UW psilocybin trials reach milestones: cancer retreat study closes at 16, veterans study reaches its estimated data date

The retreat trial closes at 16

On October 29, 2026, ClinicalTrials.gov posted an update to NCT07336238, "A Phase 2a Study of Group Retreat Psilocybin Therapy for Cancer-Related Anxiety and Depression." The record lists the trial as active, not recruiting, with 16 participants enrolled (actual). It started May 19, 2026; primary completion is estimated for December 1, 2026 and study completion for May 1, 2027.¹ The University of Washington is the sponsor, the site is the Fred Hutch/University of Washington Cancer Consortium in Seattle, and the primary outcome is the incidence of adverse events graded severe, over up to six months.¹ The public record doesn't show which fields the October 29 update changed.

Both this trial and an earlier Phase 1/2 trial of a group model of psilocybin-assisted therapy list Anthony Back as principal investigator. The earlier one enrolled 55 people with metastatic cancer and was completed on October 17, 2024.¹²

PsiloStudy reaches its estimated data date

PsiloStudy (NCT06853912) is a Phase 2, single-site, double-blind, placebo-controlled trial of psilocybin with psychological support for military veterans and first responders who have both PTSD and alcohol use disorder. It runs at UW's Center for Novel Therapeutics in Addiction Psychiatry and is listed as active, not recruiting, with an estimated enrollment of 40.³ Its estimated primary completion date was November 1, 2026, and study completion is estimated for June 1, 2027. The record was last updated August 13, 2026, so as of November 2 it doesn't say whether the November 1 milestone was met, and it shows no posted results.³

This is the state's pilot. The 2023 law 2SSB 5263 (chapter 364, Laws of 2023) set up, "subject to amounts appropriated," a psilocybin therapy services pilot program "within, and administered by, the University of Washington department of psychiatry and behavioral sciences," for groups including veterans and first responders aged 21 and older.⁴ In May 2023 UW Medicine's newsroom called it a "state-mandated psilocybin trial" and said it would include 30 to 40 veterans and first responders with post-traumatic stress and alcohol use disorders.⁵ The registry lists "Washington State Legislation" as a collaborator,³ and the 2025-27 state budget sets aside money for UW "solely for implementation of chapter 364, Laws of 2023 (psilocybin)."⁶

The October 8 paper on preparing the body

On October 8, 2026, Frontiers in Psychiatry published "Preparing the body for psilocybin therapy: receptive and generative interoception in cancer patients" (PMID 42922907). The authors are Anthony Back of UW's Department of Medicine and Fred Hutch, with colleagues from UW's nursing school, Seattle's Orion Center for Integrative Medicine and the Dawn Collective in Bozeman, Montana.⁷

It's a proposal, not a results paper. The authors write that most preparation protocols focus on "cognitive intention-setting and basic mindfulness while neglecting to address the body directly." They lay out a six-category taxonomy of bodily experiences in psilocybin therapy and say the ongoing Phase 2 group retreat trial "will provide an initial test" of their idea that training people's awareness of internal body signals may influence outcomes.⁷

Where this fits

Psilocybin remains a Schedule I substance under Washington law, so trials like these are research, not a service anyone can sign up for.⁸ The Seattle research entry covers these UW groups and their earlier studies, Seattle by the numbers collects the funding and enrollment figures, and the timeline dates the 2023 law that created the pilot.