A Study to Learn About How Safe BAY3389934 is and How it Affects Blood Clotting When Given Alone or With Aspirin in Healthy Participants

Open-label, Randomized, Three-fold Cross-over, Drug-drug-interaction Study to Investigate the Influence of Multiple Doses of Acetylsalicylic Acid (ASA) (Aspirin) on the Safety and the Pharmacodynamic Effects of BAY 3389934 in Healthy Participants.

The study treatment BAY3389934 is under development for people with blood clotting problems that occur due to sepsis.

Sepsis is a serious condition that happens when the body's reaction to an infection causes organ damage. It can eventually lead to tiny blood clots formation throughout the body.

BAY3389934 aims to work by blocking two important blood clotting proteins, called Factor IIa (thrombin) and Factor Xa, both of which help in blood clotting. By blocking them, BAY3389934 may slow down or stop excessive clotting.

Aspirin is a drug that prevents platelets from clumping together. People with sepsis are often given aspirin for underlying heart-related problems. Since aspirin and BAY3389934 both affect how the blood clots, each in a different way, it is important to check whether using them together is safe and whether they change each other's effects on blood clotting.

The main purpose of this study is to find out how safe BAY3389934 is when given together with aspirin and to see how the two affect blood clotting in healthy participants.

To do this, the researchers will assess the number and severity of medical problems in healthy adult participants after receiving BAY3389934 alone and in combination with aspirin and compare them with the medical problems when participants received either drug alone.

These medical problems are also known as "adverse events". Doctors keep track of all medical problems that happen in studies, even if they do not think they are related to study treatments.

All participants will receive a single dose of aspirin tablet prior to the study. Researchers will check their response to decide whether they can participate in the study. Eligible participants will then receive the following three treatments, each at different time and in a different order assigned randomly.

Treatment A:

• no treatment the day prior to receiving study treatment.
• BAY3389934 as an infusion into a vein on Day 1.

Treatment B:

• a single high-dose aspirin tablet on the day prior to receiving study treatment.
• a single-low dose aspirin tablet on Day 1.

Treatment C:

• a single high-dose aspirin tablet on the day prior to receiving study treatment.
• a single low-dose aspirin tablet followed by BAY3389934 4 hours continuous infusion into a vein on Day 1.

There will be a gap of 3 days after Treatment A, and 14 days after Treatments B and C, when participants will not be given any treatment.

Each participant will be in the study for around 2 months with up to 6 visits to the study clinic. They will visit the study clinic:

• twice, before the treatment starts
• once, during each of the three treatment periods
• once, at the end of the treatment

During the study, the doctors and their study team will

• check participants' health by performing tests such as blood and urine tests, measuring blood pressure, heart rate and checking heart health using an electrocardiogram (ECG).
• ask the participants questions about how they are feeling and any adverse events they are having.

In this study, the participants will not benefit from taking of BAY3389934. However, the study will provide information on how BAY3389934 may be helpful in people with blood clotting problems caused due to sepsis.

Study Overview

• Status: Recruiting
• Conditions: Drug-drug Interaction
• Intervention / Treatment: Drug: BAY3389934; Drug: Aspirin

• Study Type: Interventional
• Enrollment (Estimated): 16
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Bayer Clinical Trials Contact; Phone Number: 18888422937; Email: clinical-trials-contact@bayer.com

Study Locations

• United States
  • Florida
    • Miami, Florida, United States, 33014
      • Recruiting
      • Clinical Pharmacology of Miami, LLC - Cardiology Department

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Participant must be 18 to 55 years of age inclusive, at the time of signing the informed consent.
• Participants who are overtly healthy as determined by medical evaluation including medical history, physical examination, vital signs, laboratory tests, and cardiac monitoring.
• Body mass index within the range 18.0 to 29.9 kg/m^2 (inclusive) at screening visit.
• Male or female (Women of Non-Childbearing Potential [WONCBP]) Contraceptive use by participant partners should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.

Male participants: Participants are eligible to participate if they agree to the following during the study intervention period up to at least 1 day after end of infusion of study intervention to ensure sufficient elimination of BAY3389934 (5 times the elimination half-life of BAY3389934 is approximately 5 hours):

• Refrain from donating sperm

PLUS, either:

• Be abstinent from heterosexual intercourse as their preferred and usual lifestyle (abstinent on a long term and persistent basis) and agree to remain abstinent OR

• Must agree to use contraception /barrier as detailed below:

  • Agree to use a male condom with female partner use of an additional highly effective contraceptive method with a failure rate of < 1% per year when having sexual intercourse with a woman of childbearing potential who is not currently pregnant
  • Agree to use a male condom when engaging in any activity that allows for passage of ejaculate to another person

Female participants: A female participant is eligible to participate if she is a WONCBP.

• A WONCBP must have a negative highly sensitive pregnancy test (serum) within 24 hours before the first dose of study intervention,
• The investigator is responsible for review of medical history, menstrual history, and recent sexual activity to decrease the risk for inclusion of a woman with an early undetected pregnancy.
• Signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.

Exclusion Criteria:

• Medical disorder, condition or history of such that would impair the participant's ability to take part in or complete this study in the opinion of the investigator.
• Diseases for which it can be assumed that the absorption, distribution, metabolism, elimination and effects of the study intervention(s) will not be normal.
• Known hypersensitivity to any study intervention (active substances or excipients of the preparations) to be used in the study - including e.g. non-investigational medicinal products, challenge agents, or rescue medication.
• Known severe allergies, e.g. allergies affecting the lower respiratory tract - allergic asthma, allergies requiring therapy with corticosteroids, urticaria or significant non-allergic drug reactions.
• Aspirin hypersensitivity/ allergy.
• Febrile illness within 2 weeks before the start of the first study intervention.
• Known or suspected liver disorders and bile secretion/flow (cholestasis, also history of it).
• History of Morbus Meulengracht (Gilbert´s syndrome) or total bilirubin levels above ULN at screening.
• History of known or suspected malignant tumors.
• Tendency to develop keloids or major scars after injuries.
• Participants experienced surgery (6-months prior to first study intervention), or IM injection (2-week prior to first study intervention).
• Known disorders with increased bleeding risk (e.g., periodontosis, symptomatic hemorrhoids, acute gastritis, peptic ulcer, vascular malformations and also history of it).
• Known sensitivity to common causes of bleeding or bruises (e.g., nasal).
• Known congenital or acquired coagulation disorders (e.g. von Willebrand's disease, hemophilia, platelet dysfunction, etc.).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Treatment sequence A-B-C; Treatment A: no treatment on day -1, 4 hours infusion of BAY3389934 on day 1 in Dose A. Treatment B: 500 mg aspirin on day -1, 100 mg aspirin on day 1. Treatment C: 500 mg aspirin on day -1, 100 mg aspirin on day 1 followed by 4 hours infusion of BAY3389934 in Dose A. Participants will receive the treatments in mentioned sequence. Study periods will be separated by a wash-out phase of at least 3 days after Treatment A and at least 14 days after Treatments B, C, respectively.	Drug: BAY3389934; 4 hours infusion of BAY3389934 in Dose A.; Drug: Aspirin; Single oral dose of 500 mg tablet or 100 mg tablet.
Experimental: Treatment sequence A-C-B; Treatment A: no treatment on day -1, 4 hours infusion of BAY3389934 on day 1 in Dose A. Treatment B: 500 mg aspirin on day -1, 100 mg aspirin on day 1. Treatment C: 500 mg aspirin on day -1, 100 mg aspirin on day 1 followed by 4 hours infusion of BAY3389934 in Dose A. Participants will receive the treatments in mentioned sequence. Study periods will be separated by a wash-out phase of at least 3 days after Treatment A and at least 14 days after Treatments B, C, respectively.	Drug: BAY3389934; 4 hours infusion of BAY3389934 in Dose A.; Drug: Aspirin; Single oral dose of 500 mg tablet or 100 mg tablet.
Experimental: Treatment sequence B-A-C; Treatment A: no treatment on day -1, 4 hours infusion of BAY3389934 on day 1 in Dose A. Treatment B: 500 mg aspirin on day -1, 100 mg aspirin on day 1. Treatment C: 500 mg aspirin on day -1, 100 mg aspirin on day 1 followed by 4 hours infusion of BAY3389934 in Dose A. Participants will receive the treatments in mentioned sequence. Study periods will be separated by a wash-out phase of at least 3 days after Treatment A and at least 14 days after Treatments B, C, respectively.	Drug: BAY3389934; 4 hours infusion of BAY3389934 in Dose A.; Drug: Aspirin; Single oral dose of 500 mg tablet or 100 mg tablet.
Experimental: Treatment sequence B-C-A; Treatment A: no treatment on day -1, 4 hours infusion of BAY3389934 on day 1 in Dose A. Treatment B: 500 mg aspirin on day -1, 100 mg aspirin on day 1. Treatment C: 500 mg aspirin on day -1, 100 mg aspirin on day 1 followed by 4 hours infusion of BAY3389934 in Dose A. Participants will receive the treatments in mentioned sequence. Study periods will be separated by a wash-out phase of at least 3 days after Treatment A and at least 14 days after Treatments B, C, respectively.	Drug: BAY3389934; 4 hours infusion of BAY3389934 in Dose A.; Drug: Aspirin; Single oral dose of 500 mg tablet or 100 mg tablet.
Experimental: Treatment sequence C-A-B; Treatment A: no treatment on day -1, 4 hours infusion of BAY3389934 on day 1 in Dose A. Treatment B: 500 mg aspirin on day -1, 100 mg aspirin on day 1. Treatment C: 500 mg aspirin on day -1, 100 mg aspirin on day 1 followed by 4 hours infusion of BAY3389934 in Dose A. Participants will receive the treatments in mentioned sequence. Study periods will be separated by a wash-out phase of at least 3 days after Treatment A and at least 14 days after Treatments B, C, respectively.	Drug: BAY3389934; 4 hours infusion of BAY3389934 in Dose A.; Drug: Aspirin; Single oral dose of 500 mg tablet or 100 mg tablet.
Experimental: Treatment sequence C-B-A; Treatment A: no treatment on day -1, 4 hours infusion of BAY3389934 on day 1 in Dose A. Treatment B: 500 mg aspirin on day -1, 100 mg aspirin on day 1. Treatment C: 500 mg aspirin on day -1, 100 mg aspirin on day 1 followed by 4 hours infusion of BAY3389934 in Dose A. Participants will receive the treatments in mentioned sequence. Study periods will be separated by a wash-out phase of at least 3 days after Treatment A and at least 14 days after Treatments B, C, respectively.	Drug: BAY3389934; 4 hours infusion of BAY3389934 in Dose A.; Drug: Aspirin; Single oral dose of 500 mg tablet or 100 mg tablet.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants with treatment-emergent adverse events (TEAEs)	An AE is any untoward medical occurrence in a clinical study participant, associated with the use of study intervention, whether or not considered related to the study intervention.	From first dose of study intervention until 14 days after last study intervention

Secondary Outcome Measures

Outcome Measure	Time Frame
Ratios to baseline of Activated Partial Thromboplastin Time (aPTT) 4h and 5h after baseline	4 hours and 5 hours after baseline
Ratios to baseline of Prothrombin Time (PT) 4 h and 5 h after baseline	4 hours and 5 hours after baseline
Maximum ratio to baseline of Activated Partial Thromboplastin Time (aPTT) from baseline to 24 h post dose	Baseline and 24 hours post dose
Maximum ratio to baseline of Prothrombin Time (PT) from baseline to 24 h post dose	Baseline and 24 hours post dose

Collaborators and Investigators

• Sponsor: Bayer

Study record dates

Study Major Dates

• Study Start (Actual): May 29, 2026
• Primary Completion (Estimated): October 15, 2026
• Study Completion (Estimated): October 15, 2026

Study Registration Dates

• First Submitted: June 8, 2026
• First Submitted That Met QC Criteria: June 11, 2026
• First Posted (Actual): June 17, 2026

Study Record Updates

• Last Update Posted (Actual): June 17, 2026
• Last Update Submitted That Met QC Criteria: June 11, 2026
• Last Verified: December 5, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Organic Chemicals; Hydrocarbons; Hydrocarbons, Cyclic; Hydrocarbons, Aromatic; Phenols; Benzene Derivatives; Salicylates; Hydroxybenzoates; Aspirin
• Other Study ID Numbers: 22366

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

IPD Plan Description

Currently, there is no established plan for the sharing of Individual Patient Data (IPD) from this study. The availability of this study's data will later be determined according to Bayer's commitment to the EFPIA/PhRMA 'Principles for responsible clinical trial data sharing.' This pertains to the scope, timepoint, and process of data access.

As such, Bayer commits to considering requests from qualified researchers for patient- / study-level clinical trial data, and documents from clinical trials involving medicines and indications approved in the US and EU. However, this commitment does not reflect an active IPD sharing plan. This applies to data on new medicines and indications that have been approved by the EU and US regulatory agencies on or after January 01, 2014.

Researchers can use www.vivli.org to request access to IPD and documents from clinical studies to conduct research. Information on Bayer's criteria for listing studies is provided in the member section of the portal.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No