New Analysis Confirms Hemlibra’s Sustained Efficacy in Controlling Bleeding in Some Children With Hemophilia A

A new analysis of the Phase 3 HAVEN 2 study’s results shows that Genentech’s Hemlibra (emicizumab-kxwh) prophylaxis (preventive treatment) leads to significant reductions in the number of bleeds among hemophilia A children younger than 12 with factor VIII inhibitors.

The results showed that Hemlibra administered on different schedules — once a week, either every two or four weeks — resulted in a clinically meaningful reduction of bleeds.

The results were presented at the 60th American Society of Hematology (ASH) Annual Meeting, Dec. 1-4 in San Diego, California, in a presentation titled, “Emicizumab Prophylaxis Provides Flexible and Effective Bleed Control in Children with Hemophilia Α with Inhibitors: Results from the HAVEN 2 Study.”

“Children with inhibitors are at increased risk of life-threatening bleeds and may experience frequent, repeated bleeding into joints,” Guy Young, MD, director of the Hemostasis and Thrombosis Center, Children’s Hospital Los Angeles, said in a press release.

“These updated data from HAVEN 2 showed that the majority of children with hemophilia A with factor VIII inhibitors treated with emicizumab-kxwh [Hemlibra] had zero treated bleeds across three different dosing schedules, reinforcing the ability of this medicine to provide sustained, effective bleed control,” said Young, also a professor at the University of Southern California Keck School of Medicine, Los Angeles.

The HAVEN 2 study (NCT02795767), which enrolled 85 children younger than 12 with hemophilia A and factor VIII inhibitors, tested the efficacy and safety of preventive treatment with Hemlibra delivered either once weekly, every two weeks or every four weeks as subcutaneous (under the skin) injections.

In total, 65 children received the therapy once a week and were followed for a median of 58 weeks. Ten children received Hemlibra every two weeks and 10 received Hemlibra every four weeks, with follow-up of 21.3 weeks and 19.9 weeks respectively.

The results showed that 76.9 percent of the children treated with Hemlibra once weekly experienced zero treated bleeds.

Hemlibra delivered every two and every four weeks led to zero treated bleeds in 90 percent and 60 percent of the children, respectively.

An intra-patient analysis comparing those treated with once-weekly Hemlibra to patients treated with bypassing agents, either preventive or on-demand, showed that Hemlibra led to a 99 percent decrease in the number of treated bleeds.

Bypassing agents, rather than replacing the missing VIII factor, bypass the factors blocked by the patient’s antibodies to help form a normal clot.

Researchers reported no serious adverse effects, specifically blood clots in small vessels (called thrombotic microangiopathy).

“The updated analysis from the HAVEN 2 study supports the potential of Hemlibra to control bleeds at less frequent subcutaneous dosing, providing parents and their children more flexibility to choose a treatment schedule that is right for them,” said Sandra Horning, M.D., chief medical officer and head of Global Product Development.

“Many children with hemophilia A with factor VIII inhibitors have already experienced the benefits of Hemlibra, and with these new positive data, we are confident that this treatment will continue to make a meaningful difference in their lives,” Horning said.

Data from the HAVEN 2 study and from the previous Phase 3 HAVEN 1 (NCT02622321) trial supported Hemlibra’s approval in Taiwan to be administered as a once-weekly subcutaneous injection for hemophilia A patients with factor VIII inhibitors. Hemlibra is marketed in Japan and other countries by Chugai Pharmaceutical, a member of the Roche Group.

“We are pleased that Hemlibra has received regulatory approval for hemophilia A with factor VIII inhibitors now in Taiwan,” said Yasushi Ito, Chugai’s executive vice president, co-head of project & lifecycle management unit. “Chugai will cooperate with Chugai Pharma Taiwan so that Hemlibra may contribute to people with hemophilia A with inhibitors who have limited treatment options.”