Sangamo BioSciences awarded a grant to develop zinc finger nuclease-based stem cell therapy for AIDS

Oct 29 2009

Sangamo BioSciences, Inc. (Nasdaq: SGMO) announced today that the California Institute for Regenerative Medicine (CIRM) has granted a $14.5 million Disease Team Research Award to develop an AIDS-related lymphoma therapy based on the application of its zinc finger nuclease (ZFN) gene-editing technology in stem cells. The four year grant supports an innovative research project conducted by a multidisciplinary team of investigators led by John Zaia, M.D. the Aaron D. and Edith Miller Chair in Gene Therapy and chair of virology, City of Hope. The grant application entitled "Zinc Finger Nuclease-Based Stem Cell Therapy for AIDS" won the highest score of all grants CIRM received in this 1st round of Disease Team Research Award funding.

"Sangamo scientists have developed a ZFN-mediated gene-editing technology that has been demonstrated to make hematopoietic stem cells and mature immune system cells resistant to HIV infection," said Dr. Zaia. "This will be the first test of whether hematopoietic stem cells made HIV resistant using Sangamo's technology can correct the disease. If successful, our work could open the door to ZFN-based cell therapies for other important diseases."

Patients homozygous for a natural mutation (the delta-32 mutation) in the CCR5 gene are resistant to HIV infection by blocking the ability of the virus to enter a cell. Building on this observation, a study published in the New England Journal of Medicine in 2009 reported a potential "cure" in an AIDS patient with leukemia after receiving a bone marrow transplant from a "matched" donor with this delta-32 CCR5 mutation. This approach transferred the hematopoietic stem cells (HSC) residing in the bone marrow from the delta-32 donor, and provided a self-renewable and lifelong source of HIV-resistant immune cells. After transplantation, this patient was able to discontinue all anti-HIV drug treatments, CD4 counts increased, and the viral load dropped to an undetectable level, demonstrating effective transplantation of protection from HIV infection.

This CIRM Disease Team Research Award proposes an approach to modify a patient's own HSC to circumvent the need to find matched donors that carry the delta-32 CCR5 mutation and while providing a renewable and long-lasting source of HIV-resistant cells. Specifically, the grant funds the development of a ZFN approach to treat AIDS patients by first isolating their HSC, modifying them using CCR5-specific ZFNs, and then re-infusing them to reconstitute the immune system with CCR5-negative, HIV-resistant immune cells.

"We are delighted that this research proposal was chosen for funding by CIRM," commented Dr. Philip Gregory, Sangamo's chief scientific officer and vice president, research. "This grant brings together a team of world-renowned experts to develop this novel ZFN-based stem cell therapy for AIDS-related lymphoma through to the clinic. We look forward to working with the team which includes Paula Cannon, Ph.D., associate professor of Molecular Microbiology & Immunology, Keck School of Medicine of the University of Southern California, who has carried out extensive pre-clinical research using our technology in stem cells, and Dr. Zaia and his colleagues at City of Hope who are pioneers in hematopoietic cell transplantation."

"CIRM support for this program is a major validation of our ZFP Therapeutics platform both scientifically and financially and we are very pleased to be part of the exceptional team that received the highest score of all of the grants reviewed by CIRM," said Edward Lanphier, Sangamo's president and CEO.

The CIRM Disease Team Research Awards will fund actively managed multidisciplinary teams engaged in milestone-driven translational research for the development of stem cell-based therapies. The mission of these teams will be to conduct the necessary research and regulatory activities to prepare and file a complete, well supported Investigational New Drug Application (IND) with the Food and Drug Administration (FDA) (and, if desired, other regulatory agencies), to enable Phase I clinical testing.

SOURCE Sangamo BioSciences, Inc.