Ramucirumab (Ram) Exposure-Response (Er) Relationship In Range: A Randomized Phase Iii Trial Of Ram Plus Docetaxel (Doc) Versus Placebo (P) Plus Doc In Advanced Platinum-Refractory Urothelial Carcinoma (Uc) Patients (Pts).

353Background: Recent RANGE results showed significant improvement in PFS, a non-significant positive trend in OS, increased ORR and acceptable safety with RAM+DOC vs P+DOC in UC pts (Petrylak et al. Lancet 2017; Petrylak et al. ESMO 2018, abstr 865PD). RAM ER-OS relationships in RANGE are reported here. Methods: Pts received RAM (10 mg/kg) + DOC or P + DOC (Day 1 of a 21 day cycle) until discontinuation criteria were met. Population pharmacokinetic analysis predicted RAM minimum concentrations after first dose (RAM Cmin, 1). Multivariate Cox regression u0026 matched case control (MCC) analyses using exposure treated as a continuous covariate, or grouped as quartiles, evaluated the ER-OS relationship. Results: Several poor prognostic factors, including Bellmunt risk factors, appeared to be more frequent in the lower exposure quartiles, suggesting a possible disease-PK interaction. Increasing RAM exposure as a continuous covariate in an ER population of n=246 pts significantly (p=0.01) associated with improvem...