RICHMOND, CA, USA I February 28, 2018 I Sangamo Therapeutics, Inc. (Nasdaq: SGMO) today announced that the Medicines and Healthcare Products Regulatory Agency (MHRA) of the United Kingdom has granted the Clinical Trial Authorisation (CTA) for enrollment of subjects into the ongoing Phase 1/2 clinical trial evaluating SB-FIX, a zinc finger nuclease (ZFN)-mediated in vivo genome editing treatment for hemophilia B. The CTA allows for initiation of Europe’s first in vivo genome editing study.

The CTA permits evaluation of SB-FIX in both adults and adolescents. Once preliminary safety and efficacy have been demonstrated in the ongoing SB-FIX Phase 1/2 clinical trial in adults (18 years or older), Sangamo may then begin enrolling adolescents (12 – 17 years of age) into the study. Clinical sites in the United States have been initiated and are screening adult subjects.

“Patients with hemophilia B need improved treatment options, and we are pleased to have rapidly reached agreement with the MHRA to expand the SB-FIX clinical trial to sites in the United Kingdom,” said Edward Conner, M.D., Sangamo’s chief medical officer. “In vivo genome editing aims to provide a life-long therapeutic solution for certain genetic diseases. We believe the greatest value for this approach is in the treatment of children, and our goal with this study is to accumulate safety and efficacy data supporting progression of clinical trials into younger patient populations.”

Sangamo expects to initiate sites in the U.K. later this year for the SB-FIX Phase 1/2 clinical trial and to file additional CTAs for its SB-318 and SB-913 in vivo genome editing treatments for Mucopolysaccharidosis Type I (MPS I) and MPS II, respectively.

Sangamo’s In Vivo Genome Editing Approach
Sangamo aims to treat hemophilia B by using its proprietary ZFN genome editing technology to insert a corrective gene into a precise location in the DNA of liver cells with the goal of enabling a patient’s liver to produce a lifelong and stable supply of the Factor IX protein.

To restrict editing to liver cells, the ZFNs and the corrective gene are delivered in a single intravenous infusion using AAV vectors that target the liver. The ZFNs enter the cells as inactive DNA instructions in a format designed only for liver cells to unlock. Once “unlocked”, the ZFNs then identify, bind to and cut the DNA in a specific location within the albumin gene. Using the cells’ natural DNA repair processes, liver cells can then insert the corrective gene for Factor IX at that precise location.

The ability to permanently and precisely integrate the therapeutic Factor IX gene into the DNA differentiates Sangamo’s in vivo genome editing approach from conventional AAV cDNA gene therapy and from lenti- or retroviral-based gene therapies that insert genes randomly into the genome.

About Hemophilia B
Hemophilia, a rare bleeding disorder in which the blood does not clot normally, is caused by mutations in genes that encode factors which help the blood clot and stop bleeding when blood vessels are injured. Hemophilia B is caused by a defect in the gene encoding clotting Factor IX protein. Individuals with this mutation experience bleeding episodes after injuries and spontaneous bleeding episodes that often lead to joint disease such as arthritis.

According to the National Hemophilia Foundation and the World Federation of Hemophilia, hemophilia B occurs in about one in every 25,000 male births with approximately 4,000 males currently affected in the U.S. and approximately 1,500 affected in the U.K. The standard treatment for individuals with hemophilia is protein replacement of the defective clotting factor with regular infusion of recombinant clotting factors or plasma concentrates. These therapies are expensive and may stimulate the body to produce antibodies against the factors that inhibit the benefits of treatment. The most severe forms of hemophilia B require the need for ongoing, preventive infusions.

About Sangamo Therapeutics
Sangamo Therapeutics, Inc. is focused on translating ground-breaking science into genomic therapies that transform patients’ lives using the company’s industry leading platform technologies in genome editing, gene therapy, gene regulation and cell therapy.

SOURCE: Sangamo Therapeutics