Final results of the McCAVE trial: A double-blind, randomized phase 2 study of vanucizumab (VAN) plus FOLFOX vs. bevacizumab (BEV) plus FOLFOX in patients (pts) with previously untreated metastatic colorectal carcinoma (mCRC)

3539 Background: VEGF-A and ANG-2 have complementary roles in regulation of tumor angiogenesis. Targeting VEGF-A with BEV in combination chemotherapy (CT) in mCRC has proven to increase PFS and OS. ANG-2 is overexpressed and associated with poor outcome of mCRC pts receiving BEVcontaining treatment. Hence, dual blockade of VEGF-A and ANG-2 by the bispecific mAb VAN with standard CT may improve clinical activity in mCRC. Methods: All pts received mFOLFOX-6 and were randomized 1:1 to also receive intravenous VAN 2000 mg every other week (Q2W) (Arm A) or BEV 5 mg/kg Q2W (Arm B). The primary end point was investigator assessed progression-free survival (PFS). Key eligibility criteria included pts with non-resectable mCRC, no prior therapy for advanced disease, PS 0-1, adequate organ functions, and no history of GI fistula/perforation or intraabdominal abscess within the last 6 months. Results: 192 pts were randomized (Arms A/B, n = 95/97) by 39 sites in 7 countries, between Oct 2014 and May 2016. Median follow-up was 17.6 months (range 2.8 – 20.7). In the ITT population (n = 189; Arms A/B, n = 94/95), median PFS in Arms A and B was 11.3 and 11.0 months (stratified hazard ratio (HR) 1.00 (95%CI 0.64-1.58; p = 0.985)), respectively. Objective response rate was 52.1% vs 57.9%. Relevant prognostic factors incl. RAS/BRAF status and tumor sidedness were balanced between arms and did not significantly influence outcome. Baseline plasma ANG-2 levels were prognostic in both arms but not predictive for response to VAN. The overall incidence of adverse events (AEs) grade ≥ 3 was similar (Arms A/B, 83.9%/82.1%); AEs grade ≥ 3 attributed to the mode of action of VAN/BEV included hypertension (37.6%/18.9%), hemorrhage (2.2%/1.1%), thromboembolic events (venous 6.5%/2.1%; arterial 1.1%/3.2%) and GI perforations incl. GI fistula & abdominal abscess (10.6%/8.4%). Conclusions: The combination of VAN and FOLFOX did not improve PFS and was associated with a marked increase in hypertension compared with BEV plus FOLFOX. Our results strongly suggest that ANG-2 is not a relevant therapeutic target in the setting of first line mCRC. Clinical trial information: NCT02141295.