WATERTOWN, Mass., July 10, 2025 (GLOBE NEWSWIRE) -- Diagonal Therapeutics, a biotechnology company focused on correcting dysregulated signaling with clustering antibodies that address the underlying cause of intractable genetic diseases, today announced the publication of study results detailing new health economics and outcomes research (HEOR) that characterizes the significant healthcare utilization and costs associated with hereditary hemorrhagic telangiectasia (HHT) in the American Journal of Hematology.

"This study provides the first detailed analysis of the healthcare resource demands and costs associated with HHT, highlighting the substantial economic impact this disease places on patients and the health system," said Hanny Al-Samkari, M.D., the Peggy S. Blitz Endowed Chair in Hematology/Oncology at the Massachusetts General Hospital, Associate Professor of Medicine at Harvard Medical School, and lead author of the study. "The findings underscore the urgent need for treatments that can effectively address the underlying cause of HHT and reduce the complications related to chronic bleeding and anemia, which are major cost drivers requiring hematologic support, hospital admissions, and emergency care."

HHT is the second most common inherited bleeding disorder globally, affecting approximately 1 in 4,000 to 5,000 people and an estimated 80,000 in the U.S. The disorder leads to recurrent severe epistaxis (nosebleeds), chronic gastrointestinal bleeding, heavy menstrual bleeding, and arteriovenous malformations (AVMs) in organs such as the lungs, liver, and brain. These AVMs can cause serious or fatal bleeding events and comorbidities, including chronic and recurrent iron deficiency anemia—which occurs in nearly 60% of HHT patients. Chronic anemia is well known to increase risk for hospitalizations, heart failure, and death. Currently, there are no FDA- or EMA-approved therapeutics for HHT worldwide, and treatments are largely limited to off-label use of costly immunomodulatory and antiangiogenic drugs.

The study leveraged Komodo Health’s Healthcare Map^® claims database* to analyze real-world healthcare costs for HHT patients in 2022 and 2023. Key findings from the publication include:

• Per patient per year (PPPY) costs for people living with HHT are comparable to or surpass those of other rare and resource-intensive diseases.
• Bleeding and its consequences were identified as the primary drivers of healthcare costs.
  • Mean PPPY costs for all HHT patients were >$19,000 across 2022 and 2023, about 20% higher than those for sickle cell disease.
  • For HHT patients with anemia, the mean PPPY costs were approximately $27,000, comparable to those associated with muscular dystrophy.
  • Patients with HHT receiving hematologic support (iron infusions and/or red blood cell transfusions) had mean PPPY costs of approximately $40,000, comparable to those associated with cystic fibrosis.
  • HHT patients with anemia, while accounting for nearly 60% of the HHT patient population, were responsible for approximately 80% of the direct medical costs.
• Notably, the prevalence of liver transplantation among HHT patients, arising from complications of liver AVMs, was 40 times greater than in the general U.S. population.
  

“We are extremely grateful to partner with Dr. Al-Samkari and Cure HHT on this important study, as it puts into stark focus the impact of HHT and its associated complications on individuals and families living with this complex disease,” said Eric Duhaime, Senior Vice President of Corporate Development at Diagonal and co-author of the study. "We are committed to advancing a differentiated treatment that directly addresses the root cause of HHT and are encouraged by the compelling preclinical profile of our first-in-class, bispecific ALK1 agonist antibody. We look forward to advancing development of DIAG723 as a novel, potentially disease-modifying treatment option for people living with HHT."

*The Komodo Health’s Healthcare Map^® claims database includes de-identified data from over 330 million patients across commercial, Medicare, and Medicaid plans in the United States.

About Hereditary Hemorrhagic Telangiectasia (HHT)
HHT is a rare disease that affects more than 150,000 people in the U.S. and EU, and for which there are currently no approved therapies. In HHT, loss of function point mutations in members of the TGF-ß receptor superfamily complex create abnormal blood vessels that are fragile and susceptible to rupture and bleeding. These bleeding events drastically reduce quality of life, result in emergency visits and hospitalizations, and lead to chronic anemia, necessitating frequent iron infusions or red blood cell transfusions in many patients. Solid organ arteriovenous malformations, if left untreated, are at risk of rupturing, resulting in lung and brain hemorrhage, stroke, heart failure, and death.

About Diagonal Therapeutics
Diagonal Therapeutics is a biotechnology company advancing novel disease-modifying clustering antibodies that repair dysregulated signaling implicated in a range of illnesses. The Company's DIAGONAL Product Engine combines proprietary computational and experimental techniques to overcome historical challenges associated with antibody drug discovery and efficiently deliver optimized therapeutic assets. Diagonal’s pipeline comprises clustering antibodies designed to selectively address the underlying cause of disease across hematology, hepatology, and nephrology, offering the potential to deliver life-changing therapies for patients. DIAG723, Diagonal's first-in-class clustering antibody, recently received orphan drug designation from the U.S. FDA and a positive opinion from the EMA for treating HHT. For more information, please visit www.diagonaltx.com.

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Marites Coulter
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