Paclitaxel and carboplatin in the treatment of advanced non-small cell lung cancer

Based on the superior response rates (21% to 24%) of patients treated with single-agent paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) in Eastern Cooperative Oncology Group and M.D. Anderson Cancer Center trials in non-small cell lung cancer (NSCLC) and on the superior 1-year survival rates of NSCLC patients treated with carboplatin in a randomized study of cisplatin combination and analogues, we initiated a phase II trial of paclitaxel/carboplatin in patients with stage IV or effusion-positive stage III NSCLC. Eligibility stipulated chemotherapy-naive patients with measurable disease, good performance status, and adequate hematologic, hepatic, and renal function. Previous radiotherapy was restricted to < or = 30% of marrow-bearing bone. Paclitaxel was initially given at 135 mg/m2 over 24 hours followed by carboplatin dosed to a targeted area under the concentration versus time curve (AUC) of 7.5, with treatment repeated at 3-week intervals for six cycles. Granulocyte colony-stimulating factor was introduced during the second and subsequent cycles, with the paclitaxel dose sequentially escalated in 40 mg/m2 increments to a maximum dose of 215 mg/m2 in patients with less than grade 4 granulocytopenia and less than grade 3 thrombocytopenia. Of 54 patients enrolled, 30 currently are evaluable for response, 23 for toxicity. Myelosuppression has been the principal toxicity, with grade 3 or 4 granulocytopenia occurring in 70% of patients after the first cycle. After the introduction of granulocyte colony-stimulating factor, granulocytopenia decreased to 37% during the second cycle and then consistently to 20% or lower during subsequent cycles. Only 22% of cycles have been delayed for 1 week or more. Neutropenic fever has occurred in five (5%) of 100 evaluable cycles. Other grade 3 or 4 toxicities include thrombocytopenia (13%), anemia (9%), fatigue (9%), and hemorrhagic cystitis (1%). The paclitaxel dose was boosted to 215 mg/m2 in 12 (70%) of 17 patients by cycle 3 or 4. At an AUC of 7.5, the median first-cycle carboplatin dose was 434 mg/m2 (range, 293 to 709 mg/m2). The objective response rate is 50%, with three complete, 12 partial, and five minor responses. We conclude that the paclitaxel/carboplatin combination is active in advanced NSCLC and, with AUC-based dosing of carboplatin, can be given at 3-week intervals. Although dose limiting at a paclitaxel dose of 135 mg/m2, granulocytopenia can be reduced substantially with granulocyte colony-stimulating factor, allowing sequential dose escalation of paclitaxel to 175 mg/m2 and 215 mg/m2 in 70% of patients receiving three or more cycles.