Harbinger Health presents clinical data at ASCO supporting RESOLVE(TM) as a new blood-based category for evaluation of suspected cancer. May 29, 2026 Presentation highlights test performance in individuals presenting with signs, symptoms, or findings suggestive of cancer, reflecting the real-world clinical context RESOLVE(TM) is designed to address Cambridge, Mass., May 29, 2026 - Harbinger Health, a biotechnology company pioneering cancer resolution, today announced the presentation of clinical data on Harbinger's multi-cancer detection test in symptomatic patient populations at the American Society of Clinical Oncology (ASCO) Annual Meeting, taking place in Chicago, Illinois, May 29 - June 2, 2026. Harbinger is pioneering RESOLVE(TM), a new category of blood-based cancer detection tests designed to bring clarity to the often-uncertain period between suspicion of cancer and diagnosis. Data presented at ASCO are from the prospective arm of the completed CORE-HH (NCT05435066) study of individuals undergoing diagnostic evaluation following imaging results suggestive but inconclusive of cancer. The symptomatic population evaluated in CORE-HH reflects a similar clinical context being evaluated in the ongoing PROCARES(NCT07046260) study and the intended clinical population for RESOLVE(TM). "The data presented in symptomatic populations from CORE-HH represent a critical validation point for our platform in the exact clinical context where RESOLVE(TM) is designed to be used," said Ajit Singh, Ph.D., chief executive officer of Harbinger Health. "Today, there can be a prolonged gap between signs or symptoms suggestive of cancer and a definitive diagnosis, and we know that delays directly impact outcomes. These results strengthen our confidence that our approach can help clinicians and patients move from suspicion to resolution more quickly, and we are working to make our first RESOLVE(TM) product commercially available later this year." Title: Performance of a cfDNA methylation-based MCED test in patients with clinicoradiologic suspicion of cancer Poster Session: Prevention, Risk Reduction, and Genetics Poster Number: 504 Date/Time: Monday, June 1, 2026, at 1:30-4:30pm CDT Key Takeaways: * This analysis explored a subset of the CORE-HH study population, focusing on 209 adults aged 45 to 79 who were undergoing diagnostic evaluation following concerning imaging findings. Of these, 155 participants had a confirmed cancer diagnosis and 54 did not. * Examples of clinical indications include pulmonary nodules, hepatic masses, unexplained lymphadenopathy and other suspicious lesions. * Among participants with confirmed cancer, 85 of 155 (54.8%) received a positive test result, producing a positive likelihood ratio of 29.6, supporting the ability of a positive result to meaningfully increase the probability of cancer in this clinically suspicious population. * The test demonstrated a low false positive rate, with only 1 false positive observed among the 54 subjects without malignancy. * A positive test result raised the probability of a confirmed cancer diagnosis from 74.2% (based on clinical suspicion alone) to 98.8%, providing near-definitive diagnostic clarity. * Results from this group were consistent with findings from the broader CORE-HH case-control study (n = 4,137), supporting the test's reliability across study populations. Luke R.G. Pike, M.D., D.Phil., Director of Brain Radiation Oncology at Memorial Sloan Kettering Cancer Center and MCED Lead for the institution's Translational Oncology Partnership Program, Principal Investigator for CORE-HH and PROCARES trials, added, "Not infrequently, a test result will come back that could point to any number of potential diagnoses, producing ambiguity that often results in prolonged, invasive procedures to reach a definitive conclusion. In these moments, a blood test that performs with high predictive value in confirming cancer among patients already under clinical suspicion has meaningful implications for how we work up these patients. Findings from this subset of CORE-HH patients suggest the test may help clinicians resolve diagnostic uncertainty more confidently in settings where that uncertainty carries significant consequence." To validate findings prospectively at scale, PROCARES (NCT07046260), Harbinger's ongoing multicenter, observational study, is now enrolling this population, with enrollment anticipated to complete in the coming months. About Harbinger Health Harbinger Health is leading a transformation in cancer detection, introducing fundamentally new approaches to resolving cancer-related uncertainty across multiple clinical contexts. The company combines advances in artificial intelligence with proprietary insights into the biology of the origins of cancer to enable fit-for-purpose strategies grounded in shared biology and a common platform - all through a low-cost blood test. Harbinger is advancing multiple tests in its RESOLVE(TM) portfolio designed to help bring clarity more efficiently to clinicians when cancer is suspected. Harbinger was founded by Flagship Pioneering after three years of foundational research in its Labs unit and launched in 2020. Learn more about Harbinger by visiting Harbinger-Health.com following Harbinger Health, Inc. on LinkedIn.

Harbinger Health presented clinical data at the American Society of Clinical Oncology Annual Meeting supporting its RESOLVE blood-based cancer detection test for symptomatic patients. The data came from the CORE-HH study involving 209 adults aged 45 to 79 undergoing diagnostic evaluation following concerning imaging findings. The test correctly identified 85 of 155 confirmed cancer cases, achieving a 54.8% detection rate and a positive likelihood ratio of 29.6. With only one false positive among 54 non-cancer participants, a positive result increased cancer probability from 74.2% to 98.8%. The Cambridge-based company aims to launch its first RESOLVE product commercially later this year. The test targets the diagnostic gap between cancer suspicion and definitive diagnosis in patients presenting with suspicious symptoms or imaging findings.