AMSTERDAM, Netherlands and BOSTON, Mass. — September 29, 2026
VectorY Therapeutics announced the expansion of its global Phase 1/2 PIONEER-ALS clinical trial of investigational VTx-002 from 12 to 36 participants. The study is evaluating the safety, tolerability, pharmacokinetics and pharmacodynamic effects of VTx-002 in adults living with amyotrophic lateral sclerosis (ALS). VectorY said the threefold increase in enrollment was enabled by rapid patient recruitment and the activation of clinical sites in the United States and Europe. The expansion was announced before the company receives data relevant to patient efficacy outcomes and is intended to provide a broader dataset for evaluating secondary and exploratory measures of ALS progression.
PIONEER-ALS Evaluates VTx-002 in ALS
PIONEER-ALS is a global, multicenter, open-label, dose-escalation Phase 1/2 study evaluating two dose levels of VTx-002 in adults with ALS. The primary objectives are to assess safety, tolerability, pharmacokinetics and pharmacodynamic effects, while secondary and exploratory endpoints are designed to provide preliminary information on potential biological and clinical effects. The study includes measurements of neurofilament light chain (NfL) and TDP-43 pathway-related biomarkers, together with clinical assessments such as the ALS Functional Rating Scale-Revised (ALSFRS-R), slow vital capacity, hand-held dynamometry and survival. VectorY initiated dosing in the United States in February 2026 at the Sean M. Healey & AMG Center for ALS at Mass General and began dosing in Europe in September at University Medical Center Utrecht.
VTx-002 Targets Pathological TDP-43
VTx-002 is an investigational vectorized antibody therapy designed to target pathological TDP-43, a protein that accumulates abnormally in the nervous system and is reported by VectorY to be associated with the pathology of ALS in a large proportion of patients. The therapy uses VectorY’s vector-based delivery approach with the aim of enabling sustained antibody expression within the central nervous system. The company is investigating whether this approach can affect biological processes associated with ALS progression. However, VTx-002 has not been approved by any regulatory authority, and the current trial is primarily designed to establish safety and characterize pharmacological effects. Whether targeting TDP-43 will translate into measurable clinical disease modification remains to be determined through clinical development.
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Larger Study Supports Broader Clinical Dataset
The expansion to 36 participants is intended to increase the opportunity to characterize potential disease-related signals through secondary and exploratory endpoints. VectorY said the larger study population will generate additional information on biomarker trajectories and clinical measures that could help guide the development path for VTx-002. The company continues enrolling participants across clinical sites in the United States, Europe and the United Kingdom. VectorY is also developing additional vectorized antibody programs targeting disease-associated proteins, including mutant huntingtin and TDP-43 in Huntington’s disease, TDP-43 in frontotemporal dementia and phosphorylated tau in Alzheimer’s disease. The PIONEER-ALS expansion increases the planned clinical dataset for VTx-002, but efficacy and disease-modifying activity remain investigational until clinical results become available.
Source :VectorY Therapeutics, press release
