Here, we combined ICB (anti-CTLA-4 and anti-PD-1) treatment with a standard colitis model, in which a more severe form of colitis is induced in mice, to recapitulate the clinical observations in patients receiving combined ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1) therapy, during which colitis is the most frequent complication encountered.
Compared with chemotherapy group, the PD-1/PD-L1 inhibitors had a significantly higher risk of all grade (RR: 3.68, p < 0.001) and high-grade (RR: 2.97, p = 0.01) colitis.
Taken together, our study indicates that PD-1 expression is involved in the resistance to experimental colitis through altered bacterial communities of colon.[BMB Reports 2017; 50(11): 578-583].
Ipilimumab was associated with a higher risk of all-grade rash (<i>P</i> = 0.006) and high-grade colitis (<i>P</i> = 0.021) compared with PD-1/PD-L1 ICIs.Incidence of fatal irAE was < 1%.
All grades colitis (OR 8.7, 95% CI 5.8-12.9), hypophysitis (OR 6.5, 95% CI 3.0-14.3) and rash (OR 2.0, 95% CI 1.8-2.3) were more frequent with CTLA-4 mAbs; whereas pneumonitis (OR 6.4, 95% CI 3.2-12.7), hypothyroidism (OR 4.3, 95% CI 2.9-6.3), arthralgia (OR 3.5, 95% CI 2.6-4.8) and vitiligo (OR 3.5, 95% CI 2.3-5.3) were more common with PD-1 mAbs.