OBJECTIVES: X-Linked Myotubular Myopathy (XLMTM) is a rare monogenic disease often present from birth that leads to profound muscle weakness, respiratory failure and early death. Disease course typically requires increasing respiratory support and up to 24 hours/day of invasive ventilation. To date, the economic burden of XLMTM has not been determined. This study aims to quantify XLMTM patient costs by ventilation status.

METHODS: This retrospective longitudinal study used the IQVIA PharMetrics Plus^® commercial claims database for the period 1/1/2006 to 9/30/2018. Patients were males with 1+ reported diagnostic code(s) used for XLMTM (ICD-9-CM: 359.0 [Congenital hereditary muscular dystrophy] or ICD-10-CM: G71.2 [Congenital myopathies]) within their first 18 months of life, who also met criteria identified in the RECENSUS retrospective chart review of confirmed XLMTM patients (NCT02231697). Outcomes were mean monthly all-cause per-patient costs paid by private insurers for patients receiving no ventilation, non-invasive ventilation or invasive ventilation. Ventilation was identified using ICD (diagnosis and procedure) and Common Procedure Terminology (CPT) codes. Limited home-health care costs in commercial claims may underestimate the direct economic burden, especially in stabilized XLMTM patients.

RESULTS: Among 49 patients, mean age at first observable diagnosis was 4.4mo (SD: 5.9). Most (n=40, 82%) were initially or eventually treated with invasive ventilation. Prior to invasive ventilation, 43% (n=21) received no ventilation and 27% (n=13) received non-invasive ventilation. Mean per-patient per-month costs for patients with invasive ventilation were $29,101, with inpatient stays underlying most of these costs ($22,670 [78%]). Per-patient monthly costs were lower when patients received no ventilation ($15,606; Inpatient: $11,524 [74%]) and lowest when patients received non-invasive ventilation ($10,269; Inpatient: $6,747 [66%]), which may reflect lower disease stability in non-vented patients.

CONCLUSIONS: Annualized all-cause healthcare costs average over $349,215 per invasively ventilated patient from diagnosis to age 11, demonstrating the significant economic burden of XLMTM.