A Study to Test How Well BAY 3670549 Works and How Safe it is in Patients With Atrial Fibrillation

NCT07625215 | Not Yet Recruiting Phase 2 DMC FDA Drug

• 2 other identifiers: 229612025-523807-31-00
• Study Type: interventional
• Target: 360
• Locations: 8 countries
• Sites: 27

Brief Summary

The main goal of this study is to find out how well BAY 3670549 works, how safe it is, how well people can tolerate it, and how the body handles the medicine. The study will compare BAY 3670549 to a placebo (a dummy treatment with no active medicine) in people with AF who need a treatment called electrical cardioversion. Electrical cardioversion is a procedure that helps the heart return to a normal rhythm. In this study, each participant will get a single intravenous (IV) infusion of either BAY 3670549 or a placebo. Participants will then be observed to see whether the heart rhythm returns to a normal rhythm. If it does not, electrical cardioversion can still be performed as planned. The study will look at how many participants return from AF to a normal rhythm, without needing electrical cardioversion and how long it takes. It will also show how many participants experience medical problems after treatment and how BAY 3670549 move into, through and out of the participants' body. The total duration of the study for an individual participant may be up two months. The findings from this study may contribute to the development of a new treatment option for people with AF.

Conditions

Atrial Fibrillation

Outcome Measures

Primary Outcomes (1)

• Number of Participants with conversion from atrial fibrillation (AF) to sinus rhythm (SR), sustained for ≥1 minute, within 3 hours after start of study intervention administration, and prior to use of rescue therapy or other SoC for cardioversion

  AF = atrial fibrillation ; SR = sinus rhythm ; SoC = Standard of Care;

  Up to 3 hours after start of administration of study intervention

Secondary Outcomes (4)

• Number of Participants who experienced Treatment Emergent Adverse Events (TEAE)s

  From pre-dose* up to 48 hours after start of administration of study intervention

• Time to conversion from AF to SR as defined in the primary endpoint

  Up to 3 hours after start of administration of study intervention

• Number of Participants in SR, at 3 hours after start of study intervention administration without prior use of rescue therapy or other SoC for cardioversion

  Up to 3 hours after start of administration of study intervention

• Plasma concentration of BAY 3670549 at the end of the infusion

  From pre-dose* up to 8 hours after start of administration of study intervention

Study Arms (2)

BAY 3670549

EXPERIMENTAL

Drug: BAY 3670549

Placebo

PLACEBO COMPARATOR

Other: Placebo

Interventions

BAY 3670549 DRUG

intravenous (IV) treatment

BAY 3670549

Placebo OTHER

intravenous (IV) treatment

Placebo

Eligibility Criteria

• Age: 18 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Participant must be 18 to 85 years of age inclusive, at the time of signing the informed consent.
• Participant is hemodynamically stable and does not require emergency cardioversion, as determined by the investigator.
• Participant has a current episode of atrial fibrillation (AF) ongoing for at least 3 hours and no more than 30 days at the time of randomization.
• Participant has an indication for electrical cardioversion of AF, as determined by the investigator according to standard clinical practice and national/institutional guidelines.
• At randomization, successful initiation and achievement of therapeutic levels of anticoagulation therapy, as well as completion of imaging evaluation for left atrial thrombi, as appropriate for the duration of the AF episode and risk for the participant according to national guideline and institution-specific routine practice.
• BMI within range \[18 - 39.9\] kg/m2.
• Contraceptive use by participants or participant partners should be consistent with the study protocol and local regulations regarding the methods of contraception for those participating in clinical studies.
• Signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol
• Willing and able to comply with the receipt, home use, and return of the continuous ECG recording device, as well as with the participation in scheduled telephone follow-up assessments.

You may not qualify if:

• Current atrial flutter (AFL) or combined AF/AFL
• Contraindication for electrical cardioversion on planned treatment day
• Documented severely dilated left atrium (left atrial diameter, LAD \>5 cm) measured by any modality within the 6 months prior to screening; if several values are available, the most recent one shall be reported. If left atrium diameter was not measured in the last 6 months or a major cardiovascular event occurred within the last 6 months, a new measurement must be done at screening
• Unsuccessful conversion of current AF episode (pharmacologically or electrically)
• Known severe valvular heart disease (e.g., severe mitral regurgitation, severe aortic stenosis)
• Patients with NYHA Class ≥ III heart failure, or with active management of acute heart failure decompensation on treatment day.
• History within the preceding 3 months prior to randomization of any of the following events, or any other significant cardiovascular event as judged by the investigator:
• Stroke
• Myocardial infarction
• Unstable angina pectoris or other signs of myocardial ischemia
• Cardiac surgery
• Transcatheter valve replacement
• Percutaneous coronary intervention (PCI)
• Coronary artery bypass graft (CABG) or other revascularization procedure
• Severe renal impairment, i.e., estimated glomerular filtration rate (eGFR) \<30 mL/min/1.73m² (using CKD-EPI formula) or requiring dialysis

Sponsors & Collaborators

• Bayer: lead

Study Sites (27)

UCSF Advanced Heart Failure Comprehensive Care Center

San Francisco, California, 94143, United States

Location

UCHealth University of Colorado Hospital - Cardiology

Aurora, Colorado, 80045, United States

Location

Massachusetts General Hospital - Cardiology

Boston, Massachusetts, 02114, United States

Location

Henry Ford Hospital - Cardiology

Detroit, Michigan, 48202, United States

Location

Duke University Hospital - Cardiology

Durham, North Carolina, 27704, United States

Location

UZ Leuven Gasthuisberg - Cardiology diseases department

Leuven, Flemish Brabant, 3000, Belgium

Location

Jessa Ziekenhuis | Hartcentrum Hasselt

Hasselt, Limburg, 3500, Belgium

Location

AZ Delta | Clinical Trial Center - Cardiology

Roeselare, West Flanders, 8800, Belgium

Location

University Multiprofile Hospital For Active Treatment Sveti Georgi' - EAD Department of Intensive Cardiology"

Plovdiv, Plovdiv Province, 4001, Bulgaria

Location

Multiprofile Hospital for Active Treatment Knyaginya Klementina Sofia EAD | Cardiology Department

Sofia, Sofia City Province, 1233, Bulgaria

Location

University Hospital for Active Treatment Tsaritsa Joanna - ISUL | Cardiology Clinic

Sofia, Sofia City Province, 1527, Bulgaria

Location

Multiprofile Hospital for Active Treatment Dr. Stefan Cherkezov | Base 1 - Cardiology Department

Veliko Tarnovo, Veliko Tarnovo Province, 5000, Bulgaria

Location

Medizinische Hochschule Hannover|Kardiologie und Angiologie

Hanover, Lower Saxony, 30625, Germany

Location

Herz-und Diabeteszentrum NRW|Elektrophysiologie/Rhythmologie

Bad Oeynhausen, North Rhine-Westphalia, 32545, Germany

Location

Klinikum Altenburger Land GmbH-Klinik für Kardiologie, Pneumologie und Internistische Intensivmedizin

Altenburg, Thuringia, 04600, Germany

Location

Tolna Vármegyei Balassa János Kórház - I. Belgyógyászati Osztály: Kardiológia, Nefrológia

Szekszárd, Tolna County, 7100, Hungary

Location

Semmelweis Egyetem, Varosmajori Sziv- és Ergyogyaszati Klinika

Budapest, 1122, Hungary

Location

Ente Ecclesiastico Ospedale Generale Regionale Miulli - Cardiologia e UTIC

Acquaviva delle Fonti, 70021, Italy

Location

Centro Cardiologico Monzino S.p.A. - UO Scompenso e Cardiologia Clinica

Milan, 20138, Italy

Location

Azienda Ospedaliero-Universitaria Policlinico Umberto I - Malattie Cardiovascolari

Roma, 00161, Italy

Location

Azienda Ospedaliero Universitaria Delle Marche - Clinica di Cardiologia e Aritmologia

Torrette, 60126, Italy

Location

Maastricht UMC

Maastricht, Limburg, 6229 HX, Netherlands

Location

Universitair Medisch Centrum Groningen

Groningen, 9713 GZ, Netherlands

Location

American Heart of Poland S.A. - PAKS Centrum Kardiologii i Kardiochirurgii w Bielsku-Białej - Oddział Kardiologii

Bielsko-Biala, 43-316, Poland

Location

American Heart of Poland S.A. - MCSN, PAKS w Chrzanowie - Oddział Intensywnej Opieki Kardiologicznej

Chrzanów, 32-500, Poland

Location

Samodzielny Publiczny Specjalistyczny Szpital Zachodni im. sw. Jana Pawla II

Grodzisk Mazowiecki, 05 825, Poland

Location

USK nr 4 w Lublinie - Kliniczny Odd. Kardiologii, Reh. Kardio., Ch. Wew. z Pododdzialem Intensywnej Opieki Kardio.

Lublin, 20-090, Poland

Location

MeSH Terms

Conditions

Atrial Fibrillation

Condition Hierarchy (Ancestors)

Arrhythmias, Cardiac; Heart Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Central Study Contacts

Bayer Clinical Trials Contact

CONTACT

18888422937; clinical-trials-contact@bayer.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 13, 2026
• First Posted: June 4, 2026
• Study Start (Estimated): August 31, 2026
• Primary Completion (Estimated): May 16, 2030
• Study Completion (Estimated): May 16, 2030
• Last Updated: July 30, 2026

Record last verified: 2026-06-02

Data Sharing

• IPD Sharing: Will not share

Locations

DE (3); BE (3); HU (2); US (5); BU (4); PL (4); NL (2); IT (4)