This document discusses maintenance therapy options for patients with metastatic lung cancer. It summarizes several key clinical trials that evaluated continuation or switch maintenance strategies with drugs such as bevacizumab, pemetrexed, and erlotinib. Histology and molecular markers like EGFR mutations and ALK translocations are predictive of response to certain drugs. Ongoing trials are further exploring predictive biomarkers and sequential testing strategies to select the most effective treatment based on a patient's tumor characteristics. While maintenance therapy may delay tumor progression, it is still unclear if it provides a true survival benefit over second-line treatment administered at the optimal time.