Emicizumab promises weekly/biweekly prophylaxis in hemophilia-A patients

By Ajay V. Patil

HEMLIBRA® (emicizumab) and HAVEN-III trial

Developed by Chugai (a subsidiary of Roche), HEMLIBRA® (emicizumab) is a bispecific monoclonal antibody which reinstates the function of missing activated clotting factor VIII in Hemophilia patients. Phase 3, multicenter trial evaluated; weekly (1.5mg per kg body weight) or biweekly (3 mg per kg body weight) prophylaxis effects of Emicizumab in 152 hemophilia-A patients with 12 years of age or more. The targeted primary end point was the difference in rates of treated bleeding. Also, group in which participants who had been receiving factor VIII prophylaxis, received emicizumab at a maintenance dose of 1.5 mg per kg body weight per week; intraindividual comparisons were performed in those who had participated in a noninterventional study.

Long lasting therapy produced promising results

A total of 56% of the participants in weekly prophylaxis group and 60% of those in biweekly prophylaxis group had no treated bleeding events, compared to those in no prophylaxis group, who all had treated bleeding events. Also, intraindividual comparison with 48 participants showed that, emicizumab prophylaxis resulted in 68% lower annualized bleeding rate than that with previous factor VIII prophylaxis (P<0.001). Except minor low-grade injection-site reaction events no severe toxicity was observed.

Gauging the competitive scenario

Hemlibra is the first medicine to demonstrate better efficacy to prior factor VIII prophylaxis and it is currently under Priority Review by the FDA. Most of the prominent competitors in the market are recombinant factor-VIII (rFVIII) products. Following this HAVEN 3 trial data, the potential for Hemlibra to gain major market access has grown, primarily due its advantage over short-acting rFVIII products. Although products like, Eloctate (once-every-three to five-day dosing) or Adynovate and Afstyla (twice-weekly dosing) still pose fierce competition, ongoing HAVEN-IV trial testing once-monthly dosing of Hemlibra in hemophilia A is expected to substantially differentiate the drug from other products.

References:
1. N Engl J Med 2018; 379:811-822
2. https://clinicaltrials.gov/ct2/show/NCT02847637
3. https://clinicaltrials.gov/ct2/show/NCT03020160
4. J Clin Med. 2017 Mar 28;6(4). pii: E39
5. Roche press release – https://www.roche.com/media/releases/med-cor-2018-08-30.htm

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