Vamorolone Filing for FDA Approval for DMD Expected by June
Santhera Pharmaceuticals and ReveraGen BioPharma will seek approval of vamorolone as a treatment for Duchenne muscular dystrophy (DMD) in the U.S. this year, with a filing expected to be completed by the end of June.
The submission of the companies’ rolling new drug application (NDA) to the U.S. Food and Drug Administration (FDA) is slated to be finalized in the second quarter. The FDA is then expected to notify Santhera and ReveraGen in August as to whether the NDA is to be reviewed.
At the same time, the agency also will decide whether vamorolone is eligible for priority review, which would shorten the review time and set a potential approval date for early 2023.
If approved, the U.S. will be the first country where vamorolone will be marketed. Of note, a rolling submission means that a company can submit completed sections of an NDA for review as they are ready rather than having to submit all sections at once. It allows the FDA to begin reviewing and resolving any issues with the application sooner.
“The NDA filing for vamorolone marks a tremendous milestone for Santhera and an important next step for the Duchenne community. The potential benefits of vamorolone could address significant unmet needs that represent a burden to DMD patients and their families,” Dario Eklund, CEO of Santhera, said in a press release.
“We are fully focused on working closely with the FDA and completing the submission as soon as possible,” he added.
Santhera also expects to file a marketing authorization application (MAA) seeking the approval of vamorolone for DMD in Europe by September. Germany is expected to be the first European country to market vamorolone, if the MAA is approved.
Vamorolone is a first-in-class steroid medication that targets the same receptors as corticosteroids, anti-inflammatory medications used as standard care for DMD.
The therapy interacts with corticosteroid receptors in a specific manner, which means that it retains a similar anti-inflammatory capacity as corticosteroids but with fewer side effects.
Its efficacy was tested in VISION-DMD (NCT03439670), a Phase 2b trial that enrolled 121 boys with DMD ages 4–6. Participants were randomly assigned to receive vamorolone, a standard corticosteroid called prednisone, or a placebo. Vamorolone was given at 2 and 6 mg/kg daily as an oral, flavored liquid.
Top-line results, after 24 weeks (six months) of treatment, showed that vamorolone led to significant improvements in the Time to Stand (TTSTAND) assessment, the trial’s main goal, over the placebo. TTSTAND assesses muscle function by measuring the speed at which a patient stands from a lying position.
The experimental therapy also led to significant benefits in the six-minute walk test, which assesses the distance walked in six minutes, and the time to run/walk 10 meters (nearly 33 feet). The medication was generally well-tolerated.
Comparing vamorolone at 6 mg/kg with prednisone showed no statistically significant differences across all efficacy outcomes.
A total of 112 patients (92.5%) completed the full 48 weeks, or about 11 months, of treatment. The analysis looked at boys initially assigned to the placebo or prednisone (0.75 mg/kg daily) who switched at week 24 to vamorolone following a four-week tapering period. It also included patients who stayed on vamorolone for the entire 48 weeks.
The results continued to support vamorolone’s effectiveness, with gains in muscle function at week 24 being maintained or improved through week 48 in patients continuously treated with vamorolone.
Also, boys initially given prednisone who switched to 6 mg/kg vamorolone showed a reversal in stunted growth and stabilized their body mass index, a measure of body fat. Prednisone has many known side effects that include aggression, blurred vision, shortness of breath, and notably, weight gain.
The results showed that vamorolone’s safety profile was consistent between weeks 24 and 48 among participants who continued on the same dose.
In a pre-NDA meeting with the companies late last year, the FDA deemed the efficacy and safety data from the pivotal portion of the VISION-DMD trial as sufficient support for the application.
“We thank study participants, their families and caregivers, as well as investigators and study personnel, for their commitment to the vamorolone program,” said Eric Hoffman, PhD, president and CEO of ReveraGen.
Vamorolone received orphan drug status in the U.S. and Europe for DMD. It also has been granted fast track and rare pediatric disease designations by the FDA. In the U.K., it was granted Promising Innovative Medicine status for DMD.
“We are delighted about the initiation of the filing for approval for vamorolone as it represents a culmination of over a decade of scientific research for the benefit of patients with DMD,” Hoffman added. “In having granted Fast Track Designation, the FDA has acknowledged the significant innovation vamorolone could bring in addressing a high unmet medical need of patients with DMD.”