Feasibility and tolerability of the addition of erlotinib to 3D thoracic radiotherapy (RT) in patients (p) with unresectable NSCLC: A prospective randomized phase II study

7563 Background: RT is the standard treatment for p with unresectable or locally advanced NSCLC. Considering the high frequency of tumor recurrence it is necessary to improve the results of the RT by integrating regimens of chemotherapy and/or targeted therapies into current radiotherapy strategies. Erlotinib is an EGFR TKI that has shown activity in recurrent/metastatic NSCLC. This study aims to evaluate the feasibility of the addition of erlotinib to RT in p with unresectable NSCLC. Methods: P with unresectable stage I-IIIA NSCLC not suitable to receive chemotherapy, ECOG ≤ 2, measurable disease by RECIST were enrolled in this open-label, multicenter, prospective, randomized phase II study. P included in arm A received 3D thoracic RT (66 Gy in 33 fractions during 6 weeks). P assigned to arm B were treated with 3D thoracic RT (66 Gy in 33 fractions during 6 weeks) and concomitant erlotinib 150 mg/day po maintained for 6 months. Primary endpoint is the percentage of grade 3–4 toxicities and secondary endpoints are PFS, time to treatment failure, OS and RR. Results: A total of 30 p have been randomized from March 06 to December 07. Data from 23 p have been included in this analysis (10 Arm A, 13 Arm B). Baseline characteristics were similar in both arms. Esophagitis was observed in 4 p (40%) in arm A and 3 p (23%) in arm B, (no grade 3–4). Radiodermitis occurred in 5 p (50%) in arm A (no grade 3–4 observed) and in 1 p (8%) in arm B, being grade 3. Pneumonitis occurred in 2 p (20%) in arm A (10% grade 3) and 1 p (8%) in arm B (no grade 3–4 observed). Main toxicities related to erlotinib were skin rash (61.5%) and diarrhea (23%) being all cases mild to moderate. 15 p were evaluable for tumor response. Response rate in arm A was 55.5% and 83.3% in arm B. Disease progression is documented in 22.2% of p in arm A and 16.7% of p in arm B. Conclusions: Combination of erlotinib and RT seems to be an active treatment for this p population. The addition of erlotinib does not appear to increase in-field toxicities, being a feasible and well tolerated option for p with unresectable stage I-IIIA NSCLC. Data on survival will be presented. No significant financial relationships to disclose.