Subgroup analyses of METEOR, a randomized phase 3 trial of cabozantinib versus everolimus in patients (pts) with advanced renal cell carcinoma (RCC).

Abstract

499 Background: Cabozantinib (C) inhibits tyrosine kinases including VEGFRs, MET, and AXL. The METEOR phase 3 trial (NCT01865747) met its primary endpoint of significant improvement in PFS with C versus everolimus (E) in pts with advanced clear cell RCC and prior exposure to VEGFR TKIs (7.4 mo median PFS [C] vs 3.8 mo [E], HR = 0.58, 95% CI, 0.45 to 0.75; p < 0.001). The improvement in PFS was accompanied by a significant improvement in ORR and a trend for improved OS at an interim analysis. Safety profiles of C and E in this trial were similar to prior experience with each drug in this pt population. This analysis further evaluates PFS and ORR across pt subgroups. Methods: Pts had advanced RCC with clear cell component, measurable disease per RECIST 1.1, KPS ≥ 70%, and were stratified by MSKCC prognostic criteria and number of prior VEGFR TKIs. Pts must have progressed during treatment or within 6 months of the last dose of their most recent VEGFR TKI. 658 pts were randomized 1:1 to receive C (60 mg QD) or E (10 mg QD). The primary endpoint was PFS among the first 375 pts randomized. ORR was a secondary endpoint. Results: In the PFS group, 187 pts were randomized to C and 188 to E. 73% pts had 1 and 27% pts ≥ 2 prior VEGFR TKIs; 43% pts had favorable, 41% intermediate, and 15% poor risk by MSKCC criteria. Across multiple subgroups defined by baseline characteristics, PFS HRs favored C over E. PFS HRs were similar for subgroups defined by prior number of TKIs (HR = 0.56 [1 prior] and 0.67 [ ≥ 2 prior]), and showed higher activity of C over E in pts with fewer MSKCC risk factors (HR = 0.54 [0 factors], 0.56 [1 factor], 0.84 [ ≥ 2 factors]) or with metastases in various organs (HR = 0.47 [lung mets], 0.53 [liver mets], 0.50 [bone mets]). Detailed analysis of the clinical activity of C and E (PFS and ORR) across pt subgroups will be presented, including treatment duration with first VEGFR TKI ( < or ≥ 6mo), receipt of prior anti-PD1/PDL1 agents, time to progression after most recent TKI ( < or ≥ 3mo), and frequency/location of metastases. Conclusions: The METEOR trial met its primary endpoint of improved PFS, and subgroup analyses of the endpoints PFS and ORR generally favored C over E in patients with advanced RCC. Clinical trial information: NCT01865747.