Provides support for research on perianal fistulizing Crohn’s disease (PFCD)
Siyan “Stewart” Cao, MD, PhD, Assistant Professor, WashU Medicine Division of Gastroenterology, recently was awarded the 2026 American Gastroenterological Association Pilot Research Award. The AGA Research Foundation Pilot Research Award was presented to fifteen distinguished clinical researchers, providing funding to support early-career investigators in establishing their research programs and enabling established investigators to pursue innovative new research directions.
The Pilot Research grant from the American Gastroenterological Association (AGA) supports Dr. Cao’s lab work on perianal fistulizing Crohn’s disease (PFCD), a particularly debilitating complication that affects 30–40% of Crohn’s patients and for which current treatments remain inadequate.
A key focus of his work is understanding why standard therapies so often fail these patients. Using advanced multi-omics techniques, we recently identified an overactivated immune signaling pathway (IFN-γ) that appears to be a unique driver of perianal fistulas. This finding, published in the Journal of Clinical Investigation (2025), is now guiding the next phase of our research.
“Perianal fistulizing Crohn’s disease has been a very difficult complication to treat, largely because we haven’t had good preclinical models to study it in the lab. This award allows us to change that — and to translate what we’re learning about the pathogenic drivers of fistula formation into potential new therapies for patients who currently have very few options.”
Siyan “Stewart” Cao, MD, PhD
Critically, this project also introduces the first reliable mouse models of PFCD — a long-standing gap in the field that has slowed both mechanistic research and drug discovery. These models will allow us to directly test whether blocking IFN-γ can heal fistulas, and to identify new, disease-specific therapies.