Guardant Health, Inc. is partnering with The Royal Marsden NHS Foundation Trust on Part C of its “Tracking mutations in cell free DNA to predict Relapse in eArly Colorectal Cancer” (TRACC) study, which will evaluate the use of circulating tumor DNA (ctDNA) to guide chemotherapy treatment decisions after curative-intent surgery in patients with early-stage colorectal cancer (CRC). The trial is intended to determine whether patients can be spared unnecessary chemotherapy and the associated side effects if they test negative for ctDNA using the Guardant Reveal™ blood test following surgery. Currently, many patients with high-risk stage II and stage III CRC are routinely offered chemotherapy after surgery to help reduce the risk of relapse from microscopic minimal residual disease (MRD).

However, approximately 50-80% of these patients are cured with surgery alone, and many may be over-treated because doctors have not been able to clearly advise patients on whether they are likely to benefit from the treatment. Chemotherapy can cause debilitating and sometimes life-long side-effects, such as damage to the nerves in the hands and feet, life-threatening infections and blood clots. The study will use the Guardant Reveal blood test to detect MRD by measuring the DNA shed from tumor cells into the bloodstream.

Global studies have shown that a negative ctDNA result after surgery is associated with a significantly lower likelihood of the cancer returning. The TRACC Part C trial aims to evaluate the use of ctDNA results from the Guardant Reveal test to guide chemotherapy treatment decisions in a multi-center, prospective, randomized study over the next four years.