Phase IIb Study of Vanoxerine Shows Strong Safety and Statistically Significant Efficacy Signals for Treatment of Atrial Fibrillation

DALLAS, Nov. 18, 2013 /PRNewswire/ -- ChanRx, a pharmaceutical company developing medicines for cardiovascular diseases, today announced positive safety and statistically significant efficacy data from a Phase IIb study of vanoxerine (GBR-12909), a drug in development for the treatment of atrial fibrillation. The data were presented yesterday at the American Heart Association 2013 Scientific Sessions.

"Atrial fibrillation affects millions of patients in the US annually, causing substantial morbidity," said Peter Kowey, MD, Professor of Medicine & Pharmacology, Jefferson School of Medicine and Lankenau Institute for Medical Research. "Currently, drugs that correct this arrhythmia are inadequate and carry safety risks including life threatening arrhythmias, long-term toxicity and liver failure. Both the patients with this condition and the physicians treating them could benefit greatly from a drug that could safely treat this arrhythmia."

In the randomized, placebo-controlled trial, 104 patients presenting with symptomatic atrial fibrillation or atrial flutter of recent onset were assigned to one of three doses of vanoxerine or placebo. Vanoxerine was found to be well tolerated at all doses.  Importantly, no episodes of monomorphic or polymorphic ventricular tachycardia were seen. Ventricular tachycardia is a potentially life-threatening arrhythmia that can lead to sudden death. The majority of currently marketed drugs used for atrial fibrillation have a risk of polymorphic ventricular tachycardia.

"Historically, drugs to treat atrial fibrillation have failed, not because they are ineffective, but because they have significant safety issues," noted Arthur "Buzz" Brown, MD, PhD, founder and CEO of ChanTest and founder and CSO of ChanRx. "Thus far, the clinical data showing a lack of pro-arrhythmic effects for vanoxerine are extremely promising and mirror what we saw in preclinical studies. If this clean safety record continues in the presence of this high degree of efficacy, vanoxerine could make a real difference in the care of the millions of people afflicted by AF."

Patients participating in the trial were measured for conversion from atrial fibrillation or flutter to normal sinus rhythm. Overall, there was a highly statistically significant dose-dependent increase in the conversion to normal sinus rhythm (P-value for all doses = 0.0005) compared to placebo. The highest oral dose (400 mg) achieved a conversion rate of 76 percent at 8 hours and 84 percent within the first 24 hours, a rate approaching that of direct current (DC) cardioversion. Patients taking placebo achieved a 25 percent conversion rate at 8 hours and a 38 percent conversion rate at 24 hours.

"Not only has vanoxerine demonstrated very promising safety data, it has statistically significant efficacy signals overall and in the two highest doses tested," said Howard Dittrich, Chief Medical Officer for ChanRx. "The efficacy data, coupled with a remarkable safety profile in this phase II study, bodes well for the next phase of vanoxerine's clinical development."

About Atrial Fibrillation
According to the National Institutes of Health, atrial fibrillation (AF) is the most common type of heart arrhythmia. AF can increase the risk of stroke and can also cause chest pain or heart failure. Treatments for atrial fibrillation include drugs to prevent blood clot formation and drugs that slow down heart rate. Options to control the rhythm of the heart are limited, with DC cardioversion, a non-pharmacological option, being the most common. DC cardioversion is highly effective, but it is a costly, resource-intensive procedure that requires anesthesia and follow up observation. Drug options to control the rhythm of the heart are limited primarily due to toxicity or because they cannot be used widely.

About ChanRx
ChanRx is focused on developing small molecules for cardiovascular diseases. The company was spun out from ChanTest, the world's most trusted ion channel services company with particular expertise in testing pharmaceutical compounds for cardiac safety. Its lead candidate is vanoxerine, a small molecule under development for atrial fibrillation or atrial flutter, which has demonstrated promising data in trials through Phase IIb. ChanRx's Series A funding was provided by Sante Ventures.

SOURCE ChanRx