Data from Phase 1 safety study of SB-728-T announced

Sangamo BioSciences, Inc. (Nasdaq: SGMO) announced today that data from the University of Pennsylvania investigator sponsored Phase 1 safety study of Sangamo's zinc finger nuclease (ZFN) based product, SB-728-T, for HIV/AIDS were inadvertently and prematurely disclosed on the internet.

Data were presented in a student course at the University of Pennsylvania School of Medicine from a single subject treated with SB-728-T who, as part of the study, began a structured treatment interruption (STI) from his antiviral drug therapy four weeks after SB-728-T treatment. This subject was reported to have stable CD4+ and ZFN-modified T-cell levels and an undetectable viral load one month post STI initiation. Previous studies have shown that in subjects undergoing an STI, the average time to detection of an increase in viral load is two to four weeks. While this subject continues to demonstrate stable CD4+ T-cell counts and stable levels of ZFN-modified T-cells, by six weeks post STI initiation the subject had a detectable viral load.

As previously stated, the company and the University of Pennsylvania intend to provide updates on the two ongoing Phase 1 SB-728-T trials only at appropriate scientific or medical meetings.