Interim analysis of a phase III trial. Triple- vs double-agent chemotherapy for advanced non-small-cell lung cancer. Southern Italy Cooperative Oncology Group.

In our previous phase I/II studies, both the cisplatin (Platinol), gemcitabine (Gemzar), and vinorelbine (Navelbine) (PGV), and cisplatin, gemcitabine, and paclitaxel (Taxol) (PGT) regimens produced a median survival of approximately 1 year in patients with advanced non-small-cell lung cancer (NSCLC). The present phase III study compared the median survival of patients treated with these triple-drug regimens to that of patients receiving cisplatin plus vinorelbine (PV) or cisplatin plus gemcitabine (PG). Accrual for the trial began in 1997 and by December 1998, a total of 240 patients (stage IIIB, 98; stage IV, 142) had been enrolled. An interim survival analysis was performed in April 1999. Overall, 151 patients had died. The median survival rates of patients in the PGV, PG, and PV arms were 51, 42, and 35 weeks, respectively. At the time of this analysis, the median survival of patients in the PGT arm could not be assessed; however, the 1-year projected survival rate was 58%. At multivariate Cox analysis, the estimated risk of death for patients receiving PGV compared with those receiving PV was 0.35 (95% CI, 0.16-0.77, P = .0058). Overall response rates were 47% in the PGV arm, 30% in the PG arm, 25% in the PV arm, and 58% in the PGT arm. Severe neutropenia and vomiting were significantly more frequent in patients who received PV than in those who received PGV. The PV regimen produced a significantly shorter survival compared with the PGV combination. Since this difference in survival complied with one of the early stopping rules, accrual in the PV arm was discontinued. Enrollment in the PGV, PG, and PGT arms is ongoing.