Montanide ISA-51 VG Research Articles

TGFβ-derived immune modulatory vaccine: targeting the immunosuppressive and fibrotic tumor microenvironment in a murine model of pancreatic cancer

BackgroundPancreatic ductal adenocarcinoma (PDAC) is associated with very poor survival, making it the third and fourth leading cause of all cancer-related deaths in the USA and European Union, respectively. The...

Abstract CT258: Interim safety and immunogenicity results of a phase I trial evaluating the multi-peptide COVID-19 vaccine candidate CoVac-1 for induction of SARS-CoV-2 T cell immunity in cancer patients with disease- or treatment-related immunoglobulin deficiency

Abstract Individuals with impaired ability to mount a humoral immune response, either during natural infection or upon prophylactic vaccination, are at high risk for a severe course of COVID-19. Besides humoral immunity mediated by B cells, T cell immunity is key for the control of viral infections. We developed the peptide-based vaccine candidate CoVac-1, which primarily aims for the induction of SARS-CoV-2-specific T cells. CoVac-1 comprises six promiscuous HLA-DR-binding SARS-CoV-2-derived T cell epitopes from various viral proteins proven (i) to be frequently and HLA-independently recognized by T cells in COVID-19 convalescents, (ii) to be of pathophysiological relevance for T cell immunity to combat COVID-19, and (iii) to mediate long-term immunity after infection (Nelde et al. Nat Immunol 2021, Bilich et al. Sci Transl Med 2021). CoVac-1 vaccine peptides are adjuvanted with the novel toll-like receptor 1/2 agonist XS15 emulsified in Montanide࣪ ISA51 VG. In a first-in-human clinical trial in healthy adults (NCT04546841), CoVac-1 showed a favorable safety profile and induced profound and long-lasting T cell immunity after single dose administration in 100% of the study subjects, mediated by multifunctional T-helper 1 CD4+ and CD8+ T cells. CoVac-1-induced T cell responses surpassed those after SARS-CoV-2 infection as well as those after vaccination with approved vaccines and were unaffected by current SARS-CoV-2 variants of concern (Heitmann et al. Nature 2021). Here we present the interim safety and immunogenicity results of our Phase I/II trial evaluating CoVac-1 in patients with congenital or acquired B cell deficiency, mainly comprising leukemia and lymphoma patients (NCT04954469). 64% of study subjects had previously been vaccinated with approved vaccines without developing any humoral immune response. Alike in the healthy adults, CoVac-1 showed a good safety and tolerability profile without relevant systemic adverse events. CoVac-1-specific T cell responses could be documented in 93% of study subjects on day 28 after CoVac-1 application, with earliest responses evidenced at day 14 (71%). Vaccine-induced T cell responses were mediated by multifunctional T-helper 1 CD4+ T cells. Of note, CoVac-1 induced T cell responses in this highly immune compromised study population were similar to those occurring in healthy volunteers after natural infection or induced by approved vaccines. These results identify CoVac-1 as promising vaccine candidate for cancer and other immunocompromised patients with immunoglobulin deficiency. Recruitment of the Phase II part of the trial is ongoing with results expected for March 2022. Citation Format: Claudia Tandler, Jonas S. Heitmann, Maddalena Marconato, Yacine Maringer, Monika Denk, Marion Richter, Annika Nelde, Imma Fischer, Markus W. Löffler, Hans-Georg Rammensee, Helmut R. Salih, Juliane S. Walz. Interim safety and immunogenicity results of a phase I trial evaluating the multi-peptide COVID-19 vaccine candidate CoVac-1 for induction of SARS-CoV-2 T cell immunity in cancer patients with disease- or treatment-related immunoglobulin deficiency [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT258.

Abstract 3556: Immunopeptidomics-guided tumor antigen warehouse design and first clinical application of a personalized peptide vaccine for prostate cancer

Abstract Prostate cancer is the second most common malignancy in men with radical prostatectomy and radio-therapy being the primary curative treatment modalities in localized disease. However, up to 30% of patients experience recurrence that frequently leads to the development of metastatic disease associated with poor outcome. Therefore, novel, effective and low-side effect treatment options are essential, in particular for elderly and frail prostate cancer patients not eligible for intense therapy. Whereas, immune checkpoint inhibitors showed limited efficacy in prostate cancer so far, targeted T cell-based approaches with bispecific antibodies and cancer vaccines achieved promising results in this tumor entity. In this study, we established a prostate-associated off-the-shelf peptide warehouse, using mass-spectrometry-based immunopeptidome analysis of a large cohort of primary prostate tissue (n = 51), for the development of a broadly applicable personalized vaccine. The prostate dataset (23 prostate cancer, 12 adjacent benign, 16 benign prostate samples) comprising 29,893 HLA class I and II molecules, was compared to the immunopeptidomes of various benign non-prostate tissues (HLA-Ligand Atlas) to identify prostate exclusive antigens. Further antigen selection was based on the high presentation frequency. In total, 30 frequently expressed and prostate exclusive HLA class I peptides restricted to the six common allotypes HLA-A*02, -A*03, -A*24, -B*07, -B*08 and -B*40, covering more than 76% of the world population for at least one allotype, and five promiscuous HLA-DR restricted peptides found in up to 37% of prostates were selected. Immunogenicity was validated by IFNγ ELISPOT screening for preexisting T cell responses, as well as by in vitro priming experiments of naïve T cells in prostate cancer patients and healthy volunteers. The peptide warehouse will enable the formulation of personalized vaccines based on individual HLA allotype and immunopeptidome analysis of patient’s tumor samples in a reasonable time and cost frame within large cohort studies. We provided first evidence for the feasibility of this approach by designing a personalized immunopeptidome-guided peptide vaccine for a patient with metastatic prostate cancer. The vaccine was adjuvanted with the toll-like receptor 1/2 agonist XS15 emulsified in Montanide࣪ ISA51 VG and applied three times within a 12-week interval. Induction of a profound T cell response targeting 7/9 (78%) vaccine peptides was observed one week after the second vaccination. T cell responses have been persisting for almost two years in the patient, and in combination with androgen deprivation therapy enabled persistent PSA remission. In conclusion, we designed an immunopeptidomics-guided peptide warehouse and provided first evidence for its personalized application in prostate cancer patients. Citation Format: Yacine Maringer, Lena Freudenmann, Annika Nelde, Jonas S. Heitmann, Helmut R. Salih, Marissa Dubbelaar, Jörg Hennenlotter, Arnulf Stenzl, Jens Bedke, Hans-Georg Rammensee, Juliane S. Walz. Immunopeptidomics-guided tumor antigen warehouse design and first clinical application of a personalized peptide vaccine for prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3556.

Abstract 3574: A Phase I trial of personalized multi-peptide vaccination in combination with the TLR1/2 ligand XS15 in CLL patients under Bruton-Tyrosin-Kinase-inhibitor based regimes - Preclinical development and study design

Abstract Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. Despite the therapeutic success of novel small molecules (e.g. ibrutinib, idealisib and venetoclax), patients frequently experience disease relapse due to the persistence of minimal residual disease (MRD). Targeting the residual CLL cells by immunotherapy could further improve the depth and persistence of CLL remission. Here, we report on the preclinical development and clinical implementation of a phase I trial evaluating safety, immunogenicity and efficacy in terms of MRD response of a personalized multi-peptide vaccine adjuvanted with the novel toll-like receptor (TLR) 1/2 agonist XS15 emulsified in Montanide࣪ ISA51 VG (Rammensee et al. JIC 2019) in CLL patient receiving Bruton-Tyrosin-Kinase (BTK)-inhibitor based regimes (NCT04688385). So far, broad application of peptide vaccines in cancer patients is hampered by time- and cost-intensive design and the lack of neoepitopes from tumor-specific mutations, especially in low-mutational burden malignancies. To improve on these drawbacks, we developed an immunopeptidome-guided workflow for the design of tumor-associated off-the-shelf peptide warehouses for broadly applicable personalized therapeutics (Nelde et al., Front Immunol, 2021). For the trial reported here, comparative mass spectrometry-based immunopeptidome analyses of 61 CLL patient samples and a dataset of benign tissues samples (n = 351) enabled the identification of high-frequent non-mutated CLL-associated antigens for the most common HLA allotypes (HLA-A*02, -A*24, and -B*07). These antigens were proven to be recognized as T cell epitopes by pre-existing and de novo induced T cells in CLL patients and healthy volunteers, thereby enabling the selection of a 12-peptides panel comprising 9 HLA-class I (3 for each HLA allotype) and 3 HLA class II restricted high frequent CLL-exclusive T cell epitopes as warehouse for the personalized composition of study vaccine cocktails. Our meanwhile ongoing phase I trial recruits CLL patients eligible for treatment with BTK inhibitors. For those with matching HLA allotypes, a personalized peptide-cocktail is formulated comprising 6 CLL-associated peptides (3 HLA class I and 3 HLA class II peptides), selected from our warehouse based on individual immunopeptidome analysis, and 2 highly immunogenic HLA class II control peptides, one viral (human adenovirus C) and one tumor associated (Baculoviral IAP repeat-containing protein 5). Three doses of the vaccine are administered in a 4-weekly interval, after reduction of CLL-load by BTK inhibitors. So far, 10 CLL patients were included in the trial. The first vaccinations will be applied in November and December 2021 with first immunogenicity data expected in March 2022 and to be reported at the meeting. Citation Format: Maddalena Marconato, Annika Nelde, Yacine Maringer, Marcel Wacker, Marion Richter, Monika Denk, Helmut Salih, Jonas Heitmann, Juliane Sarah Walz. A Phase I trial of personalized multi-peptide vaccination in combination with the TLR1/2 ligand XS15 in CLL patients under Bruton-Tyrosin-Kinase-inhibitor based regimes - Preclinical development and study design [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3574.

A COVID-19 peptide vaccine for the induction of SARS-CoV-2 T cell immunity

T cell immunity is central for the control of viral infections. CoVac-1 is a peptide-based vaccine candidate, composed of SARS-CoV-2 T cell epitopes derived from various viral proteins1,2, combined with the Toll-like receptor 1/2 agonist XS15 emulsified in Montanide ISA51 VG, aiming to induce profound SARS-CoV-2 T cell immunity to combat COVID-19. Here we conducted a phase I open-label trial, recruiting 36 participants aged 18–80 years, who received a single subcutaneous CoVac-1 vaccination. The primary end point was safety analysed until day 56. Immunogenicity in terms of CoVac-1-induced T cell response was analysed as the main secondary end point until day 28 and in the follow-up until month 3. No serious adverse events and no grade 4 adverse events were observed. Expected local granuloma formation was observed in all study participants, whereas systemic reactogenicity was absent or mild. SARS-CoV-2-specific T cell responses targeting multiple vaccine peptides were induced in all study participants, mediated by multifunctional T helper 1 CD4+ and CD8+ T cells. CoVac-1-induced IFNγ T cell responses persisted in the follow-up analyses and surpassed those detected after SARS-CoV-2 infection as well as after vaccination with approved vaccines. Furthermore, vaccine-induced T cell responses were unaffected by current SARS-CoV-2 variants of concern. Together, CoVac-1 showed a favourable safety profile and induced broad, potent and variant of concern-independent T cell responses, supporting the presently ongoing evaluation in a phase II trial for patients with B cell or antibody deficiency.

Formulation of HBsAg in Montanide ISA 51VG adjuvant: Immunogenicity study and monitoring long-lived humoral immune responses

Montanide ISA 51VG adjuvant has been approved for human clinical application and stimulates cellular and humoral immune responses. Here, HBsAg was formulated in Montanide ISA51VG adjuvant to compare its potency with the Fendrix and HBsAg-alum vaccines. In particular, the long-term humoral response was assessed up to 220 days after the final immunization. BALB/c mice were allocated into six groups. Treatment groups were injected with HBsAg-Montanide ISA51VG, the Fendrix and commercial HBsAg-alum, respectively. Montanide ISA51 VG, Alum and PBS injected mice were considered as control groups. Mice were immunized three times with 2-week intervals on days 0, 14 and 28 by subcutaneous injection. Lymphocyte proliferation was assessed with the BrdU method. IFN-γ, IL-2 and IL-4 cytokines, specific total IgG and IgG1/IgG2a isotypes were assessed using ELISA.The HBsAg-Montanide ISA51VG vaccine resulted in a significant increase in lymphocyte proliferation versus HBsAg-alum and higher IL-2 cytokine production versus the Fendrix. Comparable IL-4 and IFN-γ cytokines responses were observed for these vaccines. Following the first immunization, IgG increased more in HBs-Montanide 51VG group versus the HBs-alum group, while after the second and third shots comparable responses were observed in comparison to the HBs-alum group. Monitoring for 220 days after the final vaccination showed the superiority of HBsAg-Montanide ISA 51VG vaccine versus HBsAg-alum and even the Fendrix vaccine in the induction of long-term antibody responses. This study suggests that HBsAg-Montanide ISA51VG as a novel vaccine formulation can trigger both cellular and long-lasting humoral immune responses more efficiently than conventional HBsAg vaccines.

Exploratory open-label clinical study to determine the S-588410 cancer peptide vaccine-induced tumor-infiltrating lymphocytes and changes in the tumor microenvironment in esophageal cancer patients

Cancer vaccines induce cancer-specific T-cells capable of eradicating cancer cells. The impact of cancer peptide vaccines (CPV) on the tumor microenvironment (TME) remains unclear. S-588410 is a CPV comprising five human leukocyte antigen (HLA)-A*24:02-restricted peptides derived from five cancer testis antigens, DEPDC1, MPHOSPH1, URLC10, CDCA1 and KOC1, which are overexpressed in esophageal cancer. This exploratory study investigated the immunologic mechanism of action of subcutaneous S-588410 emulsified with MONTANIDE ISA51VG adjuvant (median: 5 doses) by analyzing the expression of immune-related molecules, cytotoxic T-lymphocyte (CTL) response and T-lymphocytes bearing peptide-specific T-cell receptor (TCR) sequencing in tumor tissue or blood samples from 15 participants with HLA-A*24:02-positive esophageal cancer. Densities of CD8+, CD8+ Granzyme B+, CD8+ programmed death-1-positive (PD-1+) and programmed death-ligand 1-positive (PD-L1+) cells were higher in post- versus pre-vaccination tumor tissue. CTL response was induced in all patients for at least one of five peptides. The same sequences of peptide-specific TCRs were identified in post-vaccination T-lymphocytes derived from both tumor tissue and blood, suggesting that functional peptide-specific CTLs infiltrate tumor tissue after vaccination. Twelve (80%) participants had treatment-related adverse events (AEs). Injection site reaction was the most frequently reported AE (grade 1, n = 1; grade 2, n = 11). In conclusion, S-588410 induces a tumor immune response in esophageal cancer. Induction of CD8+ PD-1+ tumor-infiltrating lymphocytes and PD-L1 expression in the TME by vaccination suggests S-588410 in combination with anti-PD-(L)1 antibodies may offer a clinically useful therapy.Trial registration UMIN-CTR registration identifier: UMIN000023324.

Safety and Immunogenicity of a Human Epidermal Growth Factor Receptor 1 (HER1)-Based Vaccine in Prostate Castration-Resistant Carcinoma Patients: A Dose-Escalation Phase I Study Trial.

Metastatic castration-resistant prostate cancer (CRPC) remains incurable due to the lack of effective therapies. Activation of the human epidermal growth factor receptor 1 (HER1) in prostate cancer contributes to metastatic progression as well as to disease relapse. Here, we determined the toxicity and immunogenicity of a HER1-based cancer vaccine in CRPC patients included in a phase I clinical trial. CRPC patients (n = 24) were intramuscularly vaccinated with HER1 vaccine consisting of the extracellular domain of HER1 molecule (ECD) and very small size proteoliposome from Neisseria meningitidis (VSSP) and Montanide ISA-51 VG as adjuvants. Patients were included in five groups according to the vaccine dose (100, 200, 400, 600, and 800 μg). The primary endpoints were safety and immunogenicity. The anti-HER1 antibodies were measured by an ELISA, the recognition of an HER1 positive tumor cell line and the inhibition of HER1 phosphorylation by sera were determined by flow cytometry and western blot analysis, respectively. The HER1-specific T cell response was assessed by determination of IFN-γ-producing T cells using ELISpot assay. The vaccine was well tolerated. No grade III or IV adverse events were reported. High titers of anti-HER1 antibodies were observed in most of the evaluated patients. There were no significant differences regarding the geometric means of the anti-HER1 titers among the dose groups except the group of 100 μg in which antibody titers were significantly lower. A Th1-type IgG subclasses pattern was predominant in most patients. Only patients receiving the higher doses of vaccine showed significant tumor cell recognition and HER1 phosphorylation inhibition by hyperimmune sera. Forty two percent of the patients showed a specific T cell response against HER1 peptides pool in post-treatment samples. There was a trend toward survival benefit in those patients showing high anti-HER1 specific antibody titers and a significant association between cellular immune response and clinical outcome.

Abstract A006: Frameshift peptide neoantigens as vaccine targets in microsatellite-unstable cancers

Abstract Background: Deficient DNA mismatch repair (MMR) boosts the accumulation of frameshift mutations in genes encompassing coding microsatellites (cMS). This results in translation of proteins with mutation-induced frameshift peptide (FSP) neoantigens rendering MMR-deficient microsatellite-unstable (MSI) cancers highly immunogenic. Patients with MSI cancers and healthy individuals affected by Lynch syndrome, an inherited prediposition for MSI cancers, develop specific immune responses against these neoantigens. MSI cancers are unique in tumor immunology, because they express a defined set of long neoantigens that result from functionally relevant driver mutations and therefore are shared by the majority of MSI cancers. Consequently, MSI cancers in Lynch syndrome are an ideal model to evaluate the concept of cancer vaccines, which, with the increasing knowledge about mutational antigens in a wide variety of cancer types, can potentially be applied to many human cancer types. We here report the results of a clinical phase I/IIa trial as the first step to translate this concept into the clinical application. Methods: The vaccination protocol comprised 3 cycles of 4 subcutaneous applications of FSP antigens (frameshift variants of the coding microsatellite-containing genes AIM2, HT001, TAF1B) mixed with Montanide ISA-51 VG over a 6 month period. Inclusion criteria were history of MSI-H colorectal cancer (UICC stage III or IV) and completion of standard chemotherapy. Phase I of the trial evaluated safety and toxicity as the primary endpoint (6 patients), phase IIa addressed the induction of cellular and humoral immune responses (16 patients). Results: Significant induction of FSP-specific immune responses against one or more FSP antigens was observed in all patients vaccinated per protocol. No vaccination-induced systematic severe adverse events occurred. Few patients had stage IV disease and were evaluable according to RECIST. One heavily pretreated patient with bulky metastases showed a stable disease and stable CEA levels over 7 months under the study treatment. Conclusions: Vaccination with FSPs is well tolerated and leads to the induction of humoral and cellular immune responses. FSP vaccination represents a promising novel approach for treatment of MSI cancer patients and for tumor prevention in Lynch syndrome, allowing the evaluation of the concept of preventive cancer vaccines in an ideal model scenario of a defined high-risk patient population. Note: This abstract was not presented at the conference. Citation Format: Magnus von Knebel Doeberitz, Matthias Kloor, Miriam Reuschenbach, Claudia Pauligk, Mohammad-Reza Rafiyan, Salah-Eddin Al Batran, Julia Karbach, Mirjam Tariverdian, Elke Jaeger. Frameshift peptide neoantigens as vaccine targets in microsatellite-unstable cancers [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A006.

Effective induction of cytotoxic T cells recognizing an epitope peptide derived from hypoxia-inducible protein 2 (HIG2) in patients with metastatic renal cell carcinoma

PurposeThrough genome-wide expression profile analysis, hypoxia-inducible protein 2 (HIG2) has previously been identified as an oncoprotein involved in development/progression of renal cell carcinoma (RCC). We subsequently identified a highly immunogenic HLA-A*0201/0206-restricted epitope peptide (HIG2-9-4) corresponding to a part of HIG2 and applied it as a therapeutic vaccine. We conducted a phase I clinical trial using the HIG2-9-4 peptide for patients with advanced RCC.Materials and MethodsNine patients having HLA-A*0201 or HLA-A*0206 with metastatic or unresectable RCC after failure of the cytokine and/or tyrosine kinase inhibitor therapies were enrolled in this study. The patients received subcutaneous administration of the peptide as an emulsion form with Montanide ISA-51 VG once a week in a dose-escalation manner (doses of 0.5, 1.0, or 3.0 mg/body, 3 patients for each dose). The primary endpoint was safety, and the secondary endpoints were immunological and clinical responses.ResultsVaccinations with HIG2-9-4 peptide could be well tolerated without any serious systemic adverse events. Peptide-specific cytotoxic T lymphocyte (CTL) responses were detected in eight of the nine patients. Doses of 1.0 or 3.0 mg/body seemed to induce a CTL response better than did a dose of 0.5 mg/body, although the number of patients was too small to draw a firm conclusion. The disease control rate (stable disease for ≥4 months) was 77.8 %, and the median progression-free survival time was 10.3 months.ConclusionsHIG2-9-4 peptide vaccine treatment was tolerable and effectively induced peptide-specific CTLs in RCC patients. This novel peptide vaccine therapy for RCC is promising.

Therapeutic Vaccination against A Modified Minimal Survivin Epitope Induces Functional CD4 T Cells That Recognize Survivin‐Expressing Cells

During the last decade, cancer vaccination has received a great deal of attention; however, documentation of the clinical effect remains limited. The introduction of immune checkpoint inhibitors as a novel therapeutic modality 1–4 could by combination increase the ability of a peptide vaccination to induce clinical responses. Survivin is an anti-apoptotic protein, first discovered in 1997. 5 It is overexpressed in a wide array of cancers, including malignant melanoma (MM), 5,6 and expression is correlated with disease progression and a poor prognosis in e.g. colon cancer and neuroblastoma. 7,8 Survivin is an excellent target for cancer vaccines due to its universal expression in cancer; in addition, down-regulation will impair the tumor cell's ability to proliferate and expand. This article is protected by copyright. All rights reserved.

Poly-ICLC as an adjuvant for NY-ESO-1 protein vaccination with or without Montanide ISA-51 VG in patients with melanoma.

e14034 Background: Poly-ICLC (Hiltonol, Oncovir Inc) is a synthetic dsRNA complex which directly activates DCs and also triggers NK cells to kill tumor cells. Compared to LPS and R848, Poly-ICLC is...

CD20 peptides elicit a protective anti-tumor immune response in vivo (VAC5P.1126)

Abstract We have investigated whether human CD20 (huCD20)-derived peptides are able to elicit a protective anti-tumor immune response in vivo. Based on in silico prediction and in vitro binding to recombinant MHC molecules (Kb, Db, and I-Ab), we first defined candidate peptides able to bind to various MHC molecules in a restricted manner (8-mers restricted to Kb, 9-mers restricted to Db, 15-mers and 20-mers restricted to I-Ab). Naive C57Bl/6 mice were then immunized s.c. with 7 different mixtures of these peptides in presence of adjuvants (CFA/IFA, Montanide ISA 51VG, CpG) and subsequently challenged with EL4-huCD20 tumor cells. Interestingly, a longer survival could be achieved in mice immunized with 5 of the 7 huCD20-derived peptide mixtures. In addition, MHC-peptide fluorescent pentamers (generated using peptides with the highest capacity of binding to MHC molecules) allowed the detection of anti-CD20 specific CD8+ T cells in one of the groups of immunized mice. Overall, we conclude that it is possible to define huCD20-derived peptides that elicit a T-cell response against EL4-huCD20 tumor cells. We suggest that these peptides could be the targets of the adaptive anti-tumor T cell response triggered by anti-CD20 treatment that we previously reported using a mouse model in which immune competent C57Bl/6 mice were i.v. injected with human CD20+ tumor cells and then treated with an anti-huCD20 mAb (1,2). 1. Abès et al., Blood, 2010 2. Deligne et al., Leukemia, 2014

Phase I/II study of the TLR3 agonist poly-ICLC as an adjuvant for NY-ESO-1 protein vaccination with or without Montanide ISA-51 vg in patients with melanoma.

TPS9119 Background: Poly-ICLC is a synthetic dsRNA complex which directly activates DCs and also triggers NK cells to kill tumor cells. Compared to LPS and R848, Poly-ICLC is the most potent TLR ad...

A Multicenter Randomized Phase IIb Efficacy Study of Vx-001, a Peptide-Based Cancer Vaccine as Maintenance Treatment in Advanced Non–Small-Cell Lung Cancer: Treatment Rationale and Protocol Dynamics

We present the treatment rationale and study design of a multicenter, open-label, randomized, 2-arm, phase IIb study. Patients with stage IV or recurrent stage I to III non–small-cell lung cancer (NSCLC) whose disease does not progress after 4 cycles of first-line platinum-based chemotherapy will be randomized in a 1:1 ratio to 1 of 2 study arms. Patients will receive the cancer vaccine Vx-001 + Montanide ISA51 VG (Seppic, Paris, France) adjuvant subcutaneously, at a dose of 2 mg, or placebo + Montanide ISA51 VG adjuvant subcutaneously. The vaccination protocol comprises 2 injections with the TYR-Vx001 or placebo (1 at day 0 and another at week 3) and 4 injections with the ARG-Vx001 or placebo, at weeks 6, 9, 12, and 15. After the treatment assessment at week 18, patients will receive the ARG-Vx001 or placebo every 12 weeks starting from week 27 until disease progression, unacceptable toxicity, withdrawal of informed consent, or death. The primary end point of this study is the survival rate at 12 months. Secondary end points include time-to-event comparison of overall survival and comparison of time to treatment failure. Exploratory objectives include comparison of disease control rate after the end of subsequent second-line treatments, comparisons of vaccine immune responses, comparison of survival rate at 12 months in patients with vaccine-induced immune response detected after the second and sixth injections, identification of biomarkers on lymphocytes and on tumors, and comparison of safety and tolerability.

Abstract 4571: Autologous TARP peptide vaccination is associated with slowing in PSA velocity and a decrease in tumor growth rate in patients with Stage D0 prostate cancer.

Abstract Background: T-cell receptor alternate reading frame protein (TARP) is a novel, immunogenic 58 amino acid protein that is over-expressed in ∼95% of prostate cancer and ∼50% of breast cancer specimens and hence is a good candidate for therapeutic vaccination. In mice the immunogenicity of HLA-A*0201 binding TARP peptides can be improved through epitope-enhancement achieved by amino acid substitutions that result in increased HLA binding affinity. We conducted a first-in-human study to determine the safety and immunogenicity of TARP peptide vaccination and its impact on the velocity of PSA rise (expressed as slope log (PSA) or PSA doubling time (PSADT)) and tumor growth rate in men with Stage D0 prostate cancer. Methods: HLA-A*0201 positive men were randomized to receive epitope-enhanced (29-37-9V) or wild type (27-35) TARP peptides administered as a peptide emulsion with Montanide ISA 51VG plus GM-CSF (Arm A) or as an autologous peptide-pulsed dendritic cell vaccine (Arm B). Vaccines were administered q 3 weeks for a total of 5 vaccines with an optional 6th dose of vaccine at 36 weeks based on immune response or PSADT criteria and a booster dose of vaccine for all patients at 48 and 96 weeks. Results: A total of 41 patients (n = 21 Arm A, n = 20 Arm B) enrolled, with a median on study duration of 75 weeks as of 07/31/12. Baseline cohort characteristics (median): age 62 yrs, PSA 3.44, Gleason Score 7, ALC 1270, CD4%/absolute 42.5%/547 cells/mm3, 25-OH vitamin D level 28, with 30 of 41 (73%) s/p radical prostatectomy and 26 of 41 (63%) s/p EBRT for PSA biochemical recurrence. TARP vaccination was safe and well tolerated with adverse events limited to local injection site reactions < Grade 2. Twenty-eight of 39 patients (72%) reaching 24 weeks and 23 of 31 (74%) reaching 48 weeks were documented to have a decreased slope log PSA compared to their pre-vaccination baseline (p=0.0012 and p=0.0004 for overall changes in slope log PSA, respectively); there was no statistically significant difference between the two arms, although only the DC arm was significant at 48 wks on its own. TARP vaccination also resulted in a 50% decrease in calculated tumor growth rate constant: pre-vaccine g = 0.0042/day, post-vaccine g = 0.0021/day (p=0.003). TARP-specific IFN-γ ELISPOT responses were detected in the majority of subjects but did not correlate with observed decreases in slope log (PSA). Citation Format: Lauren V. Wood, William L. Dahut, Antonio Fojo, James L. Gulley, Ravi Madan, Philip Arlen, Howard L. Parnes, Brenda D. Roberson, Seth M. Steinberg, Masaki Terabe, Julia Wilkerson, Ira Pastan, Jay A. Berzofsky. Autologous TARP peptide vaccination is associated with slowing in PSA velocity and a decrease in tumor growth rate in patients with Stage D0 prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4571. doi:10.1158/1538-7445.AM2013-4571

Abstract B73: Proof of glypican-3 (GPC3) peptide specific CTLs infiltrating into tumor tissue derived from advanced HCC patient vaccinated with GPC3 peptide.

Abstract Background: Glypican-3 (GPC3) is an onco-fetal antigen which is overexpressed in human hepatocellular carcinoma (HCC), and is only expressed in the placenta and embryonic liver among normal tissues. Previously, we completed a phase I clinical trial of HLA-A2-restricted GPC3 144-152 (FVGEFFTDV) and A24-restricted GPC3 298-306 (EYILSLEEL) peptide vaccine in 33 patients with advanced HCC. This clinical trial of GPC3-derived peptide vaccine showed the vaccination was well tolerated, and indicated many immunological responses. Furthermore, GPC3-specific CTL frequency after vaccination correlated with overall survival. In addition, tumor biopsy was carried out in 7 patients to evaluate the therapeutic effect after vaccination. We evaluated the infiltration of CD8-positive T cells by immunohistochemical staining. In 5 of 7 cases, infiltration of CD8-positive T cells into the tumor was increased after vaccination. However, we did not confirm that the tumor-infiltrating lymphocytes detected after vaccination were GPC3 peptide-specific CTLs. We are currently initiating a pilot study of liver biopsies carried out before and after GPC3 peptide vaccination for advanced HCC to determine whether tumor-infiltrating lymphocytes are indeed GPC3 peptide-specific CTLs. We tried to detect GPC3 peptide-specific CTLs in biopsy specimens from vaccinated patients using GPC3-Dextramer. Materials and Methods: The trial was designed to assess clinical response, and whether tumor-infiltrating lymphocytes with anti-tumor effect are increased indeed after GPC3 peptide vaccination for advanced HCC (UMIN-CTR number: 000005093). Vaccinations with 3.0 mg of GPC3 peptide, emulsified with incomplete Freund's adjuvant (Montanide ISA-51 VG) were carried out intradermally at 14-day intervals. Peripheral blood was obtained from each patients at times designated in the protocol (before the first vaccination and 2 weeks after each vaccination) and centrifuged using a Ficoll–Paque gradient. Immunological responses were analyzed ex vivo by IFN-γ Enzyme-linked immunospot (ELISPOT) assay using peripheral blood mononuclear cells (PBMCs). Tumor biopsy was carried out after 5-6th vaccination. The cells obtained from biopsy specimens were stained anti-CD3, anti-CD8 antibody and GPC3-Dextramer and analyzed using FACSAria cell sorter. Results: We could obtain evidence of GPC3 peptide-specific CTLs infiltrating into the HCC tumor from one case. In this case, the frequency of GPC3 peptide specific CTLs after vaccination (290 of 5 x 105 PBMCs) was larger than that before vaccination (0 of 5 x 105 PBMCs) ex vivo in IFN-γ ELISPOT assay. In flow cytometer analysis, CD3+, CD8+, GPC3-Dextramer+ cells were detected in cells obtained from a biopsy specimen of this vaccinated patient. Moreover, we established GPC3 peptide specific CTL clones from these cells by single cell sort using GPC3-Dextramer. These GPC3-Dextramer+ CTL clones showed GPC3 peptide specific IFN-γ secretion. Conclusion: We could prove that the GPC3 peptide-specific CTLs have been infiltrated into the tumor tissue after peptide vaccination. The evidence serves as a proof-of concept for GPC3 peptide vaccine therapy. Citation Format: Toshiaki Yoshikawa, Mayuko Sakai, Kazuya Ofuji, Mari Takahashi, Manami Shimomura, Yu Sawada, Daisuke Nobuoka, Tetsuya Nakatsura. Proof of glypican-3 (GPC3) peptide specific CTLs infiltrating into tumor tissue derived from advanced HCC patient vaccinated with GPC3 peptide. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr B73.

Abstract B53: An autopsy case of a hepatocellular carcinoma patient with remarkable tumor necrosis immediately following glypican-3-derived peptide vaccination.

Abstract Introduction: We recently reported vaccine's safety, immunological and clinical responses in a phase I clinical trial of GPC3-derived peptide vaccine for advanced HCC patients (Clin Cancer Res 2012; 18: 3686-96). The phase I trial showed that GPC3 peptide-specific CTLs increased in peripheral blood, that many CD8 positive T cells infiltrated tumors in some patients, and the correlation between the CTL response and overall survival after the GPC3 peptide vaccination. On the basis of these results, we conducted the next trial for advanced HCC to assess histopathological findings after GPC3 peptide vaccination. We present here the clinical course and pathological study including autopsy of an advanced HCC patient, which had revealed remarkable tumor lysis immediately after the second vaccination in the ongoing clinical trial of GPC3 peptide vaccine. Study design: The trial was designed to assess clinical response, and whether tumor-infiltrating lymphocytes with anti-tumor effect are increased indeed after GPC3 peptide vaccination for advanced HCC (UMIN-CTR number: 000005093). In all cases of the trial, liver biopsies are going to be performed before and after the vaccination according to the protocol. 3.0mg of HLA-A*02 -restricted GPC3144-152 peptide (FVGEFFTDV) was administered intradermally in a liquid form emulsified with incomplete Freund's adjuvant (Montanide ISA-51VG, SEPPIC). The vaccination was scheduled every two weeks. Clinical course: A 62-year old patent, suffering from HCC refractory sorafenib therapy, was offered participation in the clinical trial of GPC3 peptide vaccine for advanced HCC. Contrast-enhanced CT before the vaccination showed multiple tumors in the liver and tumor invading into the right atrium. According to the protocol, liver biopsy was performed before the vaccination. Histopathological examination of the specimen revealed well-differentiated hepatocellular carcinoma. Immunohistochemical staining showed the expression of GPC3 and HLA class I on the membrane of carcinoma cells, and that there were little CD8-positive T cell in the specimen of liver biopsy before the vaccination. This patient had fever up, general fatigue, and remarkable impaired liver function twice subsequently after the vaccination. Contrast-enhanced CT after the second vaccination depicted multiple low density areas in the liver, indicating extended tumor necrosis. On the other hand, tumor embolism in the inferior vena cava and the right atrium was increased. Unfortunately, on day 30 after the second vaccination, he died. The autopsy was performed to determine the main causes leading to death and to evaluate the antitumor effect of vaccination. Autopsy study and immunological analysis: The main cause of death was diagnosed with circulatory failure due to tumor embolism, which occupied most of the right atrium. Histopathological examination showed the central necrosis in most of the tumor and viable carcinoma cells remained slightly around the necrotic tissue. Immunohistochemical staining showed that the infiltration of CD8 positive T cells near the residual carcinoma cells was observed, while it was not observed in the cirrhotic nodule. CD68 positive macrophages aggregated in the necrotic area around cirrhotic nodules. CD8 positive T cells also infiltrated there, suggesting probable that carcinoma cells might had been attacked by CD8 positive T cells, which might had leaded to necrosis. Ex vivo IFN-γ ELISPOT analysis of peripheral blood lymphocytes revealed vaccine-induced immune-reactivity against GPC3 peptide. Conclusion: Histopathological examination at the estimated time of the strong immunological responses can prove GPC3 peptide vaccination induce GPC3 peptide-specific CTL responses with the anti-tumor effect. Citation Format: Yu Sawada, Toshiaki Yoshikawa, Satoshi Fujii, Mari Takahashi, Tetsuya Nakatsura. An autopsy case of a hepatocellular carcinoma patient with remarkable tumor necrosis immediately following glypican-3-derived peptide vaccination. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr B53.

Non-clinical immuno-toxicological evaluation of HER1 cancer vaccine in non-human primates: a 12-month study

Human epidermal growth factor receptor (HER1) constitutes a tumor associated antigen. Its overexpression in many epithelial tumors has been associated with bad prognosis and poor survival. Cancer vaccine based on the extracellular domain (ECD) of HER1 and adjuvated in very small sized proteoliposomes (VSSP) and Montanide ISA 51-VG is a new and complementary approach for the treatment of epithelial tumors. The present study deals with the immunogenicity of this vaccine in Macaca fascicularis monkeys and evaluation of its toxicity during 12 months. Twelve monkeys were randomized into two groups of 3 animals per sex: control and vaccinated. Treated monkeys received 9 doses of vaccination and were daily inspected for clinical signs. Body weight, rectal temperature, cardiac and respiratory rates were measured during the study. Humoral immune response, clinical pathology parameters and delayed type hypensensitivity were analyzed. Skin biopsy was performed at the end of the study in all animals. Animal's survival in the study was 100% (n=12). Local reactions were observed at the administration site of four treated animals (n=6), with two showing slight inflammatory cutaneous damage. Clinical pathology parameters were not affected. HER1 vaccine induced high IgG antibodies titers in the treated animals even when DTH was not observed. The induced antibodies recognized HER1+ tumor cell lines, decreased HER1 phosphorylation and showed anti-proliferative and pro-apoptotic effects in H125 cells. In general the present study showed that HER1 vaccine induced specific immune response in M. fascicularis monkeys and was well tolerated, suggesting it could be safely used in clinical studies in epithelial cancer patients.

Phase I/II study of resiquimod as an immunologic adjuvant for NY-ESO-1 protein vaccination in patients with melanoma.

2589 Background: The TLR 7/8 agonist, Resiquimod has been shown to induce local activation of immune cells, production of cytokines, and antigen-presentation by dendritic cells, features desirable for cancer vaccine adjuvants. In this study, we evaluated the safety and immunogenicity of vaccination with NY-ESO-1 protein emulsified in Montanide ISA-51 VG when given with or without Resiquimod in patients with surgically resected stage IIB-IV melanoma patients. Methods: This is a two-part study design. Part I represents an open-label dose-escalation with Resiquimod using 2 cohorts treated with 100ug NY-ESO-1 protein emulsified in 1.25mL Montanide (day1) followed by topical application of 1000mg of the 0.2% Resiquimod gel on days 1 and 3 for cohort-1 (N=3) or days 1, 3, and 5 for cohort-2 (N=3). The cycles were repeated every 3 weeks, total of 4 cycles. Part II of the study is blinded. Patients were randomized to receive 100ug NY-ESO-1 protein emulsified in 1.25mL Montanide (day1) followed by topical application of placebo gel (Arm-A; N=8) or 1000mg of 0.2% Resiquimod gel (Arm-B; N=12) using the dosing regimen established in Part I. Blood samples were collected at baseline, one week after each cycle of vaccination, and at follow-up visit for the assessment of NY-ESO-1-specific humoral and cellular immune responses. Results: Enrollment has been completed. 25/26 patients received all 4 vaccinations. The treatment was generally well-tolerated, with no grade 4 adverse events or study-related deaths. The most common toxicities were mild to moderate and included local injection site reactions (granuloma, pruritus, induration) and systemic flu-like symptoms. One patient experienced a grade 3 syncopal episode that was deemed unrelated to the drug. Another patient experienced a grade 3 injection site necrosis that was possibly related to the study drug and was removed from the study prior to receiving the 4th vaccine. Conclusions: This study demonstrates the safety of Resiquimod as an adjuvant for NY-ESO-1 protein vaccination. The study will remain blinded until all immune monitoring assays have been completed. An updated abstract will be submitted once the study is unblinded.