US-based oncology company Guardant Health and NRG Oncology have commenced a randomised trial to investigate circulating tumour DNA-guided adjuvant therapy in stage II colon cancer.

Guardant Health states LUNAR-1 liquid biopsy assay will be used to recognise the disease, supporting its validation as a diagnostic biomarker.

Under the NRG-GI005 COBRA trial, 1,408 patients suffering from stage II colon cancer will be registered for active surveillance.

As a part of the study, patients will be randomly selected to either receive ctDNA-directed therapy or standard of care active surveillance.

The main objective of the study is to assess recurrence-free survival in patients ctDNA-positive post-operatively and treated with chemotherapy in comparison to present standard-of-care active surveillance.

MD Anderson Cancer Center principal study investigator and assistant professor Van Morris said: “Today we lack tools to predict which patients with stage II colon cancer have been successfully treated by surgery alone and which need further treatment.

“If successful, this study will validate the clinical utility of MRD as a biomarker to identify those patients who will benefit from adjuvant chemotherapy.”

LUNAR-1 assay has been built to overcome various challenges that have invalidated earlier approaches for MRD detection in early-stage cancers, including protein-based tests and biological noise.

Guardant Health state that the assay, with a single blood draw, can simultaneously detect tumour-specific genomic alterations and epigenomic signatures with high clinical sensitivity and specificity.

Guardant created LUNAR-1 assay based on its experience of processing over 100,000 liquid biopsies from patients with advanced cancer through Guardant360.

Data has revealed that the assay can identify MRD in early-stage colorectal cancer patients who may take advantage of adjuvant therapy after undergoing a curative-intent intervention.

Guardant Health president AmirAli Talasaz said: “Because five-year survival rates for stage II colon cancer are relatively high, most of these patients are not offered adjuvant chemotherapy after surgery.

“We are eager to demonstrate the clinical utility of our LUNAR-1 blood test to help identify the subset of patients who may benefit from chemotherapy based on their MRD status post-surgery.”