Eisai Gives Full Aduhelm Responsibility To Biogen Under Amended Agreement

It appears that Eisai Co., Ltd. is throwing in the towel on the troubled anti-amyloid antibody Aduhelm (aducanumab), giving Biogen, Inc. full control of decision-making for the Alzheimer’s disease therapy, effective immediately. The companies will continue to share Aduhelm profits and losses globally in 2022 – with Eisai’s development, commercialization and manufacturing costs capped at $335m this year – but the Japanese company will no longer fund those costs beyond 2022 and from 2023 onward will collect only a single-digit percentage royalty on Aduhelm sales worldwide.

Eisai’s tiered royalty will start at 2% and could rise as high as 8% under the amended agreement if annual sales hit $1bn, but at the current pace of Aduhelm sales, that seems unlikely to happen anytime soon. The amyloid-clearing antibody generated just $1.3m in sales in 2021 after winning accelerated approval from the US Food and Drug Administration in June as the first potentially disease-modifying drug for Alzheimer’s disease and Biogen expects minimal sales in 2022