Valentino, L.A. (7004797688)L.A. (7004797688)ValentinoRusen, L. (35081145800)L. (35081145800)RusenElezovic, I. (12782840600)I. (12782840600)ElezovicSmith, L.M. (55939580700)L.M. (55939580700)SmithKorth-Bradley, J.M. (6701683980)J.M. (6701683980)Korth-BradleyRendo, P. (57117832300)P. (57117832300)Rendo2025-06-122025-06-122014https://doi.org/10.1111/hae.12344https://www.scopus.com/inward/record.uri?eid=2-s2.0-84898914046&doi=10.1111%2fhae.12344&partnerID=40&md5=b73785d3eaf729b845647f9b5ad13412https://remedy.med.bg.ac.rs/handle/123456789/8820Few randomized studies have reported on the use of factor IX (FIX) for secondary prophylaxis in haemophilia B patients. This study aimed to evaluate the efficacy and safety of two secondary prophylaxis regimens of recombinant coagulation FIX, nonacog alfa, compared with on-demand therapy. Male subjects aged 6-65 years with severe or moderately severe haemophilia B (FIX:C ≤ 2, n = 50) and ≥12 bleeding episodes (including ≥6 haemarthroses episodes) within 12 months of study participation were enrolled in this multicentre, randomized, open-label, four-period crossover trial. The primary measure was the annualized bleeding rate (ABR) of two prophylactic regimens vs. on-demand therapy. In the intent-to-treat group, mean ABR values were 35.1, 2.6 and 4.6 for the first on-demand period, the 50 IU kg-1 twice-weekly period, and the 100 IU kg-1 once-weekly period respectively. Differences in ABR between the first on-demand period and both prophylaxis regimens were significant (P < 0.0001); no significant differences were observed between prophylaxis regimens (P = 0.22). Seven serious adverse events occurred in five subjects, none related to study drug. Results demonstrated that secondary prophylaxis therapy with nonacog alfa 50 IU kg-1 twice weekly or 100 IU kg-1 once weekly reduced ABR by 89.4% relative to on-demand treatment. Both prophylaxis regimens demonstrated favourable safety profiles in subjects with haemophilia B. © 2014 John Wiley & Sons Ltd.Factor IXHaemophilia BProphylaxisRecombinant factor IX