***These patients experienced a 74% (p = 0.0003) reduction in risk of AF versus no detectable reduction in patients who had alternative genotypes (beta1389 Gly carriers; 53% of the patients) who had received placebo. The Company believes this data supports the potential ability of Gencaro to prevent AF in patients who have the genotype the Company believes responds most favorably to Gencaro.
GENETIC-AF Clinical Trial
GENETIC-AF is planned as a Phase 2B/3, multi-center, randomized, double-blind clinical trial comparing Gencaro to metoprolol CR/XL for prevention of AF in patients with heart failure and reduced left ventricular ejection fraction (HFREF). ARCA plans to enroll only patients with the genetic variant of the beta-1 cardiac receptor which the Company believes responds most favorably to Gencaro. GENETIC-AF has an adaptive design, under which the Company plans to initiate it as a Phase 2B study in approximately 200 patients and then, depending on the results of an interim analysis by the trial Data Safety Monitoring Board (DSMB), expand the trial to a Phase 3 study by enrolling an estimated additional 420 patients.
Under the collaboration with Medtronic, ARCA plans to conduct a substudy that will include continuous monitoring of the cardiac rhythms of all 200 patients enrolled during the Phase 2B portion of GENETIC-AF. Each patient will have heart rhythm monitoring via a Medtronic device, either a previously implanted cardiac resynchronization or defibrillation device, or a previously or newly inserted Reveal® loop recorder. The collaboration substudy will measure AF burden, defined as a patient’s actual time in AF regardless of symptoms. For the DSMB interim analysis, AF burden and the primary endpoint of the study, time to recurrence of symptomatic AF after electrical cardioversion, or death, will be reviewed by the DSMB to determine if there is sufficient potential for a statistically significant efficacy signal to be determined for all patients enrolled in the Phase 2B/3 study.
Gencaro Data in Atrial Fibrillation
Clinical data analysis from a post-hoc review of patient forms from the from BEST trial, a Phase 3 trial in 2,708 patients with advanced heart failure, indicate that Gencaro may have a potentially enhanced and pharmacogenetically-influenced effect in reducing and preventing AF. In that trial, patients in the Gencaro arm had a reduction in the risk of new onset AF time to event compared to patients in the placebo arm of 41% (AF measured as an adverse event/serious adverse event or as detected on surveillance ECGs, time to event analysis, p = 0.0004). In a 1,040 patient DNA substudy of BEST, Gencaro exhibited potential pharmacogenetic enhancement and differentiation for AF prevention in patients with a specific genotype (beta1389 arginine homozygous (Arg/Arg) adrenergic receptor (AR); approximately 47% of the patients). These patients experienced a 74% (p = 0.0003) reduction in risk of AF versus no detectable reduction in patients who had alternative genotypes (beta1389 Gly carriers; 53% of the patients) who had received placebo. The Company believes this data supports the potential ability of Gencaro to prevent AF in patients who have the genotype the Company believes responds most favorably to Gencaro.
In prior placebo controlled trials of beta blockers in chronic HFREF, most studies comparing beta-blockers to placebo have detected a positive signal for prevention of AF, with an event rate reduction averaging approximately 27%, although AF had not been a pre-specified primary or secondary endpoint in these studies. Currently, no beta-blocker has been approved by the U.S. Food and Drug Administration for the prevention of
AF in heart failure patients.
Gencaro™ [Bucindolol Hydrochloride]
ARCA is currently developing Gencaro™ (tradename pending FDA approval) (bucindolol hydrochloride) for the prevention of atrial fibrillation and the treatment of chronic heart failure. Gencaro™ is a pharmacologically unique beta-blocker and mild vasodilator. Gencaro™ is considered part of the beta-blocker class because of its property of blocking beta-1 as well as beta-2 receptors in the heart, preventing these receptors from binding with other molecules that would otherwise activate the receptor. Because of its mild vasodilator effects, the Company believes Gencaro™ is well-tolerated in patients with advanced HF. ARCA has identified common genetic variations, or genetic markers, that it believes predict patient response to Gencaro™.