Safety Report Of A Randomized Phase Ii Trial To Evaluate The Combination Of Cetuximab Plus Accelerated Concomitant Boost Radiotherapy (Rt) Followed Or Not Followed By Cetuximab Monotherapy In Patients (Pts) With Locally Advanced Squamous Cell Carcinoma Of The Oropharynx

6076 Background: The objectives of this prospective, randomized, phase II trial conducted in 18 Spanish hospitals was to evaluate the safety and efficacy of cetuximab maintenance therapy following definitive RT with concomitant cetuximab in pts with locally-advanced oropharyngeal cancer. Methods: Main eligibility criteria: >18 yrs old, Stage III-IVM0 squamous tumors. Group A received concomitant boost RT (69.9 Gy in 28 days) + cetuximab (400 mg/m2 1 wk before RT and 250 mg/m2/wk during RT). Group B received an additional 12 consecutive wks of cetuximab maintenance therapy. Results: Demographics of the 92 enrolled pts (45 [A]; 47 [B]) were (A/B): median age (range), 60(42–75)/61(45–80); males, 80%/92%; Stage IV, 69%/72%. Compliance rates during the concomitant phase were high and similar in both groups (>85% received full dose of RT and cetuximab). In Group B, compliance in the maintenance phase was also high (86% completed >10 wks). Four pts in group B did not receive cetuximab as maintenance therapy (2 consent withdrawals and 2 AEs). Cetuximab was generally well tolerated (most AEs grade 1–2 cutaneous rash, mucositis, and asthenia). The main grade 3–4 AEs were acne-like rash (16%/15% [A/B]), mucositis (47%/64%), radiation dermatitis (31%/19%), and asthenia (2%/6%). Pts on cetuximab maintenance therapy did not have a significant delay in toxicity recovery after combined treatment (table). There were 6 deaths (4 in group, 2 in group B); none was related to study treatment but occurred in the context of disease complications or underlying disease. Conclusions: Cetuximab maintenance therapy is associated with an acceptable safety profile when administered after concomitant cetuximab + RT in locally advanced oropharyngeal carcinoma. Eficcacy results are expected by November 2008. Pts with grade 3/4 AEs (%) EndRT (A/B) Wk 4 (A/B) Wk 8 (A/B) Wk12 (A/B) Acne-like rash 8.9/8.5 6.6/4.3 0/2.1 0/0 Mucositis 40/55 6.7/10.6 0/4.3 0/2.1 Radiation dermatitis 17.8/4.3 15.6/14.9 0/0 0/0 Asthenia 0/4.3 0/2.1 0/0 2.2/0 Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Merck Serono Merck Serono