Estimated Annual Spending on Aducanumab in the US Medicare Program

The US Food and Drug Administration’s June 2021 decision to approve aducanumab for treatment for Alzheimer dementia raised concerns that a drug with uncertain benefit and high cost could, in aggregate, threaten Medicare's solvency. In response to these concerns, Biogen recently announced a 50% annual drug price reduction from $56 000 to $28 200 per patient. Preliminary US spending estimates either used extrapolated Alzheimer dementia prevalence data from 2012 or did not explicitly quantify ancillary costs, such as additional diagnostic imaging to monitor the amyloid-associated imaging abnormalities (ARIAs) that occur in 41% of treated patients, and did not incorporate the recently announced price reduction.1-3 We estimated upper bound and lower bound annualized Medicare costs for administering aducanumab to beneficiaries with the approved indications of mild cognitive impairment (MCI) or mild dementia, focusing on the degree to which associated ancillary health services affect spending.1