Deaths of 5 Hemophilia A Patients Not Related to Hemlibra Treatment, Genentech Says

Margarida Azevedo, MSc avatar

by Margarida Azevedo, MSc |

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The five adults with hemophilia A who died while using Hemlibra (emicizumab-kxwh) to treat their disease did not die of causes related to the treatment, manufacturer Genentech said in a statement.

“In each of these cases, the assessment of the treating physician or investigator was that the cause of death was unrelated to Hemlibra,” Genentech said in a March 28 press release. “Based on these assessments and the available information, these events do not change the [treatment’s] currently known benefit/risk profile.”

One of the adults — all of whom had hemophilia A with inhibitors, or antibodies that limit the effectiveness of factor VIII treatments — died in 2017 while receiving Hemlibra in a clinical trial. Another was being treated in the U.S. through an expanded access program, and the remaining three were receiving Hemlibra through compassionate use requests.

Details regarding the causes of these deaths, which date from 2016 to this year, were not given by the company.

Reuters reported that one patient died in 2017 after refusing a blood transfusion for religious reasons during a bleeding event.

Hemlibra is a prescription medicine approved in the United States since November 2017, and in the European Union since March 2018. It is a routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and children with hemophilia A who have antibodies that prevent clotting factor therapies from working as well as they should. In the case of hemophilia A patients, these antibodies are called factor VIII inhibitors.

Its approval by the U.S. Food and Drug Administration (FDA) marked the first new hemophilia A treatment in almost 20 years.

The Phase 3 clinical trial (NCT02622321) that reported one death is called Haven 1. It assessed the safety and effectiveness of once-weekly subcutaneous injections of Hemlibra prophylaxis in about 110 adult and adolescent hemophilia A patients with inhibitors to factor VIII, compared to patients not receiving prophylaxis. FDA approval was partly based on results from this trial, which found that treatment led to an 87 percent reduction in bleeds compared to patients not on prophylaxis.

A number of other Phase 3 clinical trials also tested, or are testing, Hemlibra in patients: HAVEN 2 (NCT02795767),  and the ongoing HAVEN 3 (NCT02847637) and HAVEN 4 (NCT03020160) studies.

Genentech and its parent company, Roche, first contacted hemophilia patient groups — the National Hemophilia Foundation and the Hemophilia Foundation of America — with news of the five deaths on March 26, both groups reported.

“HFA recognizes that there has been robust discussion on social media as the community has been made aware of this and other adverse events surrounding Hemlibra. We will continue to monitor the situation and share information as we learn more,” the Hemophilia Foundation said on its website.

Serious side effects associated with Hemlibra use include thrombotic microangiopathy, or blood clots and injury to small blood vessels that can harm organs like the kidneys and brain; and blood clots, especially in the arms, legs, lungs or head. More common side effects are injection site reactions, headaches, and joint pain, according to Genetech. Prescribing information is available here.

Genentech has a “Medical Communications line” at 800-821-8590 for patients, concerned community members, and healthcare providers who seek more information. Patients are encouraged to reach out to Genentech or to their treating physician with questions or concerns.

Hemlibra recently was found to be an effective and less costly treatment option for hemophilia A patients with inhibitors by the Institute for Clinical and Economic Review (ICER), a therapy rating organization.

ICER, in its mid-March release that was an update on an initial report, based its findings on a four-week public discussion period that attracted comments and suggestions from patient groups, physicians, pharmaceutical industry leaders, and others.

The group concluded that Hemlibra offers a “high certainty of a substantial net health benefit” to patients 12 and older with hemophilia A with inhibitors “compared with no prophylaxis.”

ICER’s newest report was set to be reviewed again on March 29, at a meeting of the New England Comparative Effectiveness Public Advisory Council (New England CEPAC) in Cambridge, Massachusetts. Findings are expected to be released soon.

Hemlibra was co-developed by Japan’s Chugai Pharmaceutical, Roche, and Genentech.