Regeneron said Tuesday that its experimental two-antibody cocktail reduced viral levels and improved symptoms in non-hospitalized patients with mild-to-moderate Covid-19.
When asked whether the company would apply for emergency use authorization from the U.S. Food and Drug Administration, the company said it plans to "rapidly" discuss the early trial results with regulatory agencies, including the U.S. Food and Drug Administration.
Results for the first 275 trial patients showed the greatest effect in patients who had not mounted their own immune response prior to treatment, suggesting that REGN-COV2 could provide a therapeutic substitute for the naturally-occurring immune response, Regeneron said.
REGN-COV2 is part of a class of biotech therapies known as monoclonal antibodies. Several companies are using the technology to manufacture copies of the body's own antibodies to the new coronavirus. Regeneron believes its dual-antibody formula will limit the ability of the virus’ to escape detection.
The study tested two different doses of REGN-COV2 in two patient populations: those who mounted an effective immune response on their own (seropositive), and those whose immune response was not yet adequate (seronegative).
For patients given a placebo, the seropositive group had a median time to alleviation of symptoms of 7 days, compared to 13 days for seronegative patients.
Regeneron said REGN-COV2 rapidly reduced viral load through day 7 in seronegative patients. In addition, patients with higher baseline viral levels had correspondingly greater reductions in viral load with REGN-COV2, which is given by intravenous infusion.
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For seronegative patients, median time to symptom alleviation was 13 days for the placebo group, 8 days for the high-dose group, and 6 days for the low-dose group.
Serious adverse side effects occurred in two placebo patients, one low-dose patient and no high-dose patients. There were no deaths in the trial.
REGN-COV2 is also being studied for the treatment of hospitalized patients, and for prevention of infection in people who have been exposed to Covid-19 patients.