TOKYO, July 14 — Eisai Co., Ltd., the Japanese pharmaceutical firm with a history in neurology, finds its Alzheimer’s strategy at a critical juncture as its partnership with U.S. biotechnology company Biogen Inc. enters a new phase of market scrutiny. For investors in Mumbai and across Asia, the trajectory of this collaboration carries significant weight, given Eisai’s lead role in developing lecanemab, a treatment that could reshape the region’s dementia care landscape. Eisai, founded in 1941 and headquartered in Tokyo, has long been a fixture in neurology.
Its earlier Alzheimer’s drug donepezil, sold as Aricept, won U.S. Food and Drug Administration approval in 1996, establishing the company’s credentials in a field where few therapies succeed. The firm’s partnership with Biogen, a company founded in 1978 in Geneva and now based in Cambridge, Massachusetts, dates to 2014, when the two entered a joint development and commercialization agreement for aducanumab.
That drug, however, fell far short of commercial hopes. Biogen reported revenue from aducanumab of $11.1 million in 2022, a fraction of initial expectations. The experience underscored the high-risk nature of Alzheimer’s drug development, a lesson not lost on analysts tracking the sector in Asia.
Lecanemab takes centre stage
In March 2022, Eisai and Biogen announced a new collaboration to co-develop and co-commercialize lecanemab, with Eisai taking the lead on development and regulatory filings. Under the agreement, the two companies share profits and costs, but Eisai receives a larger share — 65% in the U.S. and 75% in other markets. This structure gives the Japanese firm greater upside in regions like Asia, where aging populations are driving demand for Alzheimer’s treatments.
Eisai reported global sales of lecanemab, marketed as Leqembi, of $4.7 million in the first quarter of 2023, following its accelerated approval. While modest, the figure signals early uptake in a market that could expand rapidly if full approval and broader reimbursement follow.
The partnership leverages distinct strengths. Eisai brings deep expertise in small-molecule drugs, while Biogen contributes capabilities in biologics and global commercialization. For Indian and other Asian markets, where regulatory pathways and pricing pressures differ from the West, Eisai’s lead role in non-U.S. territories could prove decisive.
Financial pressures mount
Both companies face headwinds. Eisai’s total revenue in fiscal year 2022 was approximately $5.5 billion. Biogen’s 2022 revenue stood at $10.2 billion, down from $11 billion in 2021, as sales of its multiple sclerosis drugs declined.
The financial strain heightens the stakes for lecanemab’s commercial performance. For the Asia-Pacific region, where dementia cases are projected to rise sharply in coming decades, the Eisai-Biogen collaboration represents one of the most closely watched drug development efforts.
The ministry of health in several countries has signaled interest in new Alzheimer’s therapies, though pricing and access remain unresolved questions. Analysts note that lecanemab’s trajectory in Japan and other Asian markets will depend on local regulatory decisions and health technology assessments. Eisai’s larger profit share outside the U.S. gives it a strong incentive to navigate these hurdles effectively.
What to watch next: whether lecanemab secures full FDA approval and how Eisai manages the rollout across Asia, where the burden of Alzheimer’s is growing fastest. The coming quarters will test whether this long-running partnership can finally deliver on its promise.
