e20097 Background: Malignant Mesothelioma (MMe) is a neoplasm of mesothelium and has a very poor survival rate. Over half the patients of MMe express programmed death-ligand 1 (PD-L1) which binds to the PD-1 receptor on T-cells which in turn suppresses their ability to kill tumors. Pembrolizumab is a PD-1 inhibitor antibody and it has shown efficacy in combating MMe. Our analysis aims to summarize data related to objective response rates (ORR) and adverse effects of Pembrolizumab therapy in MMe patients. Methods: We conducted an online search through PubMed, Cochrane, and Clinicaltrials.gov databases from their inception till January 25, 2024, to identify studies that reported the use of Pembrolizumab in patients with MMe. Data were extracted and analyzed and proportions with their 95% confidence interval have been reported. Onlinemeta v1.0 was used for all analyses. Results: A total of six studies with 549 patients reported the use of Pembrolizumab in patients with MMe. ORR was observed in 36.2% (32.3% - 40.4%; p < 0.01) of patients receiving Pembrolizumab while 20.4% (17.2%- 24.0%; p < 0.01) of patients experienced adverse effects of the therapy. Median survival ranged from 9.5 to 17.3 months whereas progression-free survival ranged from 2.5 to 7.1 months in patients. Conclusions: Pembrolizumab has an ORR and safety profile comparable to other immunotherapies. Further studies are needed to extensively study the drug and its effects in detail in patients with MMe. [Table: see text]