Long-term emicizumab appears safe, effective in severe hemophilia A

Emicizumab in patients with severe hemophilia A was safe and effective for up to 5.8 years, regardless of inhibitor status, according to results of the phase 1 study and phase 1/2 extension study.

In this study, 18 patients received emicizumab subcutaneously once per week at maintenance doses of 0.3 mg/kg, 1 mg/kg, or 3 mg/kg, for up to 5.8 years. All patients eventually switched to the approved maintenance dose of 1.5 mg/kg.

Compared to rates before receiving emicizumab, annualized bleeding rates (ABRs) for bleeds treated with coagulation factors decreased or remained at zero in all patients during the study period. The median ABRs were at 1.25 during the 0.3 mg/kg dosing period, 0.83 during the 1 mg/kg dosing period, and 0.22 during the 3 mg/kg dosing period.

ABRs decreased in 4 out of 8 patients who reduced their dose from 3 mg/kg to 1.5 mg/kg, remained at zero in 2, and increased in 2. All but 2 patients experience a decrease in total time spent with symptoms associated with treated bleeds.

In addition, all patients but one said bleeding severity and time until bleeding stops had ‘improved’; the singular patient indicated they had seen a slight improvement.

The majority of patients also said they experienced improvements or slight improvements in daily life, feelings, and anxiety.

Reference

Shima M, Nagao A, Taki M, et al. Long‐term safety and efficacy of emicizumab for up to 5.8 years and patients’ perceptions of symptoms and daily life: A phase 1/2 study in patients with severe haemophilia A. Haemophilia. 2020; https://doi.org/10.1111/hae.14205