NS Pharma, Inc., a wholly owned subsidiary of Nippon Shinyaku Co., Ltd., announced the publication of long-term efficacy and safety data based on analyses at 109 weeks from the 192-week open-label extension trial of a Phase 2 study of VILTEPSO® (viltolarsen) injection in the Journal of Neuromuscular Diseases. The article, “Long-Term Functional Efficacy and Safety of Viltolarsen in Patients with Duchenne Muscular Dystrophy,” is freely available under open access (click here).
“In this VILTEPSO open-label, long-term extension study, evaluation of functional clinical endpoints demonstrated maintenance of motor function versus functional decline in a historical control group over two years,” said Leslie Magnus, MD, Vice President, Medical Affairs. “These encouraging interim results with VILTEPSO support the continued need to research its clinical profile and its potential impact on maintaining mobility.”
Data published in the Journal of Neuromuscular Diseases are from an open-label trial (N=16) that is the extension of a previous 24-week Phase 2 trial in North America. All 16 patients aged 4 to <10 years with DMD amenable to exon 53 skipping in the 24-week study elected to enroll in this long-term trial to continue evaluation of motor function and safety. Assessments of timed function tests (Time to Stand, Time to Run/Walk, 6-Minute Walk Test) were compared to a matched DMD historical control group (Cooperative International Neuromuscular Research Group Duchenne Natural History Study).
In addition to this Phase 2 open-label extension study, NS Pharma continues to investigate the efficacy and safety of VILTEPSO in the confirmatory Phase 3 RACER53 trial. This study was initiated in October 2019 and is currently enrolling patients. The purpose of this Phase 3 randomized, double-blind, placebo-controlled trial is to evaluate the efficacy of viltolarsen on functional motor endpoints compared to placebo in DMD patients amenable to exon 53 skipping. Continued approval of VILTEPSO is dependent on verification of clinical benefit.
Prior to its approval in the U.S. in August 2020, VILTEPSO was granted Priority Review as well as Rare Pediatric Disease, Orphan Drug and Fast Track Designations. In March 2020, VILTEPSO was approved in Japan for the treatment of patients with DMD who are amenable to exon 53 skipping therapy. Prior to its approval in Japan, VILTEPSO was granted with the SAKIGAKE designation, Orphan Drug designation, and designation of Conditional Early Approval System.