Pfizer has initiated a phase I clinical trial for PF-05280602, an engineered variant of recombinant human Factor VIIa developed by Catalyst Biosciences.

"We are very excited to see the lead candidate from Catalyst’s hemostasis franchise advance into human clinical trials," said Nassim Usman, Ph.D., CEO of Catalyst Biosciences.

The drug has been engineered to provide improved acute and prophylactic treatment for hemophilia A and B patients with inhibitors. The initiation of phase I clinical trials triggered $7 million in milestone payments to Catalyst Biosciences from Pfizer.