Regeneron COVID-19 Antibody Trial Pauses Enrollment of Patients With High Oxygen Needs

Regeneron Pharmaceuticals stated Friday that on the advice of the independent data monitoring committee (IDMC) for its REGN-COV2 antibody treatment trials in COVID-19, the company is suspending enrollment of hospitalized patients who require high-flow oxygen or mechanical ventilation. According to Regeneron, the recommendation was based on “a potential safety signal and an unfavorable risk/benefit profile at this time,” and that the hold will remain in place pending collection and analysis of further data on patients already enrolled.

However, Regeneron noted that the IDMC recommends continuing enrollment of hospitalized patients requiring either no or low-flow oxygen, as the risk/benefit profile “remains acceptable” in these cohorts. The committee also said the outpatient trial of REGN-COV2 can continue without modification.

In a recent analysis of a phase 2/3 study in the COVID-19 outpatient setting, REGN-COV2 was found to significantly reduce viral load and patient medical visits. The FDA is currently reviewing an emergency-use authorization submission for low-dose REGN-COV2, which consists of REGN10933 and REGN10987, in adults with mild-to-moderate COVID-19 who are at high risk for poor outcomes.

Regeneron said it has informed the FDA about the hold, and is also sharing the recommendation with the independent committee monitoring the RECOVERY trial in the UK, which is evaluating REGN-COV2 in hospitalised patients.

Second antibody therapy setback

This marks the second recent setback for a COVID-19 antibody therapy. Earlier in October, scientists at the US National Institute of Allergy and Infectious Diseases said that no more adults hospitalized with COVID-19 in the ACTIV-3 study would be receiving Eli Lilly’s bamlanivimab, also known as LY-CoV555, after that trial’s independent monitoring board suggested it was unlikely the monoclonal antibody would be of clinical value in this population. Bamlanivimab is also under review by the FDA for emergency use in higher-risk patients, while Lilly recently signed a $375-million contract to supply the US government with 300,000 vials of the treatment. The drugmaker also secured a contract valued at $312.5 million from the US Army to provide bamlanivimab.