New call-to-action
New call-to-action
New call-to-action

Acadia’s COMPASS PWS Study Fully Enrolled – Results Expected Early Q4 2025

Thanks to the PWS community, Acadia’s Phase 3 COMPASS PWS study is now fully enrolled—three months early.

Acadia’s COMPASS PWS Study Fully Enrolled – Results Expected Early Q4 2025We’re excited to share that Acadia Pharmaceuticals has officially completed enrollment for its Phase 3 COMPASS PWS clinical trial of ACP-101 in individuals with Prader-Willi syndrome (PWS)—three months ahead of schedule!


The COMPASS PWS study is evaluating ACP-101 (carbetocin nasal spray), an investigational treatment for hyperphagia and related behavioral challenges in PWS. Topline results are expected in early Q4 2025.

This enrollment milestone marks a significant step forward in the effort to expand treatment options for the PWS community.

With one treatment for hyperphagia already approved, we’re entering a new era of hope and possibility for individuals living with PWS. The potential for additional therapies, like ACP-101, builds on this momentum and underscores the importance of continued research and community participation.

We are deeply grateful to the families, individuals with PWS, investigators, and international advocacy partners who helped make this milestone possible. Thanks to your involvement and collaboration, enrollment was completed ahead of schedule—an extraordinary accomplishment that brings us all closer to new therapeutic possibilities.

We’ll continue to share updates as results become available and keep our community informed every step of the way.

PWS Clinical Trials

Topics: Research

Susan Hedstrom

author-image

Susan Hedstrom is the Executive Director for the Foundation for Prader-Willi Research. Passionate about finding treatments for PWS, Susan joined FPWR in 2009 shortly after her son, Jayden, was diagnosed with Prader-Willi Syndrome. Rather than accepting PWS as it has been defined, Susan has chosen to work with a team of pro-active and tireless individuals to accelerate PWS research in order to change the future of PWS. Inspired by her first FPWR conference and the team of researchers that were working to find answers for the syndrome, she joined the FPWR team in 2010 and led the development of the One SMALL Step walk program. Under Susan’s leadership, over $15 million has been raised for PWS related research.