BioCentury
ARTICLE | Clinical News

Long Acting rFactor lX: Phase III data

October 1, 2012 7:00 AM UTC

Top-line data from the open-label, international Phase III B-LONG trial in 123 evaluable previously treated hemophilia B patients aged 12 and older showed that rFIXFc as prophylaxis met the primary efficacy and safety endpoints. To meet the efficacy endpoint, the partners said rFIXFc as prophylaxis needed to reduce annualized bleeding rates by >=50% compared to on-demand treatment with rFIXFc. Biogen Idec did not disclose the reduction in bleeding rates, but did report that rFIXFc led to overall median annualized bleeding rates, including spontaneous and traumatic bleeds, of 2.95 in the weekly prophylaxis arm and 1.38 in the individualized interval prophylaxis arm vs. 17.69 in the on-demand episodic treatment arm. rFIXFc was generally well tolerated with no inhibitors to rFIXFc detected and no cases of anaphylaxis reported. According to the study design, the trial would have been stopped if 2 inhibitors to rFIXFc were detected.

There was 1 serious adverse event of obstructive uropathy in the setting of hematuria, which was possibly related to rFIXFc. The patient continued treatment and the event resolved with medical management. The most common adverse events, occurring outside of the perioperative management arm, were nasopharyngitis, influenza, arthralgia, upper respiratory infection, hypertension and headache. Additionally, 90.4% of bleeding episodes were controlled by a single injection of rFIXFc. Furthermore, a pharmacokinetic analysis in a protocol-defined subset of patients showed that the approximate terminal half-life of rFIXFc was 82 hours vs. 34 hours for BeneFIX recombinant coagulation Factor IX (rFIX). ...