Regeneron hit by 'safety signal' for COVID-19 cocktail as data board tells pharma to stop enrolling sicker patients

The saga of COVID-19 antibody R&D continues as the REGN-COV2 antibody cocktail used by President Donald Trump and touted as a cure has been hit by safety worries as it continues to push for an FDA emergency authorization.

The cocktail, which has been erroneously called “Regeneron,” is currently in a series of tests including for patients with COVID-19 that are currently hospitalized. But Friday morning, the independent data monitoring committee (IDMC) told Regeneron safety concerns will need to see it roll back the sickest patients on the test.  

It said: “Based on a potential safety signal and an unfavorable risk/benefit profile at this time, the IDMC recommends further enrollment of patients requiring high-flow oxygen or mechanical ventilation be placed on hold pending collection and analysis of further data on patients already enrolled.”

It did not give details on what the safety signal was. The news hit shares, which were in the red by 2.6% premarket when the news first hit.

The IDMC did, however, say that the biopharma can continue enrollment of hospitalized patients who need either no or low-flow oxygen as the “risk/benefit remains acceptable in these cohorts.” It can also continue work of the outpatient trial “without modification.”

The FDA is currently assessing the cocktails for a speedy emergency use authorization nod, specifically in mild to moderate outpatients at high risk for poor outcomes. It’s not clear how this news will impact this process.

This comes only a few days after the therapy showed it reduced COVID-19 related medical visits by 57% in early data.