Feasibility and Safety of Personalized, Multi-Target, Adoptive Cell Therapy (IMA101): First-in-Human Clinical Trial in Patients with Advanced Metastatic Cancer

IMA101 is an actively personalized, multi-targeted adoptive cell therapy (ACT), whereby autologous T cells are directed against multiple novel defined peptide-HLA (pHLA) cancer targets. HLA-A*02:01-positive patients with relapsed/refractory solid tumors expressing ≥1 of 8 predefined targets underwent leukapheresis. Endogenous T cells specific for up to 4 targets were primed and expanded in vitro. Patients received lymphodepletion (fludarabine, cyclophosphamide), followed by T-cell infusion and low-dose IL2 (Cohort 1). Patients in Cohort 2 received atezolizumab for up to 1 year (NCT02876510). Overall, 214 patients were screened, 15 received lymphodepletion (13 women, 2 men; median age, 44 years), and 14 were treated with T-cell products. IMA101 treatment was feasible and well tolerated. The most common adverse events were cytokine release syndrome (Grade 1, n = 6; Grade 2, n = 4) and expected cytopenias. No patient died during the first 100 days after T-cell therapy. No neurotoxicity was observed. No objective responses were noted. Prolonged disease stabilization was noted in three patients lasting for 13.7, 12.9, and 7.3 months. High frequencies of target-specific T cells (up to 78.7% of CD8+ cells) were detected in the blood of treated patients, persisted for >1 year, and were detectable in posttreatment tumor tissue. Individual T-cell receptors (TCR) contained in T-cell products exhibited broad variation in TCR avidity, with the majority being low avidity. High-avidity TCRs were identified in some patients' products. This study demonstrates the feasibility and tolerability of an actively personalized ACT directed to multiple defined pHLA cancer targets. Results warrant further evaluation of multi-target ACT approaches using potent high-avidity TCRs. See related Spotlight by Uslu and June, p. 865.

Phase I/II multicenter trial of a novel therapeutic cancer vaccine, HepaVac-101, for hepatocellular carcinoma

PURPOSE

Immunotherapy for hepatocellular carcinoma (HCC) shows considerable promise in improving clinical outcomes. HepaVac-101 represents a single-arm, first-in-man Phase I/II multicenter cancer vaccine trial for HCC (NCT03203005). It combines multi-peptide antigens (IMA970A) with the TLR7/8/RIG I agonist CV8102. IMA970A includes 5 HLA-A*24 and 7 HLA-A*02 as well as 4 HLA-DR restricted peptides selected after mass spectrometric identification in human HCC tissues or cell lines. CV8102 is an RNA-based immunostimulator inducing a balanced Th1/Th2 immune response.

EXPERIMENTAL DESIGN

82 patients with very early to intermediate stage HCCs were enrolled and screened for suitable HLA haplotypes and 22 put on study treatment. This consisted in a single infusion of low-dose cyclophosphamide followed by 9 intradermal coadministrations of IMA970A and CV8102. Only patients with no disease relapse after standard of care treatments were vaccinated. Primary endpoints of HepaVac-101 clinical trial were safety, tolerability and antigen-specific T-cell responses. Secondary or exploratory endpoints included additional immunological parameters and survival endpoints.

RESULTS

The vaccination showed a good safety profile. Transient mild-to-moderate injection-site reactions were the most frequent IMA970A/CV8102-related side effects. Immune responses against {greater than or equal to}1 vaccinated HLA class I tumor-associated peptide (TAA) and {greater than or equal to}1 vaccinated HLA class II TAA were respectively induced in 37% and 53% of the vaccinees.

CONCLUSION

Immunotherapy may provide a great improvement in treatment options for HCC. HepaVac-101 is a first-in-man clinical vaccine trial with multiple novel HLA class I- and class II-restricted TAAs against HCC. The results are initial evidence for safety and immunogenicity of the vaccine. Further clinical evaluations are warranted.

959 Safety and anti-tumor activity of TCR-engineered autologous, PRAME-directed T cells across multiple advanced solid cancers at low doses – clinical update on the ACTengine® IMA203 trial

Background

Adoptive cell therapy demonstrated significant clinical benefit in patients with hematological malignancies but results in most solid tumors have been less encouraging so far.

In the IMA203 trial we are treating advanced solid cancer patients utilizing TCR-engineered T cells (TCR-T) directed against an HLA-A*02-restricted peptide derived from the highly prevalent cancer testis antigen PRAME. This target was selected due to homogenous expression and exceptionally high target peptide density per tumor cell (assessed by quantitative mass spectrometry), two features we hypothesize to be critical determinants of anti-tumor activity in TCR-T trials.

Methods

This ongoing first-in-human, dose escalation, multi-indication trial enrolls HLA-A*02:01- and PRAME-positive recurrent and/or refractory solid cancer patients, who failed all available standard treatments. Eligible patients undergo leukapheresis and an autologous TCR-T product is manufactured. After lymphodepletion with fludarabine and cyclophosphamide, T cells are infused, followed by low-dose IL-2. The primary objective of the trial is to assess the safety and tolerability of IMA203. Secondary objectives are to evaluate the anti-tumor activity and pharmacodynamics using molecular and immunological methods.

Results

As of August 15, 2021, 16 heavily pre-treated patients received IMA203 T cells across multiple escalating dose levels (DL). Absolute IMA203 doses infused ranged from 0.08 to 0.81x109 transduced CD8 T cells per patient, which to our knowledge did not lead to anti-tumor responses in other TCR-T trials. Treatment-emergent adverse events after IMA203 infusion were transient and manageable. Most common events were expected cytopenias (G1-4), CRS and ICANS (both G1-2) and 1 DLT in DL2 (reported earlier). All evaluable patients (N=12) achieved disease control (i.e. best overall response: stable disease [SD] or partial response [PR]) and 6 patients demonstrated PRs according to RECIST1.1 with 2 of these PRs being confirmed. While all 3 patients treated at DL1 (median dose: 0.11x109) experienced SD, a PR was observed in 6/9 patients treated beyond DL1 (median dose: 0.30x109). Responses were seen in patients with synovial sarcoma (N=3), malignant melanoma (N=2) and head and neck cancer (N=1). Robust engraftment of T cells was observed in all patients and tumor infiltration by TCR-modified T cells was demonstrated in patients with evaluable on-treatment biopsies.

Conclusions

To our knowledge IMA203 is the first TCR-T product candidate that induced frequent tumor responses across multiple solid cancers using transduced T cells at doses below 1 billion and has a manageable safety profile. The next step is to assess response rates at higher dose levels and durability of responses.

Trial Registration

NCT03686124

Ethics Approval

The study was approved by the institutional review board/ethics committee as required for each participating site.

Publisher Correction: Actively personalized vaccination trial for newly diagnosed glioblastoma

The additional author support information was erroneously omitted from the Supplementary Information. This has been corrected online.

Abstract A015: Cellular immunomonitoring for personalized adoptive cellular therapy trial ACTolog® (IMA101-101)

Adoptive cellular therapy (ACT) has dramatically changed the landscape of immunotherapy; however, only a small proportion of solid tumor patients have benefited from these advances due to i) heterogeneity of tumor antigen expression, ii) tumor escape (e.g., only one target is addressed), or iii) off-target toxicities (e.g., expression of targets on normal tissues). ACTolog® concept, utilizing antigen specific T-cells (IMA101), identified by the Immatics’ proprietary XPRESIDENT® technology, is intended to overcome these limitations by introducing multiple novel tumor targets. ACTolog® is a personalized ACT approach in which autologous T-cell products are manufactured against the most relevant tumor target peptides for individual patients whose tumors are positive against a predefined target warehouse. Target positive tumors are identified by qPCR. Expression levels predictive for antigen presentation are determined by mass spectrometry. Autologous T-cells against ACTolog targets are in vitro primed in the presence of IL-21 followed by HLA tetramer-guided cell sorting and expansion prior to infusion. IMA101-101 is a first-in-human clinical trial in HLA-A*02:01 positive patients with relapsed or refractory solid tumors using the multitargeted ACTolog® approach in which up to four products with different tumor target-specificities are manufactured and infused for each patient. We developed two flow cytometric phenotyping assays that allow us to determine the frequency of target-specific cells in the final product and persisting cells in the blood as well as to deeply characterize the memory marker expression (CD45RA, CCR7, CD27, CD28, CD45RO, CD62L, CD57, CD127) and immune checkpoint expression (CD137, LAG-3, PD-1, TIGIT, TIM-3) of target-specific cells. Product characterization and initial persistence data of the three first treated patients revealed a high prevalence of persisting target-specific cells in the blood until 2 months after infusion as well as a favorable phenotype of target-specific cells. At the conference 6 months’ data for one patient will be available and presented.

Citation Format: Regina Mendrzyk, Alexander Ulges, Thorsten Demberg, Geoffrey Stephens, Carsten Reinhardt, Steffen Walter, Dominik Maurer. Cellular immunomonitoring for personalized adoptive cellular therapy trial ACTolog® (IMA101-101) [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 A015.

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

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.

Actively personalized vaccination trial for newly diagnosed glioblastoma

Patients with glioblastoma currently do not sufficiently benefit from recent breakthroughs in cancer treatment that use checkpoint inhibitors1,2. For treatments using checkpoint inhibitors to be successful, a high mutational load and responses to neoepitopes are thought to be essential3. There is limited intratumoural infiltration of immune cells4 in glioblastoma and these tumours contain only 30-50 non-synonymous mutations5. Exploitation of the full repertoire of tumour antigens-that is, both unmutated antigens and neoepitopes-may offer more effective immunotherapies, especially for tumours with a low mutational load. Here, in the phase I trial GAPVAC-101 of the Glioma Actively Personalized Vaccine Consortium (GAPVAC), we integrated highly individualized vaccinations with both types of tumour antigens into standard care to optimally exploit the limited target space for patients with newly diagnosed glioblastoma. Fifteen patients with glioblastomas positive for human leukocyte antigen (HLA)-A*02:01 or HLA-A*24:02 were treated with a vaccine (APVAC1) derived from a premanufactured library of unmutated antigens followed by treatment with APVAC2, which preferentially targeted neoepitopes. Personalization was based on mutations and analyses of the transcriptomes and immunopeptidomes of the individual tumours. The GAPVAC approach was feasible and vaccines that had poly-ICLC (polyriboinosinic-polyribocytidylic acid-poly-L-lysine carboxymethylcellulose) and granulocyte-macrophage colony-stimulating factor as adjuvants displayed favourable safety and strong immunogenicity. Unmutated APVAC1 antigens elicited sustained responses of central memory CD8+ T cells. APVAC2 induced predominantly CD4+ T cell responses of T helper 1 type against predicted neoepitopes.

Abstract 5365: Prolonged survival of patients with advanced renal cancer responding to multi-peptide vaccine IMA901 after single-dose cyclophosphamide

Translational research and the clinical development of therapeutic cancer vaccines requires stronger scientific rationalization. Here we demonstrate how immune response markers as well as biomarkers defining the immune regulatory environment were utilized as guiding tools from discovery to advanced clinical trials of IMA901, a novel therapeutic vaccine for the treatment of renal cell carcinoma (RCC). IMA901 consists of multiple tumor-associated peptides (TUMAPs) confirmed to be naturally presented in human RCC tissue by mass spectrometry, selected using differential transcriptomics and preclinically validated by systematic analysis of immunogenicity with artificial antigen-presenting cells. Two consecutive independent clinical studies in a total of 96 HLA-A*02+ advanced/metastatic RCC patients were conducted. The phase I study revealed that T-cell responses to multiple IMA901 antigens were significantly associated with disease control and negatively associated with the presence of FoxP3+ regulatory T cells (Tregs). The subsequent randomized phase II study demonstrated that pre-treatment with a single low dose of cyclophosphamide (Cy) reduced Treg frequencies and prolonged overall survival (OS) in patients who mounted an immune response to the IMA901 vaccine. Additionally, T-cell responses to multiple IMA901 antigens were again associated with clinical benefit. Furthermore, a comprehensive prognostic and predictive biomarker program was conducted. Among cellular biomarkers, highly significantly elevated levels of myeloid-derived suppressor cells (MDSC), IL-17-/IL-10-secreting T cells and dysfunctional T cells in RCC patients vs. healthy individuals were found. Two MDSC populations (CD14+ HLA-DR- and CD14- CD11b+ CD15+) were significantly negatively associated with survival in vaccinated RCC patients. Interestingly, both MDSC populations were also found to be negatively associated with OS in an independent trial in colorectal cancer patients (N=79) implying a broader role for these MDSC species. Additionally, among over 300 serum biomarkers tested, apolipoprotein A-I (ApoA1) and the chemokine CCL17 were found to be predictive for both immune responses to IMA901 and survival of the RCC patients. The knowledge acquired in these trials was used to design a randomized phase III study. In this ongoing study, IMA901 is combined with the tyrosine kinase inhibitor sunitinib based on the findings that sunitinib downmodulates the two MDSC populations described above. Furthermore, in this phase III study, the relevance of ApoA1/CCL17 will be explored by prospectively defined subgroup analyses.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5365. doi:1538-7445.AM2012-5365

Abstract 753: In vitro veritas: Successful prediction of clinical immunogenicity of two cancer vaccines by a high-throughput in vitro priming platform

Identification of tumor-associated peptides (TUMAPs) by HLA ligandome exploration or by means of reverse immunology allows the identification of high numbers of candidate substances for therapeutic cancer vaccines. However, the immunogenicity of such peptide antigens has to be validated by a separate step. Animal models are generally not appropriate for this task due to the high species-specificity of a) the HLA system, b) the T-cell repertoire and c) the expression of tumor antigens. Testing the immunogenicity of TUMAPs in a preclinical setting therefore requires the use of human cells. We assume that central tolerance (i.e. the deletion of T cells with distinct specificity to self-antigens during T-cell maturation) will be a major mechanism shaping the immunogenicity of TUMAPs and that “holes” in the T-cell repertoire may be identified by comparing in vitro priming efficiency of TUMAPs. Unfortunately, classical approaches for in vitro priming of human T cells are often difficult to standardize and scale.

Here, we show that highly parallel and standardized in vitro priming using fixed numbers of isolated T cells and artificial antigen presenting cells (aAPCs) is scalable to determine the in vitro immunogenicity (% positive wells or derived estimated T-cell precursor frequencies) for hundreds of different TUMAPs from multiple donors. The method has been adopted to include the HLA alleles A*0201, A*2402, B*0702 and A*0301. We have validated the platform by two steps:

First, the in vitro immunogenicity for literature-known natural ligand / altered ligands pairs (from gp100, tyrosinase and CEA) was determined and found to confirm previously reported results, with the altered ligand being the more immunogenic form in all cases.

Second, the in vitro immunogenicity for individual class I binding TUMAPs as determined with the method described herein was used for the selection of two multi-peptide cancer vaccines, IMA901 for renal cell cancer and IMA910 for colorectal cancer. The drug products contained N=9 and N=10 class I binding TUMAPs, respectively. After clinical testing in two first-in-man studies (IMA901-101: N=27 and IMA910-101: N=65 evaluable patients), the in vivo immunogenicity measured in both studies (% of patients with vaccine-induced responses) was found to strongly correlate with the previously determined in vitro immunogenicity (Spearman correlation, r=0.82, p<0.05 and r=0.95, p<0.001). Recently, the in vivo immunogenicity of the peptides contained in IMA901 was confirmed by a further phase II study (IMA901-202: N=61 evaluable patients).

To conclude, we believe that this method will be useful for the development of multi-epitope vaccines with high immunogenicity that can elicit broad immune responses in cancer patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 753. doi:10.1158/1538-7445.AM2011-753

Abstract 302: Multiple distinct populations of myeloid derived suppressor cells in IMA901 treated renal cell cancer patients correlate with survival and with T-cell dysfunctions

IMA901 is a therapeutic cancer vaccine for the treatment of renal cell cancer patients based on the selection of naturally presented tumor-associated peptides. A previous phase I study (N=28 patients) showed significant correlations of clinical benefit with T-cell responses to multiple IMA901 peptides. Based on this experience, a randomized phase II study was designed to explore the biological and clinical efficacy of IMA901. Different regulatory cell populations were assessed in patients prior to vaccination, including 6 phenotypically defined populations of myeloid derived suppressor cells (MDSCs).

A total of 68 HLA-A*02-positive RCC patients with documented progression during or after first-line therapy with cytokines or TKI were randomized to receive or not a single infusion of low-dose cyclophosphamide (CY; 300 mg/m2) three days prior to start repeated i.d. vaccinations with IMA901 in association with 75 µg GM-CSF i.d. Among them, 64 pts were eligible according to the pre-specified, per-protocol analysis. Patients receiving a single infusion of CY had a significant decrease of FoxP3-positive regulatory T cells (Tregs) after 3 days (p=0.014), particularly in Ki67+ (proliferating) Tregs (p=0.006). Patients receiving low-dose CY also showed a trend for improved overall survival (OS) as compared to the non-CY group (OS not reached after 25 months of follow-up vs. 16 months, respectively; p=0.086). Marginally significantly better OS rates were seen in immune responders compared to non-responders in the overall population (p=0.048), but highly significantly so in the subgroup of patients randomized to CY (p=0.006).

6 previously reported MDSC populations were analyzed from cryopreserved PBMCs by a single multi-color flow cytometry staining panel. A high overlap (>25%) was found for only 2 MDSC populations, so 6 populations represented five distinct MDSC subtypes. MDSC levels were significantly increased in patient samples as compared to matched healthy donors (p<0.0001 to p=0.0043). Interestingly, two populations designated MDSC4 (CD14+ HLA-DR-) and MDSC5 (CD14- CD11b+ CD15+) were negatively correlated with survival (p=0.033 and p=0.005) in the patients of this trial prior to immunotherapy intervention. Analysis of dysfunctionality of T cells characterized by decreased levels of TCR zeta chain expression revealed that patients had lower levels of TCR zeta chain expression than matched healthy donors (p<0.0001) and that low levels of TCR zeta chain were correlated with high levels of 4 MDSC phenotypes (p<0.0001 to p=0.04), suggesting that MDSC levels are linked to the suppression of T cells in RCC patients.

To our knowledge, this is the first study assessing the impact of MDSC levels on the survival of cancer patients by employing a novel method that can differentiate five distinct MDSC populations.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 302. doi:10.1158/1538-7445.AM2011-302