Treatment with a Novel Small Molecule Dual Factor IIa/Xa Inhibitor Protects Against Coagulopathy and Organ Dysfunction in a Baboon Model of Staphylococcus Aureus Sepsis

Background: Sepsis-associated coagulopathy and disseminated intravascular coagulation (DIC) significantly contribute to organ failure and mortality in sepsis patients. Factors IIa and Xa are pivotal in the coagulation cascade, and their over-activation in sepsis leads to systemic hypercoagulable states. We hypothesized that in intensive care settings, comprehensive and controllable anticoagulation and organ protection can be achieved by targeting these two key proteases in the common coagulation pathway with the short-lived dual inhibitor BAY 3389934.

Objective: To assess the efficacy and safety of BAY 3389934, a novel short-lived, small molecule dual FIIa/Xa inhibitor, in reducing coagulopathy and protecting organ function in a baboon model of Staphylococcus aureus (S. aureus) sepsis.

Methods: The study employed a baboon model infused with heat-inactivated S. aureus (3.3 x 10¹⁰ bacteria/kg bw). Baboons were treated with BAY 3389934 (1-2 mg/kg bw, continuous IV infusion up to 8 hours post-bacterial challenge) starting at T0 (before) or 2 hours post-bacterial challenge. Various parameters, including markers of coagulation, fibrinolysis, organ function, and bleeding time, were assessed. Animals were kept in anesthesia for 9 hours and subsequently followed up to 48 hours after the start of bacterial challenge.

Results: S. aureus infusion induced robust activation of coagulation, as reflected by plasma levels of protease-serpin complexes (FXIIa-AT, Kal-AT, FXIa-AT, FVIIa-AT, and T-AT) and mirrored by fibrinogen and platelet consumption. S. aureus infusion led to organ dysfunction, as indicated by elevated vital signs, increased plasma ALT, total bilirubin, pancreatic amylase, plasma creatinine, and blood urea nitrogen, as well as histological evidence of kidney damage.

Treatment with BAY 3389934 significantly decreased the coagulation markers, blocking the activation of coagulation when given at T0 and strongly reducing it when given 2 hours after the challenge. Importantly, the treatment mitigated fibrinogen and platelet consumption without causing bleeding throughout the experiment. ROTEM analysis confirmed these findings.

Additionally, BAY 3389934 protected against organ dysfunction, as evidenced by reduced markers of liver (ALT), pancreas (amylase), and kidney (BUN, creatinine) damage, and decreased lactate levels. Histological analysis showed that the treatment prevented fibrin deposition in the kidney and lungs and necrosis of the kidney’s tubular epithelium.

Conclusion: In a model of sepsis-induced coagulopathy in baboons, the dual FIIa/Xa inhibitor BAY 3389934 reduced the hypercoagulable state strongly and protected from organ damage. Further studies are warranted to explore its full therapeutic potential in the treatment of sepsis-associated DIC.