Matisse Pharmaceuticals closed Series A financing round to advance isupartob sodium through phase 2 clinical development

Geleen, September 17, 2026

Matisse Pharmaceuticals B.V., a clinical stage company developing isupartob sodium for the treatment of sepsis, today announced the successful completion of its Series A financing round.

The €14 million financing round was led by the company's existing & new shareholder base. This included participation from a group of institutional investors which included Brightlands Venture Partners & LIOF, private investors and management, further strengthening Matisse's long-term investor syndicate. The proceeds will primarily be used to execute the Phase 2 clinical trial of isupartob sodium, a key value-inflection milestone for the company, while supporting regulatory, manufacturing and operational activities. The financing reflects continued confidence in Matisse's differentiated therapeutic approach and the significant unmet medical need addressed by isupartob.

"This financing represents an important milestone for Matisse," said Marcel Jacobs, Chief Executive Officer of Matisse Pharmaceuticals. "We are grateful for the continued commitment of our existing shareholders and are pleased to welcome new investors who share our long-term vision. Their support enables us to focus on what matters most: Successfully completing our Phase 2 clinical trial in sepsis patients and generating the clinical data needed to unlock the next stage of the company's development. We believe this positions Matisse to create significant value for patients, partners and shareholders alike."

Matisse Pharmaceuticals structured the financing as a company-led round, allowing it to broaden its shareholder base with long-term investors while maintaining strategic flexibility as it advances toward its next clinical milestones.

Completion of the Phase 2 study is expected to provide important data regarding the safety, tolerability and clinical activity of isupartob in sepsis patients and will inform Matisse's subsequent development strategy.

About Sepsis and the unmet medical need
According to the WHO, sepsis is one of the leading causes of death worldwide. Currently, there is no treatment effective against sepsis approved by regulatory authorities. Of the 49 million patients globally suffering from sepsis every year, more than 20% die. Approximately 40% of the sepsis cases are children under the age of 5, with close to 3 million children dying from sepsis each year. According to a study by Buchman et al. (2020), published in Critical Care Medicine, sepsis is the most common cause of in-hospital deaths, costing over $62 billion annually in the USA alone. 

Sepsis remains one of the most significant unmet medical needs in critical care medicine and despite decades of research, no targeted therapies have been successfully developed to address the dysregulated host response that drives organ failure and death in sepsis.

Isupartob mechanism of action
Isupartob is a novel therapeutic designed to neutralize extracellular histones, key mediators of endothelial injury, inflammation and organ failure in sepsis.

In sepsis patients the innate immune system releases proteins known as histones into the bloodstream. These histones are toxic to cell membranes leading to cell death and release of additional histones. The result is a self-enforcing cascade that drives organ failure. The highly negatively charged isupartob binds to these positively charged extracellular histones. By targeting this upstream mechanism in the inflammatory cascade, the therapy aims to reduce mortality and improve outcomes in critically ill patients.

About Matisse Pharmaceuticals
Matisse Pharmaceuticals B.V. was founded in 2014 in Geleen, the Netherlands. The company develops safe and innovative therapies for disease indications characterized by elevated levels of circulating cytotoxic histones, including sepsis.

For more information, please contact: 

Marcel Jacobs, CEO
(T) +31 6 575 27 541
(E) m.jacobs@matissepharmaceuticals.com
(W) www.matissepharmaceuticals.com

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• 20260917 (NL) Matisse rondt Series A-financieringsronde af (Final)