Santhera and ReveraGen Announce New 2.5-year Treatment Data with Vamorolone in Duchenne Muscular Dystrophy

Pratteln, Switzerland, April 28, 2021 – Santhera Pharmaceuticals (SIX: SANN) and ReveraGen Biopharma announce new clinical data of 2.5-year treatment outcome with vamorolone in patients with Duchenne muscular dystrophy (DMD). These Phase 2a long-term treatment data demonstrate a maintenance of treatment effect, equivalent to a delay of about two years in decline for time to stand (TTSTAND) velocity, and confirm safety and tolerability benefits of vamorolone over the 2.5-year follow up period. Long-term treatment with vamorolone resulted in significantly fewer corticosteroid-associated adverse events than reported in other clinical trials with other steroids.

A sequence of studies investigated the safety, tolerability and long-term treatment benefit with vamorolone and provide open-label data in a total of 46 patients with DMD, aged 4 to up to 10 years (start/end of treatment), of which 41 (89%) completed a 2.5 years treatment period. 48 participants initially completed a two-week multiple ascending dose trial VBP15-002 [1], 46 of whom entered the open-label 6-month extension VBP15-003 [2], covering a dose range of vamorolone of 0.25 to 6.0 mg/kg/day. All of the 46 patients completing the latter study entered the 24-month long-term extension study VBP15-LTE [3] where all patients eventually received doses of vamorolone of 2.0 to 6.0 mg/kg/day. The total exposure to vamorolone treatment in these studies was 113 patient years. The most commonly administered dose of vamorolone was 6.0 mg/kg/day. The studies, conducted by the Cooperative International Neuromuscular Research Group (CINRG), evaluated drug-related effects of vamorolone on timed motor function outcomes and corticosteroid-associated safety concerns.

Maintenance of treatment effect indicates disease modifying potential of long-term treatment with vamorolone
Previously reported findings [2] showed that patients treated with the two highest dose levels of vamorolone (2.0 mg/kg/day or 6.0 mg/kg/day) improved on average in their time to stand (TTSTAND) velocity by approximately 0.05 rises/second after 6 months of treatment from baseline, while patients treated with lower vamorolone doses or steroid-naïve controls from the CINRG-DMD Natural History Study (DNHS) showed no change. In practice, this change of 0.05 rises/second in a velocity is equal to e.g. an improvement from 5 to 4 seconds or from 8 to 5.7 seconds in the rise time from supine to standing. The treatment effect of the two highest dose levels of vamorolone was maintained at 0.05 rises/second at 2.5 years when compared to age-matched steroid-naive patients from the CINRG-DNHS. These results are equivalent to a delay of about two years in decline in TTSTAND velocity, which is consistent with the treatment effect of glucocorticoids seen in other studies [4, 5], and suggest disease modifying potential of vamorolone treatment in DMD. A similar change in trajectory was also observed for time to run/walk 10 meters (TTRW) compared to steroid-naïve patients from CINRG-DNHS. Assessments of 6-minute walk test (6-MWT) was not conducted in an adequate number of participants in CINRG-DNHS to allow for a comparison, however, patients receiving long term treatment with vamorolone remained above their average baseline value for 6-MWT after 2.5 years which further supports the long-term efficacy of vamorolone.