GencaroTM's Norepinephrine Lowering Likely Contributes to Its Effect in Atrial Fibrillation Prevention

ARCA biopharma, Inc.

today announced results of analyses of atrial fibrillation data from the BEST trial, a previously conducted Phase 3 heart failure trial involving Gencaro (bucindolol hydrochloride), in 2,708 advanced heart failure patients. Researchers believe increasing plasma norepinephrine levels as a measure of adrenergic activity herald worsening of HF in patients with reduced left ventricular ejection fractions. In this new analysis, researchers, including Dr. Michael R. Bristow, ARCA's CEO, found that patients who developed new onset AF during the BEST trial had higher baseline NE levels than patients who did not develop AF. NE levels at three months decreased in the Gencaro subgroups compared to placebo subgroups. Researchers believe this sympatholytic effect likely contributed to an associated 41% reduction in the risk of developing AF for the 1,202 Gencaro patient cohort without AF at baseline. As previously reported at the American Heart Association's Scientific Sessions 2011, Gencaro reduced the risk of developing AF by 74% in the genetic subgroup that was homozygous for the 389 arginine version of the beta-1 adrenergic receptor, which has high affinity for norepinephrine. Researchers found that Gencaro's norepinephrine lowering properties appear to contribute to its effects in all HFREF patients, but in particular those who have only beta-1 389 arginine receptors.