Personalized Peptide Vaccination Research Articles

Development of tumour peptide vaccines: From universalization to personalization.

In recent years, relying on the human immune system to kill tumour cells has become an effective means of cancer treatment. The development of peptide vaccines, which not only break the immune tolerance of a tumour but also attack malignant cells via specific antitumour immunity, has received increased attention in tumour immunization therapy due to their safety and easy preparation. The use of large-scale sequencing technology enables the continuous discovery of new tumour antigens. With improved accuracy of epitope prediction by computer simulation and the usage of a tetramer assay, cytotoxic lymphocyte epitopes can be screened and identified more easily. Transmembrane peptide and nanoparticle technologies promote more effective intake and delivery of antigens. Consequently, considerable evolution from universal to personalized peptide vaccines has taken place, and such vaccines induce an efficient and specific immune response targeting tumour neoantigens. Recently, genomic analysis and bioinformatics approaches have greatly facilitated the breakthrough of personalized peptide vaccines targeting neoantigens, resulting in a renewed interest in this field. Further, the combination of tumour peptide vaccines with checkpoint blockades may improve patient outcomes. In this review, we discuss the development of tumour peptide vaccines and the new technological progress, from universalization to personalization, to highlight the substantial promise of tumour peptide vaccines in clinical cancer immunotherapy.

CD4/CD8 ratio is a prognostic factor in IgG nonresponders among peptide vaccine-treated ovarian cancer patients.

The identification of useful biomarkers is an urgent issue in cancer treatment, particularly for immunotherapy, as only some patients experience benefits from this treatment. The early induction of the IgG response has been reported as a useful biomarker of favorable prognosis for cancer patients treated with a personalized peptide vaccination, but a portion of these patients (IgG nonresponders) fail to achieve an early induction of IgG response yet experience long‐term survival. It is thus necessary to identify other biomarkers of favorable prognosis among these patients. Here we report the usefulness of classical T‐cell markers (ie, the CD8 content and the CD4/CD8 ratio in peripheral blood) in IgG nonresponders among advanced or recurrent ovarian cancer patients treated with a personalized peptide vaccination. Among IgG nonresponders (n = 25), the overall survival (OS) of the increased‐CD8 group (n = 7) was significantly longer than that of the decreased‐CD8 group (n = 18; P = .018), and the OS of the patients with a decreased CD4/CD8 ratio (n = 10) was significantly longer than that of the patients with an increased ratio (n = 15; P = .0055). Thus, an increased content of CD8 and a decreased CD4/CD8 ratio are each favorable prognosis markers in IgG nonresponders treated with a personalized peptide vaccination.

Abstract P5-04-21: Analysis of serum immune biomarkers for response to therapeutic personalized peptide vaccination in patients with metastatic breast cancer

Abstract Purpose: Our results from the previous clinical trials using personalized peptide vaccines (PPV) combined conventional chemo-hormonal therapies have confirmed the potential for clinical benefit in patients who had higher IgG antibody and/or CTL response to the immunized PPV (SABCS 2018 U Toh etc.). The aim of this study is to evaluate the association between the serum immunologic factors including cytokines, haptoglobin (HP), B-cell activating factor (BAFF) etc. and the clinical outcome of patients(pt) with metastatic breast cancer (mBC) who treated by personalized peptide vaccines (PPV). Methods: Peripheral blood samples from 57 pts and 52 pts obtained before and after the vaccination of PPV, respectively. Serum HP and IL-6 were analyzed by ELISA(R&D Systems, Life Technologies)and bead-based multiplex assays(Luminex 200 system)were performed for GM-CSF,IFN-γ,TNF-α, BAFF, TGF-β, IFNγ-induced protein 10(IP-10), IL-1β, IL-2,-4,-5,-8, -10. The association between each factor and clinical outcome was statistically evaluated. Results: Pt’s group (n=28) with low BAFF and high HP level (>544 pg/ml), high IFN-γ and high HP level or low IL-8 and high HP level before PPV treatment showed a significantly shorter median survival time (MST; p=0.015;0.068;0.002, respectively). There was no difference in high BAFF, low IFN-γ or high IL-8 level group(n=29). In contrast, pt’s group with low serum level of IL-10, GM-CSF, IL-5, IL-4 and low HP level (<544 pg/ml MV) after PPV treatment associated with significantly shorter MST (p=0.002; 0.001; 0.001; <0.001, respectively). Conclusions: The combination of serum levels of HP and BAFF, IFN-γ or cytokines of IL-8, -10, - 5, -4 might be useful prognostic biomarkers for mBC pts receiving PPV therapy. Citation Format: Uhi Toh, Shuko Saku, Yuko Takao, Sayaka Sakurai, Miki Takenaka, Shigeki Shichijo, Kyogo Itoh, Yoshito Akagi. Analysis of serum immune biomarkers for response to therapeutic personalized peptide vaccination in patients with metastatic breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-04-21.

Engineered hepatitis B core virus-like particle carrier for precise and personalized Alzheimer’s disease vaccine preparation via fixed-point coupling

Heterogenous aggregates of amyloid β (Aβ) and tau protein play a key role in Alzheimer’s disease (AD) progression. As the epitope profiles of Aβ and abnormally phosphorylated tau change over the course of the disease, tailor immunotherapy to specific patient groups according to the disease stage by targeting corresponding Aβ and tau species or both of tau and Aβ might improve treatment efficacy. However, epitope peptides have low immunogenicity and peptide vaccine preparation is laborious and time-consuming. We here first constructed a platform for peptide vaccine preparation by inserting SpyCatcher into the major immunodominant region (MIR) of truncated Hepatitis B core protein (HBc)(1-149). The resulted recombinant protein HBc-SpyCatcher (HBc-S) could assemble into uniform and stable virus-like particles (VLPs), and readily bind to the SpyTag conjugated epitope peptides. Several series of peptides such as linear, cyclic and phosphorylated peptides including Aβ(1-6), Aβ(1-15), cAβ(1-7), cEP1, cEP2 from β-amyloid monomer or oligomers, T294, pTau396-404, pTau422 from tau proteins, were glued onto HBc-S VLPs, forming HBc-S-peptide (HBc-S-P) VLPs and efficiently elicited specific Th2-type immune responses. When applied to AD transgenic mice, HBc-S-pTau422 alleviated cognition deficits and neuropathology progression in Tau.P301S transgenic mice. The present study provides an easy, quick, convenient and universal platform for high-throughput peptide epitope screening and personalized peptide vaccine preparation.

P2.04-65 Peptide-Based Cancer Vaccine Shortened the Overall Survival of a Large Portion, but Not All, of Advanced Cancer Patients

We have been promoting clinical trials of peptide-based cancer vaccination for various cancers, mainly at Kurume University School of Medicine. Objective: To determine biomarkers predictive of overall survival (OS) in advanced cancer patients treated with a peptide-based cancer vaccine. Patients: The samples from two randomized, double-blind, placebo-controlled, phase III trials of personalized peptide vaccine (PPV) for advanced prostate cancer patients (n=306) and recurrent glioblastoma (n=88) patients, those from one single arm phase II trial of PPV for various types of advanced cancer patients (n=2588), and those from one randomized placebo-controlled non-personalized phase II trial (n=51) for advanced prostate cancer patients were provided for this retrospective biomarker study. No significant differences in clinical benefit (overall survival, OS) were found between the patients receiving PPV and those receiving placebo in each of the two randomized, double-blind, placebo-controlled, phase III trials. The neutrophil or lymphocyte proportion in advanced prostate cancer patients prior to study entry was a biomarker discriminating the PPV patients (70%) who showed significantly shorter OS relative to placebo patients from the remaining PPV patients who showed significantly longer OS relative to placebo patients. The C-C motif chemokine 2 (CCL2) level prior to the study entry in recurrent glioblastoma patients was the other biomarker discriminating the PPV patients (40%) who showed significantly shorter OS relative to placebo patients from the remaining PPV patients who showed significantly longer OS relative to placebo patients. The neutrophil or lymphocyte proportion prior to the phase II study entry (n=2588) was also a biomarker discriminating the PPV patients (60%) with significantly shorter OS from the remaining PPV patients entered in the single arm phase II study in all the advanced cancer patients other than gastric cancer or glioblastoma patients. Notably, the median OS for the 250 of 399 lung cancer patients (62 %) who met either or both the cutoffs of neutrophils ³64% and lymphocytes <26% was significantly shorter than that of the remaining 149 patients (38%) (9.5 month,95% confidence interval: 7.6-11.9 vs 20.0 month,13.0-25.3, p<0.001). The CCL2 level, however, prior to the study entry was not a biomarker in these lung cancer patients receiving PPV. This biomarker was also predictive of OS in a randomized placebo-controlled non-personalized phase II trial of peptide-based vaccine. Peptide-based cancer vaccine shortened the OS of a large portion, but not all, of advanced cancer patients with various types of cancer. Prospective clinical studies of peptide-based cancer vaccines using the newly defined prognostic markers may be warranted.

137P - Biomarkers predictive of overall survival in advanced cancer patients treated with a peptide-based cancer vaccine

BackgroundTo determine biomarkers predictive of overall survival (OS) in advanced cancer patients treated with a peptide-based cancer vaccine. MethodsThe samples from two randomized, double-blind, placebo-controlled, phase III trials of personalized peptide vaccine (PPV) for advanced prostate cancer patients (n=306) and recurrent glioblastoma (n=88) patients, those from one single arm phase II trial of PPV for various types of advanced cancer patients (n=2588), and those from one randomized placebo-controlled non-personalized phase II trial (n=51) were provided for this retrospective biomarker study. ResultsNo significant differences in clinical benefit (overall survival, OS) were found between the patients receiving PPV and those receiving placebo in each of the two randomized, double-blind, placebo-controlled, phase III trials. The neutrophil or lymphocyte proportion in advanced prostate cancer patients prior to study entry was a biomarker discriminating the PPV patients (70%) who showed significantly shorter OS relative to placebo patients from the remaining PPV patients who showed significantly longer OS relative to placebo patients. The CCL2 level prior to the study entry in recurrent glioblastoma patients was the other biomarker discriminating the PPV patients (40%) who showed significantly shorter OS relative to placebo patients from the remaining PPV patients who showed significantly longer OS relative to placebo patients. The neutrophil or lymphocyte proportion prior to study entry was also a biomarker discriminating the PPV patients (60%) with significantly shorter OS from the remaining PPV patients entered in the single arm phase II study in all the advanced cancer patients other than gastric cancer or glioblastoma patients. This marker could also discriminate patients who showed significantly shorter OS from the remaining patients in the non-personalized peptide vaccine phase II study for prostate cancer patients. ConclusionsPeptide-based cancer vaccine shortened the OS of a large portion, but not all, of advanced cancer patients with various types of cancer. Prospective clinical studies of peptide-based cancer vaccines using the newly defined prognostic markers may be warranted. Clinical trial identificationUMIN Clinical Trials Registry, 6970, 113088, 11028, 1482, 1839, 1844, 1847, 1850, 1854, 1855, 1856, 1875, 1881, 1882, 1883, 1884, 2282, 3590, 5631, 6249, 6295, 6493, 7493, 8126, 8823, 8824, 8825, 8826, 8827, 8828, 10068, 19390, 2906, 2907, 2908, 2984, 2985, 2987, 3027, 3028, 3029, 3059, 3060, 3081, 3082, 3083, 5329, 10290, 11593, 14855, 19802, 19879, 6927,11230. Legal entity responsible for the studyPresident Kyogo Itoh,M.D., Ph.D., Cancer vaccine center, Kurume University School of Medicine, Japan. FundingGrants from the Japan Agency for Medical Research and Development (16ck0106086h0003, 18im0110802h0008), the Ministry of Health, Labor and Welfare of Japan, and FUJIFILM Corporation. DisclosureM. Noguchi: Advisory / Consultancy: BrightPath Biotherapeutics Co. Ltd. A. Yamada: Advisory / Consultancy: BrightPath Biotherapeutics Co. Ltd. K. Itoh: Advisory / Consultancy, Research grant / Funding (self): Taiho Pharmaceutical Company. All other authors have declared no conflicts of interest.

Computational Prediction of Tumor-Specific Antigens as Potential Vaccine Candidates against Germ-line Mutations in Endometrial Cancer

Endometrial cancer is the fourth most common cancer in women. It arises from the endometrium and accompanied by the abnormal growth of the cells. Sign and symptoms include pelvic pain and abnormal vaginal bleeding. It has two categories. Type 1 tumors are estrogen-dependent and they have mutations in PTEN, PIK3CA while Type 2 tumors are more sensitive and have mutations in TP53. Overactivation of the signaling pathway (PI3K) results in anti-apoptosis. Here, this study aims to identify Tumor-Specific Antigen for germline mutations in endometrial cancer which can be used as a potential vaccine candidate. The germline mutations data are obtained from cancer gene census of the cosmic database. Genes mutating with crucial role in endometrial cancer are considered. Peptides libraries are generated using peptide design library. Human leukocyte antigen alleles are identified for the peptide library through NetMHC. Binding affinities of alleles with peptide are determined. Linear regression is performed to generate graphs. PTEN, TP53, PIK3CA, KRAS, and CTNNB1 proved to have critical role. About 575 overlapping peptide libraries are generated and each peptide has a length of 18-20 amino acids. Approximately 58 HLAs are identified, having strong interactions with HLAs. Regression analysis shows that the no. of mutations are directly associated with a binding affinity of peptides. From this, we suggest that the identified TSA can be used as personalized peptide vaccines that directly target the mutated genes in endometrial cancer. This research work can be used in the laboratories for further validation.

5PD - The role of EGFR inhibitor (EGFRi) in immune cell infiltration and CD8+ T-cell activation in EGFR mutant lung cancer

BackgroundOncogenic MAP kinase pathway activating mutations have been shown to drive immune suppression in melanoma and colorectal cancers. In this study, we explored whether oncogenic EGFR mutations play an analogous role in non-small cell lung cancer (NSCLC), and whether EGFRi can relieve tumor-associated immune suppression. MethodsLung cancer cell lines expressing wild-type or mutated EGFR were treated with EGFRi, followed by collection of RNA and cell supernatants. In parallel, tumor biopsies from NSCLC patients receiving a personalized peptide vaccine with or without concurrent EGFRi treatment were obtained. RNAseq-based transcriptome profiles of tumor cell lines and patient tumor biopsies were compared to assess common gene signatures driven by EGFRi. Gene expression changes were confirmed at the protein level using Western blot, flow cytometry, and cytokine/chemokine Luminex. The impact of EGFRi on T-cell migration and tumor cell recognition by antigen-specific CD8+ T cells was also assessed. ResultsIn addition to downregulating genes associated with cell proliferation, apoptosis and survival, EGFRi increased the transcription of genes associated with TNFa and TRAIL signaling, and antigen presentation. HLA class I protein upregulation was confirmed and correlated with increased recognition of tumor cells by cytotoxic T cells. Several chemokines and cytokines were up- or down-regulated following EGFRi treatment, and Luminex analysis confirmed changes to 10 of them. Migration assays demonstrated that chemotaxis of T cells towards EGFR-mutant cell supernatants increased in an EGFRi dose-dependent manner. Transcriptome profiling of tumor biopsies revealed similar gene expression changes in on-EGFRi treatment tumor samples. Furthermore, increased tumor immune cell infiltration observed in EGFRi-treated patient tumors was consistent with the upregulation of EGFRi signature chemokines at the tumor site. ConclusionsThese results provide evidence that EGFRi has the capacity to facilitate modulation of the tumor microenvironment to favor immune cell infiltration and promote T-cell mediated antitumor immunity. Legal entity responsible for the studyThe University of Texas MD Anderson Cancer Center. FundingTianjin HengJia Biotechnology Development Co., Ltd. DisclosureF. Li: Shareholder/Stockholder/Stock options: Tianjin HengJia Biotechnology Development Co., Ltd.. G. Lizee: Advisory/Consultancy: HengJia Neoantigen Biotechnology (Tianjin) Co., Ltd.. P. Hwu: Advisory/Consultancy: Dragonfly Therapeutics; Advisory/Consultancy: GlaxoSmithKline; Advisory/Consultancy, Shareholder/Stockholder/Stock options: Immatics; Advisory / Consultancy: Sanofi; Research grant/Funding (institution): Genentech. L. Deng: Full/Part-time employment: Tianjin HengJia Biotechnology Development Co., Ltd.. Q. Zou: Full/Part-time employment: Tianjin HengJia Biotechnology Development Co., Ltd.. Y. Wang: Full/Part-time employment: Tianjin HengJia Biotechnology Development Co., Ltd.. R. Ataullakhanov: Full/Part-time employment: Bostongene. Llc. Bagaev: Full/Part-time employment: Bostongene. Llc. N. Kotlov: Full/Part-time employment: Bostongene. Llc. V. Svekolkin: Full/Part-time employment: Bostongene. Llc. N. Miheecheva: Full/Part-time employment: Bostongene. Llc. F. Frenkel: Full/Part-time employment: Bostongene. Llc. All other authors have declared no conflicts of interest.

Personalized Peptide Vaccination for Castration-Resistant Prostate Cancer Progressing after Docetaxel Chemotherapy: A Randomised, Double-Blind, Placebo-Controlled, Phase 3 Trial

Background: To develop a new treatment modality, we conducted a phase 3 randomised trial of personalized peptide vaccination (PPV) for human leukocyte antigen (HLA) -A24-positive patients with castration-resistant prostate cancer (CRPC) for whom docetaxel chemotherapy failed. Methods: This randomized, double-blind, placebo-controlled, phase 3 trial was done at 68 medical centers in Japan. Eligible patents were aged 20 years or older with HLA-A24-positive, CRPC progressing after docetaxel chemotherapy, positive immunoglobulin G (IgG) responses to at least 2 of 12 warehouse peptides, an Eastern Cooperative Oncology Group performance status of 0 or 1, life expectancy of at least 12 weeks, serum testosterone level of ≤ 50 ng/dl, and satisfactory bone marrow function, hepatic function, and renal function. Patients were randomly assigned in a 2:1 ratio to receive PPV or placebo. Four of 12 warehouse peptides selected based on pre-existing peptide-specific IgG levels or the corresponding placebo were subcutaneously injected in 6 doses weekly and then bi-weekly following the maximum of 30 doses until disease progression. The primary end point was overall survival (OS), and secondary end points were progression-free survival (PFS) and immune responses. Efficacy analyses were by the full analysis set. Findings: Between August 2013 and April 2016, 310 patients were randomly assigned (207 to PPV and 103 to placebo), and 306 patients were analyzed by the full analysis set (204 to PPV and 102 to placebo). Baseline characteristics were balanced between groups. The estimated median OS was 16.1 months (95% confidence interval [CI], 13–18·2) with PPV and 16·9 months (95% CI, 13·1–20·4) with placebo (hazard ratio [HR], 1·04; 95% CI, 0·80–1·37; p=0·77). The median PFS was not significantly different between groups. Grade < 3 adverse events were observed in 41% in both groups. The most common AEs were < grade 3 injection site reactions in both groups. The analysis of treatment arm effects among subgroups revealed lower HRs for OS in favor of the PPV arm in patients with < 64% neutrophils (HR, 0·55; 95% CI, 0·33–0·93, p=0·03) or ≥ 26% lymphocytes (HR, 0·70; 95% CI, 0·52–0·92, p=0·02) at base line by the significant interaction test (p=0·003 or p=0·007). Interpretation: PPV did not prolong OS or PFS in HLA-A24-positive patients with CRPC progressing after docetaxel chemotherapy. Subgroup analysis suggested that the patients with a lower proportion of neutrophils or a higher proportion of lymphocytes at base line can receive survival benefits from PPV treatment. Trial Regstration: This study is registered with UMIN Clinical Trials Registry (UMI11308), and patient enrollment is complete. Funding Statement: This study was supported by grants from the Japan Agency for Medical Research and Development (No. 18im0110802h0008) and Fujifilm Company. Declaration of Interests: MN has served as an advisory board consultant for BrightPath biotherapeutics Co. Ltd. KI received research funding from Taiho Pharmaceutical Company. SN has served as a consultant to BrightPath biotherapeutics Co. Ltd and received an honorarium from Sanofi. All other authors declare no competing interests. Ethics Approval Statement: The trial was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. The protocol was approved by institutional review boards or ethical committees at all of the institutions. All patients were Japanese and provided written informed consent before participating in this study.

Personalized peptide vaccination for castration-resistant prostate cancer progressing after docetaxel chemotherapy: A randomized, double-blind, placebo-controlled, phase III trial.

5033 Background: To develop a new treatment modality, we conducted a phase III randomized trial of personalized peptide vaccination (PPV) for human leukocyte antigen (HLA) -A24 positive patients with castration-resistant prostate cancer (CRPC) who failed docetaxel chemotherapy. Methods: Patients were randomly assigned in a 2:1 ratio to receive PPV or placebo. Four of 12 warehouse peptides selected based on preexisting peptide-specific immunoglobulin G levels or the corresponding placebo were subcutaneously injected 6 doses weekly followed the maximum of 30 doses bi-weekly until disease progression. The primary end point was overall survival (OS), and secondary end points were progression-free survival (PFS) and immune responses. Results: From August 2013 to April 2016, 310 patients were randomly assigned (207 to PPV and 103 to placebo), and 306 patients were analyzed by the full analysis set (204 to PPV and 102 to placebo). Baseline characteristics were balanced between groups. Estimated median OS was 16.1 months (95% CI, 13 to 18.2) with PPV and 16.9 months (95% CI, 13.1 to 20.4) with placebo (HR, 1.04; 95%CI, 0.79 to 1.37; P = 0.77). Median PFS was also not significantly different among them. Median Grade ≥ 3 adverse events were observed in 41% in both groups. The analysis of treatment arm effects among various subgroups revealed a lower HR for OS in favor of the PPV arm in patients with a &lt; 64% neutrophil proportion (HR, 0.55; 95%CI, 0.33 to 0.93), with a significant interaction test ( P = 0.003). Conclusions: PPV did not prolong either OS or PFS in HLA-A24 positive patients with CRPC progressing after docetaxel chemotherapy. Clinical trial information: 0000113088.

Abstract P4-06-06: Comparison of the immunological and clinical effect of personalized peptide vaccination for patients with breast cancer

Abstract Background: Selected therapeutic personalized peptide vaccines (PPV) were effective for boosting anticancer immune response that was associated with the clinical outcome as a prognostic factor for metastatic recurrent breast cancer (mrBC) 1-2. In this study, we investigated the immunological and clinical effect of PPV as the prophylactic cancer vaccine for non-recurrent but high-risk BC (nrhrBC) patients (pts), and we compared it's features to those of the mrBC pts who had active cancers or became resistant to the standard therapies(TR-mrBC). Methods: Material and Patient eligibility criteria: The peptides were selected from the 31 PPVs according to the results of HLA typing and peptide-specific IgG titers. Pts with a histological diagnosis of BC and their HLA-A molecules should be each of -A2, A3, A11, A24, A26, A31 or A33. The clinical protocols were approved by the institutional review board. (UMIN000003081and 00000184400000). Treatment schedule: A maximum of 4 peptides was administrated as weekly for initial four vaccinations and as biweekly for further inoculations. The concomitant standard endocrine therapy and the chemo-endocrine therapy were available for nrhrBC pts after finishing the standard adjuvant chemotherapy, and for mrBC pts concurrently. Immune and clinical response assessment: Specific T-cell responses, IgG titers and cytokines were evaluated using by interferon (IFN)-γ ELISPOT, Luminex assay and ELISA system in every 6-8 vaccinations. Toxicity, clinical response and correlation with the immune responses were investigated. Results: 16 pts with nrhrBC, 41 pts with mrBC and 79 pts with TR-mrBC received median 18, 16 and 14 vaccines, respectively. After PPV therapies, peptide-specific IgG and CTLs increased significantly in a total of 47 (77%) and 37(60%) in nrhrBC pts, 102 (63%) and 98 (61%) in mrBC pts, and 150(53%) and 100 (42%) in TR-mrBC pts. Pts experienced Grade 1-3 skin reaction at injection site, no other grade 3 or 4 SAEs were associated with PPV but with the disease progression or combination therapy. The median time to progression (TTP) and overall survival (OS) were not reached in nrhrBC pts, 7.8 and 29 months in mrBC pts, and were 7.5 and 15.9 months in TR-mrBC pts, respectively. The peptide specific CTL response was correlated significantly with OS in nrhrBC pts and the IgG levels were associated with the better OS in either non TR-mrBC pts or TR-mrBC pts. High levels of IL-6, GM-CSF, IFN-g, IL-2 receptor, BAFF were associated with worse prognosis for pts with TR-mrBC. And high levels of GM-CSF and BAFF were associated with worse prognosis for pts with nrhrBC and mrBC, respectively. In contrast, High levels of IL-2 were associated with the better prognosis for pts with mrBC. Conclusion: This study indicated that immunological features of these three groups were different from each other with most potent PPV-induced immune boosting for nrhrBC pts. Pts with mrBC who had lower immune-suppressive cytokine levels had the better prognosis. These results suggested the PPV therapy could be effective for postoperative prophylactic vaccination in patients with nrhrBC.

Abstract A020: Immunomonitoring for actively personalized peptide vaccines (APVACs) during immunotherapeutic treatment of glioblastoma

Abstract Cancer immunotherapy to gliomas has so far failed to show encouraging results, as gliomas are rarely mutated and show various mechanisms of immune escape. To improve therapy to these type of cancer, the Glioma Actively Personalized Vaccine Consortium (GAPVAC) integrated a highly personalized peptide vaccine approach into glioblastoma standard of care treatment combining neoepitope and nonmutated tumor antigens to exploit the full repertoire of tumor antigens. In this phase I clinical trial fifteen patients received two different types of personalized peptide vaccines (APVAC1 and APVAC2), that were selected based on transcriptome, immunopeptidome and mutational analysis of the patient’s individual tumors. While APVAC1 vaccines were composed of nonmutated tumor antigens selected in a warehouse-based approach, APVAC2 vaccines primarily targeted neoepitopes. Both vaccines were used in combination with poly-ICLC and GM-CSF as adjuvants and demonstrated expected safety profile and outstanding Immunogenicity. Immunomonitoring of APVAC1 peptides was carried out using a combinatorial ex vivo Class I 2D multimer (2DMM) and Class II intracellular cytokine staining (ICS) assay with an outstanding sensitivity to detect even one peptide-specific cell in one million of CD4 or CD8 T-cells. Nonmutated APVAC1 class I peptides showed induction of persistent CD8 T-cell responses, mainly consisting of a highly favorable central memory phenotype (CM). Furthermore, APVAC1 class II peptides demonstrated induction of polyfunctional CD4 T-cells predominantly of a type 1 T helper cell (TH1) phenotype. Notably, an APVAC1 class II specific T-cell response was detected in tumor-infiltrating lymphocyte (TIL) fraction obtained from resection of one patient. On the other side, immune responses to APVAC2 peptides were analyzed using a pan-ICS assay including a single in vitro sensitization step to analyze a broad array of cytokines produced by CD4 T helper (TH) cells and CD8 CTLs in parallel. APVAC2 peptides showed excellent immunogenicity and induced potent and multifunctional CD4 T-cell responses, mostly of a TH1 phenotype that often concurred with CTL responses. Furthermore, the induction of APVAC1-specific CD8 memory cells, as a marker for the potency of the vaccine-induced immune responses, reversely correlated with the baseline frequencies of regulatory T-cells (Treg). Taken together, actively personalized peptide vaccines (APVACs) were highly immunogenic and induced sustained responses of a highly favorable CD4 and CD8 T-cell phenotype. The vaccination showed the expected safety profile and the approach was feasible, even in this highly individualized setting. Therefore, the APVAC vaccination approach clearly represents a step forward on the path to bring the benefit of immunotherapy to glioblastoma patients. Citation Format: Alexander Ulges, Norbert Hilf, Wolfgang Wick, Michael Platten, Pierre-Yves Dietrich, Katrin Frenzel, Arie Admon, Sjoerd S.H. van der Burg, Andreas von Deimling, Per thor Straten, Cecile Gouttefangeas, Judith R. Kroep, Francisco Martínez-Ricarte, Hideo Okada, Christian H. Ottensmeier, Berta Ponsati, Hans S. Poulsen, Stefan Stevanovic, Ghazaleh Tabatabai, Hans-Georg Rammensee, Ugur Sahin, Dominik Maurer, Regina Mendrzyk. Immunomonitoring for actively personalized peptide vaccines (APVACs) during immunotherapeutic treatment of glioblastoma [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A020.

Abstract B124: Personalized peptide vaccination based on patient-individual tumor-specific variants induces T-cell responses in pediatric patients

Abstract Background: We established a platform for the design of patient-individual peptide vaccination cocktails by combination of whole exome sequencing of tumor and normal tissue with in silico epitope prediction algorithms for individual patient HLA types. Accumulation of somatic mutations is one characteristic feature of malignanT-cells. These single-nucleotide variants (SNVs) can lead to altered amino acid sequences of the translated proteins, which in turn can be presented by malignant cells as antigenic peptides on HLA molecules. A peptide vaccination to induce neoantigen-specific T-cell responses, therefore, is a promising and versatile immunotherapeutic approach for the treatment of malignant diseases. Such approaches were predominantly applied in malignancies with high mutational load in adult patients until now. We developed a vaccine design platform based on sequencing data generated from a cohort of acute lymphoblastic leukemia (ALL) patients and tested individualized peptide vaccines in pediatric patients suffering from a variety of tumors with low mutational profiles. Methods: Nonsynonymous mutations were identified by whole-exome and transcriptome sequencing of patient leukemic blasts and healthy reference tissue. HLA binding peptides harboring the altered amino acids were subsequently predicted in silico by algorithms SYFPEITHI, NetMHC and NetMHCpan for the patients’ individual HLA type. Individual peptides for treatment attempts were produced by chemical synthesis and vaccination cocktails were formulated. The vaccination schedule was 16 vaccinations over 33 weeks using GM-CSF and Imiquimod as adjuvants. Some patients received simultaneous checkpoint blockade treatment with pembrolizumab or nivolumab. Response to the vaccination was monitored by detection of T-cells recognizing the vaccinated peptides occurring over time in peripheral blood of the patients. Monitoring was performed for each vaccination time point by pre-stimulation with the peptides and subsequent intracellular cytokine staining (ICS) of T-cells and FACS analysis. Results: Whole-exome sequencing was performed for 25 patients to identify ALL-specific SNVs using a comparative bioinformatics pipeline. We found an average of 39.2 mutations per patient on DNA level, with an average validation rate of 47% by RNA sequencing. Based on these data, an average of 35.1 HLA binders could be predicted per patient. We applied our platform for 6 patients with various malignancies based on compassionate need and designed individual peptide vaccines. In all cases validated mutations could be identified and epitope prediction was performed for HLA Class I and II binders. In 6/6 patients a de novo induced T-cell response against the vaccinated mutated HLA-binding peptides was detectable. Combination therapy with PD-1 blockade and peptide vaccination was well tolerated. T-cell responses were predominantly, but not exclusively, CD4+-restricted. Encouraged by these findings, we started a phase I/II clinical trial in patients with primary/relapsed ALL with the aim to prevent relapse and show safety and immunogenicity of the personalized peptide vaccine. Conclusions: We established a platform for the design of patient-individual peptide vaccination cocktails by combination of whole exome sequencing of tumor and normal tissue with in silico epitope prediction algorithms for individual patient HLA types. Whole-exome sequencing of pediatric ALL patients is feasible and yields a small amount of tumor-specific mutations per patient. However, these few mutations are sufficient to predict HLA-binding peptides that are immunogenic when vaccinated and elicit specific T-cell responses in patients. The universal character of individualized peptide vaccination allows for application in virtually any malignant disease, as well as combination therapy approaches. The concept is now translated to clinical application in a phase I/II clinical trial in ALL, started in 2016 (NCT03559413). Citation Format: Armin Rabsteyn, Christina Kyzirakos, Christopher Schroeder, Marc Sturm, Christopher Mohr, Jakob Matthes, Magdalena Feldhahn, Nicolas Casadei, Martin Ebinger, Stefan Stevanovic, Peter Bauer, Oliver Kohlbacher, Cecile Gouttefangeas, Juergen Schaefer, Hans-Georg Rammensee, Rupert Handgretinger, Peter Lang. Personalized peptide vaccination based on patient-individual tumor-specific variants induces T-cell responses in pediatric patients [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr B124.

Colorectal cancer vaccines: Tumor-associated antigens vs neoantigens.

Therapeutic options for the treatment of colorectal cancer (CRC) are diverse but still not always satisfying. Recent success of immune checkpoint inhibition treatment for the subgroup of CRC patients suffering from hyper-mutated tumors suggests a permanent role of immune therapy in the clinical management of CRC. Substantial improvement in treatment outcome could be achieved by development of efficient patient-individual CRC vaccination strategies. This mini-review summarizes the current knowledge on the two general classes of targets: tumor-associated antigens (TAAs) and tumor-specific antigens. TAAs like carcinoembryonic antigen and melanoma associated antigen are present in and shared by a subgroup of patients and a variety of clinical studies examined the efficacy of different TAA-derived peptide vaccines. Combinations of several TAAs as the next step and the development of personalized TAA-based peptide vaccines are discussed. Improvements of peptide-based vaccines achievable by adjuvants and immune-stimulatory chemotherapeutics are highlighted. Finally, we sum up clinical studies using tumor-specific antigens - in CRC almost exclusively neoantigens - which revealed promising results; particularly no severe adverse events were reported so far. Critical progress for clinical outcomes can be expected by individualizing neoantigen-based peptide vaccines and combining them with immune-stimulatory chemotherapeutics and immune checkpoint inhibitors. In light of these data and latest developments, truly personalized neoantigen-based peptide vaccines can be expected to fulfill modern precision medicine’s requirements and will manifest as treatment pillar for routine clinical management of CRC.

A randomized, double-blind, phase III trial of personalized peptide vaccination for recurrent glioblastoma

We conducted a phase III trial of personalized peptide vaccination (PPV) for human leukocyte antigen (HLA)-A24+ recurrent glioblastoma to develop a new treatment modality. We randomly assigned 88 recurrent glioblastoma patients to receive PPV (n = 58) or the placebo (n = 30) at a 2-to-1 ratio. Four of 12 warehouse peptides selected based on preexisting peptide-specific immunoglobulin G levels or the corresponding placebos were injected 1×/week for 12 weeks. Our trial met neither the primary (overall survival [OS]) nor secondary endpoints. Unfavorable factors for OS of 58 PPV patients compared with 30 placebo patients were SART2-93 peptide selection (n = 13 vs 8, hazard ratio [HR]: 15.9), ≥70 years old (4 vs 4, 7.87), >70 kg body weight (10 vs 7, 4.11), and performance status (PS)3 (8 vs 2, 2.82), respectively. Consequently, the median OS for PPV patients without SART2-93 selection plus one of these 3 favorable factors (<70 y old, ≤70 kg, or PS0-2) was significantly longer than that for the corresponding placebo patients (HR: 0.49, 0.44, and 0.51), respectively. Preexisting immunity against both all 12 warehouse peptides besides SART2-93 and the other cytotoxic T lymphocyte epitope peptides was significantly depressed in the patients with SART2-93 selection (n = 21) compared with that of the patients without SART2-93 selection (n = 67). Biomarkers correlative for favorable OS of the PPV patients were a lower percentage of CD11b+CD14+HLA-DRlow immunosuppressive monocytes and a higher percentage of CD4+CD45RA- activated T cells, the intermediate levels of chemokine C-C ligand 2 (CCL2), vascular endothelial growth factor, interleukin (IL)-6, IL-17, or haptoglobin, respectively. This phase III trial met neither the primary nor secondary endpoints.

OS2.2 Highly personalized peptide vaccination for patients with newly diagnosed glioblastoma: the GAPVAC trial

OS2.2 Highly personalized peptide vaccination for patients with newly diagnosed glioblastoma: the GAPVAC trial

Peptide-Binding Groove Contraction Linked to the Lack of T Cell Response: Using Complex Structure and Energy To Identify Neoantigens.

Using personalized peptide vaccines (PPVs) to target tumor-specific nonself-antigens (neoantigens) is a promising approach to cancer treatment. However, the development of PPVs is hindered by the challenge of identifying tumor-specific neoantigens, in part because current in silico methods for identifying such neoantigens have limited effectiveness. In this article, we report the results of molecular dynamics simulations of 12 oligopeptides bound with an HLA, revealing a previously unrecognized association between the inability of an oligopeptide to elicit a T cell response and the contraction of the peptide-binding groove upon binding of the oligopeptide to the HLA. Our conformational analysis showed that this association was due to incompatibility at the interface between the contracted groove and its αβ-T cell Ag receptor. This structural demonstration that having the capability to bind HLA does not guarantee immunogenicity prompted us to develop an atom-based method (SEFF12MC) to predict immunogenicity through using the structure and energy of a peptide·HLA complex to assess the propensity of the complex for further complexation with its TCR. In predicting the immunogenicities of the 12 oligopeptides, SEFF12MC achieved a 100% success rate, compared with success rates of 25-50% for 11 publicly available residue-based methods including NetMHC-4.0. Although further validation and refinements of SEFF12MC are required, our results suggest a need to develop in silico methods that assess peptide characteristics beyond their capability to form stable binary complexes with HLAs to help remove hurdles in using the patient tumor DNA information to develop PPVs for personalized cancer immunotherapy.

Survival analysis of multiple peptide vaccination for the selection of correlated peptides in urological cancers.

Peptide‐based cancer vaccines are able to induce strong immune responses, but their clinical results are unsatisfactory. To determine clinically correlated peptides, we analyzed survival data from urological cancer patients treated by personalized peptide vaccination (PPV), in which different multiple peptides were used for individual patients based on human leukocyte antigen (HLA) type and pre‐existing immunity. Survival data were obtained from a database of 265 urological cancer patients treated in 5 clinical PPV trials comprising 154 patients with castration‐resistant prostate cancer (CRPC) and 111 patients with advanced urothelial cancer (UC). Expression of tumor‐associated antigens (TAA) was evaluated in 10 prostate cancer tissues, 4 metastatic lymph nodes from prostate cancer, and 10 UC tissues using immunohistochemical staining. Clinical efficacy of individual peptides for overall survival was evaluated by the Cox proportional hazards regression model. All TAA coding candidate peptides used in PPV treatment were expressed in tumor cells from prostate cancer and UC samples except for p56Lck in both, and prostate‐specific antigen (PSA), prostatic acid phosphatase (PAP) and prostate‐specific membrane antigen (PSMA) in the UC samples. Patients with the following peptides had a significantly longer survival than patients without the peptides (hazard ratio <1.0, 95% confidence intervals <1.0 and P < .05): SART3‐109, PTHrP‐102, HNPRL‐140, SART3‐302 and Lck‐90 in CRPC patients, and EGF‐R‐800, Lck‐486, PSMA‐624, CypB‐129 and SART3‐734 in advanced UC patients, respectively. Correlated peptides selected using both survival data and pre‐existing immunity for PPV treatment may enhance the clinical benefits for urological cancer patients.

GAPVAC-101: First-in-human trial of a highly personalized peptide vaccination approach for patients with newly diagnosed glioblastoma.

2000Background: The need for treatment personalization is obvious as every cancer is molecularly unique. In addition glioblastoma (GB) are immunologically regarded as resistant, “cold” tumor with f...

Abstract P3-05-09: Prognostic factors for therapeutic personalized peptide vaccines in patients with metastatic recurrent breast cancer

Abstract Background: We have previously reported the prognostic role of humoral antigen spreading response against prostate-related antigen (PRA) for metastatic recurrent breast cancer (mrBC) patients who received personalized peptide vaccine (PPV) therapy (Toh U, SABCS 2015). The prognostic effect was additionally evaluated by the clinical relevant factors including intrinsic subtype, the regimens of combined chemo-hormonal therapies in present study. Methods:We analyzed serum IgG responses to all of the peptide candidates included PRAs (PSA, PAP and PMSA) after PPV therapy by the Luminex systemusing peripheral blood samples from 77 vaccinated mrBC patients. The clinical factors and relevant events were statistically evaluated. Results: After 6 and 12cycles of PPV therapy, the serum IgG of anti-PSA, anti-PAP, and/or anti-PMSA increased significantly in 31 patients (PRA response group), and the median progression free survival (PFS) and median overall survival (OS) were 8.1 and 14.3 months, but were 5.1 and 10.8 months, respectively, in the remaining 46 patients with no anti-PRA IgG response (PRA non-response Group). The anti-PRA IgG level was marginally correlated withPFS (p=0.059) and OS (p=0.082) between these two groups, which was a significant prognostic factor for PFS (Log-rank: 0.009) in estrogen-positive cancer patients (ER+). The statistical analyses showed that the clinical outcome was in favor of &amp;gt; 60 year-old patients, those with longer PPV therapies (&amp;gt;3 months), and those who received combined standard hormonal therapies or bisphosphonate/anti-RANKL therapy. Conclusions: This study indicated a clinical significance between the pre-and post- PPV therapy measurement of serum anti-PRA IgG in patients with mrBC, which may be a useful prognostic marker for monitoring peptide vaccine treatment outcomes, particularly for patients &amp;gt; 60 years with ER+ breast cancer. These results also suggest that the immunotherapeutic peptide vaccine could be efficiently combined with hormonal therapy, anti-HER2 therapy, and bisphosphonate/anti-RANKL therapy in mrBC patients. Citation Format: Toh U, Saku S, Iwakuma N, Takao Y, Okabe M, Akashi M, Yamada A, Shichijo S, Itoh K, Akagi Y. Prognostic factors for therapeutic personalized peptide vaccines in patients with metastatic recurrent breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-05-09.