In the United States, someone is either diagnosed with or dies from amyotrophic lateral sclerosis (ALS) every 90 minutes. The disease is universally fatal, with a median survival of two to three years after diagnosis. That urgency complicates trial design: in rapidly progressing, fatal conditions, ethical concerns around placebo use and prolonged enrollment timelines often make placebo-controlled randomized trials difficult to execute in early-phase development. Sponsors instead turn to single-arm study designs in which all patients receive the investigational therapy.

Case in point, in February of this year, VectorY Therapeutics announced that the first participant had been dosed in its single-arm ALS study. Phase 1/2 PIONEER-ALS is a trial evaluating VTx-002, a first-in-class vectorized antibody targeting TDP-43 pathology in people with ALS. PIONEER-ALS includes only 12 patients, so every signal needs to carry its own weight. That's precisely why VectorY's team chose to partner with Unlearn.

As VectorY's Chief Medical Officer, Olga Uspenskaya-Cadoz, M.D., Ph.D., put it:

"In the PIONEER-ALS study, we are focused on generating high-quality safety and biomarker signal data for VTx-002…integrating Unlearn's patient-level digital twin technology into our prespecified exploratory analyses will help strengthen evidence generation from a single-arm design, with the aim to support more confident development decisions, disease progression modeling, and reduce timelines and patient burden."

Each of the 12 enrolled participants in PIONEER-ALS is paired with their digital twin, an individualized prediction of that patient's control outcomes generated from their baseline data. Digital twins are generated by an advanced disease-specific ML model trained on more than 13,600 ALS participants from RCTs and observational studies, including NEALS, PRO-ACT, PRO-ACE, and APST Research.

Digital twin predictions are generated across composite scales (ALSFRS-R, ALSSQOL, ALS-CBS), labs (including plasma neurofilament light), and vitals over continuous time. These cover many of the trajectories that PIONEER-ALS is tracking, including slow vital capacity and survival. The model is independently validated, and the analyses run alongside standard statistical and clinical methodologies, consistent with regulatory expectations for external comparators.

Each participant in PIONEER-ALS serves as their own comparator. Because the digital twin is generated from that participant's baseline data alone, the analysis doesn't need to reuse records from other participants, define a matching cohort in advance, or rely on whether an external dataset is sufficiently large for direct matching to VectorY's specific protocol. The analyses support the clinical team's interpretation of the data; they don't replace the statistical and clinical judgment the team is bringing to it.

Unlearn's research team has recently described the statistical framework for using digital twins as synthetic control arms in single-arm trials, with worked case studies in ALS and Huntington's disease. PIONEER-ALS applies that approach in practice.

We're proud to partner with VectorY's clinical team on this work, now underway across sites in the U.S., Europe, and the U.K.