Tumor-infiltrating lymphocytes mediate complete and durable remission in a patient with NY-ESO-1 expressing prostate cancer.

Adoptive transfer of autologous tumor-specific lymphocytes represents a viable treatment method for patients with advanced malignancies. Here, we report a patient's case with metastatic hormone-refractory New York esophageal squamous cell carcinoma 1 (NY-ESO-1) expressing prostate cancer treated with in vitro expanded tumor-infiltrating lymphocytes (TILs) in conjunction with IL-2 and immune-checkpoint blockade. Complete and durable tumor remission was observed after three TIL infusions consisting of 1.4×109, 2.0×109, and 8.0×109 T cells, respectively, lasting now for more than 3.5 years. Immunological correlates to the clinical development were the decrease of tumor-driven NY-ESO-1 serum antibody and the drop of prostate-specific antigen to <0.01 µg/L. TILs were reactive against cancer-testis antigen NY-ESO-1, individual tumor mutational proteins (eg, PRPF8, TRPS1), and the androgen receptor splice variant 12.

Phase I study with ONCOS-102 for the treatment of solid tumors - an evaluation of clinical response and exploratory analyses of immune markers.

BACKGROUND: We conducted a phase I study with a granulocyte macrophage colony stimulating factor (GMCSF)-expressing oncolytic adenovirus, ONCOS-102, in patients with solid tumors refractory to available treatments. The objectives of the study were to determine the optimal dose for further use and to assess the safety, tolerability and adverse event (AE) profile of ONCOS-102. Further, the response rate and overall survival were evaluated as well as preliminary evidence of disease control. As an exploratory endpoint, the effect of ONCOS 102 on biological correlates was examined. METHODS: The study was conducted using a classic 3 + 3 dose escalation study design involving 12 patients. Patients were repeatedly treated intratumorally with ONCOS-102 plus daily low-dose oral cyclophosphamide (CPO). Tumor response was evaluated with diagnostic positron emission tomography (PET) and computed tomography (CT). Tumor biopsies were collected at baseline and after treatment initiation for analysis of immunological correlates. Peripheral blood mononuclear cells (PBMCs) were collected at baseline and during the study to assess antigen specificity of CD8+ T cells by interferon gamma (IFNγ) enzyme linked immunospot assay (ELISPOT). RESULTS: No dose limiting toxicity (DLT) or maximum tolerated dose (MTD) was identified for ONCOS-102. Four out of ten (40 %) evaluable patients had disease control based on PET/CT scan at 3 months and median overall survival was 9.3 months. A short-term increase in systemic pro-inflammatory cytokines and a prominent infiltration of TILs to tumors was seen post-treatment in 11 out of 12 patients. Two patients showed marked infiltration of CD8+ T cells to tumors and concomitant systemic induction of tumor-specific CD8+ T cells. Interestingly, high expression levels of genes associated with activated TH1 cells and TH1 type immune profile were observed in the post-treatment biopsies of these two patients. CONCLUSIONS: ONCOS-102 is safe and well tolerated at the tested doses. All three examined doses may be used in further development. There was evidence of antitumor immunity and signals of clinical efficacy. Importantly, treatment resulted in infiltration of CD8+ T cells to tumors and up-regulation of PD-L1, highlighting the potential of ONCOS-102 as an immunosensitizing agent for combinatory therapies with checkpoint inhibitors. TRIAL REGISTRATION: NCT01598129. Registered 19/04/2012.

Long-term complete remission following radiosurgery and immunotherapy in a melanoma patient with brain metastasis: immunologic correlates.

A melanoma patient with brain metastases was treated by gamma-knife radiosurgery and immunotherapy with autologous tumor-lysate-loaded dendritic cells (DC). Ten years after the combined treatment, the patient remains in complete remission. Remarkable immunologic correlates to the clinical development were the transient induction of NY-ESO-1 antibody and the durable expansion of MAGE-A1p161-169 EADPTGHSY-specific CD8+ T cells. Although the induction of NY-ESO-1 antibody most likely resulted from gamma-knife-mediated "auto-vaccination," the persistence of circulating MAGE-A1-specific T cells, which are still detectable ex vivo in the absence of any tumor manifestation, coincides with DC-based vaccination administered monthly until today.

Local treatment of a pleural mesothelioma tumor with ONCOS-102 induces a systemic antitumor CD8+ T-cell response, prominent infiltration of CD8+ lymphocytes and Th1 type polarization.

Late stage cancer is often associated with reduced immune recognition and a highly immunosuppressive tumor microenvironment. The presence of tumor infiltrating lymphocytes (TILs) and specific gene-signatures prior to treatment are linked to good prognosis, while the opposite is true for extensive immunosuppression. The use of adenoviruses as cancer vaccines is a form of active immunotherapy to initialise a tumor-specific immune response that targets the patient's unique tumor antigen repertoire. We report a case of a 68-year-old male with asbestos-related malignant pleural mesothelioma who was treated in a Phase I study with a granulocyte-macrophage colony­stimulating factor (GM-CSF)-expressing oncolytic adenovirus, Ad5/3-D24-GMCSF (ONCOS-102). The treatment resulted in prominent infiltration of CD8+ lymphocytes to tumor, marked induction of systemic antitumor CD8+ T-cells and induction of Th1-type polarization in the tumor. These results indicate that ONCOS-102 treatment sensitizes tumors to other immunotherapies by inducing a T-cell positive phenotype to an initially T-cell negative tumor.

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.

Therapeutic administration of a synthetic CpG oligodeoxynucleotide triggers formation of anti-CpG antibodies.

The synthetic oligodeoxynucleotide CpG 7909, which contains unmethylated cytosine/guanine (CpG) motifs, has potent immunostimulatory effects when coadministered with NY-ESO-1 peptides or recombinant NY-ESO-1 protein, resulting in an enhanced cellular and humoral immune response against the vaccine antigen. In this study, we report the development of anti-CpG-ODN antibodies in 21 of 37 patients who received CpG 7909 either alone or as a vaccine adjuvant. Specific anti-CpG immunoglobulin G (IgG) antibody titers ranged from 1:400 to 1:100,000. The anti-CpG antibodies cross-reacted with other synthetic CpG-ODNs but not with the DNA of mixed bacterial vaccine and were shown to be phosphorothioate backbone specific. Vaccine-related severe side effects observed in some patients were most likely not related to the development of anti-CpG antibodies. In addition, anti-CpG antibodies did not have negative effects on the vaccine immune response. These results show that anti-CpG antibodies develop in humans against short unmethylated CpG dinucleotide sequences after administration of CpG 7909. Our data therefore substantiate the potency of CpG 7909 to directly stimulate human B-cells and suggest that anti-CpG antibody monitoring should be a part of ongoing and planned clinical trials with CpG-ODNs.

Efficient in vivo priming by vaccination with recombinant NY-ESO-1 protein and CpG in antigen naive prostate cancer patients.

PURPOSE: NY-ESO-1, one of the most immunogenic tumor antigens, is expressed in 15% to 25% of metastatic prostate cancers. The immunological and clinical effects of vaccination with recombinant NY-ESO-1 protein combined with CpG as adjuvant were evaluated. EXPERIMENTAL DESIGN: In a phase I clinical study, patients with advanced prostate cancer were vaccinated with recombinant NY-ESO-1 protein (100 µg) mixed with CpG 7909 (2.5 mg) every 3 weeks intradermally for 4 doses. Objectives of the study were the safety of the vaccine and changes of specific humoral and cellular immunological responses to NY-ESO-1 in relation to detectable NY-ESO-1 expression in the individual tumor. RESULTS: All 12 baseline sero-negative patients developed high-titer NY-ESO-1 antibody responses. B-cell epitope mapping identified NY-ESO-1 p91-110 to be recognized most frequently by vaccine-induced antibodies. Two patients developed significant antibody titers against the adjuvant CpG. NY-ESO-1-specific CD4+ and/or CD8+ T-cell responses were induced in 9 patients (69%). Five of these 9 patients did not express NY-ESO-1 in the autologous tumor. Postvaccine CD8+ T-cell clones recognized and lyzed HLA-matched tumor cell lines in an antigen-specific manner. CONCLUSION: Our data provide clear evidence for the capacity of NY-ESO-1 protein/CpG vaccine to induce integrated antigen-specific immune responses in vivo and to efficiently prime CD8+ T-cell responses in NY-ESO-1 antigen-negative patients. Our results may also support further clinical vaccination protocols with NY-ESO-1 protein not only focused on the treatment of existing cancer, but also to prevent further development of NY-ESO-1 positive cancers in vivo.

Tumor-reactive CD8+ T-cell clones in patients after NY-ESO-1 peptide vaccination.

A major objective of peptide vaccination is the induction of tumor-reactive CD8+ T-cells. We have shown that HLA-A2 positive cancer patients frequently develop an antigen-specific CD8+ T-cell response after vaccination with NY-ESO-1 peptides p157-165/p157-167. These T-cells are highly reactive with the peptides used for vaccination, but only rarely recognize HLA-matched, NY-ESO-1 expressing tumor cell lines. To address the apparent lack of tumor recognition of vaccine-induced CD8+ T-cell responses, we used autologous tumor cells for in vitro stimulation and expansion of pre- and postvaccine CD8+ T-cells. In contrast to standard presensitization methods with peptide-pulsed antigen-presenting cells, mixed lymphocyte tumor culture favored the selective expansion of low-frequency tumor-reactive T-cells. In four patients, we were able to demonstrate that antigen-specific and tumor-reactive T-cells are detectable and are indeed elicited as a result of NY-ESO-1 peptide vaccination. Further analyses of postvaccine antigen-specific T-cells at a clonal level show that vaccine-induced antigen-specific T-cells are heterogeneous in functional activity. These results suggest that the methods of immunomonitoring are critical to identify the proportion of tumor-reactive T-cells within the population of vaccine-induced antigen-specific effector cells. Our results show that immunization with NY-ESO-1 peptides leads to strong tumor-reactive CD8+ T-cell responses. Our findings suggest that approaches to peptide vaccination may be improved to induce higher numbers of antigen-specific T-cells and to selectively increase the proportion of CD8+ T-cells that have the capacity to recognize and eliminate tumor cells.

Identification of new NY-ESO-1 epitopes recognized by CD4+ T cells and presented by HLA-DQ B1 03011.

NY-ESO-1 is one of the most immunogenic cancer antigens eliciting strong humoral and cellular immune responses in patients with NY-ESO-1-expressing malignancies. Since CD4+ T cells play a critical role in generating and maintaining antigen-specific cellular and humoral immune responses, we searched for new NY-ESO-1 epitopes presented by MHC class II molecules. CD4+ T cells of patients with NY-ESO-1-expressing cancer were presensitized with 18-mer overlapping synthetic peptides spanning the entire sequence of NY-ESO-1. Two partly overlapping NY-ESO-1 epitopes p49-66 and p55-72 were identified as targets for NY-ESO-1-specific CD4+ T cells. Peptide-specific CD4+ T-cell clones were generated by repetitive stimulation with NY-ESO-1 p49-66 and p55-72. Further experiments confirmed distinct specificities for the CD4+ T-cell clones indicating that at least 2 different CD4+ T-cell epitopes are located in the region p49-72 of the NY-ESO-1 sequence. Using a set of partially histocompatible EBV-B cell lines and MHC class II-specific antibodies, we found that both CD4+ T-cell epitopes were presented in the context of HLA-DQ B1 03011(DQ7). Natural processing and presentation of these epitopes was demonstrated by recognition of an HLA-DQ B1 03011- and NY-ESO-1-expressing lymphoma cell line and by recognition of dendritic cells (DC) exogenously loaded with NY-ESO-1 protein or infected with recombinant NY-ESO-1 adenoviral constructs. The specific production of IFN-gamma and TNF-alpha suggests that the NY-ESO-1-specific CD4+ T-cell clones belong to the Th1 subtype. The characterization of the new HLA-DQ B1 03011-restricted NY-ESO-1 peptides broadens the repertoire of epitopes that can be used to monitor NY-ESO-1-specific spontaneous and vaccine-induced T-cell responses in cancer patients.