Andre Konski, Bapsi Chakravarthy, Melvin Deutsch, Mohan Suntharalingam, M. N. Horiba, David H. Ilson, V.S. Kavadi, Howard Safran, Christopher H. Crane, Lisa A. Kachnic, Adam P. Dicker, Kevin S. Roof, Harish V. Thakrar, David K. Gaffney, Jondavid Pollock, Kathryn Winter, Gregory M.M. Videtic, and Adam Raben
LBA6 Background: RTOG 0436 is a randomized Ph III trial designed to evaluate the benefit of cetuximab added to the concurrent chemoradiation for patients undergoing non-operative management of esophageal carcinoma. Methods: Pts with biopsy-proven squamous cell or adenocarcinoma of the esophagus (T1N1M0; T2-4 AnyN M0; Any T/N M1a) were randomized to weekly concurrent cisplatin (50 mg/m2), paclitaxel (25 mg/m2), and daily radiation 50.4 Gy/1.8 Gy fractions ± weekly cetuximab (400 mg/m2 day 1 then weekly 250 mg/m2). Patients were stratified by histology, tumor size (< 5 cm vs > 5cm), and the status of celiac lymph nodal involvement. Overall survival (OS) was the primary endpoint, with a planned accrual of 420 pts to detect an increase in 2-year OS from 41% to 53%; 80% power and 1-sided 0.025 alpha. An interim analysis of cCR was planned for the first 150 of each histology. Results: The study accrued 344 pts from 2008-2013 and 328 were eligible. Based on interim analyses, the study stopped accruing adeno pts in 5/2012 and SCC pts in 1/2013. Pts were well matched for pretreatment characteristics: 80% with T3/4 disease, 66% N1, and 19% with celiac nodal involvement. Incidence of grade 3/4/5 treatment (tx) related AEs was 45%, 22%, 4% in Arm 1 (cetuximab) and 49%, 17%, 1% in Arm 2 (no cetuximab). A cCR rate of 56% was observed in Arm 1 vs 59% in Arm 2 (p=0.72). No differences were seen in cCR between tx arms for either histology. The 12 and 24 mo OS rates for cCR pts were 79% and 58% vs 53% and 30% for those with residual disease (p