AVI BioPharma Presents Data on Systemic Delivery of NeuGene Antisense Drug to Treat Cardiovascular Restenosis
Studies of Novel Microbubble Carriers of Restenosis Drugs Presented at American College of Cardiology Annual Meeting
PORTLAND, Ore. - April 2, 2003 - AVI BioPharma, Inc., (Nasdaq: AVII, AVIIW, AVIIZ) today announced results from two independent preclinical studies demonstrating the feasibility of treating cardiovascular restenosis using its proprietary microbubble delivery technology in combination with its NeuGene® antisense drug, Resten-NG™. The results of these studies were represented at the American College of Cardiology's annual meeting in Chicago.
Both studies involved the use of a novel microbubble carrier system for systemic delivery of drugs that prevent restenosis. In each study, the microbubbles were coated with a restenosis inhibiting drug and injected intravenously. The drug-coated microbubbles accumulated at the sites of vascular injury, where the drug was then deposited. Together the two studies showed that microbubble delivery was sufficient to prevent restenosis in the relevant animal models.
"By offering an intravenous alternative to catheters and coated stents, the microbubble carrier system represents a major improvement in delivery systems to prevent restenosis following coronary angioplasty," said Denis R. Burger, Ph.D., AVI's CEO. "We're excited about this technology which may offer flexibility in repeated dosing regimens as well as in treatment of smaller vessels, while at the same time reducing procedural complexity. We have plans to initiate a Phase II clinical study in restenosis patients using microbubble technology with Resten-NG later this year. This trial is in addition to a planned Phase III study in restenosis patients using local delivery strategies."
Current approaches to deliver drugs to the site of angioplasty predominantly use drug eluting stents or catheters. These types of local delivery have notable disadvantages including uneven distribution, dosing levels, and an inability to repeat applications. Systemic delivery potentially overcomes these issues but requires low toxicity and must achieve sufficient drug concentrations at the sites of injury for efficacy. AVI has combined the advantages of its third-generation antisense drug Resten-NG with a proprietary systemic delivery system to achieve these requirements.
The first study, titled, "Increased Suppression of Intracoronary C-myc Protein Synthesis Within the Stent or Ballon Injury Site Using an Intravenous Microbubble Delivery System Containing Antisense to C-myc: Comparison With Direct Intracoronary Injection," was presented by Thomas R. Porter, M.D., of the University of Nebraska Medical Center. The data from this study demonstrated microbubble delivery of AVI's proprietary NeuGene antisense drug Resten-NG suppressed activity of the c-myc gene, which regulates cell proliferation and has been implicated in restenosis and scar tissue formation following balloon angioplasty.
The second study, titled, "Site Specific Systemic Delivery of Rapamycin With Perfluorobutane Gas Microbubble Carrier Reduced Neointimal Formation in the Porcine Coronary Restenosis Model," was presented by Nicholas N. Kipshidze, M.D., Ph.D., of the Lenox Hill Heart and Vascular Institute. This study showed the flexibility of the microbubble technology in delivering a restenosis inhibitor.
About AVI BioPharma
AVI BioPharma develops therapeutic products for the treatment of life-threatening diseases using two technology platforms: NeuGene antisense drugs and cancer immunotherapy. Its lead cancer agent, AVICINE®, a therapeutic cancer vaccine, has completed three Phase II trials in colorectal and pancreatic cancer and is initiating a Phase III pivotal trial in pancreatic cancer, with a supporting study in colorectal cancer. The first application of its NeuGene compounds, Resten-NG™, is designed to treat cancer, cardiovascular restenosis and other cell proliferation disorders by inhibiting the production of a cellular transcription factor, the oncogene c-myc. It is currently in Phase II trials for restenosis and in a Phase Ib trial for cancer. AVI has completed a Phase I NeuGene antisense study that successfully down-regulated the liver enzyme cytochrome P450 and modified drug metabolism, and a Phase Ib trial in polycystic kidney disease. More information about AVI is available on the Company's Web site at http://www.avibio.com/.
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