OBJECTIVE: We report end-of-trial efficacy and safety of N8-GP from pathfinder2.
METHODS: pathfinder2 main phase and extension phase part 1 results have been previously reported. During extension phase part 2, patients could switch from N8-GP prophylaxis 50 IU/kg every fourth day (Q4D) or 75 IU/kg once weekly (Q7D), depending on bleeding status. Extension phase part 2 collected long-term safety and efficacy data for all regimens until trial end (first patient in main phase, 30 January 2012; trial end, 10 December 2018).
RESULTS: Overall, 186 patients were exposed to N8-GP for up to 6.6 years (median 5.4 years). The estimated annualized bleeding rate (ABR) was 2.14 (median 0.84) for the Q4D prophylaxis arm and 1.31 (median 1.67) for the Q7D prophylaxis arm. Nearly 30% of patients experienced zero bleeds throughout the entire duration of the trial, the hemostatic response was 83.2% across all treatment arms, and patient-reported outcomes were maintained or slightly improved. No safety concerns were detected.
CONCLUSION: Data from the completed pathfinder2 trial, one of the largest and longest-running clinical trials to investigate treatment of severe hemophilia A, demonstrate the efficacy and safety of N8-GP in previously treated adolescent and adult patients.