Keytruda Shows Improved Survival Over Chemotherapy in Lung Cancer

In the phase 3 KEYNOTE-024 study, pembrolizumab (Keytruda) demonstrated superior progression-free survival (PFS) and overall survival (OS) as a first-line treatment for advanced non-small cell lung cancer (NSCLC) compared with chemotherapy.

Keytruda is a humanized monoclonal antibody that increases the immune system’s ability to detect and fight tumor cells. By blocking the interaction between PD-1 and its ligands, PD-L1 and PD-L2, T lymphocytes are activated that could affect both cancer and healthy cells.

The randomized phase 3 study evaluated Keytruda monotherapy versus standard of care (SOC) platinum-based chemotherapies in patients with advanced NSCLC.

There were 305 patients enrolled who had not received any prior systemic chemotherapy for advanced disease, and their tumors expressed high levels of PD-L1. High levels of PD-L1 were defined as a tumor proportion score of 50% or more and was determined by a central laboratory using an immunohistochemistry assay.

Participants were randomized to receive either 200-mg of Keytruda every 3 weeks or SOC platinum-based chemotherapies: paclitaxel plus carboplatin, pemetrexed plus carboplatin, pemetrexed plus cisplatin, gemcitabine plus carboplatin, or gemcitabine plus cisplatin.

Pemetrexed maintenance therapy was used for patients with non-squamous histologies. Furthermore, the patients randomized to the control were given the option to cross over to Keytruda when their disease progressed.

The primary endpoint was PFS, while secondary endpoints were OS and overall response rate. In the KEYNOTE-024 trial, Keytruda was found to be superior compared to chemotherapy for the primary endpoint of PFS and the secondary endpoint of OS.

“We believe that the KEYNOTE-024 results have the potential to change the therapeutic paradigm in first-line treatment of non-small-cell lung cancer,” said Roger M. Perlmutter, president, Merck Research Laboratories. “We look forward to sharing these data with the medical community and with regulatory authorities around the world.”

An independent Data Monitoring Committee has recommended that the trial be stopped, and that patients who received chemotherapy during the trial be offered the opportunity to receive Keytruda.