Haemophilia A patients' medication adherence to prophylaxis with efmoroctocog alfa.

Introduction Lightening the injection burden is commonly believed to improve prophylaxis adherence. Efmoroctocog alfa (rFVIIIFc) is the first recombinant FVIII-Fc fusion protein available in France. This clotting factor with an extended half-life could thus improve medication adherence. Aim The study primarily aimed to assess the real-life impact on prophylaxis adherence of haemophilia A patients, when switching from a standard to an extended half-life FVIII. Methods This study was an observational, monocentre, non-interventional study aiming at assessing haemophilia A patients' real-life adherence during the first-year post-rFVIIIFc prophylaxis initiation. Medication adherence was assessed using two methods: the medication possession ratio (MPR), which is based on the hospital pharmacy dispensing data, and self-reported VERITAS-Pro® questionnaire. Patients on rFVIIIFc prophylaxis for at least 12 months, following a 12-month standard FVIII prophylaxis, were eligible for inclusion. Results In 2019, 47 male patients were undergoing rFVIIIFc prophylaxis in our Hemophilia Center, among which 36 meeting the inclusion criteria. Switching from standard to extended half-life FVIII prophylaxis resulted in increased mean dosing, while the mean number of weekly prophylactic injections (2.6 ± 0.5 vs 1.8 ± 0.3) decreased. Following rFVIIIFc initiation, a non-significant increase in median MPR occurred and the self-reported VERITAS-Pro® questionnaire demonstrated improved adherence to rFVIIIFc prophylaxis. Comparing adherent and non-adherent patients revealed age as the only factor likely to impact adherence (p = .07). Conclusion Our patient cohort exhibited high adherence levels before and after FVIII switching, based on MPR and VERITAS-Pro® questionnaire. The latter is likely a useful tool to quantity prophylaxis adherence from a patient's perspective in daily use.