The efficacy and safety of a combination of docetaxel (Taxotere; Rhône-Poulenc Rorer, Antony, France) and vinorelbine were evaluated in two phase II studies including 46 and 39 chemotherapy-naive patients with non-small cell lung cancer, respectively. In the first study, vinorelbine 25 mg/m2 was given on day 1 and docetaxel 100 mg/m2 on day 2, with recombinant human granulocyte colony-stimulating factor support from day 5 until day 12, every 3 weeks. In the second study, docetaxel 75 mg/m2 was given on day 1 and vinorelbine 20 to 25 mg/m2 on days 1 and 5 in a 3-week schedule. Grade 3/4 neutropenia was the most severe toxicity, occurring in 46% to 85% of patients, while febrile neutropenia was observed in 25% to 41% of patients. Two treatment-related deaths occurred in each study. Patients with a poor performance status were at an increased risk of infection. The objective response rates were 36.6% and 27%, respectively (mean, 32%). In two subsequent studies, the efficacy and safety of a triple-drug combination of docetaxel, vinorelbine, and cisplatin was evaluated. In the first study, 14 patients were treated with vinorelbine 25 mg/m2 and cisplatin 80 mg/m2 on day 1 and docetaxel 100 mg/m2 and vinorelbine 20 mg/m2 on day 8, every 3 weeks. In the second study, 46 patients received docetaxel 100 mg/m2 on day 1, cisplatin 100 mg/m2 and vinorelbine 30 mg/m2 on day 21, and vinorelbine 30 mg/m2 on days 28 and 35, every 6 weeks. The main toxicity was also grade 3/4 neutropenia (57% and 80% of patients, respectively). Febrile neutropenia developed in 50% and 15% of the patients in the first and second study, respectively. The overall response rates were 33% and 39%, respectively. It is concluded that combination therapy with docetaxel/ vinorelbine or with docetaxel/vinorelbine/cisplatin has antitumor activity in the treatment of non-small cell lung cancer. Granulocytopenia and febrile neutropenia are the most severe toxicities that limit the usefulness of these regimens.