40K glycoPEGylated, recombinant FVIIa: 3-month, double-blind, randomized trial of safety, pharmacokinetics and preliminary efficacy in hemophilia patients with inhibitors

Authors


  • Manuscript handled by: L. Aledort
  • Final decision: D. Lane, 3 April 2013

Correspondence: Rolf C. R. Ljung, Paediatric Clinic, University Hospital, SE-205 02, Malmö, Sweden.

Tel.: +46 40331000; fax. +46 40336226.

E-mail: rolf.ljung@med.lu.se

Summary

Background

A 40K glycoPEGylated, recombinant activated factor VII (rFVIIa) bypassing agent (N7-GP) with a prolonged half-life (15 h) compared with rFVIIa was developed as a potential candidate for bleed-preventive regimens in patients with hemophilia and inhibitors.

Objectives

To evaluate the safety, pharmacokinetics and preliminary efficacy of multiple doses of N7-GP in congenital hemophilia A and B patients with high-titer inhibitors.

Patients/Methods

In this global, prospective, randomized, double-blinded, phase 2 trial, 25, 100 or 200 μg kg−1 N7-GP was administered intravenously once every second day during a 3-month, bleed-preventive regimen and compared with a preceding 3-month observation period with on-demand treatment of bleeds with rFVIIa. The primary endpoint was adverse events; secondary endpoints were evaluation of immunogenicity, pharmacokinetics and efficacy.

Results and Conclusions

Overall, 23 patients were randomized and dosed (= 8/7/8 for 25/100/200 μg kg−1). N7-GP was well tolerated, with a low frequency of adverse events. No serious adverse events, immunogenic or thromboembolic events related to N7-GP were reported. The pharmacokinetic properties of N7-GP were similar to those reported in phase 1. The annualized bleeding rate (ABR) decreased in the treatment period vs. the observation period at all N7-GP dose levels. However, a dose-response relationship in the reduction could not be established in the N7-GP dose range evaluated. The ABR was also reduced at two dose levels during the last part of the observation period, and increased notably in the follow-up period irrespective of previous N7-GP dose. The trial was registered at ClinicalTrials.gov (Registration Number: NCT00951405).

Ancillary