Kunwar, Digbijay

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]

e16531 Background: Hypoxia-inducible Factor-2α (HIF-2α) is a transcription factor that accumulates in clear cell renal cell carcinoma (ccRCC) and is responsible for genes involved in oncogenesis. Belzutifan is a HIF-2α inhibitor that has shown promising anti-tumor effects in patients with ccRCC. Our objective is to summarize the available literature on the safety and efficacy profile of the drug. Methods: An electronic search was conducted on PubMed, Embase, and Cochrane from inception till January 31st, 2024. We identified patients aged ≥ 18 years with ccRCC who received Belzutifan. We extracted data on objective response rate, complete response rate, any grade adverse effect (AE) and grade ≥3 AE. Data was analyzed using R (v.4.3) and reported as proportions with respective 95% confidence intervals (CI) on forest plots. Results: Three studies (n=168 patients) were identified that reported the use of Belzutifan in ccRCC. Our analysis showed that pooled proportion of objective response rate and complete response rate was 35% (95% CI: 24% – 47%) and 1% (95% CI: 0% – 5%) respectively. Pooled proportion of patients experiencing any grade AE and grade ≥3 AE was 98% (95% CI: 95% – 99%) and 49% (95% CI: 29% – 69%) respectively. Conclusions: Belzutifan is a novel drug that inhibits HIF-2α which in turn results in anti-tumor effects of the drug against ccRCC. The drug has an acceptable safety and efficacy profile from limited data but more studies are needed to establish a complete picture of drug’s adverse effects and clinical benefits. Pooled proportion of patients developing (A) Objective Response, (B) Complete response (C) Any adverse effect and (D) Grade ≥3 adverse effects. [Table: see text]