The U.S. Food and Drug Administration (FDA) has approved tremelimumab plus durvalumab and platinum-based chemotherapy for metastatic non-small cell lung cancer (NSCLC) patients lacking sensitising EGFR mutations or anaplastic lymphoma kinase (ALK) genomic tumour aberrations.
Immunotherapy is at the forefront of treatment in a variety of cancers. Tremelimumab is a monoclonal antibody against anti-CTLA-4, whereas durvalumab is an anti-PD-L1 monoclonal antibody. Last month, the FDA approved using tremelimumab plus durvalumab for patients with unresectable hepatocellular carcinoma. Based on these encouraging findings, the POSEIDON trial has investigated the efficacy of this combination for NSCLC patients.
The open-label, multicenter, randomised, phase III POSEIDON study enrolled patients with metastatic NSCLC who had not received prior systemic treatment. The participants were divided in three arms to either receive tremelimumab, durvalumab and platinum-based chemotherapy for four cycles, followed by durvalumab and maintenance chemotherapy or durvalumab plus platinum-based chemotherapy followed by durvalumab and maintenance chemotherapy or platinum-based chemotherapy followed by maintenance chemotherapy. Progression-free survival (PFS) and overall survival (OS) were set as major outcomes for measuring the efficacy of the treatment regimens.
The OS was significantly improved in patients treated with tremelimumab, durvalumab and chemotherapy than those on chemotherapy alone (median, 14 months vs 11.7 months; HR = 0.77; 95% CI, 0.65-0.92). Further, the PFS (median, 6.2 months vs 4.8 months) and overall response rate (39% vs 24%) were also improved with the triple combination versus the chemotherapy arm. Grade 3 or 4 adverse events (neutropenia, anaemia, leukopenia, lymphocytopenia, lipase increase, hyponatremia and thrombocytopenia) were seen in at least 10% of patients assigned to tremelimumab, durvalumab and chemotherapy.
Based on the promising findings from the phase 3 POSEIDON study, the FDA has granted approval for the use of tremelimumab plus durvalumab with chemotherapy for certain NSCLC patients.