Spark Therapeutics and Pfizer gain FDA Breakthrough designation for hemophilia B treatment

US biotech Spark Therapeutics (Nasdaq: ONCE) and pharma giant Pfizer (NYSE: PFE) have been granted breakthrough therapy designation from the US Food and Drug Administration for their hemophilia B treatment SPK-9001.

This is a novel bio-engineered adeno-associated virus (AAV) capsid expressing a codon-optimized, high-activity human factor IX variant, which is being investigated in an ongoing Phase I/II trial as a potential one-time therapy.

Breakthrough Therapy designation is intended to expedite the development and FDA review of drugs to treat a serious or life-threatening disease or condition. The designation requires preliminary clinical evidence that the investigational therapy may offer substantial improvement over existing therapies on at least one clinically significant endpoint.