What is SB-728-T?
- SB-728-T is an immune-based therapy being developed by the Sangamo Biosciences.
- SB-728-T is a zinc finger DNA-binding protein transcription factor (ZFP TF). It disrupts the gene responsible for making CCR5 co-receptors on the surface of CD4 cells. When CD4 cells are unable to produce these co-receptors it is much harder for HIV to infect them. The aim of SB-728-T therapy is to grow a new population of CD4 cells that are resistant to HIV infection, and thus make antiretroviral therapy unnecessary.
- ZFP TFs are being studied for a wide range of diseases including HIV disease.
What is already known about SB-728-T?
- Sangamo has partnered with researchers to conduct both animal and human studies. In mice, researchers working with Sangamo have demonstrated the ability to treat stem cells with the ZFP TFs and grow entire new populations of HIV-resistant immune cells.
- The rationale for using SB-728-T comes from the case of an HIV-positive man with leukemia in Berlin who received two stem cell transplants from a donor who was genetically unable to produce CD4 cells that carry the CCR5 co-receptor. Such individuals rarely become infected with HIV and when they do, their disease tends to progress very slowly. In the Berlin patient, the stem cell therapy not only cured his cancer, but appears to have cured his HIV infection as well. All efforts to locate HIV in the man’s body have been unsuccessful. Sangamo is hoping that treating and reinfusing a person’s own stem cells with SB-728-T will, over time, cause them to grow a new immune system that will be similarly resistant to HIV as was seen in the Berlin patient.
- Two studies are currently underway to test Sangamo’s technology: one in HIV-positive people with lymphoma or leukemia who need a stem cell transplant to treat their cancer and the other in HIV-positive people who do not have cancer.
- In the study being conducted in people with cancer, a person’s stem cells are harvested, treated with the SB-728-T and then re-infused after a person has been treated with chemotherapy to kill of a proportion of their immune cells—as is standard practice in stem cell transplants to treat these types of cancer. This study is currently recruiting and is underway in Southern California.
- A second study in HIV-positive people who do not have cancer is also proceeding. In these individuals, stem cells are treated with the SB-728-T, but the study participants do not undergo chemotherapy.
- Like other drugs, SB-728-T might interact with other medications, including those used to treat HIV. It is important that your personal physician and/or the research nurse or study investigator be aware of all drugs you are taking, including those you buy without a prescription.
What is known about side effects?
- Information regarding the long-term safety and possible side effects of SB-827-T in HIV-positive people has not yet been reported.
Who should not take SB-728-T?
- It is not known whether SB-827-T will harm an unborn baby. It is very important to treat HIV during pregnancy to reduce the risk of infecting your baby. Talk to your provider about your treatment options.
- It is not known how SB-827-T will affect babies who are breast-feeding when the mother while the mother is being treated. To prevent transmission of the virus to uninfected babies, it is recommended that HIV-positive mothers not breast feed.
Where can I learn more about clinical trials of SB-728-T?
- If you would like to find out if you are eligible for any clinical trials that include SB-827-T, visit ClinicalTrials.gov, a site run by the U.S. National Institutes of Health. The site has information about all HIV-related clinical studies in the United States. For more info, you can call their toll-free number at 1-800-HIV-0440 (1-800-448-0440) or email firstname.lastname@example.org.