Netherlands-based Matisse Pharmaceuticals B.V. has closed a EUR 14 million Series A financing round to fund a Phase II clinical trial of isupartob sodium, its lead compound targeting extracellular histones in sepsis patients.
The round drew participation from Brightlands Venture Partners and LIOF, the regional investment and development fund for the Limburg province of the Netherlands, alongside private investors and management. The proceeds will support execution of the Phase II trial as well as regulatory, manufacturing, and operational activities, the company said. The financing extends a relationship with Brightlands Venture Partners that stretches back to an earlier round that supported the company's Phase I/IIa trial, and a EUR 3.6 million raise in early 2024.
Isupartob sodium is designed to neutralize extracellular histones — proteins released by the innate immune system during sepsis that are toxic to cell membranes and drive a self-reinforcing cascade of organ failure. The compound received FDA investigational new drug clearance in May 2026 and US FDA Fast Track designation in June 2026, enabling the planned US trial. Matisse holds a worldwide exclusive license from Maastricht University and Maastricht University Medical Centre for isupartob and a next-generation variant, with foundational research contributed by Chris P. Reutelingsperger and Karin C.A.A. Wildhagen, both affiliated with Maastricht University. In a 10-patient Phase I/IIa study in critically ill sepsis patients, isupartob met its primary objectives, providing the clinical rationale for the Phase II program now being funded.