A phase I study to evaluate safety, immunogenicity and anti-tumor activity of the multi-peptide vaccine IMA901 in renal cell carcinoma patients (RCC)

5098 Background: IMA901 is a therapeutic cancer vaccine based on multiple synthetic tumor-associated peptides confirmed to be naturally presented by analysis of primary RCC tissues. IMA901 consists of 9 HLA-class I-binding and 1 HLA class II-binding peptides with the capacity to activate cytotoxic T cells (CD8+ T cells) and T helper cells (CD4+ T cells). Methods: 30 patients with stage III/IV RCC were enrolled in a single arm, multi-centre study. The endpoints were safety, T-cell responses, pharmacokinetics of the intradermal application of GM-CSF and anti-tumor activity according to RECIST. Patients had to be HLA-A*02 positive and received 8 intradermal vaccinations on days 1, 2, 3, 8, 15, 22, 36 and 64 each consisting of 4.5 mg IMA901 and 75 μg GM-CSF. Results: The most prevalent adverse events (AEs) were fatigue, cough and headache. Aseptical lymphadenitis and injection site reactions such as erythema, edema and pruritus were the most frequent possibly drug-related AEs. All possibly drug-related adverse events were mild to moderate. No patient experienced any possibly drug-related serious adverse events or deaths during the study. Pharmacokinetic data provided no evidence for accumulation of GM-CSF upon repeated i.d. administration. 74% of patients showed a vaccine-induced specific T-cell response and 30% of patients responded to multiple peptides contained in IMA901. The overall tumor assessment in patients with measurable disease revealed that 8 patients (35%) demonstrated a clinical benefit (1 PR + 7 SD). Most encouraging, patients who elicited multiple T-cell responses showed a statistically significant higher clinical benefit rate. Conclusions: IMA901 is safe, very well tolerated and immunogenic. Clinically observed tumor growth control in RCC patients may imply anti-tumor activity strongly supported by two patients with tumor regression (1 PR and 1 patient with 27% shrinkage in target lesions). The mode of action is strongly supported by the finding that multiple T-cell responders were significantly more likely to have a clinical benefit. These data clearly support the further development of IMA901. No significant financial relationships to disclose.

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The Response to Repeated Vaccination with PR1 and WT1 Peptides Admixed in Montanide Adjuvant Is Transient and Fails to Induce Sustained Anti-Leukemia Responses in Patients with Myeloid Malignancies.

Blood ◽

10.1182/blood.v114.22.4096.4096 ◽

2009 ◽

Vol 114 (22) ◽

pp. 4096-4096

Author(s):

Katayoun Rezvani ◽

Agnes S. M. Yong ◽

Stephan Mielke ◽

Behnam Jafarpour ◽

Bipin N. Savani ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cell Response ◽

T Cell Responses ◽

Cd8 T Cell ◽

T Cell Response ◽

Gm Csf ◽

Cell Responses ◽

Ifn Γ

Abstract Abstract 4096 Poster Board III-1031 We previously demonstrated the immunogenicity of a combined vaccine approach employing two leukemia-associated antigenic peptides, PR1 and WT1 (Rezvani Blood 2008). Eight patients with myeloid malignancies received one subcutaneous 0.3 mg and 0.5 mg dose each of PR1 and WT1 vaccines in Montanide adjuvant, with 100 μg of granulocyte-macrophage colony-stimulating factor (GM-CSF). CD8+ T-cell responses against PR1 or WT1 were detected in all patients as early as 1 week post-vaccination. However, responses were only sustained for 3-4 weeks. The emergence of PR1 or WT1-specific CD8+ T-cells was associated with a significant but transient reduction in minimal residual disease (MRD) as assessed by WT1 expression, suggesting a vaccine-induced anti-leukemia response. Conversely, loss of response was associated with reappearance of WT1 transcripts. We hypothesized that maintenance of sustained or at least repetitive responses may require frequent boost injections. We therefore initiated a phase 2 study of repeated vaccination with PR1 and WT1 peptides in patients with myeloid malignancies. Five patients with acute myeloid leukemia (AML) and 2 patients with myelodysplastic syndrome (MDS) were recruited to receive 6 injections at 2 week intervals of PR1 and WT1 in Montanide adjuvant, with GM-CSF as previously described. Six of 7 patients completed 6 courses of vaccination and follow-up as per protocol, to monitor toxicity and immunological responses. Responses to PR1 or WT1 vaccine were detected in all patients after only 1 dose of vaccine. However, additional boosting did not further increase the frequency of PR1 or WT1-specific CD8+ T-cell response. In 4/6 patients the vaccine-induced T-cell response was lost after the fourth dose and in all patients after the sixth dose of vaccine. To determine the functional avidity of the vaccine-induced CD8+ T-cell response, the response of CD8+ T-cells to stimulation with 2 concentrations of PR1 and WT1 peptides (0.1 and 10 μM) was measured by IC-IFN-γ staining. Vaccination led to preferential expansion of low avidity PR1 and WT1 specific CD8+ T-cell responses. Three patients (patients 4, 6 and 7) returned 3 months following the 6th dose of PR1 and WT1 peptide injections to receive a booster vaccine. Prior to vaccination we could not detect the presence of PR1 and WT1 specific CD8+ T-cells by direct ex-vivo tetramer and IC-IFN-γ assay or with 1-week cultured IFN-γ ELISPOT assay, suggesting that vaccination with PR1 and WT1 peptides in Montanide adjuvant does not induce memory CD8+ T-cell responses. This observation is in keeping with recent work in a murine model where the injection of minimal MHC class I binding peptides derived from self-antigens mixed with IFA adjuvant resulted in a transient effector CD8+ T cell response with subsequent deletion of these T cells and failure to induce CD8+ T cell memory (Bijker J Immunol 2007). This observation can be partly explained by the slow release of vaccine peptides from the IFA depot without systemic danger signals, leading to presentation of antigen in non-inflammatory lymph nodes by non-professional antigen presenting cells (APCs). An alternative explanation for the transient vaccine-induced immune response may be the lack of CD4+ T cell help. In summary these data support the immunogenicity of PR1 and WT1 peptide vaccines. However new approaches will be needed to induce long-term memory responses against leukemia antigens. To avoid tolerance induction we plan to eliminate Montanide adjuvant and use GM-CSF alone. Supported by observations that the in vivo survival of CD8+ T-effector cells against viral antigens are improved by CD4+ helper cells, we are currently attempting to induce long-lasting CD8+ T-cell responses to antigen by inducing CD8+ and CD4+ T-cell responses against class I and II epitopes of WT1 and PR1. Disclosures: No relevant conflicts of interest to declare.

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Effect of granulocyte-macrophage colony stimulating factor (GM-CSF) administered with a multipeptide vaccine on circulating CD8+ and CD4+ T-cell responses: Outcome of a multicenter randomized trial

Journal of Clinical Oncology ◽

10.1200/jco.2009.27.15_suppl.3008 ◽

2009 ◽

Vol 27 (15_suppl) ◽

pp. 3008-3008

Author(s):

C. L. Slingluff ◽

G. R. Petroni ◽

W. C. Olson ◽

M. E. Smolkin ◽

M. I. Ross ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

T Cell ◽

Clinical Outcome ◽

T Cell Responses ◽

Response Rates ◽

T Cell Response ◽

Gm Csf ◽

Cell Responses ◽

Helper Peptide

3008 Background: GM-CSF administered locally with vaccines can augment T-cell responses in animal models. Human experience with GM-CSF has mostly occurred in uncontrolled or nonrandomized trials. Thus, a multicenter prospective randomized phase II trial was performed to determine whether local administration of GM-CSF augments immunogenicity of a multipeptide vaccine administered in an emulsion with an incomplete Freund's adjuvant (IFA). A second component of the trial was designed to assess whether the vaccine administered in two sites is more immunogenic than in a single site. Methods: 121 eligible and evaluable patients with resected stage IIB-IV melanoma were administered a sequence of multipeptide vaccines, each consisting of 12 MHC Class I-restricted melanoma peptides (12MP) to stimulate CD8+ T cells, plus an HLA-DR restricted tetanus helper peptide to stimulate CD4+ T cells. Peptides were emulsified with IFA, with or without GM-CSF. T cell responses were assessed by IFN-gamma ELIspot assay and tetramer analysis, weekly x 8. Clinical outcome was evaluated for all patients. Results: Vaccination was well-tolerated, and each peptide was immunogenic. Overall CD8+ T-cell response rates to the 12MP (days 1–50), for patients vaccinated with or without GM-CSF were 43% and 75%, respectively (p < 0.001), and response magnitude was almost twice as high in patients without GM-CSF. Class I MHC tetramer analyses corroborated the functional data. There was also a greater CD4+ T-cell response to the tetanus helper peptide without GM-CSF than with it (95% and 77%, respectively, p = 0.005). There was no significant difference in immune response rates by the number of vaccine sites. For the entire patient group, 3-year overall and disease-free survival estimates [95% CI] were 76% [67, 83%] and 52% [43, 61%], respectively. There have been too few events to assess differences in clinical outcome by study arm. Conclusions: High immune response rates were achieved with this multipeptide vaccine, but CD8+ and CD4+ T-cell responses appear to be partially suppressed with addition of GM-CSF. These data challenge the value of local GM-CSF as a vaccine adjuvant in humans. [Table: see text]

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Complement-induced regulatory T cells suppress T-cell responses but allow for dendritic-cell maturation

Blood ◽

10.1182/blood-2005-07-2951 ◽

2006 ◽

Vol 107 (4) ◽

pp. 1497-1504 ◽

Cited By ~ 42

Author(s):

Winfried Barchet ◽

Jeffrey D. Price ◽

Marina Cella ◽

Marco Colonna ◽

Sandra K. MacMillan ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Regulatory T Cells ◽

T Cell Responses ◽

Cell Receptor ◽

Dendritic Cell Maturation ◽

Cytokine Profile ◽

Gm Csf ◽

Cell Responses ◽

Soluble Cd40l

Concurrent activation of the T-cell receptor (TCR) and complement regulator CD46 on human CD4+ T lymphocytes induces Tr1-like regulatory T cells that suppress through IL-10 secretion bystander T-cell proliferation. Here we show that, despite their IL-10 production, CD46-induced T-regulatory T cells (Tregs) do not suppress the activation/maturation of dendritic cells (DCs). DC maturation by complement/CD46-induced Tregs is mediated through simultaneous secretion of GM-CSF and soluble CD40L, factors favoring DC differentiation and reversing inhibitory effects of IL-10. Thus, CD46-induced Tregs produce a distinct cytokine profile that inhibits T-cell responses but leaves DC activation unimpaired. Such “DC-sparing” Tregs could be desirable at host/environment interfaces such as the gastrointestinal tract where their specific cytokine profile provides a mechanism that ensures unresponsiveness to commensal bacteria while maintaining reactivity to invading pathogens.

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MHC-restricted phosphopeptide antigens: preclinical validation and first-in-humans clinical trial in participants with high-risk melanoma

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2019-000262 ◽

2020 ◽

Vol 8 (1) ◽

pp. e000262 ◽

Cited By ~ 1

Author(s):

Victor H Engelhard ◽

Rebecca C Obeng ◽

Kara L Cummings ◽

Gina R Petroni ◽

Angela L Ambakhutwala ◽

...

Keyword(s):

Breast Cancer ◽

Mass Spectrometry ◽

Clinical Trial ◽

T Cells ◽

T Cell ◽

Adverse Events ◽

T Cell Responses ◽

Breast Cancer Cell Lines ◽

Cell Responses ◽

Phosphorylated Peptides

BackgroundPhosphorylated peptides presented by MHC molecules represent a new class of neoantigens expressed on cancer cells and recognized by CD8 T-cells. These peptides are promising targets for cancer immunotherapy. Previous work identified an HLA-A*0201-restricted phosphopeptide from insulin receptor substrate 2 (pIRS2) as one such target. The purpose of this study was to characterize a second phosphopeptide, from breast cancer antiestrogen resistance 3 (BCAR3), and to evaluate safety and immunogenicity of a novel immunotherapic vaccine comprising either or both of these phosphorylated peptides.MethodsPhosphorylated BCAR3 protein was evaluated in melanoma and breast cancer cell lines by Western blot, and recognition by T-cells specific for HLA-A*0201-restricted phosphorylated BCAR3 peptide (pBCAR3126-134) was determined by51Cr release assay and intracellular cytokine staining. Human tumor explants were also evaluated by mass spectrometry for presentation of pIRS2 and pBCAR3 peptides. For the clinical trial, participants with resected stage IIA–IV melanoma were vaccinated 6 times over 12 weeks with one or both peptides in incomplete Freund’s adjuvant and Hiltonol (poly-ICLC). Adverse events (AEs) were coded based on National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) V.4.03, with provision for early study termination if dose-limiting toxicity (DLT) rates exceeded 33%. The enrollment target was 12 participants evaluable for immune response to each peptide. T-cell responses were assessed by interferon-γ ELISpot assay.ResultspBCAR3 peptides were immunogenic in vivo in mice, and in vitro in normal human donors, and T-cells specific for pBCAR3126-134controlled outgrowth of a tumor xenograft. The pIRS21097-1105peptide was identified by mass spectrometry from human hepatocellular carcinoma tumors. In the clinical trial, 15 participants were enrolled. All had grade 1 or 2 treatment-related AEs, but there were no grade 3–4 AEs, DLTs or deaths on study. T-cell responses were induced to the pIRS21097-1105peptide in 5/12 patients (42%, 90% CI 18% to 68%) and to the pBCAR3126-134peptide in 2/12 patients (17%, 90% CI 3% to 44%).ConclusionThis study supports the safety and immunogenicity of vaccines containing the cancer-associated phosphopeptides pBCAR3126-134and pIRS21097-1105, and the data support continued development of immune therapy targeting phosphopeptides. Future studies will define ways to further enhance the magnitude and durability of phosphopeptide-specific immune responses.Trial registration numberNCT01846143

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P04.02 Diversity of CD4+ blood T-cell clonality predicts longer survival with CTLA4 or PD-1 checkpoint inhibition in advanced melanoma

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-itoc8.31 ◽

2021 ◽

Vol 9 (Suppl 1) ◽

pp. A17.1-A17

Author(s):

A Arakawa ◽

S Vollmer ◽

J Tietze ◽

A Galinski ◽

MV Heppt ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Adverse Events ◽

T Cell Responses ◽

T Cell Clones ◽

Cell Responses ◽

Cell Clones ◽

Clinical Responses ◽

Melanoma Patients ◽

Research Grant

BackgroundT cells play a central role in tumor immunity. In principle, T cell requires antigen recognition by T-cell receptor (TCR) to gain effector function. Antigen-driven activation leads to clonal T-cell expansion with generation of progeny cells that all express the same chronotypic TCR. This makes TCR analysis a useful tool to comprehensively and individually understand antigen-specific T-cell responses. Indeed, we previously showed that the TCR repertoires of CD8+ T cells but not CD4+ T cells are restricted with many clones in the blood of psoriasis patients. Together with the strong genetic association to HLA-C*06:02 causing an autoimmune CD8+ T-cell response against melanocytes in psoriasis, our results from TCR analyses clearly indicate an autoimmune pathogenesis of psoriasis.Patients and MethodsHere, we utilize our expertise to understand how anti-tumor T-cell responses affect clinical responses and immune-related adverse events (irAEs) in therapeutic checkpoint inhibitions. We analyzed melanoma patients upon the therapeutic blockade of cytotoxic T-lymphocyte-associated protein 4 (CTLA4) or programmed cell death 1 (PD-1) using TCR Vβ-gene spectratyping.ResultsSurprisingly, we observed variable levels of restriction in CD4+ and extensive restrictions in CD8+ T-cell repertoires in the blood of melanoma patients compared to healthy controls. This indicates the presence of a substantial numbers of CD4+ and CD8+ T-cell clones in the blood prior to the initiation of immunotherapy. The clones detected in the blood were enriched in tumor-infiltrating lymphocytes (TILs). This suggests that melanoma-reactive T-cell clones circulate more frequently in melanoma patients, although it is generally assumed that tumor-specific T-cell clones are only detectable in TILs. Greater diversification particularly in CD4+ blood T-cell clones before immunotherapy correlated with long-term survival after CTLA4 or PD-1 inhibition. In patients who developed severe immune-related adverse events (irAEs) during CTLA4 blockade, we detected newly expanded blood T-cell clones, suggesting that newly emerged T-cell responses contributed to these irAEs.ConclusionsOur data demonstrate that the diversity of T-cell clones in the circulation may reflect the anti-melanoma responses. This study provides a rationale for predicting clinical responses to checkpoint inhibitors using patient’s blood, and also emphasizes importance of CD4+ T cell-mediated anti-tumor immunity in melanoma.Disclosure InformationA. Arakawa: None. S. Vollmer: None. J. Tietze: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Significant; BMS. D. Speakers Bureau/Honoraria (speakers bureau, symposia, and expert witness); Modest; BMS, MSD, Novartis, Roche, Almiral. A. Galinski: None. M.V. Heppt: None. C. Berking: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Significant; Amgen, AstraZeneca, BMS, Incyte, Merck, MSD, Novartis, Pierre Fabre, Regeneron, Roche, Sanofi/Aventis. J.C. Prinz: None.

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375 Expansion of HPV-16 specific T cells in patients with HPV-related cancers treated with bintrafusp alfa

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0375 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A400-A400

Author(s):

Nicole Toney ◽

Yo-Ting Tsai ◽

Claire Rumfield ◽

Samuel Pellom ◽

Caroline Jochems ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Mouse Model ◽

Therapeutic Vaccine ◽

T Cell Responses ◽

Open Label ◽

Hpv 16 ◽

Cell Responses ◽

Link Type ◽

Anti Tumor Activity

BackgroundThe safety and efficacy of bintrafusp alfa, a first-in-class bifunctional fusion protein composed of the extracellular domain of the TGF-βRII receptor (a TGF-β ‘trap’) fused to a human IgG1 mAb blocking PD-L1, have been demonstrated in patients with human papillomavirus (HPV)-related cancers in an open label, multicenter phase 1 trial (NCT02517398), and an open-label, single center phase 2 trial (NCT03427411). The current study aimed to investigate whether HPV-16-specific T cells are expanded with therapy and associate with the clinical response of patients in these trials. We also present pre-clinical evidence from a mouse model of HPV-associated cancer supporting the combination of bintrafusp alfa with an HPV-16 targeted therapeutic vaccine and an immunostimulatory cytokine.MethodsPeripheral blood mononuclear cells (PBMC) were obtained from 33 patients prior to and 2 weeks after 1 and/or 3 cycles of bintrafusp alfa and evaluated for HPV-16 specific CD4+ and CD8+ T cells. PBMCs were stimulated with 15-mer peptide pools of the HPV-16 E6 and E7 oncoproteins, and T cell responses were assessed for the production of cytokines (TNFa, IFNg, IL-2) and positivity for the degranulation marker CD107a. Multifunctional T cells, positive for >2 measures, were also enumerated. For pre-clinical studies, a syngeneic mouse model of TC-1 carcinoma was treated with bintrafusp alfa alone or in combination with a liposomal-based HPV-16 therapeutic vaccine (PDS 0101) and a tumor targeting immunocytokine (NHS-muIL12) and evaluated for anti-tumor activity and immune responses.ResultsHPV-16 specific T cells were increased after 1 cycle of bintrafusp alfa in a greater proportion of responders (9/14) than non-responders (4/17) (p=0.03). In addition, the magnitude of HPV-16 specific T cells was greater after 1 (p=0.04) and 3 (p<0.0001) cycles of bintrafusp alfa in responders than non-responders. Multifunctional HPV-16-specific T cells were also increased to a greater extent in responders than non-responders. Preclinical studies demonstrated that the combination of bintrafusp alfa with an HPV-16-targeted therapeutic vaccine along with an immunocytokine resulted in maximal anti-tumor activity and T cell responses.ConclusionsAn early increase in HPV-16 specific T cells (after a single administration of bintrafusp alfa, prior to restaging) was associated with clinical activity in patients with HPV-related cancers undergoing bintrafusp alfa therapy. This evidence, and the pre-clinical finding of enhanced antitumor activity observed when combining bintrafusp alfa with an HPV-16 targeted vaccine and an immunostimulatory cytokine have provided the rational for an ongoing study evaluating this combination in patients with advanced HPV-associated malignancies (NCT04287868).Ethics ApprovalAll patients provided written informed consent for participation in a clinical trial that was approved by the Institutional Review Board at the National Cancer Institute (NCT02517398, NCT03427411)

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