Purpose: Treatment options for patients with previously treated metastatic colorectal cancer (mCRC) are limited, and treatments with differing mechanisms of action are needed. PTK787/ZK 222584 (PTK/ZK) is a novel oral angiogenesis inhibitor with therapeutic potential for the treatment of solid tumors.
Methods: Patients (N = 855) were randomly assigned to treatment with PTK/ZK or placebo once daily in combination with oxaliplatin, fluorouracil, and leucovorin (FOLFOX4). Stratification factors included WHO performance status (PS; 0 v 1 to 2) and lactate dehydrogenase ([LDH] ≤ 1.5× the upper limit of normal [ULN] v > 1.5 × ULN). Treatment was given until disease progression or unacceptable toxicity. The primary end point was overall survival (OS); secondary end points included progression-free survival (PFS), safety, tolerability, and pharmacokinetics of PTK/ZK.
Results: No statistically significant differences were seen between the treatment groups for the overall comparison of OS. With PTK/ZK and placebo, respectively, median OS was 13.1 and 11.9 months (hazard ratio [HR], 1.00; 95% CI, 0.87 to 1.16; P = .957). Median PFS was longer with PTK/ZK than with placebo (5.6 and 4.2 months, respectively; HR, 0.83; 95% CI, 0.71 to 0.96; P = .013). An exploratory, post hoc analysis demonstrated improved PFS in patients with high LDH, regardless of WHO PS (HR, 0.63; 95% CI, 0.48 to 0.83; P < .001).
Conclusion: PTK/ZK in combination with FOLFOX4 did not improve OS of patients with pretreated mCRC but did improve PFS. The effect of PTK/ZK was more pronounced in patients with high LDH at baseline.