Stem cell company Mesoblast (ASX:MSB) got some good news this morning — a key US regulatory committee reckons its RYONCIL drug has the capacity to be effective.

The treatment is for child patients that experience complications in connection with bone marrow transplants.

A 10-person panel of the US Oncologic Drugs Advisory Committee (ODAC) — an advisory committee to the Food & Drug Administration (FDA) — voted in favour of the view that the “available data support the efficacy of remestemcel-L (Ryoncil)”.

The 9-1 vote will help bolster Mesoblast’s chances of bringing the drug to market, with the FDA set to make a formal decision by September 30.


Rollercoaster week

The ODAC panel heard presentations from the company and various experts, and handed down its decision at around 7am (AEST) this morning.

It capped off a rollercoaster week for Mesoblast, which saw its shares tumble by more than 30 per cent on Wednesday after the release of preliminary documents indicated the ODAC would have reservations about the validity of the company’s research.

The selling continued yesterday, but in the wake of this morning’s announcement shares in Mesoblast bounced back up around 40 per cent in morning trade.

As Stockhead’s resident expert Dr Tim Boreham noted in his review of Mesoblast in early July, “while advisory committee views are not binding on the FDA, they usually presage the final decision”.

Mesoblast chief medical officer Dr Fred Grossman said transplant rejections — or steroid-refractory acute graft versus host disease (GvHD) — is an area of “extreme need” in paediatric medicine, particularly for children under 12.

GvHD afflicts about half of the 30,000 patients annually undergoing allogeneic bone marrow transplant, typically for blood cancers, with their bodies rejecting the ‘alien’ transplant.

“We are very encouraged by today’s outcome and are committed to working closely with the FDA as they complete their review of our submission regarding approval of RYONCIL for this life-threatening complication of an allogeneic bone marrow transplant,” Grossman said.

Along with graft versus host disease, the remestemcel-L is also being tested on COVID-19 patients with severe respiratory systems.

If the drug is approved, it will be the first of its type to receive regulatory approval in the US market.