Pfizer begins Phase III lead-in study of hemophilia B candidate

Pfizer Inc. (NYSE:PFE) began an open-label Phase III lead-in study evaluating fidanacogene elaparvovec (formerly SPK-FIX, SPK-9001) as prophylaxis for hemophilia B in adults.

Data from the study, which is slated to enroll about 110 patients, will serve as the within-subject control group for a subsequent Phase III trial that will enroll patients who complete at least six months of treatment in the lead-in study. Primary endpoints include annualized bleeding rate (ABR), safety and events of special interest, including Factor IX inhibitors, thrombotic events and Factor IX hypersensitivity reactions. Secondary endpoints include annualized infusion rate, dose and total Factor IX consumption and number of bleeding events...