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.