("vac 6" or "post").

{^"0083] Peripheral Blood Mononuclear Cell (PBMC) Isolation and Cultures. Blood was drawn before the first inoculation and after the third and sixth inoculations. 50 ml of blood was drawn and PB Cs were isolated. PBMCs were washed and re- suspended in culture medium and used, as a source of lymphocytes to measure immunological responses against AE37 or the wild type, AE36 peptide, from which AE37 is derived.

[0084] The A.E36 peptide used in these immunologic assays corresponds to amino acids 776-790 of the native HER2/«e« protein and has the amino acids sequence of GVGSPyVSRLLGICL (SEQ ID NO:5). The AE37 peptide

(LRM GVGSPYVSRLLGICL) (SEQ ID NO:4) used in these immunologic assays is a fusion of the li-Key peptide (LRMK) (SEQ ID NO:6) with the AE36 peptide and is the same peptide used in the vaccine. Using the AE36 peptide in the immunological assays showed that the AE37 vaccine induced an. immune response that recognized the wild type AE3.6 peptide, in addition to the modified AE37 peptide.

[0085] ELISPOT Assay. The IF -γ ELISPOT assay was used to measure in vitro immune responses. Freshly isolated PBMCs were cultured/stimulated overnight in complete medium (RPMI + 5% FCS + PSG) supplemented with- IL-7 (20 ng ml) with either AE37 or the wild type peptide AE36 at 25 g/ml or PMA + lonomycin in flat- bottom anti-human IFN-γ ELISPOT plates (BD Biosciences, San Diego, CA) at 5 x 10⁵ cells/well/200 μΐ in duplicate wells. The plate was incubated at 31^QC overnight after which the wells were washed and incubated with the biotinylated-anti-IF -γ niAb for 2 hours. The wells were washed again and incubated with streptavidin-conjugated HRP for 1 hour. After a final wash, the AEC (3-amino-9-ethyl-earbazoie; Sigma A-5754) substrate solution was added to the wells and allowed to develop for approximately 5-10 minutes at which time the we!ls were washed with deionized water to stop the reaction. The number of spots present in each well was enumerated using the CTL ELISPOT analyzer (CTL Analyzers LLC, Cleveland, OH).

[0086] The number of spots observed for the AE37 vaccine groups ('Vac ns" and "vac sim") in response to both AE36 and AE37 was similar, with both groups showing an increase in the number of spots over the course of the vaccination schedule and with the "vac sim" group showing a more consistent distribution of spots. Figures 1 A-D and 4A- D. On the other hand, the number of spots in the GM-CSF a!one groups generally decreased over the course of the vaccination schedule, indicating a less potent immune response than the AE37 vaccine groups. Figures 1E-H and 4E-H.

[0087] Proliferation Assay, Peptide-induced proliferation of T lymphocytes was used to assess in vitro immune responses through a standard radioactive ^"TLthymidine incorporation assay. PBMCs were stimulated in absence or presence of peptide or antigen. Each of the peptides (AE36 or AE37) was added as triplicates to a 96-round bottom well plate while one set of wells had no peptide added and served as control wells. The peptides were tested at two concentrations (1 g'mi and 10 μ^ηιΐ). PBMCs were resuspended in culture medium and added at 3xl0⁵ cells/200,u/well. The plate was then incubated in a humidified C0₂ incubator for four days. On day three of incubation, wells were pulsed with Ι ΟΛνβΠ of radioactive ³H-thymidine, and plates returned to the incubator. On day four, cells were harvested with a ceil harvester on to a filter mat and counted using a scintillation counter. Proliferation was measured by amount of thymidine incorporation, determined as counts per minute (cpm). Average cprn was calculated for the triplicate cultures.

[0088] The AE37 vaccine groups both showed significantly increased proliferative responses to both AE36 and AE37 as compared to the GM-CSF alone treatment groups. Figures 2 and 4. In addition, in each of the AE37 vaccine groups, patients who received the vaccine simultaneously with trastuzumab ("vac sirn") showed a markedly higher proliferative response after the sixth injection ("vac 6"), as compared to patients who received the vaccine after completing treatment with trastuzumab ("vac ns"). Figures 2A-D and 5A-D, There was no proliferative response in patients receiving GM- CSF alone.

[0089] Delayed Type Hypersensitivity (DTH). DTH assays were used to evaluate in vivo immune responses. Intradermal injections, on. the back or extremity (opposite side from vaccination), using 100 g of AE37 (without GM-CSF) in 0,5 mL saline were compared to an equal volume control inoculum of saline. DTH reactions were measured in two dimensions at 48-72 hours using the sensitive ballpoint pen method and reported as the orthogonal mean. Sokol JE, Measurement of delayed skin test responses. N Engl J Med (1975) 293:501-50.1.

[0090] Statistical Analysis. P values for clinicopathologicai factors were calculated using Wileoxon, Fisher's exact test or ^χ2 as appropriate. P values for comparing pre and post (i.e., "vac 6") vaccination DTP! assays were calculated using Student t-test, paired or impaired, as appropriate.

[0091] DTH responses were assessed at completion of the inoculation series ("post^**) as well as at 6-12 months after completing the inoculation series ("long") and compared to DTH responses prior to the start of vaccination ("pre"). DTH was assessed against both AE36, the native Fier2-derived peptide (Figures 3A, 3C, 3E, and 3G and Figures 6A, 6C, 6E, and 6G) and AE37, the modified peptide used in the vaccine (Figures 3B, 3D. 3F, and 3H and Figures 6 , 6D, 6F, and 6H). The AE37 vaccine groups showed significantly increased DTH responses as compared to the GM-CSF alone treatment groups. Figures 3 and 6. in addition, all of the AE37 vaccine groups had statistically significant increases in their pre and post vaccine DTH responses to both AE36 and AE37, Figures 3A-D and 6A~D. And while there was no significant difference in the AE37~induced DTH response between patients who received AE37 simultaneously with trastuzumab ("vac sim") and patients who received AE37 after completing treatment with trastuzumab ("vac ns"), after the sixth injection ("post"), the vac sim AE37 group had more patients (5) with a larger DTH response (>3Q mm) as compared to the vac ns AE37 group of patients (2). Figures 3B and D and 6B and D. There was no significant difference in the DTH response to AE36 or AE37 pre- versus post-vaccination for patients receiving GM-CSF alone regardless of whether it was administered sequentially or concurrently with trastuzumab. Figures 3E~H and 6E-H.

[0092] Regulatory^; T celts. CD4¾D25⁺CD 327^" regulatory T cells ("TREGS") are a subpopulatk of naturally-occurring T cells that suppress immune responses of other cells, and particularly those responses directed to self antigens (Sakaguchi S, et aL, J Immunol (1995) 155:1 151-1 164; Fontenot JD, et al., Nature Immunol (2003) 4:330-336). TREGS have been implicated with tissue destruction, tumorigenesis, and autoimmune disease (Knutson KL, et a!., (2005) Cancer Immunol immunother 54:721 -728). In addition, TREGS are elevated in breast cancer patients (Liyanage UK, et aL, (2002) J Immunol 169:2756-2761 ). Thus, an increase in TREGS can signal an attempt by the immune system to down regulate itself and would generally be undesirable in this peptide vaccine strategy. To assess whether any of the treatment arms increased the induction of TREGS, we measured the frequency of TREGS before the first inoculation ("pre") and after the sixth inoculation ("post"). The frequency of CD4⁺CD25⁺CD127^" TREGS in PMBCs from patients treated with AE37 + GM-CSF or GM-CSF alone was measured using flow cytometry. There was no significant increases in TREG levels between patients receiving the vaccine after completing trastuzumab treatment ("vac ns") and patients receiving the vaccine simultaneously with trastuzumab ("vac sim"). Figure 7. Nor was there any significant difference between vaccine groups and GM-CSF only groups. Figure ?.

[0093] Safety Data. Generally, trastuzumab is well tolerated but in a number of clinical trials, cardiotoxicity has been observed. Martin et al.. The Oncologist (2009) 14:1 -11. Thus, it is important to demonstrate that combining trastuzumab with another therapeutic, such as AE37, does not induce cardiac dysfunction. Cardiotoxicity can be assessed using echocardiography to measure the ejection fraction of the heart. An ejection fraction of 65% is normal. Figure 8 shows that there were no cardiotoxicity issues with, either the simultaneous ("vac sim") or non-sfmultaneous ("vac ns") use of the AE37 peptide in combinatio with trasfuzumab. Specifically, there were no significant differences in ejection fractions in patients receiving the AE37 + GM-CSF vaccine administered wither sequentially following trastuzumab or concurrently with trastuzumab administration (see Figures 8A and 8B). Patients receiving GM-CSF alone also demonstrated no difference in ejection fractions (see Figures 8C and 8D).

[0094] Overall the vaccine combination of AE37 + GM-CSF with either simultaneous or non-simultaneous trastuzumab treatment was well tolerated. All patients receiving AE37 and trastuzumab demonstrated potent in vitro immunologic responses and potent in vivo DTH responses post vaccination. Notably, the AE37 vaccine groups showed significantly increased DTH responses as compared to the GM-CSF alone treatment groups, including those patients who continued to receive trastuzumab concurrently with GM-CSF. The DTH response provides a useful marker for clinical outcome and, in particular, for measuring predisposition to disease recurrence, with a higher DTH con-elating with a lower predisposition to disease recurrence or a longer disease-free survival time and vice versa. See e.g. Peoples GE et al, J. Clin. Oncol. (2005) 23:7536-45: Peoples GE et ai, Clin Cancer Res (2008) 14(3) -797-803; Holmes et al, Cancer (2008) Ϊ 13: 1666-75; WO 2009/1 12792. Thus, the in vivo DTH data strongly suggest that AE37 in combination with trastuzumab should be more effective at reducing breast cancer recurrence and increasing disease-free survival time than trastuzumab alone.

[0095] All patents, patent applications, and published references cited herein are hereby incorporated by reference in their entirety. While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.

Claims

What is Claimed:

L A method of preventing cancer recurrence in a subject, wherein cancer cells from the subject express detectable levels of the RERlfneu protein and wherein the subject is in remission following treatment with a standard course of therapy, comprising administering to the subject a therapeutically effective amount of 1) a composition comprising a pharmaceutically effective carrier and a peptide having the amino acid sequence SEQ ID NO;4 and 2) an antibody that binds to the KER2/ne protein.

2. The method of claim 1 , wherein the antibody is trastuzumab.

3. The method of claim 1 or 2 wherein the composition further comprises an adjuvant.

4. The method of any one of claims 1-3, wherein the composition is administered before, after, or concurrently with the antibody.

5. The method of any one of claims 1-4, wherein the composition is administered by injection or inoculation.

6. The method of claim 5, wherein the injection is an intradermal injection,

7. The method of claim 5 or 6, wherein the composition is injected in one or more split doses,

8. The method of claim 7, wherein the injection sites on the subject are located about 5 cm apart from each other.

9. The method of any one of claims 1-8, wherein the composition is administered every three weeks for 18 weeks.

10. The method of any one of claims 1-9, further comprising administering to the subject a booster comprising an effective amount of a vaccine booster composition comprising a pharmaceutically effective carrier and a peptide having the amino acid sequence of SEQ ID NO:4.

1 1. The method of claim 10, wherein the booster is administered every six or 12 months after a primary immunization schedule is com leted.

12. The method of any one of claims 1-1 1 , wherein the subject is a human.

13. The method of claim 12, wherein the human expresses human leukocyte antigen DR.

14. The method of any one of claims 1-13, wherein the adjuvant is granulocyte macrophage-colony stimulating factor.

15. The method of claim 14, wherein the granulocyte macrophage-colony stimulating factor is recombinant human granulocyte macrophage-colony stimulating factor.

16. The method of claim 10 or 1 1 , wherein the vaccine booster composition further comprises an adjuvant.

17. The method of claim 16, wherein the adjuvant is granulocyte macrophage- coiony stimulating factor.

18. The method of any one of claims 1-17, wherein the cancer is breast cancer, ovarian cancer, prostate cancer, colon cancer, bladder cancer, gastric cancer, pancreatic cancer, non-small cell lung cancer, endometrial cancer, uterine cervix cancer, esophageal cancer, or head and neck squamous cell carcinoma,

1 . The method of any one of claims 1-17, wherein the cancer is breast cancer,

20. A vaccine composition comprising a pharmaceutically acceptable earner, an effective amount of a peptide having the amino acid sequence SEQ ID NO:4, and an antibody that binds to the HERHneu protein.

21. The vaccine composition of claim 20, further comprising an adjuvant.

22. The vaccine composition of claim 21, wherein the adjuvant is granulocyte macrophage-colony stimulating factor.

23. The composition of claim 21 or 22, wherein the effective amount of the peptide is between 1 mg/ml and 0.5 mg/ml and the dose of the adjuvant is between 0.1 and 0.5 mg/ml

24. The composition of claim 21 or 22, wherein the effective amount of the peptide is 0.5 mg/ml and the dose of the granulocyte macrophage-colony stimulating facto is 0.12.5 mg ml.