IASLC 2021: POSEIDON Trial of Durvalumab Plus Tremelimumab in Metastatic NSCLC
Posted: Tuesday, September 14, 2021
According to the phase III POSEIDON trial, the PD-1 inhibitor durvalumab plus the CTLA-4 inhibitor tremelimumab and chemotherapy appeared to significantly improve survival rates among patients with metastatic non–small cell lung cancer (NSCLC) compared with chemotherapy alone. In addition, the survival benefits did not appear to compromise safety, and no new safety signals were identified. The study was presented during the International Association for the Study of Lung Cancer (IASLC) 2021 World Conference on Lung Cancer (Abstract PL02.01).
“Durvalumab plus tremelimumab and chemotherapy may represent a new first-line treatment option for metastatic NSCLC,” Melissa L. Johnson, MD, of Sarah Cannon Research Institute, Nashville, and colleagues stated.
The researchers randomly assigned 1,013 patients with stage IV metastatic NSCLC to receive durvalumab plus chemotherapy (n = 334), concurrent durvalumab and tremelimumab plus chemotherapy (n = 330), or chemotherapy alone (n = 333). Eligible patients included those with nonsquamous or squamous disease and the full range of PD-L1 expression levels.
Patients treated with concurrent durvalumab and tremelimumab plus chemotherapy achieved significantly longer progression-free survival than patients who received chemotherapy alone (6.2 vs. 4.8 months, respectively; P < .0003). The median overall survival outcomes were also improved among those treated with the doublet therapy than chemotherapy alone (14 vs. 11.7 months, respectively; P < .003). Similarly, patients who received durvalumab plus chemotherapy achieved significant progression-free survival benefits compared with chemotherapy alone (5.5 vs. 4.8 months). Although overall survival results showed a positive trend, the outcomes did not reach significance.
The safety profile across the three treatment arms was comparable. The incidence rates of severe treatment-related adverse events with concurrent durvalumab and tremelimumab plus chemotherapy, durvalumab and chemotherapy, and chemotherapy alone were 51.8%, 44.6%, and 44.4%, respectively.
Disclosure: For study authors’ disclosures, visit library.iaslc.org.