Pazopanib as Third Line Therapy for Metastatic Renal Cell Carcinoma: Clinical Efficacy and Temporal Analysis of Cytokine Profile

Purpose: Pazopanib has been assessed primarily in cytokine refractory or treatment naive patients with metastatic renal cell carcinoma. Outcomes have been associated with a specific immunological profile. However, pazopanib activity in the third line setting and temporal changes in the immunological profile during therapy are poorly understood.Materials and Methods: Study eligibility was limited to patients with 2 prior lines of therapy, including at least 1 vascular endothelial growth factor directed therapy, as well as ECOG performance status 0 to 2 and clear cell histology. Patients received pazopanib 800 mg daily. A Simon minmax 2-stage design was used with 80% power to determine an encouraging 23% overall response rate (10% type I error). Immunological profiles were assessed monthly on a Luminex® platform using the Human Cytokine 30-Plex Cytokine Immunoassay (Invitrogen™).Results: A total of 28 patients with a median age of 63 years (range 45 to 86) were enrolled in study. Of the patients 12 (43%) ha...