Chugai Pharmaceutical has announced that positive interim results have been reported from the global phase III HAVEN 4 study (NCT03020160) for emicizumab (ACE910) subcutaneous injection, every four weeks, in patients with hemophilia A (12 years of age or older) with and without inhibitors to factor VIII. This study aims to evaluate the efficacy, safety and pharmacokinetics (PK) of emicizumab prophylaxis. At this interim analysis after a median of 17 weeks of treatment, emicizumab prophylaxis demonstrated a clinically meaningful control of bleeding over time.

These results from HAVEN 4 are consistent with previous studies of emicizumab dosed once weekly or every two weeks to evaluate the reduction of bleed rate, including the pivotal studies in hemophilia A with inhibitors, phase III HAVEN 1 study (NCT02622321) in adults and adolescents and phase III HAVEN 2 study (NCT02795767) in children, as well as the phase III HAVEN 3 study (NCT02847637) in adults and adolescents (12 years of age or older) with hemophilia A without inhibitors. The most common adverse events with emicizumab were injection site reactions, with no new safety signals observed. No thrombotic microangiopathy or thrombotic events have been reported in this study. Further details will be presented at a future medical meeting. These results will be submitted to health authorities around the world for approval consideration.

“If emicizumab prophylaxis once every four weeks is proven to be effective in controlling bleeding regardless of the inhibitor status to factor VIII, it would advance the possibility to further prolong the administration interval of emicizumab,” said Chugai’s senior vice president, head of Project & Lifecycle Management Unit, Dr. Yasushi Ito. “These interim results represent the potential to ease the burden surrounding hemophilia treatment experienced by patients or their family in their daily life and to increase the medical value of emicizumab.”

Emicizumab is an investigational bispecific monoclonal antibody, which was developed using Chugai’s proprietary antibody engineering technologies. The drug is designed to bind factor IXa and factor X. In doing so, emicizumab provides the cofactor function of factor VIII in people with hemophilia A, who either lack or have impaired coagulation function of factor VIII1). In November this year, the drug (US product name: HEMLIBRA; Genentech) was approved by the U.S. Food and Drug Administration “for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adult and pediatric patients with hemophilia A (congenital factor VIII deficiency) with factor VIII inhibitors”. An EU marketing authorization application was submitted in June 2017 and is being reviewed under Accelerated Assessment by the European Medicines Agency. In Japan, emicizumab obtained an orphan drug designation in August 2016 from the Ministry of Health, Labour and Welfare for the prevention and reduction of bleeding episodes in patients with congenital factor VIII deficiency (hemophilia A) who developed inhibitors to FVIII, followed by an application for regulatory approval filed in July 2017.

HAVEN 4 study is a single-arm, multicentre, open-label, phase III study evaluating the efficacy, safety, and pharmacokinetics of subcutaneous administration of emicizumab dosed every four weeks. The study included 48 patients (12 years of age or older) with hemophilia A with or without inhibitors to factor VIII who were previously treated with either on-demand or prophylactic factor VIII or bypassing agents, depending on their inhibitor status. The primary endpoint of the study is the bleed rate with emicizumab prophylaxis and secondary endpoints include joint bleed rate, target joint bleed rate, health-related quality of life (HRQoL)/ health status, and safety.