Background: The recommended dose of vamorolone in children with DMD is 6 mg/kg/day. Doses may be titrated down to as low as 2 mg/kg/day, based on tolerability.
Objective: To report experience with vamorolone dose titration in Expanded Access Programs (EAPs).
Methods: Data were collated from patients who had completed studies VBP15-LTE or VBP15-004 and enrolled in 1 of 3 EAPs in the US, Canada, and Israel. Available data were pooled to explore the frequency of dose titration during the EAPs. The EAPs allowed for up- or down-titration of vamorolone as medically warranted.
Results: At EAP baseline, the median age of patients (N=69) was 7.1 years, median height was 117.5 cm, and median weight was 25.8 kg. At the start of the EAPs, most patients were dosed at vamorolone 4 mg/kg/day (44.9%; n=31) or 6 mg/kg/day (39.1%; n=27), with fewer dosed at 2 mg/kg/day (15.9%; n=11). The median duration of vamorolone exposure during the EAPs was 3.3 years with a maximum of 4.9 years. The majority of patients did not change dose, and up- and down-titrations occurred at a similar frequency. Up-titration from 4 to 6 mg/kg/day and down-titration from 6 to 4 mg/kg/day were the most common dose changes, and the least common changes were down-titrations from the higher doses to 2 mg/kg/day. During the EAPs, 16 patients discontinued treatment; most of these were due to withdrawal by either the patient or parent/guardian (n=14), one was due to physician decision, and one was due to an adverse event. By the end of the EAP or treatment cutoff, most patients were dosed at vamorolone 4 mg/kg/day (43.5%; n=30) or 6 mg/kg/day (37.7%; n=26) and fewer were dosed at 2 mg/kg/day (18.8%; n=13).
Conclusions: Long-term experience in the EAPs shows that vamorolone 4 and 6 mg/kg/day are the most frequently used doses and that most patients do not change dose. However, the therapeutic dose range from 2 to 6 mg/kg/day allows physicians to up- or down-titrate dosing based on individual tolerability.