Biomarker signatures correlate with clinical outcome in refractory metastatic colorectal cancer patients receiving bevacizumab and everolimus.

A novel combination of bevacizumab and everolimus was evaluated in refractory colorectal cancer patients in a phase II trial. In this retrospective analysis, plasma samples from 49 patients were tested for over 40 biomarkers at baseline and after one or two cycles of drug administration. Analyte levels at baseline and change on-treatment were correlated with progression-free survival (PFS) and overall survival (OS) using univariate Cox proportional hazard modeling. Multivariable analyses were conducted using Cox modeling. Significant changes in multiple markers were observed following bevacizumab and everolimus treatment. Baseline levels of six markers significantly correlated with PFS and OS, including CRP, Gro-α, IGFBP-1, TF, ICAM-1, and TSP-2 (P < 0.05). At C2D1, changes of IGFBP-3, TGFß-R3, and IGFBP-2 correlated with PFS and OS. Prognostic models were developed for OS and PFS (P = 0.0002 and 0.004, respectively). The baseline model for OS consisted of CRP, Gro-α, and TF, while the on-treatment model at C2D1 included IGFBP-2, IGFBP-3, and TGFß-R3. These data demonstrated that multiple biomarkers were significantly modulated in response to bevacizumab and everolimus. Several markers correlated with both PFS and OS. Interestingly, these markers are known to be associated with inflammation and IGF signaling, key modulators of mTOR biology.

Correlation of angiogenic biomarker signatures with clinical outcomes in metastatic colorectal cancer patients receiving capecitabine, oxaliplatin, and bevacizumab.

A novel combination of capecitabine, oxaliplatin, and bevacizumab was evaluated in colorectal cancer patients enrolled in a phase II clinical trial. In this retrospective analysis, plasma samples from patients receiving capecitabine, oxaliplatin, and bevacizumab were analyzed to investigate biomarkers of clinical benefit. Forty-one protein biomarkers were tested in 38 patients at baseline and after two cycles of drug administration. Correlations among analytes were evaluated by Spearman analysis. Analyte levels at baseline and changes on-treatment were correlated with progression-free survival (PFS) and overall survival (OS) by univariate analysis. Multivariate analyses were determined using the Cox proportional hazard model. Time to event analyses were evaluated by Kaplan-Meier analysis and compared by log-rank test. Baseline levels of vWF and Ang-2 significantly correlated with PFS, while levels of VCAM-1, vWF, TSP-2, IL-8, MMP-2, and Ang-2 correlated with OS (P < 0.05). The fold change of IGF-1 levels from baseline to the end of cycle 2 was correlated with PFS, while fold changes of Ang-2, TSP-2, and TGF-ß2 correlated with OS. A baseline signature of Ang-2, IGFBP-3, IL-6, and VCAM-1 identified a low-risk and high-risk group of patients (OS: 33.9 months vs. 18.1 months, respectively, P = 0.016). For treatment-related changes, a signature consisting of Ang-2, E-Cadherin, IL-6, MCP-1, OPN, and TGF-ß1 was able to stratify patients into high- and low-risk groups (PFS: 7.7 months vs. 15.5 months, P = 0.004). Multiplex analysis of patient plasma in this trial identified several baseline- and treatment-related biomarkers associated with clinical outcome. These findings merit further exploration in larger, controlled clinical trials.