Heartseed (Heartseed Inc.), a Tokyo-based biotechnology company, today announced the successful dosing of the first patient in its domestic Phase I/II EMERALD study of HS-005, allogeneic iPS cell-derived cardiomyocyte spheroids administered via catheter, targeting severe heart failure caused by ischemic heart disease or dilated cardiomyopathy.

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Cardiomyocyte spheroids

This study marks the world's first clinical trial to administer iPS cell-derived cardiomyocyte spheroids using a catheter. The administration to the first patient suffering from dilated cardiomyopathy was successfully completed at Shinshu University Hospital in late March 2026. The patient's postoperative course has been generally uneventful, and the patient has already been discharged. Furthermore, the independent Safety Monitoring Committee evaluated the 4-week data and approved the study to continue in dilated cardiomyopathy cohort.

"Catheter administration enables the minimally invasive delivery of cardiomyocytes", said Keiichi Fukuda, CEO of Heartseed. "The inclusion of patients with dilated cardiomyopathy as a new target is a highly significant milestone in our goal to save more patients with severe heart failure.”

About HS-005 and EMERALD Study

While Heartseed's lead pipeline, HS-001 requires open-heart surgery, HS-005 enables next-gen, minimally invasive cardiac regenerative medicine by endocardial catheter delivery. The administered cardiomyocytes are expected to engraft into the patient's myocardium, improving cardiac contractility by remuscularization and promoting neovascularization. The EMERALD study aims at treating severe heart failure with reduced ejection fraction (HFrEF) caused by ischemic heart disease or dilated cardiomyopathy. The study plans to enroll 7 patients in each cohort, for a total of 14 patients to evaluate the safety and efficacy of the therapy.

About Heart Failure

Heart failure is a chronic, progressive condition in which the heart muscle is unable to pump enough blood to meet the body’s needs. It affects more than 65 million people globally. Aside from heart transplantation, there are no radical treatment options, creating a strong demand for innovative therapies.

About Heartseed

Heartseed Inc. was founded in 2015 to realize cardiac remuscularization therapy, and it was listed on the Tokyo Stock Exchange Growth Market in July 2024 (Stock Code: 219A). Heartseed has proprietary technologies throughout the entire manufacturing process of the cardiomyocyte cell product, including iPSC production, purification, and cell delivery.
For more information, visit heartseed.jp, LinkedIn and YouTube.

For details: https://heartseed.jp/en/news.html

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"Catheter administration enables the minimally invasive delivery of cardiomyocytes. The inclusion of patients with dilated cardiomyopathy as a new target is a highly significant milestone in our goal to save more patients with severe heart failure.”