Biogen Inc. and Eisai Co., Ltd. announced that the companies have amended their existing collaboration agreement on aducanumab, which is commercialized in the United States as ADUHELM^® (aducanumab-avwa). Effective as of January 1, 2023, Eisai will receive a tiered royalty based on net sales of ADUHELM rather than sharing global profits and losses.

The royalty rate starts at 2% and reaches 8% when annual sales exceed $1 billion.  Effective immediately Biogen’s existing final decision-making rights on ADUHELM have converted to sole decision making and commercialization rights worldwide. Overall, economic arrangements for both companies in 2022 are expected to remain materially unchanged with Eisai’s share of expenses capped at an agreed amount for the costs related to development, commercialization and manufacturing of ADUHELM for the period from January 1, 2022, to December 31, 2022. Once the tiered royalty model commences on January 1, 2023, Eisai will not participate in ADUHELM’s economics beyond these royalties.

The companies will continue to jointly develop and commercialize the investigational therapy lecanemab. Eisai continues to serve as the lead of lecanemab development and regulatory submissions globally with both companies co-commercializing and co-promoting the product, and Eisai having final decision-making authority. Both companies share economics equally with Eisai booking all sales for lecanemab and Biogen reflecting its 50% share of profits and losses. The supply agreement related to lecanemab has been extended from five to 10 years. Biogen will manufacture the lecanemab drug substance in its Solothurn, Switzerland facility with the goal of providing reliable commercial supply worldwide.