Phase I study of weekly nab-paclitaxel plus carboplatin and concurrent thoracic radiotherapy in elderly patients with unresectable locally advanced non-small cell lung cancer

Few clinical studies have been designed for elderly patients with locally advanced non-small cell lung cancer (NSCLC). We conducted a phase I study to evaluate the tolerability of carboplatin/nab-paclitaxel and concurrent thoracic radiotherapy in elderly patients with locally advanced NSCLC. The eligibility criteria were: unresectable stage III NSCLC, performance status 0 or 1, and age ≥ 75 years. Eligible patients received 6 weeks of weekly carboplatin/nab-paclitaxel and concurrent thoracic radiotherapy with a total dose of 64 Gy in 32 fractions. Carboplatin was fixed to an area under the plasma concentration time curve (AUC) of 2 mg/mL/min, and the recommended dose of nab-paclitaxel was evaluated using a dose-escalation study (30 or 40 mg/m²). Tolerability at the recommended dose was evaluated in an expansion study. Nineteen patients were enrolled at four institutions, all of whom were eligible and assessable. The recommended nab-paclitaxel dose was set at 30 mg/m² because two patients experienced dose-limiting toxicity at 40 mg/m². The treatment completion rate of the 17 patients analyzed at the recommended dose was 100% (80% confidence interval (CI), 83.8–100%). The overall response rate was 76.5%, and the median progression free survival was 13.4 months (95% CI, 4.2–21.4 months). Common grade 3 and 4 toxicities included leukopenia (23.5%), neutropenia (17.6%), anemia (5.9%), and infection (5.9%). One treatment-related death due to pneumonitis was observed six months after the end of the study. In conclusion, carboplatin/nab-paclitaxel and concurrent thoracic radiotherapy show good tolerability and exhibit promising efficacy in elderly patients with locally advanced NSCLC. This trial was registered with the Japan Registry of Clinical Trials on March 11, 2019 (trial no. jRCTs042180077).