Aduhelm — the pricey Alzheimer's drug that sparked congressional scrutiny of the Food and Drug Administration's process for fast-tracking approvals as well as fears of Medicare insolvency — is coming off the market, drugmaker Biogen said Wednesday.

Why it matters: Despite Aduhelm's lackluster performance, its accelerated approval in June 2021 drove urgent conversations about how the health care system can afford a new wave of expensive treatments that for the first time slow Alzheimer's progression, albeit mildly.

Driving the news: Biogen said it will prioritize other Alzheimer's drugs including Leqembi, which it developed with Japanese drugmaker Eisai and received full FDA approval in July, as well as two experimental drug candidates.

Catch up quick: Aduhelm's accelerated approval was lauded by patient advocacy groups as the first treatment available against the disease in decades.

• But it was also quickly engulfed in controversy over safety worries, concerns about its $56,000 list price (which was later halved), and questions of how closely the company and regulators worked in the lead-up to its approval.
• That led to a congressional investigation as well as strict Medicare limits on who could get the treatment.
• Biogen said it's not abandoning the drug due to any safety or efficacy concerns.

The big picture: Uptake of Aduhelm was low, with roughly 2,500 people worldwide using the drug, a Biogen official told NBC News.

• Last year, Biogen began a strategic review of its research and development efforts, including seeking potential partners or external financing for Aduhelm, but was unable to find any.
• Biogen said it is shutting down a study needed to obtain full FDA approval of the drug. The rights for the drug revert back to Switzerland-based Neurimmune.