Alto Neuroscience Launches 178-Patient Phase 2b Trial of ALTO-207, Data in H2 2027
Alto Neuroscience has initiated a 178-patient Phase 2b randomized, placebo-controlled trial of ALTO-207 for treatment-resistant depression, titrating to 3.2 mg pramipexole and 15 mg ondansetron daily. Topline data are expected in the second half of 2027, with a registrational design informed by a prior PAX-D study.
1. Trial Initiation
Alto Neuroscience has begun a Phase 2b randomized, placebo-controlled trial of ALTO-207 in treatment-resistant depression, enrolling approximately 178 adults at sites across the United States and United Kingdom, including former PAX-D NHS locations.
2. Trial Design
Participants will be randomized 1:1 to ALTO-207 or placebo over eight weeks, with ALTO-207 titrated to a target dose of 3.2 mg pramipexole and 15 mg ondansetron per day and change from baseline in MADRS as the primary endpoint, aligning with FDA guidance.
3. Timeline and Background
Topline data are expected in the second half of 2027; ALTO-207 combines pramipexole and ondansetron in a modified-release formulation to mitigate nausea and enable higher dosing after a Phase 2a trial showed a 1.1 Cohen's d effect size and favorable tolerability.