Catalyst Biosciences, Inc.announced the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation for Marzeptacog alfa (activated) – or MarzAA, the Company’s subcutaneously (SQ) administered next-generation engineered coagulation Factor VIIa (FVIIa) for the treatment of episodic bleeding in subjects with Hemophilia A or B with inhibitors that will enter a pivotal Phase 3 study CRIMSON 1 this month.

The Fast Track program is designed to facilitate and expedite the development and review of drug candidates that have demonstrated the potential to address an unmet medical need in treating serious diseases or conditions. A drug candidate with Fast Track designation is eligible for greater access to the FDA as well as a priority review and rolling review of the marketing application.

“We believe the FDA Fast Track Designation validates MarzAA’s potential to improve patient care. As the only SQ delivered therapy in development for on-demand treatment of bleeding events, MarzAA is uniquely positioned to become an important addition to the treatment landscape,” said Nassim Usman, Ph.D., president and chief executive officer of Catalyst.

The Phase 3 CRIMSON 1 study is an open-label, global, multi-center, randomized, cross-over study, designed to evaluate the safety and efficacy of MarzAA for on-demand treatment of spontaneous or traumatic bleeding episodes, in adolescents and adults with congenital Hemophilia A or B with inhibitors, compared to the Standard of Care. The study will enroll approximately 60 subjects to treat 244 eligible bleeding episodes with each treatment. The primary endpoint for the trial is the percentage of treated bleeds resulting in effective hemostasis at the 24-hour timepoint. The objective of the trial is to demonstrate non-inferiority of MarzAA compared with Standard of Care.