Medicare drug price negotiation: The complexities of selecting therapeutic alternatives for estimating comparative effectiveness.

Under the 2022 Inflation Reduction Act, the Centers for Medicare and Medicaid Services (CMS) are able to negotiate prices for topselling drugs in the Medicare Part B and D programs. In determining initial price offers, CMS will compare the prices and clinical benefits of the drugs subject to negotiation to the prices and clinical benefits of therapeutic alternatives. Despite the central role that the selection of therapeutic alternatives will play in the price negotiations, the available guidance published by CMS provides few details about how the organization will undertake this process, which will be particularly complex for drugs approved for more than one indication. To better inform the selection process, we identified all US Food and Drug Administration-approved indications for the first 10 drugs subject to negotiation. Using 2020-2021 Medicare claims data, we identified Medicare Part D beneficiaries using each of the 10 drugs. We extracted medical claims with diagnosis codes for each of the approved indications to report the relative treated prevalence of use by indication for each drug. We reviewed published clinical guidelines to identify relevant therapeutic alternatives for each of the indications. We integrated the evidence on the relative treated prevalence of indications and clinical guidelines to propose therapeutic alternatives for each of the 10 drugs. We describe challenges that CMS may face in selecting therapeutic alternatives.