Pemetrexed and carboplatin followed by pemetrexed maintenance therapy in chemo-naïve patients with advanced nonsquamous non-small-cell lung cancer

Introduction This study prospectively evaluated the efficacy and safety of pemetrexed and carboplatin followed by maintenance pemetrexed in chemo-naïve patients with advanced nonsquamous non-small cell lung cancer (NSCLC). Methods A total of 109 patients received pemetrexed (500 mg/m ²) and carboplatin (area under the curve = 6 mg/mL·min) every 21 days. For patients without disease progression after 4 cycles, pemetrexed was continued until disease progression or unacceptable toxicity. Pre-planned subgroup analysis results based on the presence of epidermal growth factor receptor (EGFR) mutations are also presented. Results The median number of treatment cycles was 5 (range: 1-30) in the entire study period. Most of the grade ≥3 toxicities observed were hematologic in nature, with no increase in the relative incidence associated with continuation maintenance therapy with pemetrexed. Among the 106 total patients assessable for efficacy, the objective response rate was 35.8 %, median progression free survival (PFS) 5.7 months, and median overall survival (OS) 20.2 months. Sixty patients received maintenance pemetrexed (median: 4 cycles, range: 1-26 cycles); median PFS from the beginning of induction treatment was 7.5 months. From the subgroup analysis for EGFR mutation status, the median OS of EGFR wild-type patients (n = 61) was 20.2 months. Conclusions Pemetrexed/carboplatin followed by pemetrexed was well tolerated and active for front-line treatment of advanced nonsquamous NSCLC. Encouraging survival outcomes were observed even in EGFR-wild type patients.