NS Pharma Shares Preliminary Phase 3 Viltolarsen (RACER53) Trial Results

PARAMUS, N.J., May 27, 2024 – NS Pharma, Inc., a subsidiary of Nippon Shinyaku Co., Ltd., has revealed preliminary analysis results from its global Phase 3 clinical trial, known as the RACER53 study, for the drug NS-065/NCNP-01 (viltolarsen). The drug, marketed as VILTEPSO®, was initially approved by the U.S. Food and Drug Administration (FDA) in 2020 for treating Duchenne Muscular Dystrophy (Duchenne) in patients with a specific mutation amenable to exon 53 skipping. This approval was granted under the FDA's accelerated approval pathway due to observed increases in dystrophin production in the skeletal muscle of treated patients. Continued approval hinges on the verification of clinical benefits through a confirmatory trial.

The RACER53 study, a randomized, double-blind, placebo-controlled trial, enrolled 77 ambulatory boys with Duchenne. Participants received either an 80 mg/kg dose of viltolarsen weekly or a placebo for 48 weeks. The study's primary endpoint was the Time to Stand from Supine, measured as velocity (rise/sec). While both the viltolarsen and placebo groups showed increased velocity from baseline after 48 weeks, there was no statistically significant difference between the two groups.

Preliminary safety data indicated that adverse events associated with viltolarsen were generally mild or moderate, with no treatment emergent adverse events leading to discontinuation.

NS Pharma President Tsugio Tanaka, MSc, commented, "We are conducting further detailed data analyses to identify factors that might have influenced the results, such as age, treatment period, and the impact of concomitant drugs, including glucocorticoid therapy. Considering results from previous studies, we remain confident that viltolarsen can be beneficial for patients with Duchenne amenable to exon 53 skipping."

Supporting this optimism is data from a Phase 2, open-label, long-term extension study, which evaluated viltolarsen in 16 boys aged 4 to 10 with Duchenne. This study showed significant improvements in the Time to Stand at week 205 compared to a historical control group, with adverse events primarily being mild or moderate.

NS Pharma is actively conducting additional post-hoc analyses and plans to collaborate closely with regulatory authorities to decide on the next steps based on the study results. Further insights and discussions with regulatory bodies will be shared in due course.

About VILTEPSO® (Viltolarsen) Injection

VILTEPSO received FDA approval in August 2020 following Priority Review and designations under the Rare Pediatric Disease, Orphan Drug, and Fast Track programs. Japan approved the drug in March 2020, granting it the SAKIGAKE designation and orphan drug status.

Indication

VILTEPSO is indicated for treating Duchenne muscular dystrophy in patients with a dystrophin gene mutation amenable to exon 53 skipping. This accelerated approval is based on increased dystrophin production in skeletal muscle, with continued approval contingent upon further clinical benefit verification.

Safety Information

Viltolarsen has demonstrated kidney toxicity in animal studies, though not in clinical trials. Given the limited clinical experience, patients should monitor kidney function regularly. Specific tests, including serum cystatin C and urine protein-to-creatinine ratio, should be conducted before and during treatment. Persistent abnormalities should prompt referral to a pediatric nephrologist.

Adverse Reactions

Common adverse reactions include upper respiratory tract infection, injection site reactions, cough, and fever.

About Duchenne Muscular Dystrophy

Duchenne muscular dystrophy is a severe form of muscular dystrophy affecting primarily males, leading to progressive weakness in skeletal, cardiac, and respiratory muscles. Early signs include delayed motor milestones, with loss of mobility typically occurring by adolescence. Cardiac and respiratory complications arise during teenage years, often leading to life-threatening conditions.

How to obtain the latest research advancements in the field of biopharmaceuticals?

In the Synapse database, you can keep abreast of the latest research and development advances in drugs, targets, indications, organizations, etc., anywhere and anytime, on a daily or weekly basis. Click on the image below to embark on a brand new journey of drug discovery!