A phase II study of patients with metastatic or locoregionally recurrent nasopharyngeal carcinoma and evaluation of plasma Epstein–Barr virus DNA as a biomarker of efficacy

Abstract

The epidermal growth factor receptor (EGFR) is commonly overexpressed in nasopharyngeal carcinoma (NPC) and gefitinib inhibits NPC growth in vitro. Patients who progressed after prior platinum-based chemotherapy for recurrent NPC were given gefitinib orally at 500 mg/day at a 28-day cycle. Plasma Epstein-Barr virus (pEBV) DNA levels were obtained at specific intervals. Sixteen patients enrolled and 15 were evaluable for response. The median age was 49 years (range 34-64 years), and most patients were males with metastatic NPC. No objective response was seen and three patients had stable disease (SD) for 2.8 to 8.5 months. Radiological progression of disease coincided with rising levels of pEBV DNA in most patients, while the level of a patient with the longest duration of SD fell to an undetectable level at study completion. The mean time to progression and overall survival was 2.7 (standard error, SE +/- 0.5 months) and 12 months (SE +/- 1.7 months), respectively. No unexpected drug-related toxicities were seen. The study was prematurely terminated because there was insufficient activity to warrant progression to the second stage of accrual. This study found limited activity of gefitinib in recurrent NPC. Further evaluation of pEBV DNA as a biomarker of response in clinical trials of target-based agents is warranted.