Lead Indication Approach Program Research Preclinical Phase 1/2 Phase 3
Research Phase complete
Preclinical Phase complete
Phase 1/2 Phase in progress
Phase 3 Phase not started

Hemophilia A is a blood clotting disorder caused by defective clotting Factor VIII gene. Sangamo Therapeutics recently announced that its Investigational New Drug (IND) application for SB-525 had been cleared by the U. S. Food and Drug Administration (FDA). SB-525 is a gene therapy approach to the treatment of hemophilia A that uses a Factor 8 cDNA AAV. The company expects to begin a Phase 1/2 clinical trial in 2017.

ZFN (insert) SB-FIX
Research Phase complete
Preclinical Phase complete
Phase 1/2 Phase in progress
Phase 3 Phase not started

Hemophilia B is a blood clotting disorder caused by a defective clotting Factor IX gene. We have initiated an open-label, dose-escalating Phase 1/2 clinical trial to assess the safety, tolerability, and preliminary efficacy of SB-FIX. SB-FIX uses our ZFN-mediated in vivo genome editing to place a normal functioning copy of the Factor 9 gene under the control of the strong albumin promoter in the patient’s liver.  This enables the liver to produce and secrete active Factor IX into the bloodstream. SB-FIX is the first in vivo genome editing product to enter the clinic.

About Hemophilia

Hemophilia is a genetic disorder in which the blood doesn't clot normally because it lacks sufficient blood clotting proteins. Individuals with hemophilia experience prolonged bleeding after injuries and spontaneous bleeding episodes into joints that often lead to arthritis. The most prevalent form of the disease, hemophilia A, is caused by a defect in clotting Factor VIII, while defects in clotting Factor IX lead to hemophilia B. While most hemophilia patients are male, females can also be affected.

Hemophilia affects 1 in 5,000 male births

All disease stats are according to the Centers for Disease Control and Prevention (CDC)


Estimated number of people with hemophilia in the United States


of cases have no family history of hemophilia


Estimated number of people with hemophilia A


Estimated number of people with hemophilia B

Our Therapeutic Approaches

SB-525 for Hemophilia A

Sangamo has developed an adeno-associated virus (AAV) carrying a clotting Factor 8 gene construct driven by Sangamo's proprietary synthetic liver specific promoter, which in preclinical studies is more potent than existing AAV-based cDNA constructs currently under evaluation for the treatment of hemophilia A. The Company’s investigational new drug (IND) application for this program has been cleared by the U.S. Federal Drug Administration (FDA) enabling the company to begin a Phase 1/2 clinical trial in adults with severe hemophilia A.

SB-FIX for Hemophilia B

SB-FIX is designed to provide stable, continuous production of Factor IX clotting protein (FIX) for the lifetime of the patient. Sangamo’s ZFN-mediated in vivo genome editing approach makes use of the albumin gene locus, a highly expressing gene in the DNA of a patient’s liver cells that can be edited with ZFNs to accept and express therapeutic genes. The approach is designed to enable the liver to permanently produce circulating therapeutic levels of a corrective protein product. Ultimately, the target population for this approach will include pediatric patients for whom it is important to be able to produce stable levels of therapeutic protein for their lifetime. With such a large capacity for protein production (approximately 15g/day of albumin), targeting and co-opting only a very small percentage of the albumin gene’s capacity could potentially produce therapeutically relevant levels of Factor IX with no significant effect on albumin production.

Clinical Trials

Clinical Trials

In 2017 Sangamo is conducting Phase 1/2 clinical trials to evaluate safety, tolerability and preliminary efficacy in Hemophilia A and Hemophilia B. Please visit the Clinicaltrials.gov webpage to learn more about our clinical trials.

Presentations + Publications

In vivo genome editing of the albumin locus as a platform for protein replacement therapy

Rajiv Sharma, Xavier M. Anguela, Yannick Doyon, Thomas Wechsler, Russell C. DeKelver, Scott Sproul, David E. Paschon, Jeffrey C. Miller, Robert J. Davidson, David Shivak, Shangzhen Zhou, Julianne Rieders, Philip D. Gregory, Michael C. Holmes, Edward J. Rebar, and Katherine A. High

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