This study focuses on patients with metastatic non-small cell lung cancer (NSCLC) who have been receiving initial treatment with medications that help the immune system fight cancer. The study uses two medications: pembrolizumab (KEYTRUDA), which works with the immune system to fight cancer cells, and pemetrexed (ALIMTA), a chemotherapy drug. Both medications are given through an intravenous infusion, which means they are delivered directly into a vein.

The purpose of this research is to determine if patients can benefit from a shorter duration of standard treatment while maintaining its effectiveness. The study involves patients who have been receiving treatment for about 6 months and whose cancer has not gotten worse during this time. These patients will continue receiving their current treatment for up to 18 months while being monitored for any changes in their condition.

During the study, doctors will regularly check how the cancer responds to treatment through various medical examinations. The medications will be given at specific doses – pembrolizumab at up to 200 mg per dose and pemetrexed at 500 mg per square meter of body surface area. The treatment will continue for up to 18 months, during which time patients will be monitored for any changes in their health and how well the treatment is working.