Outcomes following immunotherapy re-challenge after immune-related adverse event: systematic review and meta-analysis.

Background: Given the inconclusive evidence behind the safety and efficacy of immune checkpoint inhibitors re-challenge, herein, we have conducted a systematic review and meta-analysis to synthesize available data. Results/methodology: PubMed, Embase, Cochrane Database, and ASCO and ESMO were searched for studies published from conception to March 2020. Pooled incidence of recurrent immune-related adverse events (irAEs), objective response rates, and odds ratios for irAEs at initial versus re-treatment were calculated. Overall, 437 patients (ten studies) were included. Incidence of any grade, grade 3/4, and steroid-requiring recurrent irAEs were 47%, 13.2%, and 26% respectively. Objective response rate in previous non-responders was 12.5% (5.8-24.8%). Odds ratio for severe irAEs was 0.28 (0.11-0.72) and steroid-requiring irAEs 0.19 (0.06-0.56). Discussion/conclusion: This analysis suggests that immune checkpoint inhibitors re-challenge is safe and potentially efficacious.