The SB-728-T gene therapy has been designed to disrupt the CCR5 gene which is the main origin of HIV. A small but an important Phase I test has already been conducted by Sangamo Biosciences. The trial results which were presented in Chicago on Sunday at the Interscience Conference on Antimicrobial Agents and Chemotherapy statistically proved significant relationship between estimated modification of both copies of CCR5 and viral load. As per Dr. Carl June who is the trial investigator and director of translational research at the University of Pennsylvania’s Cancer Research Institute, there is a need to increase the frequency of the modified cells in HIV infected patients who would eventually cure AIDS, however, there is no clarity on how the results will be achieved.
Right on the first trial of the therapy in human beings, it was observed that the immune system of the human beings improved significantly right with a single infusion of the treatment. The trial was conducted on ten patients who were given antiretroviral therapy. However, after four weeks of trial, six of the patients were given the consent of treatment interruption during which period, they were stopped taking antiviral medication. The stoppage of antiviral medicines was done for twelve weeks. Out of the six patients, the viral load in three of them reduced significantly, with one patient, the viral load could not be found at all.
The functioning of the therapy is very simple. All human bodies are made up of two genes, one from father and the other come originates from mother. This is usually alleles of genes. If one copy of the genes get disrupted naturally, twice as many of the cells are biallelically modified, meaning both the members of CCR5 gene pair gets extinguished. It is usually found that 5 to 10 percent of HIV patients carry genetic mutation. Around 33 million people have HIV which causes AIDS. Sangamo would strategically maximize the number of cells that could “biallelically” modified by SB-728-T. For this, the company is planning to explore the options where it can target just a small fragment of patients which has mutated CCR5 genes or it can also use strategies which can boost the amount of engraftment of the modified cells.
Sangamo’s Chief Executive Officer, Edward Lanphier is extremely optimistic about the new developments in the treatment of HIV and is intending to take the HIV treatment into middle stage trials that too without partnering with anybody. The company has enough funds to carry forward the Phase II trials.