Objectives: To assess the impact of the implementation of Medicare Part D and Affordable Care Act (ACA) on the utilization and expenditures of brand drugs used to treat colorectal cancer (CRC) and other cancer treatments at the national level in the Medicaid program.

Methods: Data for each drug approved for the treatment of CRC was collected from the Orange Book and the FDA website. Data of the utilization and expenditures of all CRC drugs was collected from the Centers for Medicare and Medicaid Services (CMS). Defined daily dose (DDD) for each CRC drug was extracted from the latest FDA-approved labels. Segmented Linear Regression (SLR) analysis was performed to assess the changes in the utilization and expenditures of CRC drugs, before and after the implementation of Medicare Part D in 2006 and the ACA in 2010.

Results: The FDA approved ten CRC drugs from 1996 to 2017. All the CRC drugs that were approved by the FDA and marketed in the U.S. were also covered by the Medicaid program. Our model showed decreased utilization for four out of five CRC drugs and decreased expenditures for three CRC drugs after the implementation of Medicare Part D; and increased utilization for two CRC drugs and increased expenditures for three CRC drugs after the implementation of ACA.

Conclusions: The utilization and expenditures for mot CRC drugs decreased with statistical significance after the implementation of Medicare Part D and increased with statistical significance for some CRC drugs after the implementation of the ACA. Future studies are needed to better understand the impact of CRC generic and biosimilar versions on the utilization and expenditures associated with CRC-prescribing patterns in the Medicaid program.