Latest From Sue Sutter
Agency approved Regeneron’s monoclonal antibody cocktail Inmazeb and Ridgeback’s mAB Ebanga on data from a multi-arm, adaptive trial in which several investigational agents were independently compared to a control group. Efficacy for both drugs was demonstrated on a mortality endpoint, with lingering uncertainties to be addressed through postmarketing studies.
Sponsor preferred a tropical disease voucher because it could be redeemed for a supplemental application, but the FDA awarded a voucher under the medical countermeasures program, which prohibits redemption for supplements; agency says it takes a case-by-case approach to deciding whether tropical disease and rare pediatric disease vouchers can be redeemed for supplements.
The individual contribution of the three mABs in Regeneron’s Ebola treatment could not be clinically tested due to the highly lethal nature of the disease and the potential for development of resistance; instead, the FDA accepted nonclinical data demonstrating the mechanism of action for each component.
Chronicle of the development and review of Regeneron’s REGN-EB3, a triple mAB combination treatment for Ebola infection.
Chronicle of the development and review of Ridgeback Biotherapeutics’ ansuvimab-zykl for treatment of Ebola infection.
Efficacy against moderate to severe/critical COVID-19 was 66%-67%, well above the FDA’s stated 50% efficacy threshold for an EUA but far short of the 94%+ efficacy rates posted by the Pfizer and Moderna vaccines against symptomatic disease; agency says efficacy against specific variants cannot be evaluated at this time because sequencing data are incomplete.