Mesoblast has treated dozens of COVID-19 patients with its remestemcel-L drug

Phase 3 trial testing on severely ill COVID-19 patients has reached 50 per cent enrolment
Mesoblast expects to complete enrolment of the study by the end of the year
Waiting for readouts of its phase 3 studies on using stem cell treatments to treat heart failure and lower back pain

Closely watched biotech Mesoblast (ASX:MSB) says that over 150 severely ill COVID-19 patients on ventilators have been enrolled in a study of its stem cell treatment, remestemcel-L.

That’s over half of the 300 patients needed for phase 3 trial to see if Mesoblast’s inflammation-fighting treatment cuts death rates in the severely ill COVID-19 patients.

A pilot study involving just a dozen COVID-19 patients on ventilators being treated at New York’s Mt Sinai Hospital in March and April suggested the intravenous transfusion worked wonders, with nine of the 12 patients suffering from acute respiratory distress syndrome (ARDS) being discharged from the hospital in an average of just 10 days.

“There is an urgent need for targeted treatments to reduce the continued high mortality in COVID-19 ARDS patients who are dependent on mechanical ventilators,” Mesoblast chief medical officer Dr Fred Grossman said.

“We expect to complete the enrolment target in this important trial by the end of the year as the enrolment rate continues to increase in line with the surge in new infections across the United States.”

Because the trial is a randomised, double-blinded, controlled study – the “gold standard” of clinical trials – Mesoblast has no way to know at this stage whether the drug is working to improve patient outcomes.

But an independent Data Safety Monitoring Board recently completed an interim analysis of the trial’s safety and efficacy based on 30 days of data from the first 90 patients enrolled, and recommended that the trial continue as planned. That indicates that at the very least, there are no signs the drug is making patients worse.

The Data Safety Monitoring Board will perform a second interim analysis in early November, when 45 per cent of the enrolment target has completed 30 days of follow-up care.

Results ‘a small positive’ for Mesoblast ahead of key study readouts

Also known as Ryoncil, remestemcel-L is a stem cell treatment which Mesoblast bought from Osiris Therapeutics for $106 million in 2013 that is based on bone marrow from an unrelated donor.

Mesoblast is trying to commercialise Ryoncil to treat steroid-refractory acute graft-versus-host disease in children under 12, but the US Food and Drug Administration earlier this month asked the Melbourne biotech to instead conduct another study. Mesoblast shares plunged by a third on the news and haven’t really recovered.

Morgans health care analyst Scott Power called today’s news “a small positive… still waiting for heart failure and back pain results.”

The results of two phase 3 trials testing how different mesenchymal precursor cell treatments work to treat those conditions are overdue, having been expected to be announced last quarter.