Spotlight: CorVue could replace adenosine in detecting myocardial ischemia
Imaging using CorVue (binodenoson for injection), a selective adenosine A2a receptor agonist, detects myocardial ischemia as well as imaging using adenosine, yet causes fewer and less severe side effects, according to the results of two trials presented by James E. Udelson, MD, at the 2008 American College of Cardiology (ACC) Scientific Sessions in Chicago.

“The results showed that this new agent, binodenoson, can provide similar imaging information to the clinician as they get with adenosine perfusion imaging, but with far fewer side effects and less intense side effects,” Udelson, associate chief of the division of cardiology, director of nuclear cardiology and co-director of the Heart Failure Center at Tufts-New England Medical Center in Boston, told Health Imaging News.
The side effects commonly reported with adenosine are chest pain, shortness of breath and flushing. “There were similar clinical outcomes, but the overall experience for the patient is a lot better,” Udelson added.

The randomized, multicenter, double-blind crossover trials (VISION 302 and VISION 305), which combined had 765 patients, compared CorVue to the vasodilator adenosine for efficacy and tolerability. Patients completed two rest-stress imaging procedures within seven days in random order, one with CorVue and one with adenosine. Blinded nuclear cardiologists independently read the images and assigned perfusion scores to segments of the ventricle. The efficacy analyses were based on comparison of the extent and severity of ischemia, expressed as summed difference scores (SDS).

“We found that the extent of ischemia was very similar in the patient population with binodenoson, as with adenosine. In other words, the imaging information was very similar with regards to how much ischemia there was,” Udelson said.

The mean paired SDS difference of the CorVue and adenosine images was -0.09 in VISION 302 and -0.68 in VISION 305, and the 95 percent confidence intervals were well within the pre-specified 1.5 SDS units; only 3 percent of the images were determined to be sufficiently discordant, according to Udelson.

In addition, there were no cases of atrioventricular (AV) block, according to the findings.

In fact, Udelson said that there has never been AV blocks with binodenoson, even in the several 100 patients, who were involved in the preliminary trials. “It has never been seen once with binodenoson” he stated.

However, in the VISION trials, between 1 and 3 percent of the adenosine subjects showed AV blocks, according to Udelson.

The researchers also reported that CorVue was preferred over adenosine by seven out of 10 patients studied. Moreover, it achieved the primary trial end points for efficacy and tolerability and is administered as a single bolus dose, making it a potentially easier-to-use alternative agent.

As a result, the trial hit all its primary and secondary endpoints, the latter of which was a reduction in side effects, Udelson said.

King Pharmaceuticals, which funded the study and owns rights to CorVue, said it expects to file a new drug application with the FDA by early 2009.

Udelson speculated that if CorVue receives its FDA approval, the adoption rate of CorVue will depend on pricing. “For me, or for anyone who runs a lab, [with] these types of results, if it’s priced correctly, I’d switch tomorrow,” he noted.

Udelson presented the positive results of the two pivotal Phase III clinical trials during the ACC Late-Breaking Clinical Trials on March 31.