The United States Food and Drug Administration has granted fast track designation to Mesoblast’s (ASX:MSB) lead drug candidate to treat COVID-19.

A phase 3 study evaluating using the remestemcel-L stem cell therapy to treat up to 300 COVID-19 patients on ventilators is about two-thirds enrolled, the Melbourne biotech company said.

There’s been little word on how effective the therapy has been so far, although two interim analyses by an independent data safety monitoring board have recommended the study continue as planned, something the board wouldn’t do if the treatment was a failure.

A third and final interim analysis is planned when 180 patients have completed 30 days of follow-up, which should be soon.

NY success for Mesoblast COVID-19 trial

Earlier, the drug performed spectacularly in a small trial on a dozen COVID-19 patients at a New York City hospital in March and April of this year. Nine of patients on ventilators were discharged from the hospital on average in just 10 days.

Mesoblast recently agreed to licence remestemcel-L to Novartis, with an initial focus on acute respiratory distress syndrome, including that caused by COVID-19.

The fast track designation means the therapy would be eligible for priority review.