Cetuximab/radiotherapy (CET+RT) versus concomitant chemoradiotherapy (cCHT+RT) with or without induction docetaxel/cisplatin/5-fluorouracil (TPF) in locally advanced head and neck squamous cell carcinoma (LASCCHN): Preliminary results on toxicity of a randomized, 2x2 factorial, phase II-III study (NCT01086826)

5513 Background: The standard treatment options for LASCCHN are cCHT+RT or CET+RT. Strategies to improve the efficacy with the integration of induction chemotherapy are being investigated. Primary endpoints of this study were to compare: 1) the overall survival (OS) of induction vs. no induction arms; 2) the Grade(G)3-4 in-field toxicity of cCHT+RT vs. CET+RT. Methods: Patients (pts) with unresectable LASCCHN, stage III-IV, ECOG PS 0–1 were randomized to a 2x2 factorial design: Arm A1: cCHT+RT (2 cycles of ciplatin/5fluorouracil); Arm A2: CET+RTX; Arm B1: 3 cycles of TPF followed by the same cCHT+RT; Arm B2: 3 cycles of TPF followed by CET+RT. A total of 204 deaths over 420 pts ( including the 101 randomized in the phase II part of the study comparing cCHT+RT with or w/o induction TPF) were required to detect a HR of death of 0.675 (A1+A2 vs. B1+B2; 2-sided a=0.05; b=0.20) and a 10% difference in G3-4 in-field mucosal toxicity (A1+B1 vs. A2+B2). Results: By February 2012, 387 pts over 413 pts were evaluable for toxicity. 82% of pts were male; median age was 60y; PS: 0=77.8% and 1=22.2%. Disease stage was III (31%) or IV (69%). Sites of disease were oral cavity (21.7%), oropharynx (54.8%), hypopharynx (23.5%). At a median follow-up of 21 months, 126 deaths occurred. Data on G3-4 in-field toxicity (primary endpoint) and compliance to cCHT+RT vs CET+RT are shown in the table. Conclusions: No advantage for CET+RT over cCHT+RT was observed regarding G3-4 in-field toxicities and feasibility. Pts are still being followed-up to assess OS. [Table: see text]