Early data confirm Atea’s Covid antiviral as one to watch

An effective oral antiviral against the virus that causes Covid-19 would fill a big hole in the pandemic treatment box. Step forward Atea, which today released the first clinical data on its Roche-partnered project, AT-527. Data were from an interim look at an ongoing phase 2 study conducted in moderately ill hospitalised patients; the trial was not powered to test clinical outcomes, but the project appeared to facilitate a rapid reduction in viral loads. Subjects in the treatment arm experienced on average an 80% greater reduction from baseline in viral load than those in the control group, with a sustained difference maintained through day eight. By day 14, the last viral sampling day, approximately 47% of the AT-527 patients and 22% in the placebo arm had no detectable RNA virus. More rigorous data due in the coming months from larger trials are needed to confirm these signals but not all were convinced by this first look, with Atea’s shares falling 9% in early trade. More news on other oral antivirals should emerge before year end: Merck & Co and Ridgeback are expected to release data on the leading oral antiviral, molnupiravir, in a couple of months’ time, while Novartis and Molecular Partners' ensovipep recently moved into pivotal trials.