Systems-Level Mapping of Cancer Testis Antigen 1b/a to Sarcoma Pathways Identifies Activated Ran Binding-2 E3 SUMO-Protein Ligase and Transducin-Like Enhancer Protein 1.

Here we describe the identification of genes and their encoded proteins that are expressed in advanced grade tumors by reconstruction of a sarcoma cancer testis gene 1b/a (catg1b/a) network. CTAG1B/A is an ortholog of the yeast/Drosophila transcription factor Pcc1p, and a member of the KEOPS transcription complex. It has been implicated in telomere maintenance and transcriptional regulation through association with chromatin remodeling factors and is only expressed during adult testis germ cell differentiation. Ctag1b/a is re-activated in synovial sarcomas and myxoid liposarcomas but not in differentiated liposarcomas. We mapped CTAG1B/A protein to sarcoma transcription pathways with gene set expression analysis (GSEA) and using independent samples, we immunohistochemically identified expression of at least two network neighbors, RANBP2, and TLE1, thus validating our approach. This work demonstrates that mapping unknown genes to functional pathways by network re-construction is a powerful tool that can be used to identify candidate oncoproteins.

Results of a randomized, double-blind phase II clinical trial of NY-ESO-1 vaccine with ISCOMATRIX adjuvant versus ISCOMATRIX alone in participants with high-risk resected melanoma.

BACKGROUND: To compare the clinical efficacy of New York Esophageal squamous cell carcinoma-1 (NY-ESO-1) vaccine with ISCOMATRIX adjuvant versus ISCOMATRIX alone in a randomized, double-blind phase II study in participants with fully resected melanoma at high risk of recurrence. METHODS: Participants with resected stage IIc, IIIb, IIIc and IV melanoma expressing NY-ESO-1 were randomized to treatment with three doses of NY-ESO-1/ISCOMATRIX or ISCOMATRIX adjuvant administered intramuscularly at 4-week intervals, followed by a further dose at 6 months. Primary endpoint was the proportion free of relapse at 18 months in the intention-to-treat (ITT) population and two per-protocol populations. Secondary endpoints included relapse-free survival (RFS) and overall survival (OS), safety and NY-ESO-1 immunity. RESULTS: The ITT population comprised 110 participants, with 56 randomized to NY-ESO-1/ISCOMATRIX and 54 to ISCOMATRIX alone. No significant toxicities were observed. There were no differences between the study arms in relapses at 18 months or for median time to relapse; 139 vs 176 days (p=0.296), or relapse rate, 27 (48.2%) vs 26 (48.1%) (HR 0.913; 95% CI 0.402 to 2.231), respectively. RFS and OS were similar between the study arms. Vaccine recipients developed strong positive antibody responses to NY-ESO-1 (p≤0.0001) and NY-ESO-1-specific CD4+ and CD8+ responses. Biopsies following relapse did not demonstrate differences in NY-ESO-1 expression between the study populations although an exploratory study demonstrated reduced (NY-ESO-1)+/Human Leukocyte Antigen (HLA) class I+ double-positive cells in biopsies from vaccine recipients performed on relapse in 19 participants. CONCLUSIONS: The vaccine was well tolerated, however, despite inducing antigen-specific immunity, it did not affect survival endpoints. Immune escape through the downregulation of NY-ESO-1 and/or HLA class I molecules on tumor may have contributed to relapse.

Direct tumor recognition by a human CD4(+) T-cell subset potently mediates tumor growth inhibition and orchestrates anti-tumor immune responses.

Tumor antigen-specific CD4(+) T cells generally orchestrate and regulate immune cells to provide immune surveillance against malignancy. However, activation of antigen-specific CD4(+) T cells is restricted at local tumor sites where antigen-presenting cells (APCs) are frequently dysfunctional, which can cause rapid exhaustion of anti-tumor immune responses. Herein, we characterize anti-tumor effects of a unique human CD4(+) helper T-cell subset that directly recognizes the cytoplasmic tumor antigen, NY-ESO-1, presented by MHC class II on cancer cells. Upon direct recognition of cancer cells, tumor-recognizing CD4(+) T cells (TR-CD4) potently induced IFN-γ-dependent growth arrest in cancer cells. In addition, direct recognition of cancer cells triggers TR-CD4 to provide help to NY-ESO-1-specific CD8(+) T cells by enhancing cytotoxic activity, and improving viability and proliferation in the absence of APCs. Notably, the TR-CD4 either alone or in collaboration with CD8(+) T cells significantly inhibited tumor growth in vivo in a xenograft model. Finally, retroviral gene-engineering with T cell receptor (TCR) derived from TR-CD4 produced large numbers of functional TR-CD4. These observations provide mechanistic insights into the role of TR-CD4 in tumor immunity, and suggest that approaches to utilize TR-CD4 will augment anti-tumor immune responses for durable therapeutic efficacy in cancer patients.

PET-based compartmental modeling of (124)I-A33 antibody: quantitative characterization of patient-specific tumor targeting in colorectal cancer.

PURPOSE: The molecular specificity of monoclonal antibodies (mAbs) directed against tumor antigens has proven effective for targeted therapy of human cancers, as shown by a growing list of successful antibody-based drug products. We describe a novel, nonlinear compartmental model using PET-derived data to determine the "best-fit" parameters and model-derived quantities for optimizing biodistribution of intravenously injected (124)I-labeled antitumor antibodies. METHODS: As an example of this paradigm, quantitative image and kinetic analyses of anti-A33 humanized mAb (also known as "A33") were performed in 11 colorectal cancer patients. Serial whole-body PET scans of (124)I-labeled A33 and blood samples were acquired and the resulting tissue time-activity data for each patient were fit to a nonlinear compartmental model using the SAAM II computer code. RESULTS: Excellent agreement was observed between fitted and measured parameters of tumor uptake, "off-target" uptake in bowel mucosa, blood clearance, tumor antigen levels, and percent antigen occupancy. CONCLUSION: This approach should be generally applicable to antibody-antigen systems in human tumors for which the masses of antigen-expressing tumor and of normal tissues can be estimated and for which antibody kinetics can be measured with PET. Ultimately, based on each patient's resulting "best-fit" nonlinear model, a patient-specific optimum mAb dose (in micromoles, for example) may be derived.

NY-ESO-1 specific antibody and cellular responses in melanoma patients primed with NY-ESO-1 protein in ISCOMATRIX and boosted with recombinant NY-ESO-1 fowlpox virus.

Vaccination strategies based on repeated injections of NY-ESO-1 protein formulated in ISCOMATRIX particles (NY-ESO-1 ISCOMATRIX) have shown to elicit combined NY-ESO-1 specific antibody and T cell responses. However, it remains unclear whether heterologous prime-boost strategies based on the combination with NY-ESO-1 ISCOMATRIX with different NY-ESO-1 boosting reagents could be used to increase NY-ESO-1 CD8(+) or CD4(+) T cell responses. To address this question, we carried out a randomized clinical trial in 39 high-risk, resected melanoma patients vaccinated with NY-ESO-1 ISCOMATRIX, and then boosted with repeated injections of either recombinant fowlpox virus encoding full length NY-ESO-1 (rF-NY-ESO-1) (Arm A) or NY-ESO-1 ISCOMATRIX alone (Arm B). We have comprehensively analyzed NY-ESO-1 specific T cells and B cells response in all patients before and after vaccination for a total of seven time points per patient. NY-ESO-1 ISCOMATRIX alone elicited a strong NY-ESO-1 specific CD4(+) T cell and antibody response, which was maintained by both regiments at similar levels. However, CD8(+) T cell responses were significantly boosted in 3 out of 18 patients in Arm A after the first rF-NY-ESO-1 injection and such responses were maintained until the end of the trial, while no patients in Arm B showed similar CD8(+) T cell responses. In addition, our results clearly identified immunodominant regions in the NY-ESO-1 protein: NY-ESO-179-102 and NY-ESO-1115-138 for CD4+ T cells and NY-ESO-185-108 for CD8+ T cells in a large proportion of vaccinated patients. These regions of NY-ESO-1 protein should be considered in future clinical trials as immunodominant epitopes.

Nonclassical antigen-processing pathways are required for MHC class II-restricted direct tumor recognition by NY-ESO-1-specific CD4(+) T cells.

Tumor antigen-specific CD4(+) T cells that directly recognize cancer cells are important for orchestrating antitumor immune responses at the local tumor sites. However, the mechanisms of direct MHC class II (MHC-II) presentation of intracellular tumor antigen by cancer cells are poorly understood. We found that two functionally distinct subsets of CD4(+) T cells were expanded after HLA-DPB1*04 (DP04)-binding NY-ESO-1157-170 peptide vaccination in patients with ovarian cancer. Although both subsets recognized exogenous NY-ESO-1 protein pulsed on DP04(+) target cells, only one type recognized target cells with intracellular expression of NY-ESO-1. The tumor-recognizing CD4(+) T cells more efficiently recognized the short 8-9-mer peptides than the non-tumor-recognizing CD4(+) T cells. In addition to endosomal/lysosomal proteases that are typically involved in MHC-II antigen presentation, several pathways in the MHC class I presentation pathways, such as the proteasomal degradation and transporter-associated with antigen-processing-mediated peptide transport, were also involved in the presentation of intracellular NY-ESO-1 on MHC-II. The presentation was inhibited significantly by primaquine, a small molecule that inhibits endosomal recycling, consistent with findings that pharmacologic inhibition of new protein synthesis enhances antigen presentation. Together, our data demonstrate that cancer cells selectively present peptides from intracellular tumor antigens on MHC-II by multiple nonclassical antigen-processing pathways. Harnessing the direct tumor-recognizing ability of CD4(+) T cells could be a promising strategy to enhance antitumor immune responses in the immunosuppressive tumor microenvironment.

The human cell surfaceome of breast tumors.

INTRODUCTION: Cell surface proteins are ideal targets for cancer therapy and diagnosis. We have identified a set of more than 3700 genes that code for transmembrane proteins believed to be at human cell surface. METHODS: We used a high-throuput qPCR system for the analysis of 573 cell surface protein-coding genes in 12 primary breast tumors, 8 breast cell lines, and 21 normal human tissues including breast. To better understand the role of these genes in breast tumors, we used a series of bioinformatics strategies to integrates different type, of the datasets, such as KEGG, protein-protein interaction databases, ONCOMINE, and data from, literature. RESULTS: We found that at least 77 genes are overexpressed in breast primary tumors while at least 2 of them have also a restricted expression pattern in normal tissues. We found common signaling pathways that may be regulated in breast tumors through the overexpression of these cell surface protein-coding genes. Furthermore, a comparison was made between the genes found in this report and other genes associated with features clinically relevant for breast tumorigenesis. CONCLUSIONS: The expression profiling generated in this study, together with an integrative bioinformatics analysis, allowed us to identify putative targets for breast tumors.

Prostate cancer progression correlates with increased humoral immune response to a human endogenous retrovirus GAG protein.

PURPOSE: Human endogenous retroviruses (HERV) encode 8% of the human genome. While HERVs may play a role in autoimmune and neoplastic disease, no mechanistic association has yet been established. We studied the expression and immunogenicity of a HERV-K GAG protein encoded on chromosome 22q11.23 in relation to the clinical course of prostate cancer. EXPERIMENTAL DESIGN: In vitro expression of GAG-HERV-K was analyzed in panels of normal and malignant tissues, microarrays, and cell lines, and effects of demethylation and androgen stimulation were evaluated. Patient sera were analyzed for seroreactivity to GAG-HERV-K and other self-antigens by ELISA and seromics (protein array profiling). RESULTS: GAG-HERV-K expression was most frequent in prostate tissues and regulated both by demethylation of the promoter region and by androgen stimulation. Serum screening revealed that antibodies to GAG-HERV-K are found in a subset of patients with prostate cancer (33 of 483, 6.8%) but rarely in male healthy donors (1 of 55, 1.8%). Autoantibodies to GAG-HERV-K occurred more frequently in patients with advanced prostate cancer (29 of 191 in stage III-IV, 21.0%) than in early prostate cancer (4 of 292 in stages I-II, 1.4%). Presence of GAG-HERV-K serum antibody was correlated with worse survival of patients with prostate cancer, with a trend for faster biochemical recurrence in patients with antibodies to GAG-HERV-K. CONCLUSIONS: Preferential expression of GAG-HERV-K ch22q11.23 in prostate cancer tissue and increased frequency of autoantibodies observed in patients with advanced prostate cancer make this protein one of the first bona fide retroviral cancer antigens in humans, with potential as a biomarker for progression and biochemical recurrence rate of prostate cancer. Clin Cancer Res; 19(22); 6112-25. ©2013 AACR.

Process development and production of cGMP grade Melan-A for cancer vaccine clinical trials.

Melan-A is a cancer testis antigen commonly found in melanoma, and has been shown to stimulate the body's immune response against cancerous cells. We have developed and executed a process utilizing current good manufacturing practices (cGMP) to produce the 6 times-His tagged protein in C41DE3 Escherichia coli for use in Phase I clinical trials. Approximately 11 g of purified Melan-A were produced from a 20 L fed-batch fermentation. Purification was achieved through a three column process utilizing immobilized metal affinity, anion exchange, and cation exchange chromatography with a buffer system optimized for low-solubility, high LPS binding capacity proteins. The host cell proteins, residual DNA, and endotoxin concentration were well below limits for a prescribed dose with a final purity level of 91%.

Rebmab200, a humanized monoclonal antibody targeting the sodium phosphate transporter NaPi2b displays strong immune mediated cytotoxicity against cancer: a novel reagent for targeted antibody therapy of cancer.

NaPi2b, a sodium-dependent phosphate transporter, is highly expressed in ovarian carcinomas and is recognized by the murine monoclonal antibody MX35. The antibody had shown excellent targeting to ovarian cancer in several early phase clinical trials but being murine the antibody's full therapeutic potential could not be explored. To overcome this impediment we developed a humanized antibody version named Rebmab200, expressed in human PER.C6® cells and cloned by limiting dilution. In order to select a clone with high therapeutic potential clones were characterized using a series of physicochemical assays, flow cytometry, real-time surface plasmon resonance, glycosylation analyses, immunohistochemistry, antibody-dependent cell-mediated cytotoxicity, complement-dependent-cytotoxicity assays and quantitative PCR. Comparative analyses of Rebmab200 and MX35 monoclonal antibodies demonstrated that the two antibodies had similar specificity for NaPi2b by flow cytometry with a panel of 30 cell lines and maintained similar kinetic parameters. Robust and high producer cell clones potentially suitable for use in manufacturing were obtained. Rebmab200 antibodies were assessed by immunohistochemistry using a large panel of tissues including human carcinomas of ovarian, lung, kidney and breast origin. An assessment of its binding towards 33 normal human organs was performed as well. Rebmab200 showed selected strong reactivity with the tested tumor types but little or no reactivity with the normal tissues tested confirming its potential for targeted therapeutics strategies. The remarkable cytotoxicity shown by Rebmab200 in OVCAR-3 cells is a significant addition to the traits of stability and productivity displayed by the top clones of Rebmab200. Antibody-dependent cell-mediated toxicity functionality was confirmed in repeated assays using cancer cell lines derived from ovary, kidney and lung as targets. To explore use of this antibody in clinical trials, GMP production of Rebmab200 has been initiated. As the next step of development, Phase I clinical trials are now planned for translation of Rebmab200 into the clinic.

NY-ESO-1-specific immunological pressure and escape in a patient with metastatic melanoma.

During cancer progression, malignant cells may evade immunosurveillance. However, evidence for immunological escape in humans is scarce. We report here the clinical course of a melanoma patient whose initial tumor was positive for the antigens NY-ESO-1, MAGE-C1, and Melan-A. Upon immunization with a recombinant vaccinia/fowlpox NY-ESO-1 construct, the patient experienced a mixed clinical response and spreading of the NY-ESO-1 epitopes in the CD4+ T cell compartment. After NY-ESO-1 protein + CpG immunization, the patient's anti-NY-ESO-1 IgG response increased. Over the following years, progressing lesions were resected and found to be NY-ESO-1-negative while being positive for MAGE-C1, Melan-A, and MHC-I. The fatal, inoperable brain metastasis was analyzed after his death and also proved to be NY-ESO-1-negative, while being positive for MAGE-C1 and Melan-A, as well as MHC-I. We propose that cancer control and cancer escape in this patient were governed by NY-ESO-1-specific immunological pressure. Our findings provide evidence for the existence of immunoediting and immunoescape in this cancer patient.

A Pilot Study of Anti-CTLA4 Antibody Ipilimumab in Patients with Synovial Sarcoma.

Background. Patients with recurrent synovial sarcomas have few options for systemic therapy. Since they express large amounts of endogenous CT (cancer testis) antigens such as NY-ESO-1, we investigated the clinical activity of single agent anti-CTLA4 antibody ipilimumab in patients with advanced or metastatic synovial sarcoma. Methods. A Simon two-stage phase II design was used to determine if there was sufficient activity to pursue further. The primary endpoint was tumor response rate by RECIST 1.0. Patients were treated with ipilimumab 3 mg/kg intravenously every 3 weeks for three cycles and then restaged. Retreatment was possible for patients receiving an extra three-week break from therapy. Sera and peripheral blood mononuclear cells were collected before and during therapy to assess NY-ESO-1-specific immunity. Results. Six patients were enrolled and received 1-3 cycles of ipilimumab. All patients showed clinical or radiological evidence of disease progression after no more than three cycles of therapy, for a RECIST response rate of 0%. The study was stopped for slow accrual, lack of activity, and lack of immune response. There was no evidence of clinically significant either serologic or delayed type hypersensitivity responses to NY-ESO-1 before or after therapy. Conclusion. Despite high expression of CT antigens by synovial sarcomas of patients treated in this study, there was neither clinical benefit nor evidence of anti-CT antigen serological responses. Assessment of the ability of synovial sarcoma cell lines to present cancer-germ cell antigens may be useful in determining the reason for the observed lack of immunological or clinical activity.

Overcoming regulatory T-cell suppression by a lyophilized preparation of Streptococcus pyogenes.

Cancer vaccines have yet to yield clinical benefit, despite the measurable induction of humoral and cellular immune responses. As immunosuppression by CD4(+) CD25(+) regulatory T (Treg) cells has been linked to the failure of cancer immunotherapy, blocking suppression is therefore critical for successful clinical strategies. Here, we addressed whether a lyophilized preparation of Streptococcus pyogenes (OK-432), which stimulates Toll-like receptors, could overcome Treg-cell suppression of CD4(+) T-cell responses in vitro and in vivo. OK-432 significantly enhanced in vitro proliferation of CD4(+) effector T cells by blocking Treg-cell suppression and this blocking effect depended on IL-12 derived from antigen-presenting cells. Direct administration of OK-432 into tumor-associated exudate fluids resulted in a reduction of the frequency and suppressive function of CD4(+) CD25(+) Foxp3(+) Treg cells. Furthermore, when OK-432 was used as an adjuvant of vaccination with HER2 and NY-ESO-1 for esophageal cancer patients, NY-ESO-1-specific CD4(+) T-cell precursors were activated, and NY-ESO-1-specific CD4(+) T cells were detected within the effector/memory T-cell population. CD4(+) T-cell clones from these patients had high-affinity TCRs and recognized naturally processed NY-ESO-1 protein presented by dendritic cells. OK-432 therefore inhibits Treg-cell function and contributes to the activation of high-avidity tumor antigen-specific naive T-cell precursors.

A novel human-derived antibody against NY-ESO-1 improves the efficacy of chemotherapy.

We investigated whether antibodies against intracellular tumor-associated antigens support tumor-specific immunity when administered together with a treatment that destroys the tumor. We propose that released antigens form immune complexes with the antibodies, which are then efficiently taken up by dendritic cells. We cloned the first human monoclonal antibodies against the Cancer/Testis (CT) antigen, NY-ESO-1. We tested whether the monoclonal anti-NY-ESO-1 antibody (12D7) facilitates cross-presentation of a NY-ESO-1-derived epitope by dendritic cells to human CD8+ T cells, and whether this results in the maturation of dendritic cells in vitro. We investigated the efficacy of 12D7 in combination with chemotherapy using BALB/c mice bearing syngeneic CT26 tumors that express intracellular NY-ESO-1. Human dendritic cells that were incubated with NY-ESO-1:12D7 immune complexes efficiently stimulated NY-ESO-1(157-165)/HLA-A2-specific human CD8+ T cells to produce interferon-γ, whereas NY-ESO-1 alone did not. Furthermore, the incubation of dendritic cells with NY-ESO-1:12D7 immune complexes resulted in the maturation of dendritic cells. Treatment of BALB/c mice that bear CT26/NY-ESO-1 tumors with 5-fluorouracil (5-FU) plus 12D7 was significantly more effective than chemotherapy alone. We propose systemic injection of monoclonal antibodies (mAbs) against tumor-associated antigens plus a treatment that promotes the local release of those antigens resulting in immune complex formation as a novel therapeutic modality for cancer.

Imaging of tumor vascularization using fluorescence molecular tomography to monitor arginine deiminase treatment in melanoma.

Based on their inability to express argininosuccinate synthetase (ASS), some cancer entities feature the characteristic of L-arginine (Arg) auxotrophy. This inability to intrinsically generate Arg makes them applicable for arginine deiminase (ADI) treatment, an Arg-depleting drug. Arg is also used for the synthesis of endothelial nitric oxide (NO), which mainly confers vasodilatation but is also considered to have a major influence on tumor vascularization. The purpose of this study was to define changes in tumor vasculature in an ADI-treated melanoma xenograft mouse model using the blood pool agent AngioSense 750 and fluorescence molecular tomography (FMT). We used an ASS-negative melanoma xenograft mouse model and subjected it to weekly ADI treatment. Changes in tumor size were measured, and alterations in tumor vasculature were depicted by FMT and CD31 immunohistochemistry (IHC). On ADI treatment and effective antitumor therapy, we observed a drop in NO plasma levels and visualized changes in tumor vascularization with FMT and IHC. ADI treatment in melanoma xenografts has a tumor-reducing effect, which can be noninvasively imaged by quantifying tumor vascularization with FMT and IHC.

Phase I/II study of pegylated arginine deiminase (ADI-PEG 20) in patients with advanced melanoma.

Background Arginine deiminase (ADI) is an enzyme that degrades arginine, an amino acid that is important for growth and development of normal and neoplastic cells. Melanoma cells are auxotrophic for arginine, because they lack argininosuccinatesynthetase (ASS), a key enzyme required for the synthesis of arginine. Patients and methods Patients with advanced melanoma were treated with 40, 80 or 160 IU/m(2) ADI-PEG 20 i.m. weekly. Primary endpoints were toxicity and tumor response, secondary endpoints included metabolic response by (18)FDG-PET, pharmacodynamic (PD) effects upon circulating arginine levels, and argininosuccinate synthetase tumor expression by immunohistochemistry. Results 31 previously treated patients were enrolled. The main toxicities were grade 1 and 2 adverse events including injection site pain, rash, and fatigue. No objective responses were seen. Nine patients achieved stable disease (SD), with 2 of these durable for >6 months. Four of the 9 patients with SD had uveal melanoma. PD analysis showed complete plasma arginine depletion in 30/31 patients by day 8. Mean plasma levels of ADI-PEG 20 correlated inversely with ADI-PEG 20 antibody levels. Immunohistochemical ASS expression analysis in tumor tissue was negative in 24 patients, whereas 5 patients had <5 % cells positive. Conclusions ADI-PEG 20 is well tolerated in advanced melanoma patients and leads to consistent, but transient, arginine depletion. Although no RECIST responses were observed, the encouraging rate of SD in uveal melanoma patients indicates that it may be worthwhile to evaluate ADI-PEG 20 in this melanoma subgroup.

Phase I trial of overlapping long peptides from a tumor self-antigen and poly-ICLC shows rapid induction of integrated immune response in ovarian cancer patients.

PURPOSE: Long peptides are efficiently presented to both CD4(+) and CD8(+) T cells after intracellular processing by antigen-presenting cells. To investigate the safety and in vivo immunogenicity of synthetic overlapping long peptides (OLP) from a human tumor self-antigen, we conducted a phase I clinical trial with OLP from cancer-testis antigen NY-ESO-1 in various adjuvant combinations. EXPERIMENTAL DESIGN: Twenty-eight patients with advanced ovarian cancer in second or third remission were enrolled sequentially in three cohorts and received at least one vaccination. Patients in Cohort 1 (n = 4) received 1.0 mg OLP, Cohort 2 (n = 13) received OLP in Montanide-ISA-51, and Cohort 3 (n = 11) received OLP + 1.4 mg Poly-ICLC in Montanide-ISA-51 on weeks 1, 4, 7, 10, and 13. Humoral and cellular responses were evaluated by standardized immunomonitoring techniques (ELISA, ELISPOT assay, intracellular cytokine staining, and tetramer staining). RESULTS: The vaccine was generally well tolerated with injection site reactions and fatigue that resolved. NY-ESO-1-specific antibody and CD8(+) T cells were undetectable after vaccination with OLP alone, but were found in 6 of 13 (46%) and 8 of 13 (62%) patients, respectively, after vaccination with OLP+Montanide, and in 10 of 11 (91%) and 10 of 11 (91%) patients, respectively, after vaccination with OLP+Montanide+Poly-ICLC. NY-ESO-1-specific CD4(+) T cells were detected in all patients with greater frequency and polyclonality when Montanide-ISA-51 was used for vaccination. Inclusion of Poly-ICLC as an adjuvant further accelerated the induction of NY-ESO-1-specific immune responses. CONCLUSIONS: The current study shows that NY-ESO-1 OLP vaccine is safe and rapidly induces consistent integrated immune responses (antibody, CD8(+) and CD4(+)) in nearly all vaccinated patients when given with appropriate adjuvants.

KP-CoT-23 (CCDC83) is a novel immunogenic cancer/testis antigen in colon cancer.

Cancer/testis (CT) antigens are considered target molecules for cancer immunotherapy. To identify novel CT antigens, immunoscreening of a testicular cDNA library was performed using serum obtained from a colon cancer patient who was immunized with a new dendritic cell vaccine. We isolated 64 positive cDNA clones comprised of 40 different genes, designated KP-CoT-1 through KP-CoT-40. Three of these putative antigens, including KP-CoT-23 (CCDC83), had testis-specific expression profiles in the Unigene database. RT-PCR analysis showed that the expression of 2 KP-Cot-23 variants was restricted to the testis in normal adult tissues. In addition, KP-CoT-23 variants were frequently expressed in a variety of tumors and cancer cell lines, including colon cancer. A serological western blot assay showed IgG antibodies to the KP-CoT-23 protein in 26 of 37 colon cancer patients and in 4 of 21 healthy patients. These data suggest that KP-CoT-23 is a novel CT antigen that may be useful for the diagnosis and immunotherapy of cancer.

Phase I clinical trial of mixed bacterial vaccine (Coley's toxins) in patients with NY-ESO-1 expressing cancers: immunological effects and clinical activity.

PURPOSE: Mixed bacterial vaccine (MBV, Coley's toxins) is a historical, vaguely defined preparation of heat-inactivated Streptococcus pyogenes and Serratia marcescens used as nonspecific immunotherapy in the treatment of cancer. The mechanism of action is suspected to have an immunologic basis, yet it is poorly defined up to now. We developed a new, biochemically well defined and current good manufacturing practice-compliant MBV preparation, which has been investigated in patients with NY-ESO-1 expressing cancers. EXPERIMENTAL DESIGN: Patients received MBV subcutaneously at a starting dose of 250 EU (endotoxin units) twice a week. The MBV dose was escalated in each patient until a body temperature of 38°C to 39.5°C was induced or up to the maximum dose of 547.000 EU. Changes in serum cytokine levels were determined and immune responses to NY-ESO-1 were evaluated. Tumor response was assessed according to RECIST. RESULTS: Twelve patients were enrolled and 11 of them developed fever after the administration of MBV. Ten of 12 patients showed a consistent increase in serum IL-6 levels with the highest levels coinciding with the highest body temperature. A subgroup of patients showed increasing levels of TNF-α, IFN-γ, and IL1-ß. A patient with metastatic bladder cancer showed a partial tumor response strongly correlated with MBV-induced fever and highly elevated levels of several cytokines. CONCLUSIONS: MBV at fever-inducing dose levels can lead to a massive induction of immunoregulatory cytokines that may be involved in inducing tumor regressions. We propose to further explore the role of MBV as a potent immune modulator at higher dose levels and in conjunction with antigen-specific cancer vaccines.