VectorY Therapeutics expanded its Phase 1/2 PIONEER-ALS clinical trial of VTx-002 from 12 to 36 participants.
The global, multicenter, open-label, dose escalation study is evaluating two dose levels to assess safety, tolerability, pharmacokinetics and pharmacodynamic effects in adults with amyotrophic lateral sclerosis.
The company says the increase, made prior to any patient efficacy readouts, was supported by rapid enrollment and prompt global site activation and is intended to generate broader clinical data and increase the opportunity to detect disease-modifying signals through secondary and exploratory endpoints.
VTx-002 is described by the company as a first-in-class vectorized antibody designed to target pathological TDP-43 and enable sustained antibody expression in the central nervous system.
The company claims TDP-43 aggregates abnormally in up to 97% of ALS patients. The investigational therapy has not been approved by any regulatory authority.
VectorY reported that the first U.S. participants were dosed in February 2026 at the Sean M. Healey & AMG Center for ALS at Mass General and that dosing began in Europe in September at University Medical Center Utrecht. Secondary and exploratory measures include neurofilament light chain and TDP-43 pathway biomarker trajectories and clinical endpoints such as ALSFRS-R, slow vital capacity, hand-held dynamometry and survival.
