Biogen will stop selling its Alzheimer’s treatment Aduhelm, a drug once seen as a potential blockbuster that stumbled after its launch a few years ago.

The drugmaker also said Wednesday that it will end a study of the drug needed for full approval from the Food and Drug Administration.

Patients taking doses of Aduhelm available through the commercial market can continue until November. A company representative said there are about 2,500 people worldwide taking Aduhelm.

Biogen said it will turn its focus to other treatments for the fatal, mind-robbing disease. The company also is helping Japanese drugmaker Eisai sell another Alzheimer’s treatment, Leqembi, which received full FDA approval last summer.

Leqembi is the first medicine that’s been convincingly shown to slow the cognitive decline caused by Alzheimer’s disease, though only modestly. Regulators have approved it for patients with mild dementia and other symptoms caused by early Alzheimer’s.

When Aduhelm debuted in 2021, it was the first new Alzheimer’s drug in nearly two decades. The FDA had granted accelerated approval but required the additional study for full approval, which can spur broader insurance coverage.

Aduhelm promised to slow the progression of the disease instead of just managing its symptoms, like other drugs on the market.

Initially priced at $56,000 a year, analysts predicted it would quickly become a blockbuster that would generate billions for Biogen. The federal government’s Medicare program raised the premium it charges for its coverage partially because of an expected influx of Aduhelm claims.

But doctors were hesitant to prescribe the intravenous drug, given weak evidence that it meaningfully improved Alzheimer’s patients lives. Insurers blocked or restricted coverage. Medicare, which eventually scaled back its premium hike, imposed strict limits on who could get it.

That proved especially challenging for Biogen. Most U.S. Alzheimer’s patients are old enough to qualify for the federal program, which covers patients age 65 and older.

The drug wound up generating millions, not billions, in quarterly sales. Biogen announced in 2022 that it would largely shut down marketing of Aduhelm.

Last year, Biogen started an unsuccessful search for outside financing or partners to help with Aduhelm. That was done as part of a review the company did of its research and development program.

Biogen said it had considered during that review the time and investment that would be required for that additional study and likely advancements in the field before Aduhelm received full approval.

Aside from Leqembi, patients also may soon have another treatment option. The FDA is currently reviewing a potential drug from Eli Lilly and Co. A decision is expected early this year.

Biogen said it would book a charge of about $60 million in its fourth quarter for shutting down the Aduhelm program.

Shares of Cambridge, Massachusetts-based Biogen Inc. climbed around $4 to $251.11 in late-morning trading while the Standard & Poor’s 500 index slipped.

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