Acusphere exceeded the criteria for success for two of the primary endpoints, accuracy and sensitivity, in RAMP-2, its second Phase 3 clinical trial of Imagify, (perflubutane polymer microspheres) injectable suspension. All three of the ultrasound blinded readers had superior sensitivity and non-inferior accuracy to nuclear stress, the most frequently used imaging procedure for the assessment of coronary artery disease.
Though RAMP-2 did not achieve the specificity endpoint, the company said it had previously reported superior specificity for Imagify in its first Phase 3 trial, RAMP-1. High accuracy and sensitivity were the top priorities in RAMP-2. The company stated that these results will support a strong NDA submission in Q4 2007.
"Cardiologists put greater importance on sensitivity for patients with higher risk of disease and on specificity for patients with lower risk of disease," commented Richard Walovitch, Ph.D., senior vice president of clinical research at Acusphere. "We believe that we have now demonstrated that Imagify is non-inferior to nuclear stress, producing non-inferior accuracy in both trials, superior sensitivity in RAMP-2's higher risk patient population and superior specificity in RAMP-1's lower risk patient population. I am excited about these data."
Imagify is the first ultrasound contrast agent designed to assess perfusion. Myocardial perfusion is blood flow in the heart muscle and is a sensitive marker of coronary artery disease. Currently, perfusion information is not available using cardiac ultrasound but must be obtained using a nuclear stress test.