EGLN Inhibition Reduces Gastrointestinal Radiation Toxicity and Improves Survival in a Murine Model of Locally Advanced Pancreatic Cancer

Locally advanced pancreatic cancer (LAPC) almost always fatal since it is unresectable and chemotherapy is only modestly effective. The efficacy of radiation therapy (RT) for LAPC is limited by the potentially fatal toxicity to nearby intestines. There are no FDA-approved medications that can prevent this radiotoxicity, but we find that FG-4592, a small molecule inhibitor of EGLN proteins, significantly reduces radiation damage to the intestines without radioprotecting tumors. KPC (KrasLSL/+; Trp53FL/+; Ptf1aCre/+) animals received dose-escalated radiation treatments with and without FG-4592 for radioprotection. High-dose RT reduced death from local progression, improved survival, and shifted the patterns of failure to a late metastatic death compared to controls. The addition of FG-4592 to RT further improved survival compared to vehicle controls by eliminating radiation-induced gastrointestinal toxicity. Thus, selective protection of the intestinal tract by EGLN inhibition may enable higher, and potentially definitive doses of cytotoxic therapy to be delivered to LAPC.\n\nOne Sentence SummaryThe EGLN inhibitor FG-4592 allows higher, and potentially definitive, doses of radiation to be delivered to pancreatic cancer by reducing normal tissue toxicity without protecting tumors.