(ChemotherapyAdvisor) – A short course of treatment with erlotinib at a dose doubled for smokers is active in previously untreated patients with squamous cell carcinoma (SCC) of the head and neck, according to results of a pilot trial presented at the Multidisciplinary Head and Neck Cancer Symposium.
The primary objective of the study was to identify tissue biomarkers predictive of response to erlotinib and to identify correlation between changes in EGFR inhibition and downstream pathways activation, Mercedes Porosnicu, MD, of Wake Forest Baptist Medical Center, Winston-Salem, NC, and colleagues, noted in describing the first-of-its-kind study in patients with head and neck cancer.
“Strategies for early detection of cellular response to EGFR inhibitors are critical to personalizing therapy for SCC of the head and neck,” the investigators noted. Patients with a window of at least 15 days between time of initial biopsy and surgery received erlotinib 150mg/day (nonsmokers) or 300mg/day (active smokers). Smokers have been found to metabolize erlotinib at twice the rate of nonsmokers. An 18[F]-FDG PET scan and neck CT was performed prior to treatment initiation, after 4 to 6 days of treatment, and following administration of erlotinib.
A total of 12 patients have been treated to date; 9 patients received erlotinib 300mg. No grade 3 or 4 toxicities have been observed; the 4 female patients treated with erlotinib adjusted for smoking status had an “excellent response,” Dr. Porosnicu said.
Of 10 evaluable patients, 7 had a partial response (PR) and 3, stable disease (SD). Early 18[F]-FDG PET scans showed a decrease in SUV max to 98.75% +/- 22% in patients with SD and to 48.06% +/- 26% in those with PR, defined as at least 20% reduction in maximum diameter.
“Early changes in the 18[F]-FDG PET scan uptake should be further investigated as a marker predictive of response to EGFR inhibition,” Dr. Porosnicu said in a press conference. The study will continue to enroll patients.
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.