This was a precautionary measure. REGN-COV2 is a combination of two monoclonal antibodies (REGN10933 and REGN10987) and was designed specifically to block infectivity of SARS-CoV-2, the virus that causes COVID-19.

President Trump has been taken to hospital. He is at Walter Reed National Military Medical Centre. The reports are that he still has mild symptoms and is in good spirits.

Four days ago, Regeneron reported first data from a seamless Phase 1/2/3 trial of its investigational antibody cocktail REGN-COV2. They report reduced viral load and the time to alleviate symptoms in non-hospitalized patients with COVID-19. REGN-COV2 also showed positive trends in reducing medical visits.

Antibody Cocktail Can Fix Symptoms in 7 Days Instead of 13 days

Serological status at baseline also predicted how rapidly patients had alleviation of their COVID-19 clinical symptoms. In the untreated (placebo) patients, seropositive patients had a median time to alleviation of symptoms of 7 days, compared to seronegative patients who had a median time to alleviation of symptoms of 13 days.

Can Greatly Reduce the Viral Load

REGN-COV2 rapidly reduced viral load through Day 7 in seronegative patients (key virologic endpoint). The mean time-weighted-average change from baseline nasopharyngeal (NP) viral load through Day 7 in the seronegative group was a 0.60 log10 copies/mL greater reduction (p=0.03) in patients treated with high dose, and a 0.51 log10 copies/mL greater reduction (p=0.06) in patients treated with low dose, compared to placebo. In the overall population, there was a 0.51 log10 copies/mL greater reduction (p=0.0049) in patients treated with high dose, and a 0.23 log10 copies/mL greater reduction (p= 0.20) in patients treated with low dose, compared to placebo.