Santhera Pharmaceuticals has announced ReveraGen BioPharma’s report of positive results from the Phase IIa extension study of vamorolone to treat Duchenne muscular dystrophy (DMD) patients.

According to the findings, the drug led to a dose-dependent improvement in muscle function.

Vamorolone is designed to bind to the same receptors as corticosteroids but targets their downstream activity. This is intended to provide an alternative to high-dose corticosteroids associated with systemic side effects.

Santhera gained an exclusive sub-licence to vamorolone in all indications and markets, excluding Japan and South Korea, from Idorsia.

Data from the Phase IIa extension study demonstrated favourable safety and tolerability at all doses.

For the primary efficacy outcome of time to stand from supine measured as velocity, mean changes from baseline to weeks 12 and 24 revealed dose and time-related improvements.

It was observed that the mean difference in the change to week 24 was significant for the patients on 2 mg/kg a day and 6mg/kg a day vamorolone compared to the 0.25mg/kg a day arm.

Santhera added that the secondary endpoint motor function outcomes had a consistent dose-proportional improvement with the drug.

ReveraGen CEO Eric Hoffman said: “The six-month extension study in comparison to natural history study data demonstrated dose-dependent improvement in timed function tests. Vamorolone was reported to be safe and well-tolerated up to the highest dose tested (6mg/kg a day).

“Based on these data, vamorolone has potential to replace standard corticosteroids currently used in patients with DMD.”

The drug is being further studied in a long-term extension protocol and in the Phase IIb VISION-DMD clinical trial involving 120 patients.

Vamorolone has orphan drug, fast track and rare pediatric disease designations in the US, along with orphan drug status in Europe.