The Utilization, Reimbursement, and Cost of Targeted Therapies for Duchenne Muscular Dystrophy (DMD) in US Medicaid...

Duchenne muscular dystrophy (DMD) is a rare hereditary neuromuscular disorder caused by mutations in the dystrophin gene, leading to progressive muscle deterioration, loss of ambulation, and reduced life expectancy. The US Food and Drug Administration (FDA) has approved several novel drugs for DMD; however, their utilization, reimbursement, and cost patterns within US Medicaid programs remain unexamined.

The purpose of this study was to evaluate the utilization, reimbursement, and cost trends of targeted therapies for DMD in the US Medicaid population from 2017 to 2022.

A retrospective descriptive drug utilization study was conducted using the national Medicaid drug utilization files that were extracted from the Centers for Medicare and Medicaid Services (CMS) from 2017 to 2022. The study drugs comprised the following four FDA-approved drugs: eteplirsen (Exondys 51^®), golodirsen (Vyondys 53^®), viltolarsen (Viltepso^®), and casimersen (Amondys 45^®). The annual number of prescriptions represented drug utilization and the annual amount of reimbursement represented the total spending, which were calculated for time-series secular trend analyses. The average cost per prescription was also computed as an estimate of drug cost trends.

Over the 6-year period, the total count of DMD prescriptions increased significantly by 2988%, from 643 prescriptions in 2017, when only eteplirsen (Exondys 51^®) was available, to a peak of 19,855 prescriptions in 2022, including all four novel DMD drugs. Additionally, the overall reimbursement grew by nearly 2809%, increasing from US$22,027,999 in 2017 to US$640,890,515 in 2022. However, the average cost per prescription decreased by about 6%, from US$34,258 in 2017 to US$32,279 in 2022.

The considerable rise in the utilization and spending of novel DMD drugs has imposed a significant burden on the Medicaid budget, underlining the need for policy measures to manage rising costs and maintain equal access to treatment.