Hassan R, et al. - Researchers investigated the antitumor activity of avelumab in patients with previously treated, unresectable malignant mesothelioma by performing phase 1b open-label study (JAVELIN Solid Tumor) in 53 patients with unresectable mesothelioma that progressed after platinum and pemetrexed treatment, enrolled at 25 sites in three countries between September 9, 2014, and July 22, 2015. Avelumab was administered to patients intravenously every 2 weeks. Outcomes reveal the confirmed objective response rate of 9%, with 17% of patients free of disease progression at 12 months. Grade 3 or higher treatment-related adverse events were noted in 9% of patients. Findings thus support the clinical activity and acceptable safety of avelumab in these patients.