New Data Demonstrate that the Utilization of TissueCypher® Barrett’s Esophagus Test Results Can Significantly Improve the Management of Low-Grade Dysplasia in Patients with Barrett’s Esophagus over the Standard of Care Alone

Data presented at the 2022 American College of Gastroenterology (ACG 2022) Annual Scientific Meeting

FRIENDSWOOD, Texas--(BUSINESS WIRE)-- Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, today announced new data showing that the use of TissueCypher® Barrett’s Esophagus Test results can significantly improve management decisions for Barrett’s esophagus (BE) patients with low-grade dysplasia (LGD) to improve health outcomes. TissueCypher is Castle’s precision medicine test designed to predict future development of high-grade dysplasia (HGD) and/or esophageal adenocarcinoma (EAC) within five years for patients diagnosed with BE.

Overall, the study results suggest that TissueCypher may be used to standardize the management of BE patients with LGD to improve health outcomes, by helping ensure that patients at a high risk of progression receive earlier interventions and by potentially reducing unnecessary use of endoscopic eradication therapy (EET) and endoscopies for lower risk patients.

“A diagnosis of low-grade dysplasia in Barrett’s esophagus warrants expert pathology review, as these patients may have a significant risk of developing esophageal cancer. However, expert pathology review lacks standard criteria, is highly variable and is fraught with logistical challenges,” said Lucas C. Duits, M.D., Ph.D., Department of Gastroenterology and Hepatology at University Medical Center in Amsterdam, The Netherlands. “The use of TissueCypher test results can reduce inconsistencies in management decisions for Barrett’s esophagus patients with low-grade dysplasia. We believe there are potential implications to this finding, including a reduction in the incidence and mortality of esophageal cancer and a reduction in the use of unnecessary clinical treatments, when appropriate.”

The study results were shared in a podium presentation at the 2022 American College of Gastroenterology (ACG2022) Annual Scientific Meeting, being held Oct. 21-26 in Charlotte, North Carolina. The presentation was titled “An Objective Spatialomics Test Standardizes Management Decisions with Potential to Improve Outcomes for Barrett’s Esophagus Patients,” and was given by Lucas C. Duits, M.D., Ph.D.

The study involved a cohort of 154 real patients with known outcomes who were followed prospectively as part of the SURF trial. Twenty-four of these patients progressed to HGD/EAC within five years. Each patient’s baseline specimens were independently reviewed by 30 pathologists from five countries and also tested with TissueCypher in a blinded manner. Management decision simulations were performed, where each patient's baseline specimens were first evaluated by a generalist pathologist, and then referred to an expert pathologist from the same country for any diagnoses of LGD. In one arm of the study, management for the patients was determined by the current standard of care, which includes pathology review of tissue samples and management according to current guidelines. In the other arm, patients were managed by the current standard of care with additional guidance from TissueCypher test results. The percentage of patients receiving appropriate management per their known outcome was compared between the two study arms, with appropriate management defined as:

• Three- to five-year surveillance for patients who did not progress to HGD/EAC during surveillance; and
• Either surveillance in less than one year or EET for patients who did progress to HGD/EAC during surveillance.

The study results showed the following:

• Using TissueCypher test results to guide patient management decisions significantly increased the likelihood of BE patients with LGD receiving appropriate management per their known outcome (p=0.0007). 58.4% of patients had a 100% chance of receiving appropriate management when TissueCypher test results were used to guide decisions despite different pathologists reviewing their baseline specimens, compared to 9.1% of patients who were managed according to the standard of care pathology review alone.
• Use of TissueCypher test results improved the consistency of management decisions for BE patients with LGD by reducing the impact of variable pathology review (p