6/29/23, 1:42 AM POSEIDON (chemotherapy plus durvalumab and tremelimumab) Pathway Feedback Search Clinical Topics Home Studies POSEIDON (chemotherapy plus durvalumab and tremelimumab) POSEIDON (chemotherapy plus durvalumab and tremelimumab) Disease Non-small cell lung cancer Trial question What is the role of first-line tremelimumab plus durvalumab and chemotherapy in patients with metastatic non-small cell lung cancer? Study design Multi-center Open label RCT Population Characteristics of study participants 23.0% female N = 675 77.0% male 675 patients (158 female, 517 male) Inclusion criteria: adult patients with epidermal growth factor receptor/ALK wild-type metastatic non-small cell lung cancer Key exclusion criteria: mixed small cell lung cancer and non-small cell lung cancer histology; autoimmune or inflammatory disorders; brain metastases or spinal cord compression; active infection Interventions N=338 tremelimumab plus durvalumab and chemotherapy (at a dose of 75 mg plus 1500 mg and platinum-based chemotherapy, respectively, for up to four 21-day cycles, followed by durvalumab once every 4 weeks until progression and one additional tremelimumab dose) https://web.pathway.md/studies/recTjXm9zwpK5xC8U 1/2 6/29/23, 1:42 AM POSEIDON (chemotherapy plus durvalumab and tremelimumab) Pathway N=337 chemotherapy (chemotherapy for up to six 21-day cycles with or without maintenance pemetrexed) Primary outcome Progression-free survival 6.2 months 6.2 4.8 4.7 months 3.1 months 1.6 months Significant increase 0.0 months Tremelimumab plus durvalumab and chemotherapy Chemotherapy Significant increase in progression-free survival (6.2 months vs. 4.8 months; HR 1.38, 95% CI 1.16 to 1.66) Secondary outcomes Significant increase in overall survival (14 months vs. 11.7 months; HR 1.29, 95% CI 1.08 to 1.53) Borderline significant increase in unconfirmed objective response rate (46.3% vs. 33.4%; OR 1.72, 95% CI 1.26 to 2.37) Safety outcomes No significant differences in adverse events, grade 3/4 treatment-related adverse events. Conclusion In adult patients with epidermal growth factor receptor/ALK wild-type metastatic non-small cell lung cancer, tremelimumab plus durvalumab and chemotherapy were superior to chemotherapy with respect to a progression-free survival. Reference Melissa L Johnson, Byoung Chul Cho, Alexander Luft et al. Durvalumab With or Without Tremelimumab in Combination With Chemotherapy as First-Line Therapy for Metastatic Non-Small- Cell Lung Cancer: The Phase III POSEIDON Study. J Clin Oncol. 2022 Nov 3;JCO2200975. Open reference URL https://web.pathway.md/studies/recTjXm9zwpK5xC8U 2/2