OBI’s Oxycyte improves imaging of penumbra following acute ischemic stroke

Oxygen Biotherapeutics, Inc. ("OBI") (NASDAQ: OXBT) announced today that recent research conducted by its partner, Aurum Biosciences ("Aurum"), Glasgow, Scotland, has shown that Oxycyte^®, OBI's proprietary perfluorocarbon-based intravenous emulsion, improves imaging of the penumbra following acute ischemic stroke in a rat model. The penumbra is the region of the brain where blood supply is inadequate to support normal brain function but sufficient to maintain tissue viability for a limited period of time following stroke. It represents potentially salvageable tissue which, if the oxygen supply can be restored, could lead to improved functional outcomes for stroke patients.

In the clinical management of stroke, it is important to accurately identify patients with potentially salvageable penumbral tissue. The development of neuroprotective agents continues to be complicated due to the absence of accurate diagnostic imaging as patients with no remaining penumbra are enrolled in clinical trials. The gold standard for identification of penumbra based on metabolism is PET; however, this technique has low resolution and involves injection of radioisotopes, making it impractical as a routine clinical tool. Aurum scientists have been working for a number of years to develop a rapid and sensitive MRI-based diagnostic technique.

Aurum's T2 Oxygen Challenge (OC) MRI imaging technique is based on conversion of deoxyhemoglobin to oxyhemoglobin, a change made possible by Oxycyte's ability to provide oxygen into areas otherwise inaccessible to red blood cells. The use of Oxycyte allows for greater efficiency in oxygen delivery, reducing the OC from 100% to 50% oxygen, thus avoiding potential toxicities associated with 100% oxygen inhalation. This work, conducted by researchers at the University of Glasgow Institute of Neuroscience & Psychology, was presented at the prestigious Gordon Research Conference on Brain Metabolism Energy & Blood Flow held at Colby College in Waterville, Maine on August 11-12, 2012.

The development of this improved diagnostic technique paves the way for follow-on research by Aurum scientists, in accord with a research agreement in place between Aurum Biosciences and Oxygen Biotherapeutics, to investigate the therapeutic potential of Oxycyte in the treatment of acute ischemic stroke. Planned preclinical studies will investigate the use of Oxycyte combined with normobaric hyperoxia to improve oxygen delivery to the ischemic brain tissue, limiting brain damage and extending the lifespan of potentially salvageable penumbra thereby increasing the therapeutic time window for thrombolytic therapy. The use of recombinant tissue plasminogen activator (rt-PA) thrombolytic therapy is currently the only licensed therapeutic option for ischemic stroke but few patients (<5%) present early enough to receive treatment.

Timothy Bradshaw, Ph.D., Executive Vice President of Drug Development at OBI said, "We are excited by the data coming out of our partnership with Aurum Biosciences. Based on our clinical studies in traumatic brain injury, we already know of Oxycyte's ability to supply oxygen to badly injured tissues. Developing the product for acute ischemic stroke is a rather obvious extension of that work. While there is still much to be done, the possibility of neurologists having both a diagnostic tool and an interventional drug in the same product is going to garner the attention of the medical community."

Added Gerry McGettigan, Chief Executive Officer of Aurum: "This is another important piece of data to add to our growing body of evidence supporting the combined use of Oxycyte and Aurum's MRI techniques in the management of acute stroke. We look forward to completing the research and preclinical development work with our colleagues at OBI, and moving towards clinical trials at the earliest opportunity."