Vamorolone Extension Trial Supports Muscle Gains in DMD with Fewer Side Effects, Topline Data Show

Vamorolone, an experimental treatment for Duchenne muscular dystrophy (DMD) being developed by ReveraGen Biopharma, continues to improve muscle function in DMD patients with fewer side effects than standard corticosteroids, topline data in 23 boys in an ongoing Phase 2 trial show.

These findings were detailed in a late-breaking presentation by Eric Hoffman, PhD, chief executive officer of ReveraGen, at the World Muscle Society (WMS) Congress that took place Oct. 1-5 in Copenhagen.

Vamolorone (VBP15) is an anti-inflammatory steroid treatment that aims to slow DMD progression without the severity of side effects seen in treatment with corticosteroids, such as prednisone and deflazacort, like weight gain.

Findings presented covered data on treatment tolerability and changes in motor function among 23 DMD patients treated daily for at least 18 months with vamorolone at 2.0 or 6.0 mg/kg (oral liquid suspension) in the VBP15-LTE (NCT03038399) long-term and open-label extension study.

A total of 45 boys are in this two-year extension trial, all of whom rolled over from a core study in Duchenne children, VBP15-003 (NCT02760277), testing vamorolone’s safety and efficacy at doses that ranged from 0.25 to 6.0 mg/kg daily. Another also completed core study, VBP15-002 trial (NCT02760264), did the same.

Previous findings from VBP15-003 showed that vamolorone had a favorable safety profile and was able to improve boys’ muscle function in a dose-dependent manner.

Muscle function improvements were found in these 23 boys, measured by time to stand tests — measures of the speed at which they are able to stand from lying in a supine position — taken the study’s beginning (baseline) to month 18.

Additional improvements in motor function from baseline to month 18 were also observed in the time to run/walk 10 meters (11 yards) and to climb stairs.

Boys receiving vamorolone in VBP15-LTE also had better performances in all measures of motor function when compared to 19 age-matched, untreated DMD boys in a natural history study of this disease.

“These data demonstrate that vamorolone treatment results in persistently improved motor function in DMD patients, similar to that of corticosteroids,” Hoffman said in a press release put out by Santhera, which owns sub-license rights to this potential treatment.

“Importantly, however, vamorolone treatment over a period of 18 months showed better tolerability with less corticosteroid-specific side effects, including no stunting of the growth of DMD children,” Hoffman added.

Motor abilities shown by boys treated with vamorolone in VBP15-LTE were also compared to age-matched DMD patients from an external control group being treated with prednisone. Although both medications led to similar gains in gross motor function in children, those being treated with vamorolone were reported to be maintaining a normal growth rate and to be less prone to weight gain.

A separate randomized, double-blind and placebo-controlled Phase 2b trial (NCT03439670) is currently comparing vamorolone at daily doses of 2.0 mg/kg and 6.0 mg/kg to prednisone at 0.75 mg/kg a day or to a placebo. Measures of effectiveness on motor function will be taken after 24 weeks of treatment, and then treatment will continue for another 20 weeks, with boys on prednisone or placebo moving to vamorolone at either dose.

This trial is now enrolling up to 120 boys, ages 4 to 7, at sites across the U.S., Canada, Europe, Australia, and Israel. More information is available here.

Vamolorone has received orphan drug and  rare pediatric disease designations, and was placed on fast track development by the U.S. Food and Drug Adminsitration (FDA).