New data strengthen safety profile of emicizumab in patients with hemophilia A


A final analysis of data from the phase 3b STASEY study confirms the benefit and risk profile of emicizumab (Hemlibra) in patients with hemophilia A, according to a press release from Genentech.

Emicizumab is a bispecific antibody against factors IXa and X that is designed to join both factors IXa and X. These proteins are needed to activate the natural coagulation cascade and restore the blood clotting process in patients. patients with hemophilia A.

The trial did not identify any new safety signals, and emicizumab continued to demonstrate effective bleeding control with a high proportion of participants reaching zero treated bleeds, the researchers said. The trial looked at longer-term treatment with emicizumab in adults and adolescents with hemophilia A with inhibition of factor VIII, the clotting protein that is lacking in patients with hemophilia A.

Almost a third of patients with severe hemophilia A develop factor VIII inhibitors, which bind to replacement factor VIII and block its effectiveness. People with these inhibitors have a higher risk of frequent bleeding, including life-threatening bleeding, and may have more difficulty in their daily life than patients who do not have factor VIII inhibitors.

The final analysis from the STASEY trial included data from 193 people with hemophilia A and factor VIII inhibitors who received emicizumab prophylactically once a week for up to 2 weeks. years. Analysis of the data showed no new cases of thrombotic microangiopathy or serious drug-related thrombotic events.

The most common adverse events (AEs) that occurred in 10% or more of patients in the STASEY study were joint pain (17.1%), nasopharyngitis (15.5%), headache (15%) , injection site reactions (11.4%) and fever. (10.9%). Additionally, 18.1% of participants reported an AE related to emicizumab, with injection site reaction being the most common (9.8%).

The results of the study also reinforced that emicizumab is associated with a low incidence of anti-drug antibody (ADA) development. Ten (5.2%) participants tested positive for ADA, of which 2.6% were classified as having neutralizing ADA in vitro. Development of ADA did not impact the efficacy or safety of emicizumab in any of the 10 patients, and none had ADA that resulted in decreased plasma concentration of emicizumab. None of the ADA-positive participants had any treated bleeding and the ADAs disappeared over time, according to the study.

Emicizumab continued to demonstrate effective bleeding control, with 82.6% of participants having no bleeding episodes requiring treatment. The annualized bleeding rates were consistent with previously reported data from the pivotal HAVEN studies.

“As the therapeutic landscape evolves, determining the long-term benefit / risk profile of drugs for people living with hemophilia A remains a top priority for the community,” said Levi Garraway, MD, PhD, Chief Medical Officer and responsible for global product development. at Genentech, in the press release. “These results strengthen confidence in the favorable safety profile of Hemlibra in people with hemophilia A with factor VIII inhibitors, who have historically faced significant treatment challenges.


New Data for Hemlibra (emicizumab-kxwh) from Genentech Strengthens Safety Profile in People with Hemophilia A. Press Release. Genentech. July 18, 2021. Accessed July 19, 2021.


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