Vedolizumab Dose Escalation Resolves Immune Checkpoint Inhibitor-Induced Colitis in Two Patients.

Colitis is a common side effect of all currently approved immune checkpoint inhibitors (ICIs). Vedolizumab is an α 4 β 7 monoclonal antibody approved for treating inflammatory bowel disease (IBD) and is commonly used off-label to manage checkpoint inhibitor colitis (CIC). Previous studies have attempted dose escalation of vedolizumab for clinically unresponsive IBD patients and have been able to achieve clinical remission in 49.6% of these patients without an associated increase in adverse events. However, this has yet to be reported in patients with CIC. Here, we report on two patients who developed CIC after being treated with ICIs for metastatic cancer and received a double dose of vedolizumab. Both patients' colitis was initially treated with infliximab, steroids, and standard 300-mg vedolizumab dosage with an incomplete response. When administered a double dose of 600-mg vedolizumab, colitis symptoms were resolved without further recurrence or the need for treatment in both patients. This case series outlines effective clinical experience in treating patients with CIC refractory to standard vedolizumab dosage and supports further study of vedolizumab dose escalation in this patient population.