Helixate®Nexgen in the Treatment of Patients with Hemophilia A: A Long-Term Pharmacovigilance Surveillance.

Comprehensive large-scale pharmacovigilance surveillances are very effective tools to collect data on products in the post authorization period. The evaluation presented here was set up to assess the long-term efficacy, safety and tolerability of the recombinant FVIII concentrate, Helixate®NexGen (in the US: Helixate®FS). Sixty-five hemophilia centers in Germany, Austria, Italy, France, and Sweden are participating in this ongoing international project. Previously untreated (PUP) and previously treated patients (PTP) at any age suffering from hemophilia A treated with Helixate®NexGen were eligible for the surveillance. Based on the standard schedule preferred at the centers, patients are routinely screened every 3 to 12 months. At these visits, the following parameters, as used routinely for these patients, were documented (non-interventional design): overall clinical response, pharmacokinetics, occurrence of bleedings, adverse drug reactions including the incidence of inhibitors, other laboratory safety parameters, coagulation parameters, relevant concomitant diseases, and medication. To determine the level of exposure, treatment modalities with Helixate®NexGen, including average factor consumption per month and exposure days are recorded. One hundred and ten patients have been included into the investigation up to now; data from 104 patients were available for this interim analysis including 2 PUPs. The median age was 25 years (range: 8 months – 68 years). One patient suffered from mild, eleven from moderate, and 89 from severe hemophilia A; in three patients the information on severity was missing. Most of the patients were treated prophylactically (92%, at least one infusion per week). Exposure to Helixate®NexGen during the pharmacovigilance ranged between 5 and 703 days. A total of 112 bleedings were documented during the observation period, with a range of 0 to 20 bleedings per patient per year. Efficacy of Helixate®NexGen was assessed as good or excellent in 97% of all cases. There were no cases of inhibitor development during the 2-year observation period, especially no cases of inhibitors when patients were switched from products produced in Chinese hamster ovary (CHO) cells to Helixate®NexGen, which is produced in baby hamster kidney (BHK) cells. The good tolerability of Helixate®NexGen was further supported by the fact that there were no other relevant side effects documented. In summary this pharmacovigilance supports the good tolerability and good/excellent efficacy data of Helixate®NexGen.