By Kathleen Berger, Executive Producer for Science and Technology

ChromoSeq is a new test for two blood cancers developed by a team at Washington University School of Medicine in St. Louis. The ChromoSeq test advances precision medicine at the Siteman Cancer Center for treating blood cancers. It identifies the full suite of genetic changes in a patient’s cancer cells, providing crucial information that physicians can use to determine the optimal treatment strategy for individual patients. ChromoSeq is intended for the comprehensive clinical genomic evaluation of known or suspected hematologic neoplasms, including acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS).

“It’s a single test that gives you all the information you need. We can turn it around in as little as three days. It’s really the first comprehensive, single assay for risk stratification and diagnosis in myeloid neoplasms,” said Eric Duncavage, MD, a professor of pathology & immunology and director of the Division of Genomic and Molecular Pathology at Washington University School of Medicine in St. Louis.

The testing for blood cancers is performed on the Washington University Medical Campus, in the McDonnell Genome Institute, where the scientists were the first in the world to demonstrate whole-genome sequencing for identifying genetic errors responsible for the development and progression of cancer.

“It is a blood test, but what it actually tests are cells in the blood, including potentially rare malignant cells,” said Richard Cote, MD, the Edward Mallinckrodt Professor and head of the Department of Pathology & Immunology, which runs the pathology service in collaboration with the clinical sequencing laboratory at WashU Medicine’s McDonnell Genome Institute.

ChromoSeq is now the first whole-genome sequencing test for cancer to be approved for reimbursement by the Centers for Medicare & Medicaid Services (CMS).

“In about 270 different patient samples, we demonstrated the analytic performance and accuracy of whole-genome sequencing compared to conventional testing. Additionally, about 20% of patients had new findings that were validated and not detected by conventional methods,” said Duncavage. “This highlights the added value of ChromoSeq in identifying genetic alterations that conventional testing might miss.”

Washington University oncologists have been using the test successfully since 2021. With Medicare approval for the test, physicians nationwide caring for Medicare patients with blood cancers will be able to order it through Washington University Pathology Services, with Medicare covering the cost.

“This approval reflects the power and clinical validity of ChromoSeq in assessing the full range of genetic mutations responsible for some of the most deadly blood cancers, which can help guide treatment decisions for individual patients,” said Cote. “Private insurance companies often follow Medicare’s lead in coverage decisions, so we expect that there will be demand for this test across the country. This approval stands as a testament to the vision of WashU physician-scientists Eric Duncavage, Dave Spencer, Molly Schroeder, and their team, who spent years developing and validating this test.”

Meanwhile, more trials are underway.

“We’re seeking to understand how the ChromoSeq assay and the information it provides influence patient management and physicians’ approaches to treatment,” said Duncavage.

The researchers are also experiencing success with another test, called MyeloSeq.

“It is also for blood-based cancers,” said Cote. “In this case, it’s for myeloid leukemias, which is why it’s called MyeloSeq.”

MyeloSeq is currently used for patients at Siteman Cancer Center after treatment, following a ChromoSeq diagnosis.

“We’re using that assay now for most of our MDS and AML patients post-therapy to monitor their condition,” said Duncavage. “We want to know if the treatment was effective. MyeloSeq is very sensitive; by focusing on 50 specific genes, we can achieve a deep analysis.”