Open-label, Multicenter, Randomized Phase II Trial of Treatment With Cisplatin and Pemetrexed or Cisplatin and Oral Vinorelbine in Chemotherapy Naïve Patients Affected by Stage IIIB-IV Non-Squamous Non-Small Cell Lung Cancer With High Thymidylate Synthase Expression

An Open-label, Multicenter, Randomized Phase II Trial of Treatment with Cisplatin and Pemetrexed or Cisplatin and Oral Vinorelbine in Chemotherapy Naïve Patients affected by stage IIIB-IV Non-Squamous Non-Small Cell Lung Cancer with high Thymidylate Synthase (TS)expression After signing the informed consent for TS expression evaluation (see Appendix A), patients will be tested for TS expression status of their tumor tissue. If TS expression is more than 70 in the nucleus or ≥210 in nucleus and in the cytoplasm of tumor cell, they will be categorized as high TS expression patients, and if it is less, they will be considered as TS-negative. Study Treatment: Eligible patients will be randomly assigned to the following treatment Arms: A. Oral vinorelbine 60-80 mg/m2 on days 1 and 8 (first cycle 60 mg/m2) + Cisplatin 80 mg/m2 on day 1 every 3 weeks, for 4 cycles. Maintenance with Metronomic Oral Vinorelbine 50 mg three times a week on Monday, Wednesday and Friday continuously until disease progression, patient refusal or excessive toxicity (1 cycle: 3 weeks). B. Pemetrexed, 500 mg/m2, day 1 + Cisplatin, 75 mg/m2, day 1 every 3 weeks, for 4 cycles. Maintenance with Pemetrexed 500 mg/m2 day1 q 21 until disease progression (1 cycle: 3 weeks). 7-10 days before treatment administration, premedication with vitamin B12 1000µg intramuscular injection (every 9 weeks) and folate 1mg every day should be commenced. The total duration of the study will be 3 years. The enrollment period wil be 2 years and 1 year of follow up. Treatment period: until disease progression, intolerable toxicity or patient refusal. Number of Subjects :130 patients (65 patients per arm) Statistical Methodology The primary variable of this study is Disease Control Rate (DCR). According to primary variable, assuming a DCR≥70% for patients with high TS expression treated with cisplatin and vinorelbine and a DCR=44% for patients with high TS expression treated with cisplatin and pemetrexed, considering a 2-tailed alpha=0.05 and beta=0.10, it is necessary to enroll 65 patients per arm (130 patients in total) in a 24-month period and the subsequent 12-month follow-up.