Ziv-Aflibercept (A) Combined To Folfiri As First Line Treatment For Metastatic Colorectal Cancer (Mcrc): Interim Safety And Efficacy Results Of The Phase Ii Pulsar Trial.

737Background: A is approved in combination with FOLFIRI (A-FOLFIRI) for the treatment of mCRC patients (pts) previously treated with oxaliplatin. PULSAR trial (NCT02173990) aims to measure the activity A-FOLFIRI as 1st-line mCRC treatment. Key secondary objectives are safety, as well as circulating biomarkers and dynamic contrast-enhanced ultrasound measurements as PFS prognosticators. We present here interim analysis of safety and activity. Methods: Pts received A (4 mg/kg I.V.) every 2 weeks in combination with FOLFIRI (Irinotecan: 180 mg/m2, leucovorin: 200 mg/m2, Bolus FU: 400 mg/m2, infusional FU: 2400 mg/m2 over 46hrs). The primary endpoint is 10-month [m] PFS (RECIST 1.1). The target sample size is 72 pts for the following assumptions: P0 = 0.40, P1 = 0.55, α = β = 0.1. Results: Among the first 30 recruited mCRC pts with unresectable metastases (mets), 29 received at least 1 cycle of A-FOLFIRI. 30, 23, and 28 pts were evaluable for survival (intent-to-treat), tumor response, and safety, respective...