Results of an interim analysis of a multinational randomized, double-blind, phase III study in patients (pts) with previously treated metastatic colorectal cancer (mCRC) receiving FOLFOX4 and PTK787/ZK 222584 (PTK/ZK) or placebo (CONFIRM 2)

3508 Background: PTK/ZK is a novel, oral, small molecule, antiangiogenic compound that inhibits tyrosine kinase signaling of all known vascular endothelial growth factor (VEGF) receptors. Methods: 855 pts were randomized to FOLFOX4 plus PTK/ZK (1250 mg, qd), or placebo. Eligibility included histologically or cytologically documented mCRC, pretreatment for metastatic disease with irinotecan/fluoropyrimidine-based chemotherapy, measurable disease by RECIST, PS of 0–2 and adequate organ and bone marrow function. The primary endpoint is overall survival (OS). Secondary endpoints included OS and PFS in high LDH pts (stratifiedbybaseline serum LDH levels > 1.5 × ULN). Results: OS was 12.1 mo in the PTK/ZK arm and 11.8 mo in the placebo arm (HR: 0.94; p=0.511). A pre-planned triangular test suggested a low probability of demonstrating an improvement in OS at the final analysis (4Q 2006). The response rates (CR+PR) were 18.5% in the PTK/ZK arm, 17.5% in the placebo arm. PFS was significantly longer in the PTK/ZK arm (5.5 mo vs. 4.1 mo; HR: 0.83; p=0.026). LDH, usually a poor prognostic factor in mCRC, is predictive of the outcome in the PTK/ZK arm. Pts with high LDH showed a strong improvement in PFS when treated with PTK/ZK (5.6 mo vs. 3.8 mo; HR: 0.63; p [Table: see text]