The study was an international, open-label, controlled phase 2 trial that randomly assigned patients with locally advanced head and neck squamous cell carcinoma.
The patients were from 22 cancer centers from eight countries. The study randomly assigned (2:3) patients with stage 3, 4a, or 4b disease with previously untreated disease who were age 18 or older and having an Easter Cooperative Oncology Group performance status of 0 to 1 to open-label chemoradiotherapy (two cycles of cisplatin 100 mg/m2 during radiotherapy) or radiotherapy plus panitumumab (three cycles of panitumumab 9 mg/kg every 3 weeks administered with radiotherapy).
All patients were given 70 to 72 Gy to gross tumor and 54 Gy to areas of subclinical disease. Researchers identified the primary endpoint as local-regional control at 2 years. One hundred and fifty-two patients were enrolled and 151 received treatment—61 patients were enrolled in the chemoradiotherapy arm and 90 patients were in the radiotherapy ply panitumumab arm.
In the chemoradiotherapy arm, 61% of patients experienced local-regional control at 2 years (95% CI 47,72). In the radiotherapy plus panitumumab arm 51% of patients experienced local-regional control at 2 years (95% CI 40,62). Grade 3 to 4 adverse events were experienced, the most frequent being mucosal inflammation, dysphagia, and radiation skin injury.
Twenty five (40%) patients in the chemoradiotherapy arm and 30 (34%) patients in the chemoradiotherapy arm reported serious adverse events. The researchers concluded that panitumumab cannot replace cisplatin in combination with radiotherapy for patients with stage 3 to 4b head and neck squamous cell carcinoma.
The researchers aimed to compare panitumumab, a fully human monoclonal antibody against EGFR, plus radiotherapy with chemoradiotherapy in patients with unresected, locally advanced squamous-cell carcinoma of the head and neck.