For BRAF V600E-mutated metastatic colorectal cancer (mCRC), the BEACON phase 3 trial showed survival benefit of triplet therapy with cetuximab (anti-EGFR antibody), encorafenib (BRAF inhibitor) and binimetinib (MEK inhibitor) as well as doublet therapy with cetuximab and encorafenib over irinotecan-based chemotherapy plus anti-EGFR antibody. Both regimens are standards of care in Japan, but definite biomarkers for predicting efficacy and selecting treatment remain lacking. The mechanisms underlying resistance to these regimens also warrant urgent exploration to further evolve treatment. This prospective observational/translational study evaluated real-word clinical outcomes with cetuximab and encorafenib with or without binimetinib for BRAF-mutated mCRC patients and investigated biomarkers for response and resistance by collecting blood samples before and after treatment. Clinical Trial Registration: UMIN000045530 (https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000051983).
Keywords: BRAF mutated; binimetinib; biomarker; cetuximab; encorafenib; liquid biopsy; metastatic colorectal cancer.
The BEETS trial is a study that looks at how well two combinations of targeted therapies (cetuximab + encorafenib with or without binimetinib) work and how safe they are for patients with advanced colorectal cancer that has a mutation (change) in the BRAF gene. In this trial, patients participate voluntarily instead of being assigned to one of the two therapy groups. When a patient has BRAF-mutated advanced colorectal cancer, it means that the cancer cells in their body have changes in a gene called BRAF. This gene normally produces a protein called BRAF, which is involved in the growth of cells. However, when there is a mutation in this gene, it can cause the production of an overactive BRAF protein, leading to fast and excessive cell growth and division. For patients with BRAF-mutated advanced colorectal cancer, combinations of targeted therapies have been found to be effective as a second- or third-line treatment, based on the results of a phase 3 clinical trial. The main goal of the BEETS trial is to evaluate how well these treatments work and how safe they are when used in real-world clinical practice. Additionally, the study will use laboratory tests (liquid biopsy) to explore new biomarkers that can help predict how well a treatment will work and assist in selecting the most suitable treatment plans. We hope that the findings of this study will contribute to improving the overall management of this specific type of cancer.