Sangamo BioSciences Announces Completion of Enrollment of Phase 2 Clinical Trial of ZFP Therapeutic for Diabetic Neuropathy

RICHMOND, Calif., Dec. 4 /PRNewswire-FirstCall/ -- Sangamo BioSciences, Inc. (Nasdaq: SGMO) announced today that the company has completed enrollment of its randomized, double-blind, repeat-dosing, placebo-controlled, multi-center Phase 2 clinical trial evaluating SB-509, a ZFP Therapeutic(TM) for the treatment of mild to moderate diabetic neuropathy (DN). The company expects to have data from this trial in the second half of 2008.

"The completion of enrollment of our first Phase 2 clinical trial represents a significant milestone for Sangamo and I am pleased that we achieved this major clinical goal as planned, before the end of 2007," commented Edward Lanphier, Sangamo's president and CEO. "We have been very encouraged by the disease-altering improvements that we observed in our preclinical studies and in the Phase 1b trial and look forward to presenting the data from this current study by the end of 2008."

This Phase 2 trial followed a positive Phase 1 study that demonstrated clinical safety of a single treatment with SB-509 as well as statistically significant improvements in Quantitative Sensory Testing (QST), clinically relevant improvements in motor and sensory nerve conduction velocities (NCV) and a trend towards improvement in Total Neuropathy Score (TNS), suggesting an alteration of disease progression in subjects with DN. The Phase 2 study was designed to confirm and expand these findings and to evaluate repeat dosing with SB-509.

The trial has been partially funded by a $3.0 million commitment from the Juvenile Diabetes Research Foundation International (JDRF) pursuant to a research agreement between Sangamo and JDRF. Completion of enrollment of the trial triggers a milestone payment from JDRF under this agreement.

About SB-509

SB-509 is a formulation of a zinc finger DNA-binding protein transcription factor (ZFP TF) designed to upregulate the expression of the gene encoding vascular endothelial growth factor (VEGF-A). Sangamo is currently evaluating this ZFP Therapeutic in a second ongoing Phase 2 clinical trial for the treatment of moderate to severe DN; plans to initiate a third Phase 2 trial to evaluate the effect of SB-509 on the mobilization of stem cells in subjects with DN; and has a preclinical program targeting spinal cord injury. Sangamo has also announced a new clinical program, the initiation of a Phase 2 clinical trial in Amyotrophic Lateral Sclerosis (Lou Gehrig's disease) in the first half of 2008.

Phase 2 study of SB-509 for mild to moderate DN

The clinical trial is a double-blind, placebo-controlled, repeat-dosing study designed to evaluate the clinical safety and clinical effects of repeat administration of SB-509 in diabetics with mild to moderate diabetic peripheral sensory motor neuropathy in the legs.

A total of 102 subjects have been enrolled into the trial. Subjects were randomized to one of two groups in a 2:1 ratio. The larger group is being treated by intramuscular injection of 60 mg of SB-509 (30 mg of SB-509 per leg) into the lower limb every 2 months. The remaining group is receiving an equal volume of placebo on the same schedule. Each subject will receive a total of three treatments (Day 0, 60 and 120). Subjects will receive injections in a distribution pattern that targets the skeletal muscle adjacent to the major peripheral nerves in the legs and feet.

The symptoms of diabetic peripheral neuropathy and any changes that occur during the trial will be evaluated based on neurological examination data, electrophysiological testing data, subject neurological questionnaire, and subject pain assessment. Investigators will use quantitative sensory testing (QST) with the Vibratron II instrument to assess the threshold of detection of vibration, electrophysiological testing using nerve conduction velocity (NCV) to assess the rate at which a nerve can conduct an electrical signal, and a composite scoring system, the total neuropathy score (TNS) to assess signs and symptoms of the condition. In addition, skin biopsies will be taken to evaluate the direct therapeutic effect of SB-509 on nerve regrowth. This test may provide an important mechanistic marker for efficacy. Subjects will be assessed for seven months following the last dosing.

About Diabetic Neuropathy

Diabetic peripheral neuropathy is one of the most frequent complications of diabetes. Symptoms include numbness, tingling sensations and pain particularly in the toes or feet. This gradually evolves to loss of sensation and motor function as nerve damage progresses. Ulcers and sores may appear on numb areas of the foot because pressure or injury goes unnoticed. Despite adequate treatment, these areas of trauma frequently become infected and this infection may spread to the bone, necessitating amputation of the leg or foot. More than 60 percent of non-traumatic lower-limb amputations in the United States occur among people with diabetes. In the period from 2000 to 2001, this translated to approximately 82,000 amputations. The American Diabetes Association estimates that there are approximately 20.8 million people with diabetes in the United States and that of those about 60 percent to 70 percent have mild to severe forms of neuropathy. According to the Centers for Disease Control, diabetes is becoming more common in the United States. From 1980 through 2002, the number of Americans with diabetes more than doubled.

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 program is currently in Phase 2 clinical trials for evaluation of safety and clinical effect in patients with diabetic neuropathy. Phase 1 clinical trials are ongoing to evaluate a ZFP Therapeutic for peripheral artery disease. Other therapeutic development programs are focused on Amyotrophic Lateral Sclerosis (ALS), cancer and HIV/AIDS, neuropathic pain, nerve regeneration, Parkinson's disease 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 gene modification. Sangamo has established strategic partnerships with companies outside of the human therapeutic space including Dow AgroSciences, Sigma-Aldrich Corporation and several companies applying its ZFP Technology to enhance the production of protein pharmaceuticals. For more information about Sangamo, visit the company's web site at

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 SB-509, research and development of novel ZFP TFs and ZFNs, therapeutic applications of Sangamo's ZFP technology platform and payments upon achievement of research milestones. 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 SB-509 clinical trials, whether the SB-509 clinical trials will validate and support tolerability and efficacy of SB-509, 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 Quarterly Reports on Form 10-Q. Sangamo BioSciences, Inc. assumes no obligation to update the forward-looking information contained in this press release.

SOURCE Sangamo BioSciences, Inc.