Outcomes after early initiation of nonsteroidal immunosuppressive therapy in patients with immune checkpoint inhibitor-induced colitis.

2571 Background: Current treatment guidelines for immune-mediated colitis (IMC) recommend 4 to 6 weeks of steroids as first-line therapy, followed by nonsteroidal immunosuppressive therapy (NSIST) (infliximab or vedolizumab) in patients who do not respond to steroids. We assessed the effect of early NSIST introduction and number of NSIST infusions on clinical outcomes. Methods: We performed a retrospective review of patients with IMC who received NSIST between January and December 2018. Logistic regression analyses were used to assess associations between clinical features and outcomes of IMC (Table). Results: Of the 1,459 patients who received immune checkpoint inhibitor, 179 developed IMC of any grade; 84 of them received NSIST. Of the 84 patients who received NSIST, 79% were males with mean age of 60. Compared with patients who received NSIST >10 days after IMC onset, patients who received early NSIST (≤10 days) required fewer hospitalizations ( P=0.03), experienced steroid taper failure less frequently ( P=0.03), had fewer steroid tapering attempts ( P<0.01), had a shorter course of steroid treatment ( P=0.09), and had a shorter duration of symptoms ( P<0.01). Risk factors of IMC recurrence after weaning off steroids included: 1) needing multiple hospitalizations ( P<0.01), 2) experiencing steroid taper failure after NSIST ( P=0.02), 3) receiving infliximab rather than vedolizumab ( P=0.02), 4) receiving fewer than three infusions of NSIST ( P=0.02), 5) having higher fecal calprotectin levels after NSIST ( P=0.01), and 6) receiving a longer course of steroids ( P=0.02), hospitalization ( P<0.01) and IMC symptoms ( P<0.01). Unsuccessful weaning from steroids after NSIST was associated with high IMC grades ( P<0.01); multiple hospitalizations ( P<0.01); steroid-resistant IMC ( P<0.01); long interval from IMC to NSIST initiation ( P=0.01); and long duration of steroids ( P<0.01), IMC symptoms ( P<0.01), and hospitalization ( P<0.01). Conclusions: NSIST should be introduced early in the disease course of IMC instead of waiting until failure of steroid therapy or steroid taper. Patients who received three or more infusions of NSIST had more favorable clinical outcomes.