Efficacy and safety of rVIII-Singlechain: results of a phase 1/3 multicenter clinical trial in severe hemophilia A

Johnny Mahlangu, Kazimierz Kuliczkowski, Faraizah Abdul Karim, Oleksandra Stasyshyn, Marina V. Kosinova, Lynda Mae Lepatan, Aleksander Skotnicki, Lisa N. Boggio, Robert Klamroth, Johannes Oldenburg, Andrzej Hellmann, Elena Santagostino, Ross I Baker, Kathelijn Fischer, Joan C. Gill, Stephanie P'Ng, Pratima Chowdary, Miguel A. Escobar, Claudia Djambas Khayat, Luminita RusenDebra Bensen-Kennedy, Nicole Blackman, Tharin Limsakun, Alex Veldman, Katie St Ledger, Ingrid Pabinger, for the AFFINITY Investigators

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40 Citations (Scopus)

Abstract

Recombinant VIII (rVIII)-SingleChain is a novel B-domain-truncated recombinant factor VIII (rFVIII), comprised of covalently bonded factor VIII (FVIII) heavy and light chains. It was designed to have a higher binding affinity for von Willebrand factor (VWF). This phase 1/3 study investigated the efficacy and safety of rVIII-SingleChain in the treatment of bleeding episodes, routine prophylaxis, and surgical prophylaxis. Participants were ≥12 years of age, with severe hemophilia A (endogenous FVIII <1%). The participants were allocated by the investigator to receive rVIII-SingleChain in either an on-demand or prophylaxis regimen. Of the 175 patients meeting study eligibility criteria, 173 were treated with rVIII-SingleChain, prophylactically (N 5 146) or on-demand (N 5 27). The total cumulative exposure was 14 306 exposure days (EDs), with 120 participants reaching ≥ 50 EDs and 52 participants having ≥100 EDs. Hemostatic efficacy was rated by the investigator as excellent or good in 93.8% of the 835 bleeds treated and assessed. Across all prophylaxis regimens, the median annualized spontaneous bleeding rate was 0.00 (Q1, Q3: 0.0, 2.4) and the median overall annualized bleeding rate (ABR) was 1.14 (Q1, Q3: 0.0, 4.2). Surgical hemostasis was rated as excellent/good in 100% of major surgeries by the investigator. No participant developed FVIII inhibitors. In conclusion, rVIII-SingleChain is a novel rFVIII molecule showing excellent hemostatic efficacy in surgery and in the control of bleeding events, low ABR in patients on prophylaxis, and a favorable safety profile in this large clinical study. This trial was registered at www.clinicaltrials.gov as #NCT01486927.

Original languageEnglish
Pages (from-to)630-637
Number of pages8
JournalBlood
Volume128
Issue number5
DOIs
Publication statusPublished - 4 Aug 2016
Externally publishedYes

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