NEW YORK – Voyager Therapeutics on Tuesday said it will evaluate alternate payloads for a gene therapy program it's developing for a genetic form of amyotrophic lateral sclerosis (ALS).
The Lexington, Massachusetts-based biotech in 2023 said it would advance a small interfering RNA (siRNA) drug, dubbed VY9323, designed to treat ALS caused by mutations in the SOD1 gene. However, new three-month data from a study of nonhuman primates suggest that an alternate payload would be necessary to achieve the desired product profile, according to Voyager.
Voyager does not expect to make changes to the capsid component of the gene therapy, which is the same capsid it's using for its tau-silencing gene therapy, VY1706, for Alzheimer's disease.
"Emerging preclinical data indicate the siRNA payload component of VY9323 does not meet our high standards due to what appears to be an off-target effect resulting in a narrowed therapeutic window," Voyager CEO Alfred Sandrock Jr. said in a statement. "While we are disappointed that the development candidate VY9323 will not advance, we hope that we may be able to identify an alternate payload and find a path forward for this program."
Voyager no longer anticipates filing an investigational new drug (IND) application for the SOD1-ALS gene therapy mid-year as it makes these changes. Its other programs remain on track, with the company expecting to file IND applications this year for programs in GBA1 Parkinson's disease and Friedreich's ataxia, and in 2026 for VY1706.
Voyager expects its cash runway to extend into mid-2027.