(ChemotherapyAdvisor) – In patients with recurrent or metastatic squamous cell carcinoma of the head and neck (HNSCC) refractory to platinum-based therapy, subsequent treatment with the oral ErbB-family blocker afatinib was comparable to cetuximab, results of a phase II study reported during the Multidisciplinary Head and Neck Symposium have found.
The open-label, phase II trial randomized 124 patients (median age 58.0 years, 87.1% male) to afatinib 50mg/day, or weekly cetuximab 400mg/m2 loading dose followed by 250mg/m2/week until disease progression or treatment-related adverse events (AEs)(stage 1), at which point they could opt to cross over treatment arms (stage 2), noted Tanguy Seiwert, MD, of the University of Chicago Medical Center, Chicago, IL, and colleagues.
Following stage 1, mean tumor shrinkage, the primary end point, was comparable for afatinib and cetuximab, -16.6% vs. -10.1% by independent central review (P=0.30). Objective response rate was 8.1% for afatinib and 9.7% for cetuximab (P =0.78) and median progression-free survival was 13 weeks and 15 weeks (P =0.99). In stage 1, most common treatment-related AEs were diarrhea, 78.7% for afatinib vs 20.2% for cetuximab, and rash/acne, 78.7% vs. 76.6%, respectively.
For Stage 2, in which 68 patients crossed over arms (32 from afatinib and 36 from cetuximab), disease control rate was 33.3% (afatinib as second treatment) vs. 18.8 % (cetuximab second); duration of disease control was 17.3 weeks vs. 16.6 weeks. In the afatinib and cetuximab arms, 29.5% and 3.3% of patients had AEs leading to dose reduction, and 37.7% and 16.7% leading to discontinuation.
The investigators concluded that in stage 2, disease control rate was “particularly notable for afatinib,” with both agents showing safety profiles characteristic of EGFR/HER2 inhibitors.
The Multidisciplinary Head and Neck Cancer Symposium is sponsored by the American Head and Neck Society, the American Society of Clinical Oncology, the American Society for Radiation Oncology, and the Society of Nuclear Medicine.