Nivolumab plus ipilimumab in malignant pleural mesothelioma

Unresectable pleural mesothelioma is a poor prognosis disease. Improvement in overall survival (OS) has been shown with PEMETREXED combined with CISPLATIN. BEVACIZUMAB combined with chemotherapy is associated with an improvement in OS, compared to chemotherapy alone, but is not supported by health insurance everywhere.

Immune Checkpoint Inhibition (ICI) monotherapy seemed to be promising but is controversial. ICI combination showed significant results. NIVOLUMAB, an anti-Programmed-Death-receptor 1, associated with IPILIMUMAB, an anti-Cytotoxic-T-Lymphocyte-Associated-protein 4, was evaluated in two phase II trials and a phase III trial, recently published. This combination led to a significant benefit in survival in first line compared to chemotherapy (OS 18.1 months (95%CI (16.8-21.4)) vs 14.1 (95%CI (12.4-16.2) HR 0.74 (95%CI 0.6-0.91) p = 0.002).

These results represent a big step in unresectable pleural mesothelioma. The benefit in non-epithelioid subtype is impressive (OS 18.1 months (95%CI 12.2-22.8) vs 8.8 months 95%CI (7.4-10.2) HR 0.46 (95%CI (0.31-0.68))). Benefit in epithelioid subtype (OS 18.7 months 95%CI (16.9-22) vs 16.5 95%CI (14.9-20.5) HR 0.86 95%CI (0.69-1.08)) is similar to the benefit of the combination of BEVACIZUMAB and chemotherapy. Identification of predictive biomarkers is needed to identify patients who are most likely to benefit from each therapeutic strategy.