RICHMOND, Calif., Jan. 25 /PRNewswire-FirstCall/ -- Sangamo BioSciences, Inc. announced today the publication of preclinical efficacy data demonstrating the potential utility of zinc finger DNA binding protein transcription factors (ZFP TFs(TM)) as a new class of human therapeutics for the treatment of severe late-stage peripheral artery disease (PAD). This stage of PAD, known as critical limb ischemia (CLI), is a major health issue that results in limb loss in a significant number of patients around the world.
The study, reported in the current issue of the FASEB Journal, was conducted in the laboratory of Frank Giordano, M.D., Assistant Professor of Medicine, Cardiovascular Medicine Department at Yale University School of Medicine. The study was designed to test the efficacy of a ZFP TF engineered to activate the vascular endothelial growth factor (VEGF) gene in a preclinical model of CLI. This model is particularly relevant to the older PAD patient population. Sangamo scientists developed the VEGF ZFP Therapeutic(TM) under an agreement with Edwards Lifesciences and Edwards is currently testing it in a Phase 1 human clinical trial for CLI at the Duke University Medical Center. An additional Phase 1 trial of the ZFP Therapeutic for the treatment of the earlier stage of PAD, intermittent claudication, is underway at the National Heart Lung and Blood Institute at the National Institutes of Health.
“The strength of the data published in the FASEB article was an important factor in the decision to move this ZFP Therapeutic into a human trial in critical limb ischemia, the more severe stage of PAD,” said Edward Lanphier, Sangamo’s president and CEO. “The work also highlights important technical advantages of our ZFP TF technology platform over previous approaches to this problem. By activating the cell’s own copy of the VEGF gene using an engineered ZFP TF, we mimic the cell’s natural process and enable the production of all of the protein isoforms of VEGF in the same ratios that are normally produced. These studies, and previous in vivo studies, show that this results in the generation of functionally intact blood vessels, which we believe will be a critical advantage for new therapies aimed at stimulating new blood vessel growth in ischemic cardiovascular and vascular disease. We are optimistic about the potential benefits that this ZFP Therapeutic could offer to ischemic vascular disease patients worldwide.”
“This work is an important step towards the development of a new approach to therapeutic angiogenesis and we are very pleased to see significant effects on critical end-points in this more severe model of peripheral artery disease,” said Dr. Giordano. “Our study shows that ZFP TF treatment produces all forms of the VEGF protein in oxygen-starved muscles, statistically significant improvement in blood vessel growth and, most importantly, significantly increased blood flow and promotion of limb salvage as measured over a period of four weeks.”
The authors used an engineered ZFP TF designed to activate the expression of the endogenous VEGF A gene. VEGF A has been extensively documented as an important factor in angiogenesis or blood vessel growth. Using a ZFP TF to increase the expression of this gene and the protein that it encodes in ischemic muscle resulted in statistically significant changes in treated limbs in a number of measures of efficacy. These efficacy end-points included: decreased gangrene of the limb and overall cell death in the treated muscle, increased cell growth and increased blood vessel density and blood flow.
In June 2005, Edwards Lifesciences announced the initiation of a Phase 1 clinical trial of EW-A-401, a formulation of the VEGF ZFP TF tested in these recently reported studies. Patients with CLI are currently being enrolled and treated in the trial conducted at Duke University Medical Center by Brian Annex, M.D., professor of medicine and director of vascular medicine. Designed as a multi-dose, dose-escalation study involving up to 16 patients with 12 months of follow-up, the trial primarily seeks to measure EW-A-401’s safety in treating patients with critical limb ischemia. Among other measurements, changes in progenitor cell populations will be evaluated to determine the extent to which tissue repair can be accomplished. In addition, investigators hope to obtain preliminary data on the therapy’s effectiveness in improving patients’ clinical status. Edwards has reported an interest in pursuing additional indications for the therapy, including ischemic heart disease
Peripheral Artery Disease Affects between 8 Million and 10 Million Americans
According to the American Heart Association, PAD is estimated to affect between 8 million and 10 million people in the United States, although the condition is often under-diagnosed and undertreated. PAD is caused by blockages to the arteries that supply the legs with blood. The initial sign of PAD is leg muscle pain during exercise. As the disease progresses, patients can experience leg pain even when resting. Eventually, some PAD patients have such poor blood flow that they develop leg ulcers that do not heal.
About Sangamo
Sangamo BioSciences, Inc. is focused on the research and development of novel DNA-binding proteins for therapeutic gene regulation and modification. The most advanced ZFP Therapeutic(TM) development programs are currently in Phase 1 clinical trials for evaluation of safety in patients with diabetic neuropathy and peripheral artery disease. Other therapeutic development programs are focused on macular degeneration, ischemic heart disease, congestive heart failure, neuropathic pain, and infectious and monogenic diseases. Sangamo’s core competencies enable the engineering of a class of DNA-binding proteins known as zinc finger DNA-binding proteins (ZFPs). By engineering ZFPs that recognize a specific DNA sequence Sangamo has created ZFP transcription factors (ZFP TF(TM)) that can control gene expression and, consequently, cell function. Sangamo is also developing sequence-specific ZFP Nucleases (ZFN(TM)) for therapeutic gene modification as a treatment for a variety of monogenic diseases, such as sickle cell anemia, and for infectious diseases, such as HIV. Sangamo has established several Enabling Technology Agreements with companies to apply its ZFP Technology to enhance the production of protein pharmaceuticals. For more information about Sangamo, visit the company’s web site at www.sangamo.com.
This press release may contain forward-looking statements based on Sangamo’s current expectations. These forward-looking statements include, without limitation, references to the clinical trials of ZFP Therapeutics, research and development of novel ZFP TFs and ZFNs and therapeutic applications of Sangamo’s ZFP technology platform. Actual results may differ materially from these forward-looking statements due to a number of factors, including uncertainties relating to the initiation and completion of stages of the ZFP Therapeutic clinical trials, whether the clinical trials will validate and support tolerability and efficacy of the ZFP Therapeutics, technological challenges, Sangamo’s ability to develop commercially viable products and technological developments by our competitors. See the company’s SEC filings, and in particular, the risk factors described in the company’s Annual Report on Form 10-K and its most recent 10-Q. Sangamo BioSciences, Inc. assumes no obligation to update the forward-looking information contained in this press release.
Sangamo BioSciences, Inc.
CONTACT: Elizabeth Wolffe, Ph.D. of Sangamo BioSciences, Inc.,+1-510-970-6000, ext. 271, or ewolffe@sangamo.com; or Justin Jackson(media), +1-212-213-0006, or John Cummings (investors), +1-415-352-6262,both of Burns McClellan, Inc., for Sangamo BioSciences, Inc.
Web site: http://www.sangamo.com/