Treatment with cetuximab(Drug information on cetuximab) continued until progression or unacceptable toxicity. Crossover was not allowed. The primary endpoint was overall survival.The majority of patients (about 60%) had well-differentiated or moderately differentiated tumors. Most (about 80%) had received prior radiotherapy, and about 40% had prior chemotherapy (allowed for locally advanced SCCHN if completed 6 months prior to study entry). Following randomization, about two-thirds of patients received cisplatin(Drug information on cisplatin) (based on individual institution choice).
Survival analysis was conducted after 343 events were reached. Median survival was 10.1 months for patients in the cetuximab plus chemotherapy arm vs 7.4 months in the chemotherapy-alone arm (HR 0.797, P = .036). One-year survival was 39% in the experimental arm vs 31% in the control arm.A subgroup analysis did not reveal any predictors of poor response to cetuximab, including prior radiotherapy or current treatment with cisplatin vs carboplatin(Drug information on carboplatin), although the evidence for benefit in the patients receiving cisplatin was somewhat greater than for those receiving carboplatin.
An interim safety analysis on 429 patients (median number of cycles, four) showed a similar incidence of grade 3-4 adverse events (72% in the experimental arm vs 69% in the control arm), with a slightly higher incidence in the cetuximab arm of grade 3-4 vomiting/diarrhea and, as expected, acne-like rash and infusion reactions, Dr. Vermorken reported.
A total of 9% of cetuximab-treated patients vs 6% of controls discontinued therapy because of adverse events. Deaths were mostly a result of tumor progression, not toxic death, Dr. Vermorken said. Data on clinical response and time to tumor progression will be available at a later date.
"The survival benefit is among the longest ever seen in a large clinical trial among these patients," Dr. Vermorken concluded. "With new targeted agents such as cetuximab, we are on the brink of changing the way we treat patients with head and neck cancers."