OBJECTIVES: Duchenne muscular dystrophy (DMD) is a rare neuromuscular disorder that causes progressive weakness and early death. Several clinical trials using gene therapy initiate in 2018. This qualitative study explored factors influencing parents’ and adult patients’ preferences about gene therapy as a potential therapeutic option for DMD.
METHODS: We report qualitative data from phone interviews with 17 parents of children with DMD (ages 5 to 32) and 6 adult patients. Participants responded to a hypothetical vignette of an approved gene therapy with features including non-curative stabilizing benefits to muscle, cardiac and pulmonary function; a treatment-related risk of death; and one-time dosing with time-limited benefit of 8-10 years. We used NVivo 11 to code responses and conduct thematic analyses.
RESULTS: All participants placed high value on benefits to skeletal muscle, cardiac, and pulmonary functioning, with the relative importance of cardiac and pulmonary function increasing with disease progression. More than half were tolerant of a hypothetical 1% risk of death when balanced against Duchenne progression and limited treatment options. Risk tolerance increased in adults and at later stages. Participants perceived a ‘right time’ to initiate gene therapy. Most parents preferred to wait until functional decline began in school-age children. Most adults preferred to initiate when a valued function was about to be lost. Two adults would have preferred to initiate in the past when they had better functioning.
CONCLUSIONS: Participants demonstrated a complex weighing of potential benefits against harms and the inevitable decline of untreated Duchenne. Disease progression increased risk tolerance as participants perceived fewer treatment options and placed greater value on maintaining remaining function. In the context of a one-time treatment like gene therapy, our finding that preferences about timing of initiation are influenced by disease state suggest the importance of measuring ‘lifetime’ preferences across the full spectrum of disease progression.
