Dr. Venook on the Unmet Need Addressed by The GALAXY Trial Examining ctDNA in CRC

Alan P. Venook, MD, The Madden Family Distinguished Professor of Medical Oncology and Translational Research at the University of California, San Francisco Helen Diller Family Comprehensive Cancer Center, discusses the unmet need addressed by the GALAXY trial (UMIN000039205), part of the CIRCULATE-Japan project, which is examining circulating tumor DNA (ctDNA) in patients with resectable colorectal cancer (CRC).

It is known that many patients with resectable CRC are overtreated with chemotherapy, according to Venook. As such, the GALAXY study is examining the use of a personalized, tumor-informed ctDNA assay, Signatera, to assess which patients will not benefit from additional treatment with chemotherapy, Venook says. These would be patients who are ctDNA negative at 6 weeks to 12 weeks after surgery, Venook notes.

The assumption is that if a patient has no evidence of ctDNA 6 weeks after surgery, and all characteristics of their disease are accounted for, then additional treatment with chemotherapy is not needed, Venook explains. However, this assumption needs to be validated with further data and patient follow-up, Venook adds. Overall, the unmet need addressed by the study is determining which patients do not require further treatment with chemotherapy, Venook concludes.