{"success":true,"data":{"pressRelease":{"id":"138987","rtpr_id":"nBw6GGxyMa-20260909","ticker":"BAYGN","exchange":"XETRA","all_tickers":["BAYGN"],"title":"BAYER INITIATES PHASE II STUDY OF INVESTIGATIONAL GIRK4 INHIBITOR IN PATIENTS WITH ATRIAL FIBRILLATION","author":"Business Wire","published_at":"2026-09-09T11:42:00.139Z","article_body":"BAYER INITIATES PHASE II STUDY OF INVESTIGATIONAL GIRK4 INHIBITOR IN PATIENTS\nWITH ATRIAL FIBRILLATION\n\n\n * GIRK4 (BAY 3670549) is an investigational highly selective G-protein-coupled\ninwardly rectifying potassium channel 4 (GIRK4) inhibitor being evaluated as a\npotential new approach to control the electrical activity of cardiomyocytes in\npatients with atrial fibrillation (AFib)\n\n * AFib is the most common type of sustained cardiac arrhythmia (irregular heart\nrhythm), affecting more than 60 million people worldwide, and a significant\nrisk factor for stroke and heart failure(1,2,3)\n\n * Positive data from the Phase I first-in-human, dose-escalation study supports\nadvancing GIRK4 inhibitor to the next phase of development\n\n * Derived from the strategic research alliance with the Broad Institute of MIT\nand Harvard, BAY 3670549 further strengthens Bayer’s cardiovascular\ndevelopment portfolio\n\nNot intended for UK Media\n\nBayer announced today the initiation of a global Phase II clinical trial\n(NCT07625215\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fclinicaltrials.gov%2Fstudy%2FNCT07625215%3FlocStr%3DUnited%2520States%26country%3DUnited%2520States%26aggFilters%3Dstatus%3A&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=NCT07625215&index=1&md5=f2c2e46c299b60afa061da85f19d8d1d)\n) evaluating BAY 3670549, an investigational highly selective\nG-protein-coupled inwardly rectifying potassium channel 4 (GIRK4) inhibitor,\nwhich has the potential as a new approach to control the electrical activity\nof heart cells in patients with atrial fibrillation (AFib). The Phase II\nsingle-treatment study in a randomized, double-blind, placebo-controlled,\nparallel-group, multi-cohort design, will investigate the efficacy, safety and\ntolerability, as well as pharmacodynamics and pharmacokinetics of BAY 3670549\nin adult patients with AFib. BAY 3670549 showed a generally favorable safety\nand tolerability profile in healthy participants in the completed\nfirst-in-human single-ascending-dose Phase I study, supporting its continued\nclinical advancement and strengthening Bayer’s cardiovascular development\nportfolio.\n\nBAY 3670549, which emerged from Bayer’s strategic research alliance with the\nBroad Institute, is being investigated as a novel approach for rapid\ncardioversion to normal sinus rhythm. If successful, it could provide a\npotential alternative to electrical cardioversion, the current gold standard\nfor AFib.\n\nAFib is the most common type of sustained cardiac arrhythmia (irregular heart\nrhythm), affecting more than 60 million people worldwide, and a significant\nrisk factor for stroke and heart failure.(4,5,6)\n\nAbout GIRK4 inhibitor (BAY 3670549)\n\nBAY 3670549 is an investigational highly selective G-protein-coupled inwardly\nrectifying potassium channel 4 (GIRK4) inhibitor being evaluated as a\npotential new approach to help control the electrical activity of heart cells\nin patients with atrial fibrillation (AFib).\n\nGIRK4 channels are specialized proteins that regulate the electrical activity\nof heart cells by facilitating the flow of potassium ions (K+) in response to\nthe neurotransmitter acetylcholine (ACh). This mechanism is particularly\ncrucial during the later phases of the heart’s electrical signaling,\nspecifically during the atrial effective refractory period (AERP). Increased\nactivity of these channels shortens the AERP in the atria (the upper chambers\nof the heart), thereby reducing the recovery time after each heartbeat. This\nalteration in recovery time can contribute to the onset and persistence of\nAFib.\n\nAbout the study (NCT07625215\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fclinicaltrials.gov%2Fstudy%2FNCT07625215%3FlocStr%3DUnited%2520States%26country%3DUnited%2520States%26aggFilters%3Dstatus%3A&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=NCT07625215&index=2&md5=e88781998944256ae60f871ed89c0b27)\n)\n\nA placebo-controlled, parallel-group, double blind, randomized, multi-cohort\nPhase II study will investigate efficacy, safety, tolerability,\npharmacodynamics and pharmacokinetics of BAY 3670549 in adult participants\nwith AFib.\n\nThe study will compare BAY 3670549 to a placebo in patients with AFib who need\na treatment called electrical cardioversion. Electrical cardioversion is a\nprocedure that helps the heart return to a normal rhythm.\n\nIn the Phase I study, BAY 3670549 was generally well-tolerated in healthy male\nand female participants.\n\nAbout Atrial fibrillation\n\nAFib is one of the most common sustained cardiac rhythm disorders\n(arrhythmias). It results from rapid, disorganized electrical signals in the\nupper chambers (atria) of the heart, causing them to quiver and contract\nquickly and irregularly. As a result, the atria do not empty efficiently,\nleading to impaired blood flow and an increased risk of blood clot formation.\nThese clots can break loose, travel to the brain, and cause a stroke. In\naddition, AFib disrupts the coordinated function of the upper and lower\nchambers of the heart, impairing overall cardiac performance and leading to\nsymptoms such as palpitations, shortness of breath, fatigue, and a reduced\nquality of life in many patients. The prevalence of AFib continues to increase\nglobally. Projection studies show that the number of people with AFib will\nrise to 15.9 million in 2050 in America and 17.9 million in 2060 in Europe.(7)\nPeople with AFib are 5 times more likely to suffer a stroke than people\nwithout AFib.(8) AFib-related strokes are also associated with a 50%\nlikelihood of death within one year.(9)\n\nAbout Bayer\n\nBayer is a global enterprise with core competencies in the life science fields\nof health care and nutrition. In line with its mission, “Health for all,\nHunger for none,” the company’s products and services are designed to help\npeople and the planet thrive by supporting efforts to master the major\nchallenges presented by a growing and aging global population. Bayer is\ncommitted to driving sustainable development and generating a positive impact\nwith its businesses. At the same time, the Group aims to increase its earning\npower and create value through innovation and growth. The Bayer brand stands\nfor trust, reliability and quality throughout the world. In fiscal 2025, the\nGroup employed around 88,000 people and had sales of 45.6 billion euros.\nR&D expenses amounted to 5.8 billion euros. For more information, go to\nwww.bayer.com\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.bayer.com&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=www.bayer.com&index=3&md5=866283f93d5ba360b0ddd5bb75e297b4)\n.\n\nFind more information at https://pharma.bayer.com/ \n(https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fpharma.bayer.com%2F&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=https%3A%2F%2Fpharma.bayer.com%2F&index=4&md5=7a2179357fa81754ac96b72cadff82f3)\n\nFollow us on Facebook: http://www.facebook.com/bayer\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.facebook.com%2Fbayer&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=http%3A%2F%2Fwww.facebook.com%2Fbayer&index=5&md5=188e3213839b46f212a38951ae5163ff)\n\naka (2026-0153e)\n\nForward-Looking Statements\n\nThis release may contain forward-looking statements based on current\nassumptions and forecasts made by Bayer management. Various known and unknown\nrisks, uncertainties and other factors could lead to material differences\nbetween the actual future results, financial situation, development or\nperformance of the company and the estimates given here. These factors include\nthose discussed in Bayer’s public reports which are available on the Bayer\nwebsite at www.bayer.com\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fwww.bayer.com%2Fen&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=www.bayer.com&index=6&md5=aa059fff2ad893539eb3da49a1f5cd17)\n. The company assumes no liability whatsoever to update these forward-looking\nstatements or to conform them to future events or developments.\n\nBayer AG is a holding company with operating subsidiaries worldwide.\nReferences to “Bayer” or “the company” herein may refer to one or more\nsubsidiaries as context requires.\n ____________________________                                                                                                                                                                                                                                                                                                                                                   \n (1) Atrial fibrillation: epidemiology, screening and digital health, Linz,                                                                                                                                                                                                                                                                                                     \n Dominik et al., The Lancet Regional Health – Europe, Volume 37, 100786                                                                                                                                                                                                                                                                                                         \n (2) American Heart Association, Why Atrial Fibrillation Matters | American                                                                                                                                                                                                                                                                                                     \n Heart Association                                                                                                                                                                                                                                                                                                                                                              \n (https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fwww.heart.org%2Fen%2Fhealth-topics%2Fatrial-fibrillation%2Fwhy-atrial-fibrillation-af-or-afib-matters&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=Why+Atrial+Fibrillation+Matters+%7C+American+Heart+Association&index=7&md5=a5ec178e7d811eca5c9dade992b6defe)                               \n (3) Kornej J, Benjamin EJ, Magnani JW, Atrial fibrillation: global burdens and                                                                                                                                                                                                                                                                                                 \n global opportunities, Heart 2021;107:516-518.                                                                                                                                                                                                                                                                                                                                  \n (4) Atrial fibrillation: epidemiology, screening and digital health, Linz,                                                                                                                                                                                                                                                                                                     \n Dominik et al., The Lancet Regional Health – Europe, Volume 37, 100786                                                                                                                                                                                                                                                                                                         \n (5) American Heart Association, Why Atrial Fibrillation Matters | American                                                                                                                                                                                                                                                                                                     \n Heart Association                                                                                                                                                                                                                                                                                                                                                              \n (https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fwww.heart.org%2Fen%2Fhealth-topics%2Fatrial-fibrillation%2Fwhy-atrial-fibrillation-af-or-afib-matters&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=Why+Atrial+Fibrillation+Matters+%7C+American+Heart+Association&index=8&md5=a94489af05fd7876d802b15b12da3111)                               \n (6) Kornej J, Benjamin EJ, Magnani JW, Atrial fibrillation: global burdens and                                                                                                                                                                                                                                                                                                 \n global opportunities, Heart 2021;107:516-518.                                                                                                                                                                                                                                                                                                                                  \n (7) Atrial fibrillation: epidemiology, screening and digital health, Linz,                                                                                                                                                                                                                                                                                                     \n Dominik et al., The Lancet Regional Health – Europe, Volume 37, 100786                                                                                                                                                                                                                                                                                                         \n (8) Singleton MJ, Imtiaz‐Ahmad M, Kamel H, O'Neal WT, Judd SE, Howard VJ,                                                                                                                                                                                                                                                                                                      \n Howard G, Soliman EZ, Bhave PD. Association of atrial fibrillation without                                                                                                                                                                                                                                                                                                     \n cardiovascular comorbidities and stroke risk: from the REGARDS study. Journal                                                                                                                                                                                                                                                                                                  \n of the American Heart Association. 2020 Jun 16;9(12):e016380.                                                                                                                                                                                                                                                                                                                  \n (9) Alberts M, Chen YW, Lin JH, Kogan E, Twyman K, Milentijevic D. Risks of                                                                                                                                                                                                                                                                                                    \n Stroke and Mortality in Atrial Fibrillation Patients Treated With Rivaroxaban                                                                                                                                                                                                                                                                                                  \n and Warfarin. Stroke. 2020 Feb;51(2):549-555. doi:                                                                                                                                                                                                                                                                                                                             \n 10.1161/STROKEAHA.119.025554. Epub 2019 Dec 31. PMID: 31888412; PMCID:                                                                                                                                                                                                                                                                                                         \n PMC7004448.                                                                                                                                                                                                                                                                                                                                                                    \n\n\n \n\n\n\nView source version on businesswire.com:\nhttps://www.businesswire.com/news/home/20260908525929/en/\n(https://www.businesswire.com/news/home/20260908525929/en/)\n\nBayer U.S. Media Contact: \n\nElaine Colon, phone +1 732 236 1587 \n\nEmail: elaine.colon@bayer.com (mailto:elaine.colon@bayer.com)\n\nBayer Media Contact: \n\nAnna Kanmaz, phone +49 174 146 3541 \n\nEmail: anna.kanmaz@bayer.com (mailto:anna.kanmaz@bayer.com)\n\n\nCopyright Business Wire 2026","article_body_html":"","raw_payload":{"data":{"id":"nBw6GGxyMa-20260909","title":"BAYER INITIATES PHASE II STUDY OF INVESTIGATIONAL GIRK4 INHIBITOR IN PATIENTS WITH ATRIAL FIBRILLATION","author":"Business Wire","ticker":"BAYGN","created":"2026-09-09T11:42:00.139Z","tickers":["BAYGN"],"exchange":"XETRA","article_body":"BAYER INITIATES PHASE II STUDY OF INVESTIGATIONAL GIRK4 INHIBITOR IN PATIENTS\nWITH ATRIAL FIBRILLATION\n\n\n * GIRK4 (BAY 3670549) is an investigational highly selective G-protein-coupled\ninwardly rectifying potassium channel 4 (GIRK4) inhibitor being evaluated as a\npotential new approach to control the electrical activity of cardiomyocytes in\npatients with atrial fibrillation (AFib)\n\n * AFib is the most common type of sustained cardiac arrhythmia (irregular heart\nrhythm), affecting more than 60 million people worldwide, and a significant\nrisk factor for stroke and heart failure(1,2,3)\n\n * Positive data from the Phase I first-in-human, dose-escalation study supports\nadvancing GIRK4 inhibitor to the next phase of development\n\n * Derived from the strategic research alliance with the Broad Institute of MIT\nand Harvard, BAY 3670549 further strengthens Bayer’s cardiovascular\ndevelopment portfolio\n\nNot intended for UK Media\n\nBayer announced today the initiation of a global Phase II clinical trial\n(NCT07625215\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fclinicaltrials.gov%2Fstudy%2FNCT07625215%3FlocStr%3DUnited%2520States%26country%3DUnited%2520States%26aggFilters%3Dstatus%3A&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=NCT07625215&index=1&md5=f2c2e46c299b60afa061da85f19d8d1d)\n) evaluating BAY 3670549, an investigational highly selective\nG-protein-coupled inwardly rectifying potassium channel 4 (GIRK4) inhibitor,\nwhich has the potential as a new approach to control the electrical activity\nof heart cells in patients with atrial fibrillation (AFib). The Phase II\nsingle-treatment study in a randomized, double-blind, placebo-controlled,\nparallel-group, multi-cohort design, will investigate the efficacy, safety and\ntolerability, as well as pharmacodynamics and pharmacokinetics of BAY 3670549\nin adult patients with AFib. BAY 3670549 showed a generally favorable safety\nand tolerability profile in healthy participants in the completed\nfirst-in-human single-ascending-dose Phase I study, supporting its continued\nclinical advancement and strengthening Bayer’s cardiovascular development\nportfolio.\n\nBAY 3670549, which emerged from Bayer’s strategic research alliance with the\nBroad Institute, is being investigated as a novel approach for rapid\ncardioversion to normal sinus rhythm. If successful, it could provide a\npotential alternative to electrical cardioversion, the current gold standard\nfor AFib.\n\nAFib is the most common type of sustained cardiac arrhythmia (irregular heart\nrhythm), affecting more than 60 million people worldwide, and a significant\nrisk factor for stroke and heart failure.(4,5,6)\n\nAbout GIRK4 inhibitor (BAY 3670549)\n\nBAY 3670549 is an investigational highly selective G-protein-coupled inwardly\nrectifying potassium channel 4 (GIRK4) inhibitor being evaluated as a\npotential new approach to help control the electrical activity of heart cells\nin patients with atrial fibrillation (AFib).\n\nGIRK4 channels are specialized proteins that regulate the electrical activity\nof heart cells by facilitating the flow of potassium ions (K+) in response to\nthe neurotransmitter acetylcholine (ACh). This mechanism is particularly\ncrucial during the later phases of the heart’s electrical signaling,\nspecifically during the atrial effective refractory period (AERP). Increased\nactivity of these channels shortens the AERP in the atria (the upper chambers\nof the heart), thereby reducing the recovery time after each heartbeat. This\nalteration in recovery time can contribute to the onset and persistence of\nAFib.\n\nAbout the study (NCT07625215\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fclinicaltrials.gov%2Fstudy%2FNCT07625215%3FlocStr%3DUnited%2520States%26country%3DUnited%2520States%26aggFilters%3Dstatus%3A&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=NCT07625215&index=2&md5=e88781998944256ae60f871ed89c0b27)\n)\n\nA placebo-controlled, parallel-group, double blind, randomized, multi-cohort\nPhase II study will investigate efficacy, safety, tolerability,\npharmacodynamics and pharmacokinetics of BAY 3670549 in adult participants\nwith AFib.\n\nThe study will compare BAY 3670549 to a placebo in patients with AFib who need\na treatment called electrical cardioversion. Electrical cardioversion is a\nprocedure that helps the heart return to a normal rhythm.\n\nIn the Phase I study, BAY 3670549 was generally well-tolerated in healthy male\nand female participants.\n\nAbout Atrial fibrillation\n\nAFib is one of the most common sustained cardiac rhythm disorders\n(arrhythmias). It results from rapid, disorganized electrical signals in the\nupper chambers (atria) of the heart, causing them to quiver and contract\nquickly and irregularly. As a result, the atria do not empty efficiently,\nleading to impaired blood flow and an increased risk of blood clot formation.\nThese clots can break loose, travel to the brain, and cause a stroke. In\naddition, AFib disrupts the coordinated function of the upper and lower\nchambers of the heart, impairing overall cardiac performance and leading to\nsymptoms such as palpitations, shortness of breath, fatigue, and a reduced\nquality of life in many patients. The prevalence of AFib continues to increase\nglobally. Projection studies show that the number of people with AFib will\nrise to 15.9 million in 2050 in America and 17.9 million in 2060 in Europe.(7)\nPeople with AFib are 5 times more likely to suffer a stroke than people\nwithout AFib.(8) AFib-related strokes are also associated with a 50%\nlikelihood of death within one year.(9)\n\nAbout Bayer\n\nBayer is a global enterprise with core competencies in the life science fields\nof health care and nutrition. In line with its mission, “Health for all,\nHunger for none,” the company’s products and services are designed to help\npeople and the planet thrive by supporting efforts to master the major\nchallenges presented by a growing and aging global population. Bayer is\ncommitted to driving sustainable development and generating a positive impact\nwith its businesses. At the same time, the Group aims to increase its earning\npower and create value through innovation and growth. The Bayer brand stands\nfor trust, reliability and quality throughout the world. In fiscal 2025, the\nGroup employed around 88,000 people and had sales of 45.6 billion euros.\nR&D expenses amounted to 5.8 billion euros. For more information, go to\nwww.bayer.com\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.bayer.com&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=www.bayer.com&index=3&md5=866283f93d5ba360b0ddd5bb75e297b4)\n.\n\nFind more information at https://pharma.bayer.com/ \n(https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fpharma.bayer.com%2F&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=https%3A%2F%2Fpharma.bayer.com%2F&index=4&md5=7a2179357fa81754ac96b72cadff82f3)\n\nFollow us on Facebook: http://www.facebook.com/bayer\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.facebook.com%2Fbayer&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=http%3A%2F%2Fwww.facebook.com%2Fbayer&index=5&md5=188e3213839b46f212a38951ae5163ff)\n\naka (2026-0153e)\n\nForward-Looking Statements\n\nThis release may contain forward-looking statements based on current\nassumptions and forecasts made by Bayer management. Various known and unknown\nrisks, uncertainties and other factors could lead to material differences\nbetween the actual future results, financial situation, development or\nperformance of the company and the estimates given here. These factors include\nthose discussed in Bayer’s public reports which are available on the Bayer\nwebsite at www.bayer.com\n(https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fwww.bayer.com%2Fen&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=www.bayer.com&index=6&md5=aa059fff2ad893539eb3da49a1f5cd17)\n. The company assumes no liability whatsoever to update these forward-looking\nstatements or to conform them to future events or developments.\n\nBayer AG is a holding company with operating subsidiaries worldwide.\nReferences to “Bayer” or “the company” herein may refer to one or more\nsubsidiaries as context requires.\n ____________________________                                                                                                                                                                                                                                                                                                                                                   \n (1) Atrial fibrillation: epidemiology, screening and digital health, Linz,                                                                                                                                                                                                                                                                                                     \n Dominik et al., The Lancet Regional Health – Europe, Volume 37, 100786                                                                                                                                                                                                                                                                                                         \n (2) American Heart Association, Why Atrial Fibrillation Matters | American                                                                                                                                                                                                                                                                                                     \n Heart Association                                                                                                                                                                                                                                                                                                                                                              \n (https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fwww.heart.org%2Fen%2Fhealth-topics%2Fatrial-fibrillation%2Fwhy-atrial-fibrillation-af-or-afib-matters&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=Why+Atrial+Fibrillation+Matters+%7C+American+Heart+Association&index=7&md5=a5ec178e7d811eca5c9dade992b6defe)                               \n (3) Kornej J, Benjamin EJ, Magnani JW, Atrial fibrillation: global burdens and                                                                                                                                                                                                                                                                                                 \n global opportunities, Heart 2021;107:516-518.                                                                                                                                                                                                                                                                                                                                  \n (4) Atrial fibrillation: epidemiology, screening and digital health, Linz,                                                                                                                                                                                                                                                                                                     \n Dominik et al., The Lancet Regional Health – Europe, Volume 37, 100786                                                                                                                                                                                                                                                                                                         \n (5) American Heart Association, Why Atrial Fibrillation Matters | American                                                                                                                                                                                                                                                                                                     \n Heart Association                                                                                                                                                                                                                                                                                                                                                              \n (https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fwww.heart.org%2Fen%2Fhealth-topics%2Fatrial-fibrillation%2Fwhy-atrial-fibrillation-af-or-afib-matters&esheet=54600471&newsitemid=20260908525929&lan=en-US&anchor=Why+Atrial+Fibrillation+Matters+%7C+American+Heart+Association&index=8&md5=a94489af05fd7876d802b15b12da3111)                               \n (6) Kornej J, Benjamin EJ, Magnani JW, Atrial fibrillation: global burdens and                                                                                                                                                                                                                                                                                                 \n global opportunities, Heart 2021;107:516-518.                                                                                                                                                                                                                                                                                                                                  \n (7) Atrial fibrillation: epidemiology, screening and digital health, Linz,                                                                                                                                                                                                                                                                                                     \n Dominik et al., The Lancet Regional Health – Europe, Volume 37, 100786                                                                                                                                                                                                                                                                                                         \n (8) Singleton MJ, Imtiaz‐Ahmad M, Kamel H, O'Neal WT, Judd SE, Howard VJ,                                                                                                                                                                                                                                                                                                      \n Howard G, Soliman EZ, Bhave PD. Association of atrial fibrillation without                                                                                                                                                                                                                                                                                                     \n cardiovascular comorbidities and stroke risk: from the REGARDS study. Journal                                                                                                                                                                                                                                                                                                  \n of the American Heart Association. 2020 Jun 16;9(12):e016380.                                                                                                                                                                                                                                                                                                                  \n (9) Alberts M, Chen YW, Lin JH, Kogan E, Twyman K, Milentijevic D. Risks of                                                                                                                                                                                                                                                                                                    \n Stroke and Mortality in Atrial Fibrillation Patients Treated With Rivaroxaban                                                                                                                                                                                                                                                                                                  \n and Warfarin. Stroke. 2020 Feb;51(2):549-555. doi:                                                                                                                                                                                                                                                                                                                             \n 10.1161/STROKEAHA.119.025554. Epub 2019 Dec 31. PMID: 31888412; PMCID:                                                                                                                                                                                                                                                                                                         \n PMC7004448.                                                                                                                                                                                                                                                                                                                                                                    \n\n\n \n\n\n\nView source version on businesswire.com:\nhttps://www.businesswire.com/news/home/20260908525929/en/\n(https://www.businesswire.com/news/home/20260908525929/en/)\n\nBayer U.S. Media Contact: \n\nElaine Colon, phone +1 732 236 1587 \n\nEmail: elaine.colon@bayer.com (mailto:elaine.colon@bayer.com)\n\nBayer Media Contact: \n\nAnna Kanmaz, phone +49 174 146 3541 \n\nEmail: anna.kanmaz@bayer.com (mailto:anna.kanmaz@bayer.com)\n\n\nCopyright Business Wire 2026"},"type":"article","timestamp":"2026-09-09T11:42:00.174510858Z","server_sent_at_ms":1788954120174},"received_at":"2026-09-09T11:42:00.330Z","source_url":"https://www.businesswire.com/news/home/20260908525929/en/"},"analysis":{"id":"127834","press_release_id":"138987","analysis_json":{"industry":{"label":"Pharmaceuticals","sector":"Health Care"},"redFlags":["Phase I experience is limited to healthy volunteers; no patient efficacy data exists yet for BAY 3670549","Even on success, a Phase II start implies years of development before any regulatory filing or revenue contribution"],"eventType":"clinical_trial","narrative":"Bayer has initiated a global Phase II trial (NCT07625215) of BAY 3670549, an investigational highly selective GIRK4 potassium-channel inhibitor, in adult patients with atrial fibrillation, evaluating efficacy, safety, tolerability, pharmacodynamics and pharmacokinetics.\n\nThe advancement follows a completed first-in-human Phase I single-ascending-dose study in which BAY 3670549 showed a generally favorable safety and tolerability profile in healthy participants, and the asset emerged from Bayer's strategic research alliance with the Broad Institute of MIT and Harvard.\n\nIf successful, the compound could provide a pharmacological alternative to electrical cardioversion, the current gold standard for AFib, a condition affecting more than 60 million people worldwide and a significant stroke and heart-failure risk factor, further strengthening Bayer's cardiovascular development portfolio alongside fiscal 2025 Group sales of 45.6 billion euros.","sentiment":"bullish","agentHooks":{"shouldPost":false,"suggestedAngle":"First-in-class GIRK4 mechanism extends Bayer's cardiovascular pipeline, but this is an early readout-free milestone with commercial impact years away."},"keyFigures":{"revenue":"45.6 billion euros","drugName":"BAY 3670549 (GIRK4 inhibitor)","phaseOfTrial":"Phase II","customDimensions":{"trial_design":"randomized, double-blind, placebo-controlled, parallel-group, multi-cohort","afib_prevalence":"more than 60 million people worldwide","trial_registration":"NCT07625215","fiscal2025_employees":"around 88,000","fiscal2025_rd_expense":"5.8 billion euros"}},"quotedText":"BAY 3670549, which emerged from Bayer’s strategic research alliance with the\nBroad Institute, is being investigated as a novel approach for rapid\ncardioversion to normal sinus rhythm.","namedEntities":{"people":[{"name":"Elaine Colon","role":"Bayer U.S. Media Contact"},{"name":"Anna Kanmaz","role":"Bayer Media Contact"}],"products":["BAY 3670549"],"companies":[{"name":"Bayer AG","relationship":"filer"},{"name":"Broad Institute of MIT and Harvard","relationship":"strategic research alliance partner"}],"dollarAmounts":[{"amount":"45.6 billion euros","context":"Bayer fiscal 2025 Group sales"},{"amount":"5.8 billion euros","context":"Bayer fiscal 2025 R&D expenses"}]},"materialImpact":{"score":2,"reasoning":"Initiation of a Phase II trial is a routine pipeline-advancement milestone, not a binary readout, and it covers a single early-stage asset inside Bayer's diversified portfolio. Positive Phase I tolerability data is supportive but no patient efficacy data exists yet and any commercial impact is years away."},"tickerRelevance":{"others":[],"primary":"BAYGN"},"globalImportance":30,"audienceRelevance":35,"eventTypeSecondary":[],"importanceComponents":{"tickerTier":"mega-cap (DAX-listed, household brand)","eventGravity":"Phase II trial initiation, non-binary milestone","sectorWeight":"pharma pipeline progression","pipelineStage":"Phase 2","nearTermCatalyst":"none — data readout years away","householdBrandBoost":"moderate (Bayer consumer/pharma brand recognition)"}},"event_type":"clinical_trial","event_type_secondary":null,"sentiment":"bullish","material_impact_score":2,"narrative":"Bayer has initiated a global Phase II trial (NCT07625215) of BAY 3670549, an investigational highly selective GIRK4 potassium-channel inhibitor, in adult patients with atrial fibrillation, evaluating efficacy, safety, tolerability, pharmacodynamics and pharmacokinetics.\n\nThe advancement follows a completed first-in-human Phase I single-ascending-dose study in which BAY 3670549 showed a generally favorable safety and tolerability profile in healthy participants, and the asset emerged from Bayer's strategic research alliance with the Broad Institute of MIT and Harvard.\n\nIf successful, the compound could provide a pharmacological alternative to electrical cardioversion, the current gold standard for AFib, a condition affecting more than 60 million people worldwide and a significant stroke and heart-failure risk factor, further strengthening Bayer's cardiovascular development portfolio alongside fiscal 2025 Group sales of 45.6 billion euros.","key_figures":{"revenue":"45.6 billion euros","drugName":"BAY 3670549 (GIRK4 inhibitor)","phaseOfTrial":"Phase II","customDimensions":{"trial_design":"randomized, double-blind, placebo-controlled, parallel-group, multi-cohort","afib_prevalence":"more than 60 million people worldwide","trial_registration":"NCT07625215","fiscal2025_employees":"around 88,000","fiscal2025_rd_expense":"5.8 billion euros"}},"named_entities":{"people":[{"name":"Elaine Colon","role":"Bayer U.S. Media Contact"},{"name":"Anna Kanmaz","role":"Bayer Media Contact"}],"products":["BAY 3670549"],"companies":[{"name":"Bayer AG","relationship":"filer"},{"name":"Broad Institute of MIT and Harvard","relationship":"strategic research alliance partner"}],"dollarAmounts":[{"amount":"45.6 billion euros","context":"Bayer fiscal 2025 Group sales"},{"amount":"5.8 billion euros","context":"Bayer fiscal 2025 R&D expenses"}]},"model_name":"glm-5.3-flash","prompt_hash":"sha256:727b4b9429a443af","schema_hash":"sha256:05005c02d9cffac9","created_at":"2026-09-09T11:45:51.177Z","global_importance":30,"audience_relevance":35,"importance_components":{"tickerTier":"mega-cap (DAX-listed, household brand)","eventGravity":"Phase II trial initiation, non-binary milestone","sectorWeight":"pharma pipeline progression","pipelineStage":"Phase 2","nearTermCatalyst":"none — data readout years away","householdBrandBoost":"moderate (Bayer consumer/pharma brand recognition)"}},"durationMs":58449,"modelName":"glm-5.3-flash"}}