549 An RNA-lipoplex (RNA-LPX) vaccine demonstrates strong immunogenicity and promising clinical activity in a Phase I trial in cutaneous melanoma patients with no evidence of disease at trial inclusion

Background

Lipo-MERIT is an ongoing, first-in-human, open-label, dose-escalation Phase I trial investigating safety, tolerability and immunogenicity of BNT111 in patients with advanced melanoma. BNT111 is an RNA-LPX vaccine targeting the melanoma tumor-associated antigens (TAAs) New York esophageal squamous cell carcinoma 1 (NY-ESO-1), tyrosinase, melanoma-associated antigen 3 (MAGE-A3), and transmembrane phosphatase with tensin homology (TPTE). A previous exploratory interim analysis showed that BNT111, alone or combined with immune checkpoint inhibition (CPI), has a favorable adverse event (AE) profile, gives rise to antigen-specific T-cell responses and induces durable objective responses in CPI-experienced patients with unresectable melanoma.1 Here, we present preliminary data in patients with no evidence of disease (NED) at trial inclusion in the BNT111 monotherapy subgroup.

Methods

Patients with stage IIIB/C and IV pre-treated cutaneous melanoma were intravenously administered with BNT111 using a prime/repeat boost protocol. Patients were treated in seven dose escalation cohorts (7.2 to 400 µg total RNA) and three expansion cohorts to further explore dose levels of 14.4, 50 and 100 μg. In this analysis, patients receiving BNT111 monotherapy were grouped as having evidence of disease (ED) or NED, and immunogenicity, efficacy and safety were evaluated. Vaccine-induced immune responses were analyzed using an interferon-γ enzyme-linked immune absorbent spot (ELISpot) assay directly ex vivo.

Results

As of May 24, 2021, 115 patients have received BNT111 within the Lipo MERIT trial. Of 71 patients treated with BNT111 monotherapy, 38 patients had ED and 33 patients had NED after prior therapies. Baseline characteristics were similar between the two groups. ELISpot data revealed comparable BNT111-induced T-cell responses against at least one TAA in ED vs. NED patients (14/22 [64%] and 19/28 [68%] patients with available ELISpot-evaluable samples, respectively), suggesting that BNT111 has the ability to induce T-cell immunity irrespective of the presence of a detectable tumor. As previously reported for ED patients, vaccine-induced CD4+ as well as CD8+ T-cell responses were also observed in NED patients, with a substantial fraction of de novo induced responses undetectable prior to vaccination. In NED patients, clinical efficacy was promising; median disease-free survival was 34.8 months (95% confidence interval: 7.0–not reached). The safety profile was similar in ED vs. NED patients; 38/38 (100%) and 32/33 (97%) patients experienced related treatment-emergent AEs, respectively, of which the majority were mild-to-moderate flu-like symptoms.

Conclusions

Immunogenicity and safety profiles of BNT111 monotherapy were comparable in ED and NED patients. Promising signs of clinical activity were observed in NED patients.

Acknowledgements

The authors would like to acknowledge Camilla West (BioNTech SE) for medical writing support.

Trial Registration

Clinicaltrials.

gov: NCT02410733; EudraCT No. 2013-001646-33.

References

Sahin U, Oehm P, Derhovanessian E, et al. An RNA vaccine drives immunity in checkpoint-inhibitor-treated melanoma. Nature 2020;585(7823):107–112.

Ethics Approval

Ethics & Institutional Review Board approval was obtained prior to initiation of the trial (2018-13393_21-AMG federführend).

A shared tumor-antigen RNA-lipoplex vaccine with/without anti-PD1 in patients with checkpoint-inhibition experienced melanoma

3136

Background: Cancer vaccines are considered unsuitable for patients with advanced tumours and have not been clinically successful. Methods: Lipo-MERIT is an ongoing phase 1/2 trial (NCT02410733) with melanoma FixVac, a liposomal RNA vaccine targeting four non-mutant shared tumour-associated antigens (TAAs) (MAGE-A3, NY-ESO-1, tyrosinase, TPTE). Patients with stage IIIB-C and IV melanoma are eligible. The trial comprises 7 dose escalation and 3 dose expansion cohorts, the latter with FixVac alone or combined with anti-PD1. Eight doses of FixVac are administered i.v. weekly/bi-weekly followed by optional continued monthly treatment. This abstract summarizes the findings of an exploratory interim analysis (cut-off JUL2019) of 89 patients. Results: 42 of 89 patients had measurable disease at baseline and were eligible for assessment of best objective overall response. All but one patient were stage IV and had undergone previous lines of treatment, 41 patients were checkpoint-inhibitor (CPI)-experienced, and 35 had been exposed to both anti-CTLA4 and anti-PD1 therapy. In the vaccine monotherapy group (n = 25) three patients experienced a partial response (PR) and 7 patients had stable disease (SD). An additional patient showed a complete metabolic remission of metastatic lesions based on [18F]-FDG PET/CT imaging. In the group of patients treated with melanoma FixVac and PD1 blockade, 6 of 17 patients developed a PR. Patients with PR showed induction of poly-epitopic and strong CD4+ and CD8+ T cell immunity against the vaccine antigens. The number of antigen-specific cytotoxic T cells in some responders reached up to low 2-digit percentages of circulating CD8+ T cells and was maintained at high levels by continued vaccination. Overall, 75% of the 50 patients tested by ex vivo IFNg ELISpot analysis and all 20 patients tested by IFNg ELISpot after in vitro stimulation showed vaccine-induced immune responses against at least one vaccine antigen. Typically, antigen-specific T cells ramped up within the first 4-8 weeks to single-digit and low double-digit percent fractions of circulating CD8+ T cells. Immune responses were of effector memory phenotype and their strength and frequency did not depend on disease status at baseline (measurable versus non-measurable disease), on vaccine dose or on treatment (FixVac alone versus in combination with anti-PD1). Conclusions: FixVac alone and in combination with anti-PD1 mediates durable objective responses in pre-treated, CPI experienced patients with advanced progressing melanoma. Clinical trial information: NCT02410733 .

Abstract CT032: A first-in-human phase I/II clinical trial assessing novel mRNA-lipoplex nanoparticles for potent cancer immunotherapy in patients with malignant melanoma

Immunotherapeutic approaches have evolved as promising and valid alternatives to available conventional cancer treatments. Amongst others, vaccination with tumor antigen-encoding RNAs by local administration is currently successfully employed in various clinical trials. To allow for a more efficient targeting of antigen-presenting cells (APCs) and to overcome potential technical challenges associated with local administration, we have developed a novel RNA immunotherapeutic for systemic application based on a fixed set of four liposome complexed RNA drug products (RNA(LIP)), each encoding one shared melanoma-associated antigen.

The novel RNA(LIP) formulation was engineered (i) to protect RNA from degradation by plasma RNases and (ii) to enable directed in vivo targeting of APCs in lymphoid compartments, thus (iii) allowing for intravenous administration of multiple RNA products advancing from local to systemic targeting of APCs. Here, RNA(LIP) products trigger a Toll-like receptor (TLR)-mediated Interferon-α (IFN-α) release from plasmacytoid dendritic cells (DCs) and macrophages stimulating DC maturation and hence inducing innate immune mechanisms as well as potent vaccine antigen-specific immune responses.

Notably, BioNTech RNA Pharmaceuticals′ RNA(LIP) formulation is a universally applicable potent novel vaccine class for intravenous APC targeting and the induction of potent synchronized adaptive and type-I interferon-mediated innate immune responses for cancer immunotherapy. Similar to other liposomal drugs, the ready-to-use RNA(LIP) products are prepared individually in a straight-forward manner directly prior to use from three components, namely solutions containing RNA drug product, NaCl diluent, and liposome excipient, that are provided as a kit.

A multi-center phase I/II trial to clinically validate this pioneering RNA(LIP) formulation for the treatment of malignant melanoma was initiated in 2015 (NCT02410733). The objective of the clinical trial is to study the feasibility, safety, tolerability, immunogenicity and evaluate potential clinical activity of the RNA(LIP) immunotherapy concept.

Detailed information on the ongoing trial, the recruitment and treatment status as well as data on the assessment of vaccine-induced immune responses will be presented.

Citation Format: Robert A. Jabulowsky, Carmen Loquai, Mustafa Diken, Lena M. Kranz, Heinrich Haas, Sebastian Attig, Nicole Bidmon, Janina Buck, Evelyna Derhovanessian, Jan Diekmann, Daniel Fritz, Veronika Jahndel, Alexandra Kemmer-Brueck, Klaus Kuehlcke, Andreas N. Kuhn, Peter Langguth, Ulrich Luxemburger, Martin Meng, Felicitas Mueller, Richard Rae, Fatih Sari, Doreen Schwarck-Kokarakis, Christine Seck, Kristina Spieß, Meike Witt, Jessica C. Hassel, Jochen Utikal, Roland Kaufmann, Sebastian Kreiter, Christoph Huber, Oezlem Tuereci, Ugur Sahin. A first-in-human phase I/II clinical trial assessing novel mRNA-lipoplex nanoparticles for potent cancer immunotherapy in patients with malignant melanoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT032.

Abstract CT201: The Mutanome Engineered RNA Immuno-Therapy (MERIT) project

The Mutanome Engineered RNA Immuno-Therapy (MERIT) consortium will clinically and industrially validate a pioneering RNA-based immunotherapy concept that targets individual tumor antigens and tumor-specific mutations in triple negative breast cancer (TNBC) patients. This biomarker-guided, personalized therapy is a collaborative effort of five partners from academia and industry and is funded by the European Commission's FP7 and led by BioNTech AG. TNBC is an aggressive, molecularly heterogeneous cancer that accounts for 20% of all breast cancer patients. The 5-year survival rate is less than 80%. The molecular heterogeneity across TNBCs results in a lack of common targetable molecular alterations, and thus targeted therapies frequently fail to provide clinical benefit. The MERIT concept attempts to address this unmet medical need. The personalized treatment consists in (i) injecting vaccines containing “off the shelf” mRNAs selected from a pre-synthesized mRNA vaccine warehouse (MERIT WAREHOUSE) that encode tumor specific antigens expressed in the respective patient's tumor; and (ii) thereafter mRNAs engineered on-demand that encode patient-specific sequence stretches incorporating non-synonymous mutations identified by next generation sequencing (NGS) and ranked by predicted immunogenicity (MERIT MUTANOME). The mRNAs are administered intravenously as a nanoparticulate lipoplex formulation and are selectively delivered to splenic APCs. The encoded antigens are translated into proteins that are rapidly processed. Subsequent peptide presentation on the surface of APCs induces antigen-specific T cell responses. The central part of the MERIT project, a multi-center first in human trial, will assess the feasibility, safety and biological efficacy of this innovative personalized immunotherapy in TNBC patients. After discussing the regulatory challenges with the German national regulatory agency (PEI), a phase I study is now in preparation. The trial will start in Q2 2015 in five academic centers in Europe and will recruit thirty TNBC patients. Furthermore, the project includes a comprehensive T-cell immunomonitoring and biomarker program. Moreover, an extensive research program will address the optimization of algorithms for improved prediction of immunogenic mutations. Additionally, compounds to enhance vaccine efficacy will be developed and improved to support further clinical development. We have established a RNA delivery platform as well as a MERIT WAREHOUSE containing mRNAs coding for a selection of TNBC specific antigens. Additionally, we have built a multi-disciplinary clinical workflow and trial design tailored to this unique therapeutic concept. We will describe the therapeutic concept and the critical skills, and methodologies required for this project, including cancer genomics, NGS, bioinformatics, tumor immunomics, industrial drug development, GMP manufacturing, clinical immunotherapy and immunological monitoring.

Citation Format: Sandra Heesch, Cedrik M. Britten, Valesca Bukur, Janina Buck, John Castle, Jan Diekmann, Mustafa Diken, Katrin Frenzel, Sebastian Kreiter, Andreas N. Kuhn, Klaus Kuehlcke, Martin Loewer, Heinrich Haas, Alexandra Kemmer-Brueck, Bjoern-Philipp Kloke, Burkhard Otte, Anna Paruzynski, Sebastian Petri, Doreen Schwarck-Kokarakis, Marcus Schmidt, Fabrice André, Jacques De Greve, Thomas Kuendig, Henrik Lindman, Steve Pascolo, Tobias Sjöblom, Kris Thielemans, Laurence Zitvogel, Oezlem Tuereci, Ugur Sahin. The Mutanome Engineered RNA Immuno-Therapy (MERIT) project. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT201. doi:10.1158/1538-7445.AM2015-CT201