RICHMOND, Calif., Oct. 28, 2013 /PRNewswire/ -- Sangamo BioSciences, Inc. (Nasdaq: SGMO) announced today the presentation of new data demonstrating sustained control of HIV viral load (VL) at or below the limit of detection for 14 weeks (at last measurement) in an SB-728-T- treated HIV-infected subject who was not on antiretroviral therapy (ART). The CCR5 delta-32 heterozygote subject is enrolled in Sangamo's clinical trial (SB-728-902 Cohort 5) and, as part of the clinical trial protocol, is undergoing an ART treatment interruption (TI), which is ongoing. (Logo: http://photos.prnewswire.com/prnh/20130102/SF35903LOGO) Data were presented at the Annual Meeting of the European Society of Gene and Cell Therapy (ESGCT and SETGyC Collaborative Congress) which is being held in Madrid from October 25-28, 2013. "These data demonstrate that sustained functional control of HIV in the absence of ART is possible with a single SB-728-T treatment," stated Geoff Nichol, M.B., Ch.B ., Sangamo's executive vice president of research and development. "Our aim is to provide a population of immune memory cells that are protected from HIV infection and are capable of generating an effective immune response against the virus throughout the body. These data represent a further step toward demonstrating the efficacy and durability of this therapeutic approach." Dr. Nichol added, "We continue to follow these Cohort 5 subjects and look forward to presenting a complete data set from this study, and a second ongoing trial (SB-728-1101), designed to maximize the engraftment of SB-728-T in subjects who are not CCR5 delta-32 heterozygotes, later this year." Data from Sangamo's Phase 1 and 2 studies demonstrate that VL became undetectable during a TI from ART in three of seven evaluable CCR5 delta-32 heterozygote HIV-infected subjects, including two of six subjects that had completed TI in the ongoing SB-728-902 Cohort 5 study and an additional CCR5 delta-32 heterozygote subject from an earlier Phase 1 clinical trial of SB-728-T. In one SB-728-902 Cohort 5 subject, VL has remained undetectable (at or below the limits of quantification of the current ultra-sensitive assays for HIV) for 14 weeks (to last measurement taken) and the TI is ongoing. Reduction in VL from peak during TI showed a statistically significant correlation (p=0.015) with estimated numbers of engrafted ZFN modified cells (SB-728-T) in which both copies of the CCR5 gene had been disrupted (biallelic modification), in line with previously presented data from this program.