More than four years later—and after two rejections from the agency—Mesoblast has finally gained an endorsement from the U.S. regulator for its first approved drug.

The U.S. Food and Drug Administration on Wednesday approved Mesoblast's cell therapy for treating a type of complication that occurs after a stem cell or bone marrow transplant called graft-versus-host disease (GVHD).

Ryoncil (remestemcel-L) as the first mesenchymal stromal cell (MSC) therapy in the U.S. Ryoncil is the only MSC therapy approved in the U.S. for any indication and the only therapy for steroid-refractory acute graft versus host disease (SR-aGvHD) in children 2 months and older,