Phase II study of sequential first-line pazopanib (PAZ) followed by everolimus (EVE) in patients (pts) with advanced or metastatic renal cell carcinoma (RCC) (CATChEz Study)

648 Background: EVE following failure of sorafenib or sunitinib for RCC was first approved by the FDA in 2009. CATChEz (NCT01545817) was designed to test the activity of EVE following first-line PAZ in pts with advanced or metastatic RCC who had not received prior systemic therapy. Methods: From 2012 to 2016, pts received first-line PAZ followed by EVE until progressive disease (PD), death, unacceptable toxicity, consent withdrawal, or study termination. Pts with PD during or within 6 months of stopping PAZ were eligible for EVE. Pts off study treatment were evaluated for PD, survival, and updates on anticancer treatment every 8 weeks until death or end of study. The primary efficacy endpoint was median progression-free survival (mPFS) for the second-line EVE treatment period; secondary endpoints included other survival measures, and safety evaluations were for second-line EVE and grade 3/4 toxicities attributable to PAZ and EVE. Results: Of 74 pts who started first-line PAZ, 38 received ≥1 dose of second-line EVE. The primary endpoint of mPFS from the start of second-line EVE and the secondary endpoint of mPFS with first-line PAZ (Table) were consistent with previous reports; no unexpected adverse events (AEs) were reported. All pts had ≥1 treatment-emergent AE, 83.8% had grade ≥3 AEs, and 71.6% had serious AEs. Of 34 total deaths, 29 were due to PD and 5 were due to AEs (2 related to EVE [lower respiratory tract infection; pulmonary sepsis]; 3 unrelated to study treatment). Conclusions: Efficacy and safety outcomes were consistent with published phase III data. The CATChEz study supports sequential first-line use of PAZ followed by EVE for the treatment of pts with advanced or metastatic RCC. Clinical trial information: NCT01545817. [Table: see text]