Delandistrogene moxeparvovec is one of several commercially approved gene therapies for Duchenne Muscular Dystrophy (DMD), but real-world post-infusion safety data remain limited. The goal of this project is to characterize real world post-infusion safety outcomes in patients with DMD being treated with delandistrogene moxeparvovec.
Retrospective chart review was conducted on 12 ambulatory patients, aged 7-16, seen at Arkansas Children’s Hospital, the only pediatric tertiary care center in Arkansas. Patients had a history of baseline corticosteroid use and were monitored for 3 months, following treatment-related toxicities, liver enzymes, cardiac structural changes, and troponin levels. Treatment-related toxicities were defined based on clinician documentation and laboratory abnormalities.
Of the 12 patients, 11 experienced treatment-related toxicities, but only 2 required an escalation of corticosteroids. Most common among these side effects were mild-to-moderate GI symptoms (n=9), liver enzyme abnormalities (n=6), acute liver injury (n=2), and troponin elevations (n=1). GI symptoms included nausea and vomiting within the first few days after administration; all cases required anti-emetics and resolved after a maximum of a week post-infusion. One case of acute liver injury resolved spontaneously while the other required an escalation in corticosteroid use. The case of troponin elevation resolved without an escalation in corticosteroid use, but it was associated with a newly identified structural abnormality on echocardiography.
These findings highlight the incidence of early, predominantly low-grade toxicities and show that hepatic and cardiac complications, though less common, merit close surveillance in real-world practice. Longer-term follow-up and multicenter studies with larger cohorts are needed to better clarify the durability of these effects, identify predictors of high-grade toxicities, and optimize peri-infusion corticosteroid protocols.