Vamorolone is a dissociative steroidal anti-inflammatory drug that seeks to retain efficacy and reduce safety concerns in patients with Duchenne Muscular Dystrophy compared to corticosteroids via changes to structure/activity relationships with the glucocorticoid receptor.
The objective of this analysis is to evaluate the efficacy and safety in patients who switched from prednisone to vamorolone in the second period of the study
VISION-DMD (VBP15-004) is a 48-week randomized, double-blind study consisting of two periods. During Period 1, 121 patients were randomized 1:1:1:1 to vamorolone 2 or 6 mg/kg/day, prednisone 0.75 mg/kg/day or placebo for 24 weeks. During Period 2, patients initiated on vamorolone continued their assigned treatment and those on placebo or prednisone crossed over to treatment with vamorolone 2 or 6 mg/kg/day. Changes in efficacy outcomes were assessed by time to stand velocity (TTSTANDV), 6-minute walk distance (6MWT), 10-meter run/walk velocity (TTRWV), NSAA score and 4-stair climb velocity (TTCLIMBV).
Out of 121 patients, 30 received prednisone during Period 1 followed by vamorolone treatment during Period 2. All 30 completed vamorolone treatment to Week 48. Efficacy was maintained across all functional endpoints after switching from prednisone to vamorolone 6 mg/kg/day. No significant differences were seen at Week 48 in any efficacy endpoints versus patients continuously treated with vamorolone 6 mg/kg/day throughout the study. No serious adverse events were reported after the switch. Annualized rates of adverse events were reduced after the switch from prednisone to vamorolone (all events: 20% reduction, steroid-related events: 40% reduction). Stunting of growth observed with prednisone during Period 1 was reversed during treatment with vamorolone during Period 2.
There was no loss of efficacy after switching from prednisone to vamorolone 6 mg/kg/day. After the switch, the rate of adverse events on vamorolone was reduced compared to that reported on prednisone and stunting of growth reversed.