757 M9657, a novel tumor-targeted conditional anti-CD137 agonist displays MSLN-dependent anti-tumor immunity

Autor: Amit Deshpande, Barroq Safi, Martina Hubensack, Lindsay Webb, Rene Schweickhardt, Natalya Belousova, Payel Ghatak, Francisca Wollerton, Joern-Peter Halle, Marat Alimzhanov, Frederic Christian Pipp, Jacques Moisan, Brain Rabinovich, Neil Brewis, Xueyuan Zhou, Andree Blaukat, Chunxiao Xu, Jose Munoz-Olaya, Clotilde Bourin, Sireesha Yalavarthi
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Journal for ImmunoTherapy of Cancer, Vol 9, Iss Suppl 2 (2021)
ISSN: 2051-1426
Popis: BackgroundThe costimulatory receptor CD137 (also known as 4-1BB and TNFRSF9) plays an important role in sustaining effective cytotoxic T cell immune responses and its agonism has been investigated as a cancer immunotherapy. In clinical trials, the systemic administration of the 1st generation CD137 agonist monotherapies, utomilumab and urelumab, were suspended due to either low anti-tumor efficacy or hepatotoxicity mediated by recognized epitope on CD137 and FcγR ligand-dependent clustering.MethodsM9657, a bispecific antibody was engineered a tetravalent bispecific antibody (mAb2) format with the Fab portion binding to the tumor antigen Mesothelin (MSLN) and a modified CH2-CH3 domain as Fc antigen binding (Fcab) portion binding to CD137. M9657 has a human IgG1 backbone with LALA mutations to abrogate the binding to Fcγ receptor. The biological characteristics and activities of M9657 were investigated in a series of in vitro assays and the in vivo efficacy was investigated in syngeneic tumor models with FS122m, a murine-reactive surrogate with the same protein structure of M9657.ResultsM9657 binds efficiently to both human and Cynomolgus CD137 as well as MSLN. In the cellular functional assay, M9657 displayed MSLN- and TCR/CD3 interaction (signal 1)-dependent cytokine release and tumor cell cytotoxicity associated with Bcl-XL activation and immune memory formation. FS122m demonstrated potent MSLN- and dose- dependent in vivo anti-tumor efficacy (figure 1). Comparing with 3H3, a Urelumab surrogate Ab, FS122m displayed an improved therapeutic window with significantly lower for on-target /off-tumor toxicity.ConclusionsTaken together, M9657 exhibits a promising developability profile as a tumor-targeted immune agonist with potent anti-cancer activity, but without systemic immune activation.Ethics ApprovalAll animal experiments were performed in accordance with EMD Serono Research & Development Institute (protocol 17-008, 20-005) and Wuxi AppTec Animal Care and Use Committee (IACUC) guidelines.Abstract 757 Figure 1FS122m displayed dose-dependent anti-tumor efficacy
Databáze: OpenAIRE