Pemetrexed for advanced stage nonsquamous non-small cell lung cancer: latest evidence about its extended use and outcomes.

Non-small cell lung cancer (NSCLC) is still the leading cause of cancer-related death, and the treatment of advanced NSCLC relies on systemic treatments. During the last decade, pemetrexed, an antifolate agent, gradually became a key component of the treatment for patients with advanced nonsquamous NSCLC. It has indeed been shown to be efficient for first-line, maintenance and second- or third-line treatment in this subgroup of NSCLC. Moreover, it is usually well tolerated, with few grade 3 and 4 toxicities. Several studies have tried to identify predictive biomarkers of pemetrexed efficacy. Due to pemetrexed's mechanism of action, thymidilate synthase expression predictive value was investigated but could not be demonstrated. Currently, more than 400 trials of pemetrexed for the treatment of nonsquamous NSCLC are ongoing.