New Immunotherapy for Metastatic Lung Cancer 

The FDA approved the immune checkpoint inhibitor tremelimumab to treat certain patients with non-small cell lung cancer. 

The U.S. Food and Drug Administration (FDA) has approved the immunotherapeutic tremelimumab (Imjudo) in combination with the immunotherapy durvalumab (Imfinzi) and platinum-based chemotherapy for the treatment of adult patients with metastatic non-small cell lung cancer (NSCLC) whose tumors do not have mutations in the EGFR or ALK genes. 

Tremelimumab is a type of immunotherapeutic called an immune checkpoint inhibitor. It targets the protein CTLA-4, which is expressed on the surface T cells and prevents them from attacking the tumor. Tremelimumab is a monoclonal antibody that binds to CTLA-4 and blocks its inhibitory signal thereby allowing the immune cells to target the tumor cells. 

Tremelimumab was approved for use in combination with platinum-based chemotherapy and durvalumab, another immune checkpoint inhibitor that targets PD-L1. It is intended for patients whose tumors do not have mutations in the cancer drivers EGFR or ALK, as patients with these mutations have other effective targeted therapies available to them. 

The approval was based on results from POSEIDON, a phase III, randomized, multi-center, active-controlled, open-label clinical trial. Patients who had not received prior systemic treatment were randomly assigned to receive platinum-based chemotherapy alone, durvalumab plus chemotherapy, or tremelimumab, durvalumab, and chemotherapy. The approval was based on the comparison of the tremelimumab, durvalumab, and chemotherapy regimen with chemotherapy alone. 

Patients receiving the tremelimumab-containing combination had a 23 percent lower risk of death than those receiving chemotherapy alone. The median overall survival was 14 months in patients treated with the tremelimumab combination and 11.7 months in patients treated with chemotherapy alone. The median progression-free survival was 6.2 months in patients treated with the tremelimumab combination and 4.8 months in patients treated with chemotherapy alone. 

Patients treated with tremelimumab, durvalumab, and chemotherapy had an overall response rate of 39 percent and a median response duration of 9.5 months. Patients treated with chemotherapy alone had an overall response rate of 24 percent and a median response duration of 5.1 months. 

According to federal statistics, over 236,000 individuals were estimated to be diagnosed with lung cancer and over 130,000 patients were estimated to die of the disease in the U.S. in 2022. Approximately 85 percent of lung cancer cases are NSCLC, of which 12 to 49 percent have EGFR mutations and around 5 percent have ALK rearrangements. 

The FDA rendered its decision on November 10, 2022.