NS Pharma, Inc. has shared preliminary analysis results from RACER53, the global Phase 3 clinical trial of NS-065/NCNP-01 (viltolarsen). Viltolarsen is an antisense oligonucleotide drug intended to treat patients with Duchenne who are amenable to exon 53 skipping. The drug was approved by the FDA in 2020 under the brand name VILTEPSO® under the FDA accelerated approval pathway.

The RACER53 study, a randomized, double-blind, placebo-controlled, comparative study of 77 ambulatory boys with Duchenne, evaluated the efficacy and safety of an 80 mg/kg once weekly dosing of the treatment for 48 weeks and was intended to serve as a confirmatory study.

The primary endpoint of the study was Time to Stand from Supine evaluated as velocity (the speed at which participants stand from a lying position). Both the viltolarsen and placebo groups showed a trend of increased velocity from baseline after treatment for 48 weeks, with no statistically significant difference between the groups. Preliminary results indicate that viltolarsen has a favorable safety profile.

According to NS Pharma, the company is currently conducting further detailed data analyses and plans to work closely with regulatory authorities to determine how to proceed based on the results of this analysis and in the best interests of patients. NS Pharma will report on additional analyses and discussions with the regulatory authorities at a later date. 

Considering both the increase in dystrophin production in skeletal muscle that formed the basis of the FDA’s accelerated approval of viltolarsen, as well as previously reported positive results of the Phase 2, open label, long-term extension study, PPMD remains optimistic that the clinical benefits of the drug will be confirmed. PPMD looks forward to further updates from NS Pharma.

Read NS Pharma’s press release here.