Phase I/II study of weekly irinotecan and concurrent radiation therapy for locally advanced non-small cell lung cancer

Abstract

A study was undertaken to determine the maximum tolerated dose, the dose-limiting toxicities, and the response rate of irinotecan administered weekly with concurrent thoracic radiation therapy in patients with locally advanced non-small-cell lung cancer. In a phase I/II clinical trial, patients with histologically documented, surgically unresectable stage IIIA or IIIB non-small cell lung cancer (NSCLC) were enrolled. Irinotecan was administered as a 90 min intravenous infusion once weekly for 6 weeks. The starting dose was 30 mg m-2 and dose escalation was done in 15 mg m-2 increments. Dose-limiting toxicity was defined as grade 3 nonhaematologic toxicity (excluding nausea, vomiting and alopecia) or grade 4 haematologic toxicity according to the WHO criteria. Radiation was delivered to the primary tumour and regional lymph nodes (40 Gy), followed by a boost to the primary tumour (20 Gy). Twenty-seven patients were entered into this study at three irinotecan dose levels (30, 45 and 60 mg m-2). Twenty-six eligible patients were evaluated for toxic effects and clinical outcome. Severe oesophagitis, pneumonitis, and diarrhoea occurred at 45 and 60 mg m-2. Three of the five patients given 60 mg m-2 developed grade 3 or 4 oesophagitis and pneumonitis. In addition, one patient died of pneumonitis after completing therapy at 45 mg m-2 in the phase II study. The objective response rate was 76.9% (95% CI, 53.0-88.9%). Oesophagitis, pneumonitis, and diarrhoea are the dose-limiting toxicities of weekly irinotecan combined with thoracic irradiation. The maximum tolerated dose and the dose for the phase II study were 60 and 45 mg m-2 wk-1, respectively. This combined therapy for locally advanced non-small cell lung cancer is promising and shows acceptable toxicity.