San Francisco, California – An innovative therapy using a patient’s own stem cells, modified to resist infection with the AIDS virus, has been given approval by the Food and Drug Administration (FDA) to begin a clinical trial in people. CIRM, California’s stem cell agency, is funding that trial.
The therapy focuses on a protein found on cells in the immune system. HIV hijacks this protein, using it to penetrate and infect our cells.
Researchers at City of Hope near Los Angeles – working with Keck Medicine of the University of Southern California (USC) and Sangamo BioSciences plan to take blood stem cells from HIV infected individuals, then treat them with zinc finger nucleases (ZFNs), a kind of molecular scissors, to disrupt the CCR5 gene in those cells. The hope is that this will make those stem cells, and their progeny, resistant to HIV. The modified cells will then be reintroduced into the patient with the hope that they will create a new, AIDS-resistant immune system.
‘While we have a number of drugs that are effective in holding HIV at bay, we have nothing that cures it,” says John Zaia, M.D., the Principal Investigator in the trial at City of Hope. “In addition, for many patients, these medications come with significant long-term problems so there is a real need for a therapy that can help eradicate the virus from a patient completely. That is where our work is focused.”
CIRM is investing $5.6 million as part of its Strategic Partnership Award to fund the trial. Sangamo is matching that amount.
The clinical trial will include people with HIV/AIDS who have had a poor response to standard therapies. This first phase will determine if this approach is safe for these patients, to evaluate what, if any, side effects there may be and to see how the gene-modified stem cells perform when returned to the body.
CIRM is also funding another trial using a similar approach. Calimmune, an HIV gene medicines company focused on developing cell-based therapies for HIV, began its human clinical trial in July 2013 and has already shown that the first group of patients treated did well enough for the company to start treating a second group more intensively. This trial is enrolling HIV patients whose immune cells have not returned to normal levels even after success in suppressing the virus with antiretroviral therapy, and even if it doesn’t lead to a cure it could still result in a therapy that offers clinical benefit to patients at risk for opportunistic infections.”