Phase I study of induction chemotherapy and concomitant chemoradiotherapy with irinotecan, carboplatin, and paclitaxel for Stage III non-small cell lung cancer

Background: The aim of this study was to determine the maximum tolerated dose (MTD), dose limiting toxicities (DLTs), and determine the phase II dose for the combination of irinotecan-carboplatin-paclitaxel given as induction chemotherapy and with concomitant chest radiotherapy for patients with Stage III non-small cell lung cancer. Methods: Patients with Cancer and Leukemia Group B performance status of 0 to 2, stage IIIA and IIIB NSCLC patients with resectable or unresectable disease were treated with induction chemotherapy (irinotecan 100 mg/m(2), carboplatin AUC 5, and paclitaxel 175 mg/m(2) days 1 and 22) followed by concomitant chemotherapy (irinotecan, carboplatin, and paclitaxel) and chest radiotherapy (66 Gy for unresectable and 50 Gy for resectable disease) beginning on week 7. The primary objective was to escalate the dose of irinotecan during chemoradiation in sequential cohorts to determine the DLT and MTD of the regimen. Results: Thirty-eight patients were enrolled (median age 63 years, 57% male, 41% performance status 0, 30% resectable). Induction chemotherapy was tolerable and active (response rate 26%; stable disease 60%). Eight patients did not receive concurrent chemoradiotherapy because of progressive disease (5), death (1), hypersensitivity reaction to paclitaxel (1), and withdrawal of consent (1). Twenty-nine patients received concurrent chemoradiotherapy. The concomitant administration of chest radiotherapy with weekly irinotecan, carboplatin, and paclitaxel was not feasible at the first, second, and third dose levels. DLT was failure to achieve recovery to <= grade 1 absolute neutrophil count by the day of scheduled chemotherapy administration. Dose de-escalation to irinotecan 30 mg/m(2), paclitaxel 40 mg/m(2) (with omission of carboplatin) delivered on weeks 2, 3, 5, and 6 of radiotherapy was the MTD. After induction chemotherapy, partial responses, stable disease, and progressive disease was observed in 26%, 60%, and 14% of patients, respectively. After chemoradiotherapy, partial responses were attained in 16 (55%) patients, whereas 12 patients (41%) attained disease stabilization. Median overall survival was 21 months for the entire cohort. Resectable patients had a median survival of 24 months, whereas unresectable patients had a median survival of 19 months. Differences in overall and progression-free survival rates between resectable and unresectable patients was not statistically significant (p = 0.52 and p = 0.90, respectively). Discussion: Carboplatin, paclitaxel, and irinotecan with concurrent chemoradiotherapy was poorly tolerated as a result of neutropenia. Although dose de-escalation was required for delivery of the regimen, the response rates and survival outcomes were comparable to other similar regimens.