UPDATED: Biogen insists Eisai relationship 'solid' as questions remain over lecanemab commercialization

Biogen may still be basking in the positive phase 3 data of its Eisai-partnered Alzheimer’s drug lecanemab, but the big pharma's CEO has remained vague on exactly what role his company will play in the therapy's commercialization.

“I can tell you that the relationship is very solid since many years,” Michel Vounatsos said on the company’s third-quarter earnings call this morning. “The commercialization [and] co-marketing is being discussed when we speak and is not yet determined. But overall the relationship is sound and solid.”

The outgoing CEO, who was responding to a question regarding the two companies' partnership and whether there had been any contractual disputes, added that he speaks with his “counterpart” at Eisai on a “very regular basis” and will do so again in the coming days. 

The brief reassurance comes as the two companies are fast approaching critical regulatory decisions regarding lecanemab, which in September posted the most encouraging clinical data on reducing clinical decline due to Alzheimer’s to date. Notably, Vounatsos didn't directly address whether or not there was any friction regarding Biogen’s role moving forward. In a statement from an Eisai spokesperson, the company reaffirmed that it "will continue to lead on Lecanemab regulatory, development, commercialization, and promotional efforts." 

"Eisai has responsibility for, control over and final decision-making authority on all matters and activities relating to lecanemab."

Eisai has led development and regulatory efforts for lecanemab from the jump with “both companies co-commercializing and co-promoting the product,” according to a March release. Eisai has a final decision-making say on the drug but both companies will share its profits and losses. Biogen is responsible for manufacturing the lecanemab drug substance, with Eisai extending that supply agreement from five to 10 years.

The two companies originally teamed up on the controversial Alzheimer's therapy Aduhelm, for which the FDA granted accelerated approval in June 2021 against the recommendations of its own advisors. It was the first drug to be approved to treat the underlying causes of the degenerative condition rather than just symptoms, but the evidence was suspect. The partnership was amended earlier this year to give Biogen sole decision-making authority and commercialization rights, emblematic of Aduhelm’s dwindling commercial prospects after the Centers for Medicare and Medicaid restricted its reimbursement. 

The FDA is currently reviewing lecanemab under the accelerated approval pathway with a decision deadline of January 6, 2023. Eisai is also gearing up for full approval submissions in the U.S., EU and Japan, with filings slated before the end of the first quarter of 2023. 

Editor's note: This story was updated to include a comment from an Eisai spokesperson.