Phase II trial of induction chemotherapy of pemetrexed plus split-dose cisplatin followed by pemetrexed maintenance for untreated non-squamous non-small-cell lung cancer

Purpose We conducted a phase II trial to evaluate the efficacy and safety of induction chemotherapy of pemetrexed plus split-dose cisplatin followed by pemetrexed maintenance for advanced non-squamous non-small-cell lung cancer (NSCLC). Methods Patients with advanced or recurrent untreated non-squamous NSCLC received split-dose cisplatin (40 mg/m 2 , days 1 and 8) plus pemetrexed (500 mg/m 2 , day 1) tri-weekly. After four cycles of induction, patients without disease progression received pemetrexed maintenance until disease progression or unacceptable toxicity. The primary endpoint was the 1-year survival rate. The secondary endpoints were progression-free survival (PFS), overall survival (OS), response in induction phase, and safety. Results From February 2012 to September 2014, 53 assessable patients were enrolled in this study. Thirty-eight (71.7%) patients completed induction therapy, while 35 (66.0%) received maintenance therapy. The 1-year survival rate was 67.7%. The median PFS and OS were 5.3 and 18.6 months, respectively. The response rate and disease control rate (DCR) during the induction phase were 37.7 and 86.8%, respectively. Eight patients (15.1%) discontinued the therapy due to adverse events (AEs) during the induction phase, but both hematological and non-hematological AEs were infrequent. Conclusions Treatment with induction chemotherapy of pemetrexed plus split-dose cisplatin showed a promising 1-year survival rate, DCR, and transition rate into maintenance phase. This regimen is feasible and well-tolerated. A phase III study comparing this regimen with conventional tri-weekly regimen is warranted.