Immunotherapy by checkpoint inhibitor is effective for a number of solid tumors including malignant mesothelioma. Studies utilizing single-agent PD-1 or PD-L1 inhibitor for mesothelioma have reported tumor response rates in approximately 10-20% of patients treated. Given the success of combining these agents with CTLA-4 inhibitor in melanoma, there is a strong rationale to study it in mesothelioma. Recently results from clinical trials investigating this approach have been released. Though limited by small sample size, the studies conclusively demonstrated feasibility and suggested a modestly higher tumor response rate than one would expect from treatment with single-agent PD-1 or PD-L1 inhibitor. Nevertheless, toxicity was also increased. Immunotherapy-related deaths due to encephalitis, renal failure and hepatitis were observed. Further studies are warranted.
Keywords: immune checkpoint inhibitor; immunotherapy; ipilimumab; mesothelioma; nivolumab.