A Study to Assess the Safety and Effects of Different Doses of an Investigational Drug, BAY 3389934, in Healthy Japanese Volunteers.

This study is designed to evaluate a new investigational drug, BAY 3389934, in healthy Japanese volunteers. The primary purpose is to see how safe the drug is and how well it is tolerated by the body when given at different doses. BAY 3389934 is being developed for the potential treatment of a serious blood clotting condition called sepsis-associated disseminated intravascular coagulation (DIC). The research will be conducted as a single-blind, placebo-controlled, dose-escalation study. This means that participants will be randomly assigned to receive either the active drug (BAY 3389934) or a placebo (an inactive substance), and they will not know which one they are receiving. The study will involve up to 16 healthy male and female Japanese participants, aged between 18 and 55. The study consists of two parts, called dose steps. In the first step, participants will receive a single 4-hour intravenous (IV) infusion of BAY 3389934 at a dose of 15 mg/h, or a placebo. Based on the safety and tolerability results from this first step, a second, higher dose will be selected for the next group of participants in the second step. Throughout the study, researchers will closely monitor participants for any side effects (adverse events). They will also collect blood and urine samples to study how the drug is absorbed, distributed, and eliminated by the body (pharmacokinetics or PK) and what effects it has on the body's clotting system (pharmacodynamics or PD). This involves measuring specific substances in the blood, such as activated partial thromboplastin time (aPTT) and prothrombin time (PT). Participants will stay at the study center for 4 days and will have a follow-up visit 3 to 5 days after they are discharged. The information gathered from this study is crucial for the future clinical development of BAY 3389934 in Japan and for designing future studies in patients with septic DIC.