A Safety Study of ST316 in Participants With Familial Adenomatous Polyposis (FAP).

This is a Phase 1b, open- label, dose-optimization study evaluating ST316 in adult participants with familial adenomatous polyposis (FAP) who have undergone colectomy and have recurrent polyps. This study uses a three-cohorts, sequential adaptive design to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of ST316, as well as its preliminary efficacy in reducing polyp recurrence.

Inclusion Criteria: 1. Male or female participants aged 18 years or older at the time of informed consent. 2. Ability to understand and willingness to sign a written informed consent document, prior to undertaking any study-related procedures. 3. Confirmed Familial Adenomatous Polyposis (FAP) by molecular genetic testing and at least six polyps of 5-9 mm. Patients with FAP that present thyroid nodule and/ or desmoid tumors are eligible. 4. History of prophylactic colectomy with either ileo-rectal anastomosis (IRA) or ileal pouch-anal anastomosis (IPAA), performed at least 12 months prior to screening, and without ongoing surgical complications. 5. Presence of rectal/pouch polyps at baseline; polyps must be \