Should cemiplimab be considered a first-line treatment for advanced non-small-cell lung cancer?

This study aimed to examine the effectiveness and safety of cemiplimab (Libtayo) in the first-line treatment of patients with advanced non-small-cell lung cancer (NSCLC) with a high quantity of PD-L1 protein. The study concluded cemiplimab improved survival of these patients compared to standard chemotherapy.

NSCLC is the most common form of lung cancer. About 85% of lung cancers are NSCLC. Despite current treatment options of improving survival rates, advanced NSCLC remains difficult to treat. Chemotherapy, radiotherapy, and surgery are the most common treatment option for treating NSCLC. However, to improve responses, other therapies are needed.

PD-L1 is a protein present on some of the cancer cells that helps them evade the immune system. This helps cancer cells grow and spread. Cemiplimab is an immunotherapy that blocks the PD-L1 protein and helps the immune system to attack the cancer cells. 

In patients with advanced NSCLC, platinum-doublet chemotherapy is the standard of care. However, in patients with more than 50% of cancer cells expressing the PD-L1 protein, the effectiveness of cemiplimab as the first-line treatment is unknown.

This study involved 710 patients. The patients were randomly assigned to undergo either cemiplimab (356) or standard chemotherapy (354) treatment. Of these, 283 patients in the cemiplimab group and 280 in the chemotherapy group had more than 50% of cancer cells expressing the PD-L1 protein. The average follow-up for patients was 10.8 months for the cemiplimab group and 10.9 months for the chemotherapy group.

Significant improvement in overall survival of 22.1 months with cemiplimab versus 14.3 months with chemotherapy. Improvement of progression-free survival 6.2 months with cemiplimab compared to 5.6 months with chemotherapy.

In patients with more than 50% PD-L1 cells, cemiplimab improved survival by 43% compared to chemotherapy. After 2 years, it was estimated that 50% of patients on cemiplimab were alive compared to 27% of patients in the chemotherapy group.

The average survival time without cancer worsening was 8.2 months in the cemiplimab group compared to 5.7 months in the chemotherapy group. The average duration of response was 16.7 months with cemiplimab compared to 6 months in the chemotherapy group. 

Side effects related to treatment were reported in 57% of the cemiplimab group and 89% of the chemotherapy group. The most common severe side effects in the cemiplimab group were increased liver enzymes and pneumonia. In the chemotherapy group, the most common side effects were low white and red blood cell counts.

The study concluded that cemiplimab improved the survival of patients with advanced NSCLC with more than 50% of cells expressing the PD-L1 protein.

The study was supported by Regeneron Pharmaceuticals and Sanofi, the manufacturers of cemiplimab.