Primary prophylaxis implementation and long-term joint outcomes in Swedish haemophilia A patients

Primary prophylaxis is the gold standard in severe haemophilia A (SHA) but time to escalate the prophylaxis regimen varies.

Assess prophylaxis implementation and long-term joint health outcomes in SHA with primary prophylaxis.

Adult male patients born after 1980, with SHA on primary prophylaxis, started before the age of 3 years and second joint bleed, and no history of FVIII inhibitors, were enrolled. Repeated joint-health examinations were performed with HJHS or HEAD-US; VERITAS-PRO assessed adherence.

Thirty patients were enrolled with, at inclusion, median age 33.5 years, annualized bleed rate and joint bleed rate 0, and FVIII consumption 4232 IU/kg/year, respectively. The median age was 1.2 years, at prophylaxis start once weekly with a median FVIII dose of 47.7 IU/kg, and 1.7 years, by the time escalation to a final regimen had occurred, with a median infusion frequency of thrice weekly and FVIII dose 41.7 IU/kg, respectively. Older age correlated with later transition to escalated prophylaxis (p < .001). Longer time to escalated prophylaxis correlated to more bleeds (p < .001). Median HJHS increased slowly, reaching 4 at 35-40 years. HJHS at 15-20 years correlated with higher HJHS afterwards. Median total HEAD-US score was 1 and correlated with HJHS (p < .001). Median VERITAS-PRO score was 36, indicating good treatment adherence.

Primary prophylaxis is effective but does not completely prevent the gradual development of arthropathy in SHA. Joint assessments with HJHS should start at an early age, as they correlate with arthropathy in later life. Prophylaxis escalation should proceed expeditiously to prevent bleeds.