475 Background: The vascular disrupting agent (VDA) BNC105P shows synergy with everolimus in preclinical models. The DisrupTOR-1 trial included a phase I component exploring this combination and a randomized phase II component comparing everolimus with BNC105P (Arm A) to everolimus monotherapy (Arm B) (Pal et al. ESMO 2014). Methods: Pts with clear cell mRCC and 1-2 prior therapies (including ≥1 VEGF-TKI) were randomized in the phase II study component. In Arm A, patients received a 7 day lead-in dose of everolimus followed by dosing with BNC105P. Patients in Arm A had optional blood collections prior to administration of BNC105P and 3 hours after receiving BNC105P. A fluorescence-based assay was used to characterize a broad panel of analytes at each time point. Biomarkers were assessed in both a static and dynamic fashion. For the former, biomarkers were stratified by median value, and progression-free survival (PFS) was compared in resulting subgroups using the Kaplan-Meier method. For the latter, change in biomarker level before and after BNC105P infusion was stratified by median difference, and PFS was compared in resulting subgroups using the Kaplan-Meier method. Results: 139 pts were randomized with 69 and 67 evaluable pts in Arms A and B, respectively. Dynamic biomarkers were assessed in a total of 44 patients who received everolimus with BNC105P. Increases in matrix metalloproteinase-9 (MMP-9) and stem cell factor (SCF) were associated with improved PFS (p=0.0421 and p=0.0291, respectively). Decreases in sex hormone binding globulin (SHBG) and serum amyloid protein (SAP) were associated with improved PFS (p=0.0184 and p=0.0063). With respect to static biomarkers, elevated baseline ferritin and lower baseline IL-8 were associated with improved PFS (p=0.0291 and p=0.0149, respectively). Conclusions: Several static and dynamic biomarkers in the DisrupTOR-1 trial were associated with PFS. A prospective biomarker-driven study examining everolimus with BNC105P selected by baseline IL-8 and ferritin is in development. Clinical trial information: NCT01034631.