High efficacy of erlotinib in Taiwanese NSCLC patients in an expanded access program study previously treated with chemotherapy

Purpose: Erlotinib is the first epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) which has demonstrated a survival benefit in non-small-cell lung cancer (NSCLC) patients. An open label phase II study was conducted in Taiwanese patients with NSCLC to evaluate its efficacy. Methods: Patients with proven stage IIIB/IV NSCLC who had received at least one line of standard chemotherapy or radiotherapy were enrolled into this study. All patients were given oral erlotinib, 150 mg/day till disease progression. Results: From May 2005 to July 2006, 300 patients were entered from 14 hospitals in Taiwan. This analysis was based on 299 patients who received at least one dose of erlotinib. The best response rates were a 29% partial response and 44% stable disease in 273 patients who had response data available. Non-smoking (p = 0.033), adenocarcinoma/BAC (p = 0.0027), female (p = 0.0013), aged less than 65 years (p = 0.0115), stage IV (p = 0.0492), patients with skin rash (p = 0.0216), and a higher grade of skin rash (p = 0.003) were significantly correlated with response to treatment. Skin rash was a common adverse event (any grade: 84%, Gr 3-4: 16%). The median time to disease progression was 5.6 months. Cox regression model for progression free survival showed patients most at risk of early progression were males of low performance status having squamous cell carcinoma. Conclusions: This was the largest multicenter prospective clinical study of NSCLC in Taiwan. The results demonstrated the excellent response rates, time-to-progression and overall survival of erlotinib in a large population of Taiwanese NSCLC patients who had been previously treated with chemotherapy or radiotherapy.