Biogen takes full control of troubled Aduhelm in revamped Eisai deal

Even before a highly anticipated coverage decision, Eisai has decided to abandon Aduhelm, bowing out of the marketing of the controversial Alzheimer’s disease drug that it co-developed with Biogen amid a dismal commercial outlook.

Biogen and Eisai have amended a previous pact signed in 2017, leaving Biogen with “sole decision making and commercialization rights” for Aduhelm worldwide, the companies said Monday.

Staring next year, Eisai will exit its supporting role in Aduhelm as well as its cut in profits or losses. Instead, the Japanese pharma will take a tiered royalty based on sales of Aduhelm. The rate starts at 2% and caps at 8% when annual sales exceed $1 billion.

The restructuring reflects the worsening commercial outlook for Aduhelm. Last June, when Aduhelm became the first FDA-approved Alzheimer’s drug in about 20 years, the question wasn’t if it can exceed $1 billion sales but when. Industry watchers had said it could reach $9 billion at peak.

But concerns over the drug’s efficacy and safety profile, plus Biogen’s reportedly dubious interactions with the FDA, have stopped U.S. doctors from prescribing it. Besides, drug reviewers in Europe and Japan have also declined to approve Aduhelm based on existing clinical trial data. In the fourth quarter of 2021, Aduhelm only posted $1 million in sales.

In another serious blow to Biogen, the Centers for Medicare & Medicaid Services (CMS) is proposing to restrict Medicare coverage of anti-beta-amyloid antibodies like Aduhelm to patients who are enrolled in preapproved randomized clinical trials. Biogen recently expanded Aduhelm’s confirmatory trial, dubbed ENVISION, but it still only expects to enroll 1,500 early Alzheimer’s patients, including some who will receive placebo. And a planned 6,000-participant phase 4 study dubbed ICARE AD-US isn’t randomized.

The new Eisai agreement will “increase operational efficiency and agility in addressing market developments, including the final determination of CMS on coverage of Aduhelm,” Biogen CEO Michel Vounatsos said in a statement. The final CMS decision is expected next month.

Meanwhile, struggling with slow Aduhelm uptake, Biogen has launched a restructuring plan and recently started laying off employees.

Eisai first teamed up with Biogen on Alzheimer’s in 2014 and expanded the pact to include Aduhelm in 2017. Under the deal, Eisai was originally set to receive 45% of Aduhelm’s profits in the U.S. and higher shares in Europe and Japan.

Now, the Japanese pharma is shifting focus to lecanemab, another anti-beta-amyloid drug that’s covered in the initial Biogen collaboration. Financial terms related to lecanemab remain unchanged as both companies will co-develop and co-commercialize the drug. The companies have extended a supply agreement under which Biogen will now make the drug for 10 years instead of five years. Unlike Aduhelm, Eisai has final say in—and will book sales for—lecanemab.

“We believe this new arrangement will be more effective and enable more focused execution with the goal of maximizing the value of both Aduhelm and lecanemab,” Eisai CEO Haruo Naito said in a statement.

Eisai kicked off a rolling submission of lecanemab to the FDA in September 2021. The hope is to get an accelerated approval based on biomarker data linking the antibody to a dose-dependent drop in amyloid plaques. The drug’s ongoing phase 3 trial, which will confirm whether lecanemab can slow patients’ cognitive decline, is also expected to read out in the third quarter this year.