Comparing GOZILA and COLOMATE: Ongoing Umbrella/Basket Trials Examining Genetic Testing in Gastrointestinal Malignancies.

Circulating tumor DNA (ctDNA)-based next-generation sequencing (NGS) assays have advantages over classic tissue-based analyses because of their low invasiveness and availability of repeated sampling. Because of the low incidence of target gene alterations such as HER2 or BRAF V600E in gastrointestinal cancers, very large screening platforms are needed to develop genome-based clinical trials. For those reasons, ctDNA-based screening studies are being actively conducted; among them are the GOZILA (Guardant Originates in Zipangu Liquid biopsy Arrival) study in Japan and the COLOMATE (COlorectal Cancer Liquid BiOpsy Screening Protocol for Molecularly Assigned ThErapy) study in the United States. Although only patients with metastatic colorectal cancer (mCRC) who had previously received standard chemotherapies are eligible for the COLOMATE study, patients with various types of solid tumors at any line of treatment are eligible for GOZILA. This broad coverage of the eligible population allows a target of 5000 patients. By contrast, effective screening of selected candidate patients for companion trials using rapid turnaround time by ctDNA-based NGS assay is the key for COLOMATE. The companion trials of targeted therapies in mCRC are similar between GOZILA and COLOMATE. Both studies have identified patients eligible for studies by examining ERBB2 (HER2), BRAF V600E, BRAF non-V600E, and FGFR alterations, as well as MET amplification and rechallenge with anti-EGFR antibodies. The existence of various companion trials for common alterations that can be potential therapy targets on the 2 platforms can lead to future international collaboration.