Five Deaths in Genentech’s Hemlibra Patients

The Hemophilia Federation of America and the National Hemophilia Foundation announced that they had been contacted by Genentech, a Roche company, about the deaths of five patients receiving Hemlibra (emicizumab-kxwh) for hemophilia A.

The Hemophilia Federation of America and the National Hemophilia Foundation announced that they had been contacted by Genentech, a Roche company, about the deaths of five patients receiving Hemlibra (emicizumab-kxwh) for hemophilia A.

Although there isn’t much detail, one of the patients was part of the company’s HAVEN 1 emicizumab trial, which was announced on February 22, 2017. The other four patients received the drug as part of a compassionate use and expanded patient access program.

Genentech indicated it had “limited information” about the deaths, but that all were determined to be unrelated to Hemlibra by the investigator or treating physician.

David Steinberg, an analyst with Jefferies, as reported by First Word Pharma, stated, “With very limited information, it is unclear if there are additional safety concerns with Hemlibra at this point. It’s a possibility that heightened concerns—which arose after the initial death…—could re-emerge.”

In June 2017, the companies indicated that in the HAVEN 1 trial, two patients had experienced thromboembolic events and three had experienced thrombotic microangiopathy. Hemlibra was approved by the U.S. Food and Drug Administration (FDA) for the prevention or reduction of the frequency of bleeding episodes in hemophilia A patients who developed Factor VIII inhibitors. About 25 to 30 percent of patients with severe hemophilia A develop Factor VIII antibodies, which are called inhibitors. They block replacement Factor VIII, which prevents the factor from working properly.

A company spokesperson told Endpoints News yesterday, “that one of the patients who died was in an expanded access protocol, three received it following compassionate use requests and one was in the HAVEN 1 trial. She added: ‘To date, five adults taking Hemlibra have passed away. For all, the treating physician or investigator’s assessment was that the cause of death was unrelated to Hemlibra (emphasis provided by Roche). We provided the national advocacy groups with this updated via phone yesterday.”

The earlier cases of thromboembolic and thrombotic microangiopathy were associated with bypassing agents (BPAs), which are a treatment option for patients who develop high levels of inhibitors. The FDA required the drug to have a boxed warning specifically citing the risks of thrombotic microangiopathy and thrombotic events.

John Carroll, with Endpoints News, noted that when the BPA-linked problems were reported, it “angered Shire and Novo Nordisk, the two key rivals who are feeling the biggest impact from the arrival of Hemlibra. Shire in particular came out gunning against Hemlibra, which has a peak sales estimate of $4 billion. Shire has claimed before that Roche has issued ‘inaccurate and misleading’ statements about the serious adverse events tracked in its Phase III—events which conspired to keep this would-be blockbuster under a cloud.”

The FDA approved the drug anyway, and the European Medicines Agency (EMA) gave the drug the nod shortly afterwards, as did regulatory authorities in Japan.

In separate but related news today, Roche announced that a Japanese court ruled in favor of its subsidiary, Chugai Pharmaceutical, in a patient lawsuit filed by Shire’s Baxalta unit. The drug was approved this month in Japan for routine prophylaxis to prevent or reduce the bleeding episodes in patients with congenital factor VIII deficiency with factor VIII inhibitors. The Japanese court dismissed the entire claim and forced Baxalta to pay all court costs.

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