Discovery of potent gap-junction modifiers as novel antiarrhythmic agents: From stable hexa-peptides to orally available small molecules

MEDI 450

John A. Butera, buteraj@wyeth.com1, Bjarne Due Larsen, bdl@zp.dk2, Edward Kerns, Kernse@wyeth.com3, Li Di, Dil@wyeth.com4, James K. Hennan, hennanj@wyeth.com5, Robert Swillo5, Gwen Morgan5, Christine Huselton6, Ray J Unwalla3, and Jørgen Petersen, jsp@zp.dk2. (1) Chemical & Screening Sciences, Wyeth Research, Princeton, NJ, CN 8000, Princeton, NJ 08543, (2) Medicinal Chemistry, Zealand Pharma A/S, Smedeland 26 B, DK-2600, Glostrup, Denmark, (3) Chemical and Screening Sciences, Wyeth Research, CN 8000, Princeton, NJ 08543, (4) Chemical and Screening Sciences, Wyeth Research, Princeton, NJ, CN 8000, Princeton, NJ 08543, (5) Cardiovascular and Metabolic Diseases Research, Wyeth Research, 500 Arcola Road, Collegeville, PA 19426, (6) Biotransfomation Division, Drug Safety and Metabolism, Wyeth Research, 500 Arcola Road, Collegeville, PA 19426
Ventricular and atrial arrhythmias contribute significantly to overall morbidity and mortality in the developed world. Uncontrolled ventricular tachycardia (VT) can quickly cascade to ventricular fibrillation (VF) and then to sudden cardiac death. While less likely to induce sudden death, atrial fibrillation (AF) is a more prevalent form of cardiac arrhythmia which is associated with palpitations, dizziness, angina, hemodynamic impairment, and an increased risk of stroke. Pivotal failed clinical studies have illustrated the unmet medical need to discover safer and more efficacious antiarrhythmic agents. Impaired gap-junction intracellular communication has been implicated as an underlying mechanism for the propagation of unorganized cardiac electrical signals. Rotigaptide, a novel, stable hexapeptide shown to re-establish gap-junctional intercellular communication, is a first-in-class molecule being developed for the prevention (iv) of VT/VF. This presentation will review its discovery and its in vitro and in vivo characterization as a potent and efficacious antiarrhythmic agent. SAR from the hexapeptide series coupled with pharmaceutical profiling and focused screen of an internal small peptide library led to the identification and characterization of several structural classes of orally active small molecule gap-junction modifiers possessing remarkable stability and potency. The second half of the talk will focus on the characterization of these leads as potential agents to treat chronic arrhythmias such as AF.