Geleen, May 19th, 2026
Matisse Pharmaceuticals B.V., a clinical stage company developing a medicinal product for the treatment of sepsis, today announced that the U.S. Food and Drug Administration (FDA) has cleared the company’s Investigational New Drug (IND) application for its lead compound isupartob sodium. The clearance enables the initiation of a Phase II clinical trial in patients with sepsis.
“IND clearance represents a key development milestone for the company. It advances its lead program into mid-stage clinical development,” said Marcel Jacobs, CEO of Matisse Pharmaceuticals. “Two Phase I studies have been successfully completed, including one in sepsis patients. We are now positioned to evaluate the broader clinical potential of isupartob sodium in Phase II to improve outcomes in this devastating medical condition.”
Unmet Medical Need
Sepsis remains one of the most significant unmet medical needs in critical care medicine. The condition affects approximately 49 million people worldwide each year and causes an estimated 11 million deaths annually. 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.
Mechanism of action
Isupartob sodium is a novel therapeutic designed to neutralize extracellular histones, key mediators of endothelial injury, inflammation and organ failure in sepsis. By targeting this upstream mechanism in the inflammatory cascade, the therapy aims to reduce mortality and improve outcomes in critically ill patients.
“Advancing isupartob sodium into Phase II represents an important step in validating extracellular histone neutralization as a therapeutic strategy,” said Kees Groen, Chief Development Officer of Matisse Pharmaceuticals. “We believe this mechanism may address a central driver of inflammation and organ damage in sepsis and potentially other inflammatory conditions.”
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.
Matisse’s lead compound isupartob sodium is based on a specific discovery that in sepsis patients the innate immune system releases proteins knows 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. It thereby inhibits the self-enforcing cascade, with the ultimate goal to prevent further organ damage and death.
About sepsis
According to the WHO, sepsis is one of the leading causes of death worldwide. Currently, there is no effective treatment against sepsis approved by regulatory authorities. From 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.
For more information, please contact:
Marcel Jacobs, CEO
(T) +31 6 575 27 541
(E) m.jacobs@matissepharmaceuticals.com
(W) www.matissepharmaceuticals.com
Attachments
- Matisse production image
- 20250519 (NL) Matisse Pharmaceuticals ontvangt FDA IND-goedkeuring voor isupartob natrium - Notified
