Phase II study of pemetrexed as first-line treatment in elderly (≥75) non-squamous non-small-cell lung cancer: Kyoto Thoracic Oncology Research Group Trial 0901.

Single-agent chemotherapy with third-generation non-platinum agents, such as docetaxel, vinorelbine, is a standard therapeutic option for elderly patients with non-small-cell lung cancer (NSCLC). Subset analysis of a previous phase III study comparing pemetrexed with docetaxel in the second-line setting showed the superiority of pemetrexed in an elderly (≥70) population in both efficacy and toxicity. This was a single-arm phase II study of pemetrexed in elderly (≥75) Japanese patients with advanced non-squamous NSCLC. Patients received four cycles of pemetrexed (500 mg/m(2)) every 3 weeks. The primary endpoint was the response rate, and secondary endpoints were safety and survival. Twenty-eight patients were enrolled between January 2010 and April 2012. The median age of the patients was 77 years (range 75-88). All but one patient had adenocarcinoma histology. The median number of chemotherapy cycles administered was 4 (range, 1-12). Seventeen (60 %) patients completed four cycles of chemotherapy. Partial response was achieved in 7 patients (response rate: 25 %) and stable disease in 11 patients (disease control rate: 64 %). Median progression-free survival and overall survival were 3.3 and 17.5 months, respectively. Grade 3/4 neutropenia and thrombocytopenia were observed in 8 patients (29 %) and 2 (7 %), respectively. Non-hematologic toxicities were generally mild, and there were no treatment-related deaths. Although this study did not meet our primary endpoint, pemetrexed showed favorable antitumor activity with mild toxicity in elderly patients with non-squamous NSCLC. Further investigations of pemetrexed in this population are warranted (UMIN-CTR number, 000002452).