MLD is an ultra-rare neurodegenerative disease leading to motor and cognitive decline and premature death. Prior to the approval of atidarsagene autotemcel (arsa-cel), patients with early-onset MLD had no disease modifying treatment options and very poor survival outcomes, often reaching a decerebrated state before adolescence. Arsa-cel is a one-time ex-vivo gene therapy, potentially enabling affected children to retain their motor and cognitive function into adulthood and contribute to society. Due to the debilitating nature of early-onset MLD, parents are often forced to give up work to care for their affected children. The aim of this study was to determine the lost family income due to caring for early-onset MLD patients, and potential productivity gains associated with arsa-cel treatment from a Dutch perspective.

Data from a cross-national MLD caregiver survey were used to inform changes in employment status and lost family income was calculated using average annual salaries and number of working days in the Netherlands in 2020. Future productivity gains were calculated using the Human Capital Approach. Due to lack of employment data in MLD patients, published data from cerebral palsy and Down’s syndrome were utilised as a proxy for impact of motor and cognitive dysfunction on employment, alongside expected earnings based on the Dutch education levels of achievement. A 3.5% discount rate was used to adjust productivity gains and lost family income.

In untreated patients over a 30-year timeframe, the estimated family income lost as a result of caring for a MLD patient was €214,416. In an arsa-cel treated patient, the productivity gains accrued over a working life were estimated at €317,484.

There are significant productivity gains for patients treated with arsa-cel compared to untreated patients who do not have opportunities to enter the workforce; significant family income is lost through non-treatment particularly in the later stages of MLD.