7641 Background: Erlotinib is the first EGFR tyrosine kinase inhibitor which demonstrated the survival benefit to NSCLC patients in randomized trial. An expanded access program (EAP) was conducted to evaluate the efficacy and safety profiles of erlotinib in Taiwanese patients with NSCLC. Methods: Patients with proven stage IIIB/IV NSCLC and received at least first line standard chemotherapy or radiation therapy were enrolled in this study. No more than 2 prior chemotherapy regimens are permitted. All patients were given oral erlotinib, 150 mg/day till disease progression. Patients were monitored monthly and tumor assessments were evaluated every 2 months according to RECIST criteria. Results: From Apr. 2005 to Mar. 2006, 300 patients were entered from 15 medical centers in Taiwan. This interim study evaluated the first 297 patients (data cut-off date of November 8, 2006). Of them, 53% pts were male, 80% pts were with ECOG PS 0 or 1, 68% pts had adenocarcinoma, 62% pts receiving erlotinib as 2nd-line treatment, and 55% patients were non- smoker. The best response rate was 27.8% PR and 47.1% SD in 263 evaluable patients according to RECIST (disease control rate= 74.9%). Non-smoker (p=0.048 and 0.002), adenocarcinoma (p=0.001 and <0.001), female (p=0.0005 and <0.0001), and skin rash (Gr 3–4, p=0.0095 and 0.0019) were significantly correlate with best response and disease control to the treatment. Skin rash was a common adverse event (any grade: 83%, Gr 3–4: 15%). Erlotinib-related SAEs were seen in 4% patients and 3% patients discontinued treatment due to treatment-related SAEs. 24% of patients needed dose reductions, mainly due to skin rash. The median time to progression and median overall survival will be matured at the time of ASCO annual meeting. Conclusions: This is the largest multicenter prospective clinical study of NSCLC in Taiwan. This interim results demonstrating the superb response rates, time-to-progression and overall survival of erlotinib in a large population of Taiwanese or Chinese in previous chemotherapy or radiotherapy treated NSCLC patients. No significant financial relationships to disclose.