A Phase II study of pazopanib in Asian patients with recurrent/metastatic nasopharyngeal carcinoma.

PURPOSE: Nasopharyngeal carcinoma is endemic in Asia and angiogenesis is important for growth and progression. We hypothesized that pazopanib would have antiangiogenic activity in nasopharyngeal carcinoma. EXPERIMENTAL
DESIGN: A single arm monotherapy study of pazopanib in patients with WHO type II/III nasopharyngeal carcinoma who had metastatic/recurrent disease and failed at least one line of chemotherapy. A Simon's optimal 2-stage design was used. Patients with Eastern Cooperative Oncology Group (ECOG) 0-2 and adequate organ function were treated with pazopanib 800 mg daily on a 21-day cycle. The primary endpoint was clinical benefit rate (CR/PR/SD) achieved after 12 weeks of treatment. Secondary endpoints included toxicity and progression-free survival. Exploratory studies of dynamic-contrast enhanced computed tomography (DCE-CT) paired with pharmacokinetics (PK) of pazopanib was done.
RESULTS: Thirty-three patients were accrued. Patients were ECOG 0-1 with median age of 50 years (range 36-68). There were 2 (6.1%) partial responses, 16 (48.5%) stable disease, 11 (33.3%) progressive disease, 4 (12.1%) were not evaluable for response. The clinical benefit rate was 54.5% (95% CI: 38.0-70.2). Ten patients (30.3%) received more than 6 cycles (4 months) of treatment and 7 (21.2%) had PR/SD that lasted at least 6 months. One patient each died from epistaxis and myocardial infarction. Common grade 3/4 toxicities included fatigue (15.2%), hand-foot syndrome (15.2%), anorexia (9.1%), diarrhea (6.1%), and vomiting (6.1%). Serial DCE-CT scans show significant reductions in tumor blood flow, permeability surface area product, and fractional intravascular blood volume.
CONCLUSION: Pazopanib showed encouraging activity in heavily pretreated nasopharyngeal carcinoma with an acceptable toxicity profile. ©2011 AACR.