IDE Study Begins for TherOx's Next-Generation Supersaturated Oxygen Therapy to Treat AMI

February 6, 2013—TherOx, Inc. (Irvine, CA) announced the initiation of a multicenter investigational device exemption (IDE) pilot study of the company's second-generation system that delivers supersaturated oxygen (SSO₂) therapy to reduce infarct size after an acute myocardial infarction.

The pilot phase of the IDE study will enroll 20 patients at five medical centers in the United States. The first patient in the trial was treated by Amr Abbas, MD, Director of Interventional Cardiology Research at Beaumont Hospital in Royal Oak, Michigan.

The Principal Investigator for the IDE trial is Gregg W. Stone, MD, Professor of Medicine at Columbia University Medical Center in New York City. Other investigators include Simon Dixon, MD, Chair of Cardiovascular Medicine at Beaumont Hospital; Shukri David, MD, at Providence Hospital Cardiology in Detroit, Michigan; Chris Metzger, MD, at Wellmont CVA Heart Institute at Holston Valley Medical Center in Kingsport, Tennessee; and David Rizik, MD, at Scottsdale Heart Group in Scottsdale, Arizona.

The company stated that SSO2 therapy is intended to provide interventional cardiologists with the first treatment option beyond percutaneous coronary intervention (PCI) to salvage heart muscle in heart attack patients. SSO2 therapy, an adjunct to PCI, is a solution of highly oxygenated saline mixed with the patient's blood that is delivered through a catheter to the targeted ischemic area of the heart. SSO2 therapy is intended to salvage the jeopardized myocardium and thus reduce infarct size.

Dr. Dixon, who was also involved in the previous SSO2 therapy trial, AMIHOT II, commented in the TherOx press release, “During AMIHOT II, we found the infarct size reduction achieved by SSO2 therapy was clinically significant. Because of this, I believe SSO2 therapy shows great potential in improving outcomes for high-risk patients.”

Dr. Stone stated, “Randomized clinical studies show that final infarct size correlates with improved cardiac function as well as mortality in heart attack patients. Further reducing infarct size in heart attack patients is an unmet clinical need, which SSO2 Therapy may help address.”

The first-generation system received European CE Mark approval and was successful in meeting the safety and effectiveness endpoints in the AMIHOT II trial. Statistical results from the AMIHOT II trial of SSO2 therapy, together with PCI and stenting, demonstrated a relative reduction of 26% in infarct size compared to PCI and stenting alone. In addition, the finding of device effectiveness was supported by additional analyses that showed a 53% increased likelihood of having a small (< 5% damage of the left ventricle) infarct among SSO2 therapy patients. The results were published in October 2009 in Circulation: Cardiovascular Interventions (2009;2:366–375).

The company advised that this study of the second-generation system builds on the success of AMIHOT II and includes the additional benefits of shortening the treatment time to 60 minutes and broadening the treatment area to the entire left coronary system so that no ischemic area goes untreated. SSO2 therapy is consistent with the 90-minute door-to-balloon initiative and supports the current guidelines for interventional cardiology procedures. In the United States, SSO2 therapy is delivered by an investigational device, which is limited by law to investigational use and is not for sale or distribution in the United States.