Guardant Health is touting the results of a new study showing its Reveal blood test can detect whether chemotherapy is failing months before evidence shows up on regular scans, allowing oncologists to switch treatment sooner.
Guardant’s Reveal is a noninvasive liquid biopsy that tracks cancer by looking for circulating tumor DNA (ctDNA) in a patient’s blood.
The study, published in the Journal of Liquid Biopsy, used a tissue-free, methylation-based ctDNA tumor fraction signal to track changes in cancer over time. It looked at de-identified data from 278 patients who had undergone first- or second-line chemotherapy for various advanced solid tumors, such as colorectal, pancreatic and gastric carcinoma.
To be included, a patient needed to have been given at least two Guardant blood tests between July 2014 and June 2024, with the first given just before starting chemotherapy and the others given while actively receiving treatment.
Billing it as “the first robust clinical validation study of pan-cancer chemotherapy monitoring,” Guardant said the research provides “real-world evidence that changes detected in a blood-based tumor signal correlate strongly with patient outcomes.”
According to the study, if a blood test showed a decrease in the cancer signal after chemotherapy started, the patient generally experienced longer treatment duration and longer survival times. Patients whose blood tests showed a 98% or greater reduction in the cancer signal saw the most significant benefits.
Meanwhile, a rise in tumor signal could identify disease progression up to 18 months ahead of scans, the study found, with a median lead time of 2.3 months, giving oncologists an early warning that a treatment has stopped working.
“Guardant Reveal’s ability to detect molecular changes weeks or months before they show up on scans give doctors more time to adjust care and potentially spare patients from the toxicity of ineffective treatment,” Guardant Health Chief Medical Officer Craig Eagle, M.D., said in a press release.
Besides Reveal, Guardant Health markets several other cancer-detecting blood tests, including its Guardant360 CDx test, which has FDA approval for monitoring breast cancer treatment, and its Shield screening blood test for colorectal cancer.