OBJECTIVES: Duchenne muscular dystrophy (DMD) has a substantial economic impact on caregivers, as they are unable to fully participate in the workforce due to caregiving demands. This study estimated the potential impact delandistrogene moxeparvovec, a gene therapy (GT) approved for the treatment of ambulatory patients aged 4 through 5 years with DMD, would have on the work opportunity for caregivers of individuals with DMD.

METHODS: A lifetime 5-state partitioned survival model (early and late ambulatory, early and late non-ambulatory, death) was developed to assess outcomes of a homogeneous cohort of 4-year-old early ambulatory individuals with DMD. Disease progression estimates when treated with standard of care (SoC) were obtained from published literature; predicted GT effect was determined via clinical expertise and published hazard ratios. Beginning at age 31 years, caregiver work opportunity was estimated from age-based median US salaries, mortality-adjusted employment by age, and caregiver worktime loss estimates relative to the general population. Annual 2.8% salary growth and 3% discount rates were applied. Total work hours and income loss were calculated for caregivers of individuals with DMD treated with delandistrogene moxeparvovec and SoC versus SoC alone and compared to the US general population.

RESULTS: Caregivers of individuals treated with SoC were estimated to lose 7194 (15.5%) hours, resulting in a lifetime income loss of $249,697 (16.1%; undiscounted, $431,911 [16.2%]) versus the general population. Caregivers of individuals treated with delandistrogene moxeparvovec and SoC were estimated to lose 4564 (9.8%) hours, resulting in a lifetime income loss of $153,396 (9.9%; undiscounted, $318,375 [11.9%]) versus the general population.

CONCLUSIONS: DMD substantially impacts caregiver work opportunity and income. Based on this model, delandistrogene moxeparvovec could potentially increase caregiver work opportunity.