Exposure-response relationship for ramucirumab from the randomized, double-blind, phase 3 REVEL trial (docetaxel versus docetaxel plus ramucirumab) in second-line treatment of metastatic non-small cell lung cancer.

PURPOSE: Ramucirumab plus docetaxel improved survival in REVEL, a randomized phase 3 trial for patients with Stage IV non-small cell lung cancer after standard platinum-based chemotherapy. This exploratory analysis evaluated the exposure-response relationship of ramucirumab from REVEL. METHODS: Patients received ramucirumab (10 mg/kg) or placebo plus docetaxel (75 mg/m2) every 3 weeks. Pharmacokinetic samples were collected. A population pharmacokinetic analysis predicted ramucirumab minimum concentration after first-dose administration (Cmin,1) and average concentration at steady state (Cave,ss). Predicted Cmin,1 and Cave,ss were used to evaluate the relationship between ramucirumab exposure and efficacy and safety, respectively. Exposure-efficacy was assessed by Kaplan-Meier and Cox regression analyses; exposure-safety was assessed by ordered categorical analyses. RESULTS: Analyses included 376 patients treated with ramucirumab plus docetaxel and 366 patients treated with placebo plus docetaxel (364 for safety population). After adjusting for corresponding prognostic factors, the association between overall survival (OS) and Cmin,1 was statistically significant (p = 0.0110), although progression-free survival (PFS) showed a marginal association (p = 0.0515). At high ramucirumab exposures (Cmin,1), greater improvements (smaller hazard ratios) were seen for OS and PFS when stratified by Cmin,1 exposure quartiles. A statistically significant correlation was observed between ramucirumab Cave,ss and grade ≥ 3 febrile neutropenia and hypertension. CONCLUSIONS: An association was observed between ramucirumab exposure and efficacy. Higher ramucirumab exposure was associated with improved clinical outcomes and increased toxicity in this analysis. Two exposure-response prospective randomized trials are being conducted to address causation (NCT02443883 and NCT02514551), with encouraging preliminary results (Ajani et al. in Ann Oncol 28:abstr 698P, 2017).

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

PURPOSE: To characterize ramucirumab exposure-response relationships for efficacy and safety in patients with metastatic colorectal cancer (mCRC) using data from the RAISE study. METHODS: 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. RESULTS: 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 < 0.0001 for both). This association remained significant after adjusting for baseline factors associated with OS or PFS (p < 0.0001 for both). Median OS was 11.5, 12.9, 16.4, and 16.7, and 12.4 months for ramucirumab C min,ss Q1, Q2, Q3, Q4, and placebo group, respectively. Median PFS was 5.4, 4.6, 6.8, 8.5, and 5.2 months for ramucirumab C min,ss Q1, Q2, Q3, Q4, and placebo group, respectively. The risk of Grade ≥3 neutropenia was associated with an increase in ramucirumab exposure. CONCLUSIONS: 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.