Preclinical Efficacy of IMM-BCP-01, a Highly Active Patient-Derived Anti-SARS-CoV-2 Antibody Cocktail

Using an unbiased interrogation of the anti-viral memory B cell repertoire of convalescent COVID-19 patients, we identified three human antibodies that when combined demonstrated both robust viral suppressive properties against all tested SARS-CoV-2 variants of concern in vitro and profound anti-viral efficacy in vivo . In this report, we describe the pre-clinical characterization of an antibody cocktail, IMM-BCP-01, that consists of three unique, patient-derived recombinant antibodies directed at non-overlapping surfaces on the Spike protein, each with particularly effective antiviral activity. One antibody has a composite epitope blocking ACE2 binding, one antibody bridges two Spike proteins, and one antibody neutralizes virus by binding to a conserved epitope outside of ACE2 binding site. These antibodies, when administered after viral infection, potently decreased viral load in lungs of infected Syrian golden hamsters in a dose-dependent manner, elicited broad anti-viral neutralizing activity against multiple SARS-CoV-2 variants, and induced a robust anti-viral effector function response, including phagocytosis, and activation of classical complement pathway. Our pre-clinical data demonstrate that the unique three antibody cocktail IMM-BCP-01 is a potent and dose-efficient approach to treat early viral infection and prevent SARS-CoV-2 in susceptible individuals. One sentence summary We describe three human antibodies that recognize unique non-overlapping epitopes on Spike protein and, when combined, exhibit highly potent in vitro activity against multiple SARS-CoV-2 variants of concern, including Delta, that translates into a striking dose-dependent efficacy against two SARS-CoV-2 isolates in vivo , augmented by a robust, rare epitope-driven Fc effector response. ### Competing Interest Statement The described approach, antibodies and cocktail composition have been included in patent applications. PAN, JMD, JPD, NBP, JLBS, BCH, NH, CN, AP, MN, HS, JPF, LFL, TS, PS, DHG, MJM and MKR are employees and shareholders of Immunome, Inc.