Sangamo BioSciences Presents Data From Non-Human Primates Providing Proof Of Concept For Disruptive And Broadly Leverageable

 Sangamo BioSciences Presents Data From Non-Human Primates Providing Proof Of
     Concept For Disruptive And Broadly Leverageable Platform For Protein
                            Replacement Therapies

Data Presented at American Society of Hematology (ASH) Meeting Demonstrates
Therapeutic Levels of Gene Modification in Sangamo's In Vivo Protein
Replacement Platform

PR Newswire

RICHMOND, Calif., Dec. 10, 2013

RICHMOND, Calif., Dec. 10, 2013 /PRNewswire/ -- Sangamo BioSciences, Inc.
(Nasdaq: SGMO) announced the presentation of new pre-clinical data
demonstrating therapeutic levels of gene modification in non-human primates
(NHPs) from its In Vivo Protein Replacement Platform. Based on Sangamo's zinc
finger DNA-binding protein (ZFP) genome-editing technology, the platform
enables the permanent production of therapeutic proteins from a specific
genomic site in the liver with a single systemic treatment, potentially
providing curative treatments for a range of monogenic diseases such as
hemophilia and lysosomal storage disorders (LSD) including Gaucher and Fabry
disease. Such diseases are currently treated by regular infusions of protein
or enzyme replacement therapy (ERT) throughout the patient's life.The data
were presented at the 55^th Annual Meeting of the American Society of
Hematology (ASH) which is being held in New Orleans.

(Logo: http://photos.prnewswire.com/prnh/20130102/SF35903LOGO)

"These data provide proof of concept for this broadly applicable genome
editing strategy by demonstrating that our process is scalable to large
animals and by validating the use of the albumin safe harbor as a site for
expression of therapeutic proteins," said Philip Gregory. D. Phil., Sangamo's
vice president of research and chief scientific officer. "We have further
optimized Sangamo's ZFN system and demonstrated that a single systemic
treatment enables stable liver-specific production of replacement protein.
Early data in primates suggest that we can achieve circulating levels of
protein above the threshold for therapeutic effect, which we believe are
sufficient for the correction of a range of monogenic diseases. Our data
demonstrate expression of replacement enzymes for multiple different proteins,
including those deficient in lysosomal storage disorders, which serves to
demonstrate the potential of this approach for a broad range of other
monogenic diseases."

Sangamo's In Vivo Protein Replacement Platform makes use of a highly expressed
and liver specific genomic "safe-harbor site" that can be edited with ZFP
nucleases (ZFNs) to accept and express any therapeutic gene and thus
permanently produce high levels of the missing protein with a single
treatment. The gene encoding albumin, the most abundant protein in blood
serum, was chosen as a safe harbor site because it is active exclusively in
the liver. The albumin promoter is highly active, continuously producing
large amounts of albumin protein (approximately 15g/day) which is in excess of
the body's requirements. With such a large capacity for protein production,
targeting and co-opting a very small percentage of the albumin gene's
production capacity is sufficient to safely produce the needed replacement
protein at therapeutically relevant levels with no significant effect on
albumin production. The study was performed as part of Sangamo's collaboration
with Shire and in the laboratory of Katherine A. High, M.D., director of the
Center for Cellular and Molecular Therapeutics at The Children's Hospital of
Philadelphia. Dr. High isa Howard Hughes Medical Institute Investigator, and
Professor of Pediatrics at the Perelman School of Medicine at the University
of Pennsylvania.

"These data represent an important milestone in the progress of our monogenic
disease programs towards the clinic," stated Edward Lanphier, Sangamo's
president and chief executive officer. "Our In Vivo Protein Replacement
Platform is a highly leverageable and disruptive application of our
ZFN-mediated genome editing technology and can potentially be applied toany
disease-relevant gene where enabling the liver to provide a stable source of
corrective replacement protein will be therapeutic. The NHP data presented at
ASH represent a significant de-risking step and provide important proof of
concept and validation for this entire strategy."

The data were presented in an oral presentation:

Abst. #720 ZFN Mediated Targeting of Albumin "Safe Harbor" Results in
Therapeutic Levels of Human Factor VIII in a Mouse Model of Hemophilia A
Session: 801
Monday, December 9, 2013: 5:45 PM

Scientists demonstrated efficient ZFN-mediated gene addition into the albumin
locus in adult mouse models of hemophilia A and B with a single systemic
administration of ZFNs and a donor DNA sequence encoding a corrective human
Factor VIII or IX gene, respectively. This permanent correction resulted in
the production of robust, stable levels of circulating active Factor VIII and
Factor IX protein that normalize clotting times in hemophilic mice.

Data were presented demonstrating the broad utility of this method for the
potential treatment of a wide range of monogenic diseases. In these
additional studies, the albumin-specific ZFN strategy was used in combination
with appropriately designed donor DNA sequences encoding a diverse range of
protein factors including alpha-galactosidase which is deficient in Fabry
disease, beta-glucosidase (Gaucher disease), Iduronate-2 Sulfatase (Hunter
disease) and alpha-L-Iduronidase (Hurler disease).

The feasibility and scalability of the approach was also evaluated in NHPs
(Rhesus monkeys), an important large animal model that has been previously
used in the development of novel gene-based therapies for monogenic diseases
such as hemophilia. These NHP data revealed specific ZFN-mediated modification
of the albumin locus by deep-sequencing analysis of liver biopsy samples from
treated animals. There were no significant alterations in circulating albumin
levels. Analysis of T-cells isolated from both spleen and lymph node,
demonstrated that the animals did not mount an immune response to either the
ZFNs or the vector used for delivery. Importantly, ZFN-mediated modification
of the albumin locus in NHPs resulted in levels of modification which are
sufficient to provide a therapeutic effect. In a program update, early
experiments demonstrate expression of the encoded therapeutic protein at
levels that were up to three-fold the amount required for therapeutic effect.

About Sangamo
Sangamo BioSciences, Inc. is focused on research and development of novel
DNA-binding proteins for therapeutic gene regulation and genome editing. The
Company has ongoing Phase 2 and Phase 1/2 clinical trials to evaluate the
safety and efficacy of a novel ZFP Therapeutic® for the treatment of HIV/AIDS.
As part of its acquisition of Ceregene, Inc., Sangamo acquired a
fully-enrolled and funded, double-blind, placebo-controlled Phase 2 trial to
evaluate NGF-AAV (CERE-110) in Alzheimer's disease. Sangamo's other
therapeutic programs are focused on monogenic diseases, including hemophilia,
Huntington's disease and hemoglobinopathies such as beta-thalassemia and
sickle cell anemia. Sangamo's core competencies enable the engineering of a
class of DNA-binding proteins known as zinc finger DNA-binding proteins
(ZFPs). Engineering of ZFPs that recognize a specific DNA sequence enables
the creation of sequence-specific ZFP Nucleases (ZFNs) for gene modification
and ZFP transcription factors (ZFP TFs) that can control gene expression and,
consequently, cell function. Sangamo has entered into a strategic
collaboration with Shire AG to develop therapeutics for hemophilia,
Huntington's disease and other monogenic diseases and has 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, the potential of ZFNs to treat a broad range of human monogenic
diseases, including hemophilia and LSDs, 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 our clinical trials, whether the
clinical trials will validate and support the tolerability and efficacy of
ZFNs, technological challenges, Sangamo's ability to develop commercially
viable products and technological developments by our competitors. For a more
detailed discussion of these and other risks, please see Sangamo's SEC
filings, including the risk factors described in its Annual Report on Form
10-K and its most recent Quarterly Report 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.

Website: http://www.sangamo.com
Contact: Elizabeth Wolffe, Ph.D., Sangamo BioSciences, Inc., 510-970-6000,
x271, ewolffe@sangamo.com