(SGMO) Unanimous Recombinant DNA Advisory Committee Approval Of ZFP Phase 1 Protocol

First Application of Sangamo’s In Vivo Protein Replacement Platform (IVPRP) for Potential Cure of Hemophilia B

RICHMOND, Calif., Sept. 10, 2015  — Sangamo BioSciences, Inc. (Nasdaq: SGMO), a leader in therapeutic genome editing, announced unanimous approval by the National Institutes of Health’s Recombinant DNA Advisory Committee (RAC) of a Phase 1 study protocol for a ZFP Therapeutic as a potential curative therapy for hemophilia B. The Factor IX program will be the first clinical study of in vivo genome editing and the first therapeutic application of Sangamo’s In Vivo Protein Replacement Platform (IVPRP).

Sangamo expects to file an Investigational New Drug (IND) Application with the U.S. Food and Drug Administration (FDA) by the end of 2015 and, pending FDA clearance, plans to initiate a Phase 1 clinical trial in 2016. The Company recently reacquired all of its hemophilia assets from Shire plc as a result of the amendment to the companies’ 2012 collaboration and license agreement.

“Hemophilia B is the first clinical application of our IVPRP which can be applied to many other diseases that are currently treated by protein replacement including hemophilia A and lysosomal storage disorders,” said Geoff Nichol, M.B., Ch.B., Sangamo’s executive vice president of research and development. “Successful review, by the NIH RAC, of the first human in vivo genome editing clinical protocol is a major milestone for Sangamo. We appreciate this careful consideration and unanimous approval of our proposed clinical trial and look forward to the commencement of our Phase 1 study in the near future.”

“We are pleased with the outcome from this thorough review, by the NIH RAC, of our first IVPRP clinical protocol,” said Edward Lanphier, Sangamo’s president and chief executive officer. “We will continue to leverage the potential of this strategy for development of ZFP Therapeutics for other monogenic diseases, and remain on track to file IND applications for the hemophilia B program and the first of our lysosomal storage disorder programs by the end of 2015.”

Sangamo’s IVPRP

The IVPRP approach makes use of the albumin gene locus, a highly expressing and liver-specific genomic “safe-harbor site”, that can be edited with zinc finger nucleases (ZFNs) to accept and express any therapeutic gene. The platform enables the patient’s liver to permanently produce therapeutic levels of a corrective protein product such as factor VIII or IX to treat hemophilia, or replacement enzymes to treat lysosomal storage disorders. With such a large capacity for protein production (approximately 15g/day of albumin), which is in excess of the body’s requirements, targeting and co-opting only a very small percentage of the albumin gene’s capacity is sufficient to produce the needed replacement protein at therapeutically relevant levels with no significant effect on albumin production.

Sangamo

Sangamo BioSciences, Inc. is focused on Engineering Genetic Cures^TM for monogenic and infectious diseases by deploying its novel DNA-binding protein technology platform in therapeutic gene regulation and genome editing. The Company has a Phase 2 clinical program to evaluate the safety and efficacy of novel ZFP Therapeutics® for the treatment of HIV/AIDS (SB-728). Sangamo’s other therapeutic programs are focused on monogenic and rare diseases. The Company has formed a strategic collaboration with Shire International GmbH to develop therapeutics for Huntington’s disease, and with Biogen Inc. for hemoglobinopathies, such as sickle cell disease and beta-thalassemia. It has also established strategic partnerships with companies in non-therapeutic applications of its technology, including Dow AgroSciences and Sigma-Aldrich Corporation. For more information about Sangamo, visit the company’s website at www.sangamo.com.

ZFP Therapeutic® is a registered trademark of Sangamo BioSciences, Inc.

This press release may contain forward-looking statements based on Sangamo’s current expectations. These forward-looking statements include, without limitation, references to the research and development of novel ZFNs, potential therapeutic applications of its ZFP technology for the treatment of hemophilia A and B, lysosomal storage disorders and other monogenic diseases, the potential therapeutic applications of the IVPRP,  the expected timing for filing of IND applications and commencement of clinical trials. Actual results may differ materially from these forward-looking statements due to a number of factors, including technological challenges, uncertainties and risks relating to clinical trials, compliance with regulatory and other requirements, the ability of Sangamo to develop commercially viable products and technological developments by our competitors. See the SEC filings, and in particular, the risk factors described in Sangamo’s Annual Reports on Form 10-K and most recent Quarterly Reports on Form 10-Q. Sangamo does not assume any obligation to update the forward-looking information contained in this press release.