Maintenance therapy is a treatment given after a disease has responded to previous treatment. In the case of cancer, this would mean that the tumor has decreased in size or gone into remission. Maintenance therapy is given to help prevent spread or recurrence of the tumor.
With lung cancer, the medication pemetrexed (Alimta) was approved in 2009 for maintenance therapy in people who have adenocarcinoma or large cell lung cancer (forms of non-small cell lung cancer). This treatment can be given to individuals who have completed a course of chemotherapy and would not otherwise receive further treatment unless their tumors started to grow again.