Abstract CT201: The Mutanome Engineered RNA Immuno-Therapy (MERIT) project
Authors: Heesch Sandra , Britten Cedrik M. , Bukur Valesca , Buck Janina , Castle John , Diekmann Jan , Diken Mustafa , Frenzel Katrin , Kreiter Sebastian , Kuhn Andreas N. , Kuehlcke Klaus , Loewer Martin , Haas Heinrich , Kemmer-Brueck Alexandra , Kloke Bjoern-Philipp , Otte Burkhard , Paruzynski Anna , Petri Sebastian , Schwarck-Kokarakis Doreen , Schmidt Marcus , André Fabrice , De Greve Jacques , Kuendig Thomas , Lindman Henrik , Pascolo Steve , Sjöblom Tobias , Thielemans Kris , Zitvogel Laurence , Tuereci Oezlem , Sahin Ugur 
Published: August 2015

Abstract
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