Exposure-response relationship of ramucirumab in patients with advanced second-line colorectal cancer: exploratory analysis of the RAISE trial

To characterize ramucirumab exposure-response relationships for efficacy and safety in patients with metastatic colorectal cancer (mCRC) using data from the RAISE study. Sparse pharmacokinetic samples were collected;a population pharmacokinetic analysis was conducted. Univariate and multivariate Cox proportional hazards models analyzed the relationship between predicted ramucirumab minimum trough concentration at steady state (C (min,ss)) and survival. Kaplan-Meier analysis was used to evaluate survival from patients in the ramucirumab plus folinic acid, 5-fluorouracil, and irinotecan (FOLFIRI) treatment arm stratified by C (min,ss) quartiles (Q). An ordered categorical model analyzed the relationship between C (min,ss) and safety outcomes. Pharmacokinetic samples from 906 patients were included in exposure-efficacy analyses;samples from 905 patients were included in exposure-safety analyses. A significant association was identified between C (min,ss) and overall survival (OS) and progression-free survival (PFS) (p 3 neutropenia was associated with an increase in ramucirumab exposure. Exploratory exposure-response analyses suggested a positive relationship between efficacy and ramucirumab exposure with manageable toxicities in patients from the RAISE study with mCRC over the ranges of exposures achieved by a dose of 8 mg/kg every 2 weeks in combination with FOLFIRI