Matisse Pharmaceuticals successfully completes study with prolonged infusion of M6229 in healthy volunteers

Geleen, November 13^th, 2025.

Matisse Pharmaceuticals B.V., a clinical stage company developing a medicinal product for the treatment of sepsis, today announced top line results from its phase 1 study evaluating the safety, tolerability & pharmacokinetics of a 120-hour intravenous (IV) continuous infusion with its lead compound M6229. The study met its primary objectives, showing  favorable safety and tolerability in healthy volunteers. This study also confirmed that M6229, shows a predictable pharmacokinetic behavior for a 120-h continuous infusion.

The data from this healthy volunteer study, together with previously obtained results from a study in intensive care sepsis patients, provide sufficient basis for the design and execution of a Phase 2 study in sepsis patients to select the preferred dosing strategy in these patients. Matisse will submit regulatory dossiers for approval of the study in the US, Europe and Asia. 

The Matisse sponsored single-blind, randomized, placebo-controlled study has been executed and managed by Charité Research Organisation located in Berlin, Germany.

 “We believe that a prolonged infusion duration could offer an effective solution for irreversibly stopping the harmful inflammatory responses that occur in sepsis patients. With these data we take a very important step in applying this extended  infusion in our phase 2 study to treat sepsis patients, which is currently in preparation”, says Kees Groen, Chief Development Officer of Matisse Pharmaceuticals.

In Matisse’s first and successful human clinical trial in severely ill sepsis patients, finalized in 2024, a 6 hour continuous IV infusion was applied. The study showed a favorable safety and tolerability profile as well as close to dose-proportional pharmacokinetics of IV administered M6229 in critically ill patients with sepsis. The study also showed beneficial pharmacodynamic effects on histones, CRP levels and other inflammatory biomarkers. A decrease in SOFA (Sequential Organ Failure Assessment) score was found for 70% of the patients following the three days after the infusion day. 

About Matisse Pharmaceuticals
Matisse Pharmaceuticals B.V. was founded in 2014 in Geleen, the Netherlands. Matisse is dedicated to develop a product portfolio of safe and innovative therapies for disease indications characterized by elevated levels of circulating cytotoxic histones, such as in sepsis.

Matisse’s platform technology M6229 is based on the discovery that in patients suffering from sepsis, proteins called histones are released into the blood stream by the innate immune system which are toxic to cell membranes leading to cell death and release of additional histones. Due to this self-enforcing cascade, septic patients threaten to die from organ failure. The highly negatively charged M6229 preferentially binds to the positively charged extracellular histones and inhibits the self-enforcing cascade of increasing histone levels, thereby preventing 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 not surviving sepsis. According to a study by Buchman et al. (2020), published in the Journal of 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

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