The Phase 1/2 ACCEPT Trial: Concurrent Cetuximab and Intensity Modulated Radiation Therapy with Carbon Ion Boost for Adenoid Cystic Carcinoma of the Head and Neck

Abstract

The adenoid cystic carcinoma (ACC), Erbitux, and Particle Therapy (ACCEPT) phase 1/2 trial (NCT01192087) evaluated a combined-modality approach (concurrent cetuximab and intensity modulated radiation therapy with carbon ion boost) for newly diagnosed nonmetastatic head and neck ACC. Twenty-three patients with ACC were enrolled between June 2012 and June 2017 after initial diagnosis or postoperatively. All received a 400 mg/m2 cetuximab loading dose a week before radiation therapy, followed by weekly 250 mg/m2 doses starting on the first day of radiation therapy. The carbon ion radiation therapy boost was 24 Gy (relative biological effectiveness) in 8 daily fractions, followed by intensity modulated radiation therapy (54 Gy). The primary endpoint was safety and feasibility (defined based on Common Terminology Criteria for Adverse Events grade ≥3 events). Secondary endpoints included local and distant relapse, disease-free survival, and overall survival. Disease was most commonly in the paranasal sinuses (30%), palate (17%), and nasopharynx (17%). Nine (39%) patients underwent surgery (R1: 22%, R2: 78%). Median follow-up was 38.5 months. No patients experienced grade 4 to 5 events. Rates of grade 3 rash and radiation dermatitis were 17% and 22%, respectively. Grade 2 and 3 mucositis and dysgeusia occurred in 43% and 48% and in 9% and 0%, respectively. Grade 2 to 3 dysphagia and xerostomia were present in 43% and 4% and in 26% and 0%, respectively. At last follow-up, 5 (22%) patients experienced in-field relapse and 6 (26%) developed distant metastases. The 3-year disease-free survival was 67%, and median overall survival was 54 months. Outcomes of this trial were satisfactory. Although the trial did not meet the predefined criteria of feasibility owing to the comparatively high rates of grade 3 dermatitis, numbers are comparable to existing data on cetuximab + radiation therapy.