A recent article in Biospace reported an 83% survival rate for COVID-19 patients after two infusions of the experimental drug Ryoncil, developed by Mesoblast Ltd. The patients who were tested had mid-level to severe acute respiratory distress syndrome (ARDS) a severe type of lung complication.
These patients received care at Mt. Sinai hospital in accordance with either the emergency Investigational New Drug application or expanded access.
A total of 75% ( 9 out of 12) patients were removed from the ventilators within ten days after infusions of Ryoncil. Seven were discharged.
The 83% survival rate contrasts to only 9% of COVID-19 patients at another New York City hospital who received the standard of care and were taken off ventilators during the same period of time. At a second New York Hospital the rate was 12%.
Ryoncil (remestemcel-L) is currently undergoing FDA priority review for treatment of steroid-refractory acute graft versus host disease (acute GvHD).
Note that in 2012, Ryoncil was conditionally approved in Canada as Prochymal for acute GvHD in children unable to respond to steroid therapies.
It is well known that GvHD occurs in ten to eighty percent of patients undergoing stem cell transplantation.
Thirty to forty percent of patients who develop GvHD will develop a durable response to the disease when given high doses of corticosteroids.
Other patients, however, will experience a resistance to steroids (steroid-refractory acute GvHD) that has up to an eighty percent mortality rate.
Ryoncil is being reviewed for the treatment of GvHD and recently for COVID-19.
About Ryoncil (remestemcel-L)
While Ryoncil is still in the testing stage, it is believed to mitigate inflammatory conditions through the reduction of pro-inflammatory cytokines that tend to increase inflammation.
Conversely, the drug increases anti-inflammatory cytokines.
The CEO of Mesoblast announced that the company intends to go forward with the Phase II/III COVID-19 ARDS trial to confirm that Ryoncil improves survival for critically ill COVID-19 patients.
Mesoblast’s technology is built around adult stem cells that maintain healthy tissues. These rare cells respond to signals sent out when tissue is damaged. They secrete molecules promoting the repair of tissue and regulation of immune response.
Efficacy and Safety
Ryoncil has been evaluated for efficacy and safety in several clinical trials involving over 1100 patients. This includes the Phase III trial studying children with steroid-refractory acute GvHD.
On April 5, 2020 the FDA cleared Mesoblast’s New Drug application for the use of Ryoncil (remestemcel-L) for COVID-19 ARDS.