Eisai Turns Over Majority of Aduhelm Rights to Biogen

John Tlumacki/The Boston Globe via Getty

Tokyo-based Eisai Inc. has been somewhat in the shadows regarding the Alzheimer’s drug Aduhelm (aducanumab) it developed with Biogen. However, they have partnered on it all along the way. Today, the two companies announced modifications to their existing pact on the drug.

Starting Jan. 1, 2023, Eisai will receive tiered royalties based on Aduhelm’s net sales instead of sharing global profits and losses. The royalties begin at 2% and hit 8% when annual sales surpass $1 billion. Starting immediately, Biogen’s existing final decision-making rights on the drug have shifted to sole decision-making and commercialization rights worldwide. Otherwise, economic arrangements in 2022 will remain materially unchanged. Eisai’s share of expenses will be capped at an agreed amount for development, commercialization and manufacturing costs for Aduhelm from Jan. 1, 2022, to Dec. 31, 2022.

This appears to mark Eisai’s decision to turn over control and responsibility for the controversial drug to Biogen. The original deal was inked in 2017. The economic outlook for the drug isn’t good and sales to date have been dismal. The third quarter of 2021 only brought in $300,000 compared to an original analyst average estimate of $10.79 million, with peak projections of $9 billion. The fourth quarter only brought in $1 million in sales.

Then, the U.S. Centers for Medicare & Medicaid Services issued a draft national coverage decision for the drug that would only cover the cost of the drug and any required scans “if they are enrolled in qualifying clinical trials.” Those trials would require demonstration of “a clinically meaningful benefit in cognition and function.” Although the public comment period is over, there was a fair amount of pushback against the guidance by other companies in the space, including Eli Lilly and Roche, because the guidance also broadly affected the entire class of Alzheimer’s therapeutics in development. It was also unusual for the CMS to be reluctant to pay for a drug approved by the U.S. Food and Drug Administration.

Although CMS might loosen up its guidance before making a final decision, the Biogen-Eisai amendments suggest Eisai doesn’t think it will and has chosen to cut its losses. Drug regulators in Europe and Japan have chosen not to approve Aduhelm based on current clinical trial data.

Biogen and Eisai will continue to work together to develop and commercialize another Alzheimer’s drug, lecanemab. Eisai is heading the lecanemab program with Biogen joining to co-commercialize and co-promote the drug, with Eisai having final decision-making rights. Eisai will book sales for the drug and Biogen is up for 50% of profits and losses. The drug’s supply deal was also extended from five to 10 years. Biogen will produce the drug in its facility in Solothurn, Switzerland. Eisai and Biogen initiated a rolling submission to the FDA for the drug in Sept. 2021. It is an investigational anti-amyloid beta protofibril antibody.

“This amended collaboration agreement will increase operational efficiency and agility in addressing market developments, including the final determination of CMS on coverage of Aduhelm,” said Biogen’s chief executive officer, Michel Vounatsos. “In addition, we are pleased to be expanding our agreement with Eisai through a new long-term manufacturing contract.”

Eisai’s chief executive officer, Haruo Naito, was diplomatic, saying, “The collaboration between both companies has resulted in the approval of Aduhelm in the U.S. as the first treatment to address a defining pathology of Alzheimer’s disease, which is a significant step into a new chapter of Alzheimer’s therapy. 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 and remains committed to bringing a new treatment option expeditiously to patients in need worldwide.”