Acadia discontinued carbetocin after its Phase 3 failed in Prader-Willi syndrome

A biopharma company developing neuroscience therapies, including a potential treatment for Alzheimer's disease psychosis.

That carbetocin, acquired with Levo Therapeutics in 2022, could succeed where Levo had already failed — winning approval for Prader-Willi hyperphagia.

Levo Therapeutics developed intranasal carbetocin for Prader-Willi syndrome but failed to win regulatory approval; Acadia bought the company in 2022 and kept the candidate, ACP-101, in development.

Acadia ran the Phase 3 COMPASS PWS trial: 175 participants aged 5–30, intranasal carbetocin three times daily against placebo, with hyperphagia reduction as the primary endpoint over 12 weeks.

No statistically significant improvement on hyperphagia or any secondary endpoint; Acadia terminated the program on 25 September 2025. Its stock fell 11% while Soleno's rose 13%.

The trial risk was on the record before the acquisition: carbetocin had already failed once at Levo, and Phase 3 reproduced that outcome at scale.

With Vykat XR approved, a placebo-controlled win had become both harder to achieve and less commercially decisive.

Acadia cut the program immediately rather than iterating, protecting the remaining neuroscience pipeline it says it still believes in.

Buying a drug that already failed once doesn't reset its biology — a new sponsor inherits the same trial risk, now at Phase 3 scale.

The carbetocin program was terminated on 25 September 2025, leaving Soleno's Vykat XR as the only approved therapy for hyperphagia in Prader-Willi syndrome. Acadia maintained a positive outlook on its remaining pipeline, including Alzheimer's disease psychosis.