NCT07226440

Examining a Novel Gastrointestinal Intervention to Negate Environmental Toxicants (ENGINE)

Assessing the Impact of a Bile Acid Sequestrant on Serum PFAS Levels in Highly Exposed Individuals

• Status: Recruiting
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 40 (estimated)
• Sponsor: University of California, San Francisco · Academic / Other
• Sex: Male
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This randomized, placebo-controlled crossover trial will test the feasibility and acceptability of using colesevelam in male firefighters with high per- and polyfluoroalkyl substances (PFAS) exposure. This trial will also explore whether colesevelam lowers blood PFAS levels and urine environmental toxicant and mold mycotoxin levels.

Detailed description

Firefighters experience elevated exposure to per- and polyfluoroalkyl substances (PFAS) through firefighting foams, turnout gear, and dust in fire stations. PFAS persist in the body due to their long biological half-lives, leading to bioaccumulation and raising concern for adverse effects on hormone regulation, immune function, reproduction, and cancer risk. Despite growing awareness, there are no approved treatment options to reduce PFAS levels in humans. Bile acid sequestrants, such as colesevelam, bind bile acids in the gastrointestinal tract and may interrupt enterohepatic recirculation of PFAS, thereby enhancing elimination. Observational studies and one small randomized trial suggest that bile acid sequestrants can meaningfully reduce PFAS levels. This trial will evaluate the feasibility, adherence, and acceptability of colesevelam in male firefighters with elevated PFAS, while exploring its effects on serum PFAS concentrations and urine environmental toxicant and mold mycotoxin levels.

Conditions

• Toxicant Exposure
• Firefighter
• Occupational Exposure to Chemicals

Interventions

Type	Name	Description
DRUG	Colesevelam	Colesevelam in 625-mg tablets. Participants will take 3 tablets orally, twice daily (total daily dose 3.75 g) for 12 weeks.
DRUG	Placebo	Matching inert oral tablets designed to mimic colesevelam 625 mg tablets in size, shape, and color, but containing no active pharmaceutical ingredient. Participants will take 3 orally, twice per day for 12 weeks.

Timeline

• Start date: 2026-03-01
• Primary completion: 2028-12-01
• Completion: 2028-12-01
• First posted: 2025-11-10
• Last updated: 2026-03-06

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study