Heartseed Inc.
219A・Growth Market・Pharmaceuticals
Business
Heartseed Inc. was established in 2015 as a biotech venture originating from Keio University. The company aims to commercialize "Remuscularization" therapy, in which "cardiomyocyte spheroids" — microscopic tissue formed by aggregating cardiomyocytes derived from iPS cells — are transplanted into the hearts of patients with severe heart failure. The target disease is severe heart failure, a condition within heart disease (the world's leading cause of death) that has a five-year survival rate of approximately 20%, lower than that of many cancers. The company has completed dosing in all 10 cases of the Phase I/II clinical trial (LAPiS trial) for its lead pipeline candidate HS-001 (administered via open-chest surgery), and is also prepared to begin clinical trials for its next-generation product HS-005 (administered via catheter). The company operates as a single segment in the pharmaceutical business.
Business Model
The main revenue source at this stage is development milestone income based on an exclusive technology alliance and license agreement with a global pharmaceutical company. Of the ¥3,026 million in net sales for the fiscal year under review (an irregular 14-month accounting period), ¥3,025 million was milestone income from Novo Nordisk A/S. The agreement was terminated in September 2025, and worldwide rights to HS-001 and HS-005 have been returned to the Company. Going forward, the Company aims to monetize product sales following the acquisition of conditional and time-limited approval in Japan, and to diversify revenue by concluding license agreements with new global partners. R&D expenses are also partially covered by subsidies such as those from AMED.
Company Strengths
As remuscularization therapy using iPS cell-derived cardiomyocyte spheroids, the company has completed nonclinical studies and entered patient-dosing verification, making it one of the few companies worldwide at this stage. In the LAPiS trial, dosing was completed in all 10 patients, and data from the low-dose group at 52 weeks and the high-dose group at 26 weeks confirmed suggestive efficacy and favorable safety (no tumor formation, no refractory arrhythmia, no serious adverse events).
Based on over 20 years of research achievements, the company holds multiple proprietary patents and know-how, including ventricle-specific differentiation induction technology, purification technology using lactate medium (reducing tumor formation risk), cardiomyocyte spheroid fabrication technology (engraftment rate over 14 times that of single-cell suspension), and H1foo-based high-quality iPS cell fabrication technology. Patent transfer and exclusive licensing rights have already been obtained from Keio University.
With the termination of the license agreement with Novo Nordisk A/S in September 2025, worldwide development, manufacturing, and sales rights, as well as intellectual property rights, related to HS-001 and HS-005 have been returned to the company. In addition, the company received, at no additional cost, the know-how and IP independently developed by Novo Nordisk during the partnership period, giving the company full, sole ownership of options for global expansion.
ENVALITH's Perspective
Performance Trend
For Q1 cumulative FY2026 (ending December 2026) (January–March 2026), the company recorded revenue of ¥465 million, an operating loss of ¥75 million, and a quarterly net loss of ¥58 million. In the previous Q1 (November 2024–January 2025), revenue was zero and the operating loss was ¥485 million, so the loss margin narrowed significantly due to the recognition of milestone income. However, the full-year earnings forecast calls for revenue of ¥467 million, an operating loss of ¥2,207 million, and net income of ¥−2,158 million, with the outlook indicating that R&D expenses and other costs will continue to accumulate with essentially no income from Q1 onward. The financial position remains sound, with total assets of ¥7,613 million, net assets of ¥7,147 million, and an equity ratio of 93.8%. Cash and deposits stood at ¥6,412 million, down ¥424 million from the end of the previous fiscal year. As an external factor, foreign exchange fluctuations are a contributing factor to the revision of earnings forecasts, and uncertainty in the international situation is expected to continue to have an impact.
Growth Strategy
Aiming to realize pipeline value through the parallel advancement of progress toward HS-001 approval application and the initiation of HS-005 clinical trials
Data compilation and third-party data interpretation are underway for all 10 cases in the Phase I/II clinical trial (LAPiS trial) combined with coronary artery bypass surgery. Depending on the results, a transition to application for conditional and time-limited approval is expected.
Submission of the clinical trial notification to the PMDA has been completed, and collaboration with clinical trial sites and Japan Lifeline Co., Ltd. is proceeding smoothly. The company aims to begin patient dosing during the first half of 2026, initiating clinical verification of a less invasive treatment option compared to HS-001.
The company holds exclusive worldwide rights to HS-001 and HS-005, and aims to strengthen its revenue base by negotiating licensing agreements and securing milestone income from overseas pharmaceutical companies and others, backed by accumulated clinical data. Addressing foreign exchange impacts also remains a challenge.
Last updated: July 17, 2026