Phase I/II/III clinical trial of REGN COV2 passed futility trial in COVID-19.- Regeneron Pharma

Regeneron Pharmaceuticals announced encouraging initial data from an ongoing Phase I/II/III clinical trial of the Regeneron antibody cocktail, REGN COV2 (casirivimab and imdevimab), in hospitalized COVID-19 patients requiring low-flow oxygen. The analysis was prospectively designed to focus on patients who had not yet mounted their own immune response to SARS-CoV-2, as prior evidence suggested these patients were at greater risk. The primary clinical objective of this initial analysis was to determine if there was sufficient efficacy in these patients to warrant continuing the trial (i.e., futility analysis). The results passed the futility analysis (p<0.3 one-sided as seronegative patients treated with the antibody cocktail had a lower risk of death or receiving mechanical ventilation hr: 0.78 80 ci: 0.51-1.2. the benefit was driven by results starting one week post-treatment when the risk of death or receiving mechanical ventilation was reduced by approximately half with antibody cocktail treatment based on a post-hoc analysis. seronegative patients n="217)" had much higher viral loads than those who had already developed their own antibodies seropositive to sars-cov-2 at the time of randomization. in seronegative patients the antibody cocktail reduced the time-weighted average daily viral load through day 7 by -0.54 log10 copies ml and through day 11 by -0.63 log10 copies ml nominal p="0.002" for combined doses. at day 5 the relative reduction compared to placebo was -1.1 log10 copies ml nominal p="0.002" for combined doses. as expected in seropositive patients n="270)" the clinical and virologic benefit of the antibody cocktail was limited clinical endpoint hr: 0.98 time-weighted average viral load reduction by day 7 of -0.20 log10 copies ml for combined doses. both antibody cocktail doses were well-tolerated. in the overall trial population the incidence of serious adverse events was 21 for high dose 20 for low dose and 24 for placebo. infusion reactions were more common with the high dose of the antibody cocktail 2.7 high dose 0.9 low dose 1.4 placebo and there were 2 discontinuations due to infusion-related reactions both of which occurred in the high dose group.>