A Korean multi-center, real-world, retrospective study of first-line pazopanib in unselected patients with metastatic renal clear-cell carcinoma

Background: The efficacy and/or tolerability of pazopanib in patients with metastatic renal cell carcinoma (mRCC) have been found to differ in Western and Asian populations. This retrospective multicenter study analyzed the results of first-line pazopanib treatment in 93 consecutive patients with mRCC who were treated at the medical oncology departments of three tertiary cancer centers in Seoul, Korea. Methods: The decision to administer pazopanib as first-line therapy was at the discretion of the treating physician in all patients with mRCC. Patients enrolled in clinical trials were excluded to ensure that the results would reflect real-world outcomes representative of daily clinical settings. All patients received 800 mg/day pazopanib. Outcomes included response rate, progression-free survival (PFS), overall survival (OS), and safety. Results: The 93 patients included72 (77 %) male and 21 (23 %) female individuals, of median age 65 years (range, 19-84 years). The median number of metastatic sites per patient was two (range, 1-5), with the lungs being the most frequently involved site. Most patients had favorable (n = 46) or intermediate (n = 36) risk as determined by Memorial Sloan Kettering Cancer Center criteria. Pazopanib was generally welltolerated: the major hematologic adverse effect was grade 1/2 anemia (14 %); and the most frequently observed non-hematologic toxicity was grade 1/2 mucositis (22 %), followed by hair discoloration and hypertension. Of the 93 patients, three (3 %) showed complete response, 52 (56 %) showed partial response, and 21 (23 %) showed stable disease, making the objective response rate 59 % and the disease control rate 82 %. At a median follow-up of 21 months, the estimated median PFS and OS were 12.2 months (95 % confidence interval, 7.1-17.4 months) and 21.9 months (95 % confidence interval, 12.9-30.9 months), respectively. Conclusions: In this retrospective study, first-line therapy with pazopanib demonstrated clinically relevant efficacy and tolerability in unselected real-world Korean patients with mRCC. OS and PFS of these Korean patients were similar to those reported in phase III trials.