Gemcitabine and pemetrexed administered in rapid sequence as front-line chemotherapy for advanced non-small-cell lung cancer: a phase II clinical trial

Background: Previous studies of the gemcitabine-pemetrexed combination in patients with late-stage non-small-cell lung cancer (NSCLC) utilized a 90-min delay between gemcitabine and pemetrexed administration. This phase II study evaluated activity when these agents were administered in rapid succession. Materials and methods: Chemonaive patients with late-stage NSCLC received gemcitabine 1250 mg/m(2) on days 1 and 8, with pemetrexed 500 mg/m(2) immediately following day 8 gemcitabine every 21 days for six cycles, folic acid, B-12, and steroid prophylaxis. Results: Fifty-four enrolled patients (53 treated) completed a median of four cycles. Median dose intensity was 84% (gemcitabine) and 83% (pemetrexed); 68% of patients required dose adjustments. Response was as follows: complete response, 0; partial response, 7 (13%); stable disease, 29 (54%); progressive disease, 9 (17%); and unknown/unavailable, 9 (17%). Median progression-free and overall survival was 4.6 and 12.4 months, respectively. Common grade 3 or 4 toxic effects were as follows: neutropenia (40%); fatigue and dyspnea (21% each); pneumonia (17%); febrile neutropenia and thrombocytopenia (11% each); and anemia (6%). Conclusions: The gemcitabine-pemetrexed combination is minimally active in late-stage NSCLC, with a high incidence of grade 3 or 4 toxic effects requiring frequent dose adjustments. A gemcitabine dose < 1250 mg/m(2) warrants consideration for future trials exploring this doublet. Administering day 8 pemetrexed immediately after gemcitabine does not appear to negatively impact therapeutic index.