Biogen will stop developing its Alzheimer’s treatment Aduhelm, a drug once seen as a potential blockbuster before stumbling soon after its launch a couple years ago.

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

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 more to other Alzheimer’s treatments. It also is helping Japanese drugmaker Eisai sell another Alzheimer’s treatment, Leqembi, which already has full FDA approval.

Aduhelm was the first new Alzheimer’s disease drug introduced in nearly two decades when it received accelerated approval from the FDA in 2021. Initially priced at $56,000 a year, analysts predicted it would quickly become a blockbuster drug that would generate billions for Biogen.

But doctors were hesitant to prescribe it given weak evidence that the drug slows the progression of Alzheimer’s, a fatal, mind-robbing disease. Insurers have blocked or restricted coverage, and the federal government’s Medicare program imposed strict limits on who could get it.

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