ETCTN Phase 1 Safety Run-In and Phase 2 Randomized Clinical Trial of Anetumab Ravtansine and MK-3475 (Pembrolizumab) Compared to MK-3475 (Pembrolizumab) Alone for Mesothelin-Positive Malignant Pleural Mesothelioma Adult CIRB - Early Phase Emphasis Active Available to Open