Paclitaxel and G-CSF in previously untreated patients with extensive stagesmall-cell lung cancer - A phase II study of the North Central Cancer Treatment Group

Paclitaxel is an antimicrotubule agent that interferes with cell division. It has demonstrated promising single-agent activity against non-small-cell lung cancer. The purpose of this study was to evaluate the therapeutic effe ctiveness of paclitaxel in previously untreated patients with extensive sta ge small-cell lung cancer (SCLC). The study was designed as a two-stage pha se 11 trial. All patients who entered received paclitaxel by intravenous in fusion at a dose of 250 mg/m(2) during 24 hours. Granulocyte colony stimula ting factor was also provided to ameliorate neutropenia. Cycles were repeat ed at 21-day intervals. Patients who achieved a complete response received a maximum of 10 cycles of treatment, whereas those who achieved a partial r esponse/regression continued treatment until progression or undue toxicity developed. Patients who progressed or maintained stable disease for six cyc les were crossed over to cisplatin and etoposide. Forty-three patients ente red the study and all were evaluable for analysis. Responses were observed in 23 (53%) of the patients. There was no significant difference in the res ponse rates in patients with measurable or evaluable disease (13/23 versus 10/20, p = 0.76). At the time of analysis, 39 patients had progressed with a median time to progression of 95 days, and 39 patients had died with a me dian survival of 278 days. The 1-year achieved survival rate was 24%. Signi ficant neutropenia (absolute neutrophil count <1,000/mu l) occurred in 24 ( 56%) of the patients, but only 2 patients experienced severe infection (gra de greater than or equal to 3), and there were no septic deaths. The result s indicate that paclitaxel is active against SCLC. Myelosuppression was the main side effect in this patient population. Response duration was short ( median = 3.4 months), which suggests that paclitaxel is not sufficient as a single agent. Further studies of paclitaxel in combination with other agen ts against SCLC are currently in progress within the North Central Cancer T reatment Group and other cancer treatment groups.