The results of the studies of maintenance pemetrexed therapy are encouraging; the observed survival benefit is clinically relevant and relatively large considering the poor survival in patients with advanced NSCLC. Furthermore, pemetrexed appears to be well tolerated. There are, however, several limitations to the studies that have been conducted: Relatively few elderly patients and no PS 2 patients were enrolled - and not all patients on the control-arms received pemetrexed at progression.