Dose-finding study of irinotecan and cisplatin plus concurrent radiotherapy for unresectable stage III non-small-cell lung cancer

Abstract

Irinotecan hydrochloride (CPT-11) shows marked anti-tumour activity alone and in combination with cisplatin in non-small-cell lung cancer (NSCLC). It is necessary to investigate combined-modality therapy including novel effective anti-cancer agents to improve long-term survival of patients with unresectable stage III NSCLC. A phase I/II study of concurrent chemoradiotherapy with CPT-11 and cisplatin was conducted to determine the maximum tolerated dose (MTD) and efficacy in this group of patients. Thirteen previously untreated patients with unresectable stage IIIA/B NSCLC were enrolled and efficacy and toxicity was evaluated in 12 of them; one patient was ineligible. Chemotherapy was repeated every 4 weeks for three courses. Radiation therapy was started on day 2 of the first course of chemotherapy and 60 Gy in 30 fractions was given over 6 weeks. Four of six patients enrolled at level 1 completed the scheduled treatment. Another two received only one and two courses of chemotherapy as a result of persistent leucopenia and neutropenic fever respectively. Three of six patients given level 2 therapy completed the scheduled treatment. Another three received only one and two courses of chemotherapy, two refused treatment because of diarrhoea and one died of pneumonia. Radiation therapy was inadequate in these three patients. As the CPT-11 dose intensity in this trial was low, because of the necessity of omitting CPT-11 administration on days 8 and/or 15 as a result of leucopenia or diarrhoea, and the low radiation therapy completion rate, the trial was discontinued at level 2. Five patients at level 1 and three at level 2 showed partial responses, an overall response rate of 67%. Although neither MTD nor dose-limiting toxicity could be identified, chemotherapy with CPT-11 and cisplatin plus concurrent radiation therapy was deemed unacceptable. We are now conducting a phase I/II study of chemotherapy using CPT-11 as a single agent in combination with radiation therapy.