Purpose: To evaluate the efficacy of the combination of vinorelbine and gemcitabine as a non-platinum chemotherapy regimen in patients with inoperable locally-advanced or metastatic non-small-cell lung cancer (NSCLC). Efficacy was assessed primarily in terms of response rate, and secondarily in terms of toxicity, time to progression and survival.
Patients and methods: Patients with cytologically- or histologically-proven stage IIIB-IV NSCLC, bi-dimensionally measurable lesions, adequate haematological, hepatic and renal function, WHO performance status < or = 2 and no previous chemotherapy or radiotherapy were eligible. The first 12 patients were entered in a pilot study and received vinorelbine (VNR) 30 mg/m2 on days 1, 8, 15 and 22, and gemcitabine (GEM) 1000 mg/m2 on days 1, 8 and 15, of a 28-day cycle. Subsequently, patients were entered in a phase II trial of VNR 35 mg/m2 and GEM 1200 mg/m2 on days 1 and 15 of each 28-day cycle. Treatment consisted of three cycles of the chemotherapy, with a further three cycles for those patients who achieved stable disease or a complete or partial response (CR/PR) to the first three cycles. Patients who had achieved CR or PR after six cycles continued with the treatment until relapse.
Results: The dosage and scheduling of VNR and GEM in the pilot study resulted in neutropenia necessitating reductions or delays in treatment, and consequently low dose intensity. The schedule was thus modified to VNR 35 mg/m2 and GEM 1200 mg/m2 on days 1 and 15 of each 28-day cycle for the phase II trial. Thirty-three patients were enrolled in the phase II trial, and 28 were evaluable for response. The overall intent-to-treat response rate of all 45 patients was 40% (18 of 45), comprising 4 CR (9%) and 14 PR (31%). For the 28 evaluable patients who received the fortnightly chemotherapy the response rate was 46% (13 of 28), CR 11% (3 of 28) and PR 36% (10 of 28). Seven patients (25%) had stable disease. The one-year cumulative survival rate for the 33 patients receiving the fortnightly chemotherapy was 24% and median time-to-progression 4 months (range 1-16 months). Median survival for these patients was eight months. Nine out of twelve patients in the pilot study (75%) suffered grade 3-4 neutropenia. There was one toxic death, attributed to neutropenic fever and sepsis, and two cases of pulmonary embolism. One patient suffered Grade 4 thrombocytopenia. Only eight patients (24%) on the fortnightly schedule suffered grade 3-4 neutropenia, resulting in dose reductions or delays for three of them (9%). None of the patients on the fortnightly schedule suffered thrombocytopenia or anaemia.
Conclusions: The fortnightly schedule of gemcitabine and vinorelbine was a well-tolerated out-patient regimen, producing response and survival rates comparable to those of cisplatin combination regimens, but with a more favourable toxicity profile. Gemcitabine and vinorelbine should now be tested in a triplet combination with a taxane as the third drug, or against a platinum-containing regimen in a phase III study.