The effect of continuing therapy for more than one course and CRP level on PFS and OS in the general practice of sunitinib therapy in Japanese patients with metastatic renal cancer.

Abstract

e15069 Background: Sunitinib is a multikinase inhibitor used as first- and second-line treatment of metastatic renal cell carcinoma (mRCC). However, there are few reports on the efficacy and adverse events (AE) profile of sunitinib in general practice with Japanese patients. We examined clinical outcomes of sunitinib therapy in a multi-institutional study. Methods: A study population of 98 mRCC patients was eligible for this investigation. Clinical outcomes were evaluated according to clinical features and duration of therapy. Results: he most frequent grade 3/4 laboratory AE were decreased platelet (30.6%) and white blood cell (20.4%) counts. Treatment was discontinued in 20 patients (32.8%) initially receiving a 50-mg/day dose within only one course, and only 2 patients (3.3%) who were initially medicated with 50 mg/day could continue this oral dose. Median PFS time was 2.3 months in patients treated for only one course and 10.8 months in patients treated for more than one course (P < 0.0001). Multivariate analysis showed that duration of treatment, regardless of initial sunitinib dose (50 mg/day or <50 mg/day) was significantly associated with both PFS (HR: 0.120, 95% CI: 0.049-0.294, P < 0.001) and OS (HR: 0.196, 95% CI: 0.082-0.472, P < 0.001). Moreover, C-reactive protein level was significantly associated with PFS and OS times. Conclusions: Sunitinib therapy of 50 mg/day might be an overdose in Japanese patients. Continuing therapy for more than one course and CRP level were very important in the prolongation of PFS and OS times.