Findings for Pembrolizumab Plus mFOLFOX6 in Advanced CRC

Matthew Farren, PhD, post-doctoral fellow, Winship Cancer Institute, Emory University, discusses findings from a multicenter, single-arm phase II clinical trial evaluating the combination of pembrolizumab (Keytruda) and modified leucovorin/5-fluorouracil/oxaliplatin (mFOLFOX6) in patients with advanced colorectal cancer (CRC).

Results showed that there were 8 clinical responses to the combination, 7 of which were partial and 1 of which was complete by RECIST criteria. There were 16 partial responses by immune-related response criteria. The progression-free survival (PFS) in these patients was approximately 1 year. Overall survival (OS) had yet to be reported. At the time of data cutoff at about 17.5 months, 76% of patients were still alive, says Farren.

Biomarkers of response were also examined. T-cell checkpoint molecules were identified and showed that CD4 and CD8 T cell expression was negatively associated with clinical response, he adds. Patients who had higher levels of LAG-3 on their CD4 and CD8 T cells at baseline were less likely to have a partial or complete response, Farren explains. Additionally, patients who expressed cytokines at higher than median levels were less likely to experience a clinical response.