However, Bauer says, he is “not so sure” the company will be able to create a functional cure. T cells don’t live forever, he points out.
“This is encouraging,” says Ellen Feigal, vice president of R&D at the California Institute for Regenerative Medicine, “and it provides supporting evidence for a study we funded that would take the work to the next step.” This study, by researchers at City of Hope, a cancer center in Duarte, California, aims to provide patients with a permanent supply of HIV-resistant T cells. The strategy calls for modifying patients’ blood-forming stem cells, which produce all future T cells as well as the macrophages and dendritic cells that can also be HIV targets.
Sangamo is also exploring the potential of stem-cell modification with City of Hope researchers, but the company does not concede that modified stem cells will be necessary or any better than T cells. “Yes, T cells turn over,” says Geoff Nichol, who joined Sangamo as executive vice president of R&D a few months ago to commercialize the platform, “but there are some very long-lasting subsets that can live for years and years and remember the epitope they came up against. We are feeling bullish about T cells because of our data.”
Sangamo’s news is “certainly scientifically interesting,” observes Warner Greene, director of the Gladstone Institute at the University of California, San Francisco. But, he points out, no cell therapy, whether it involves T cells or stem cells, is a practical approach to treating HIV/AIDS throughout the developing world, where seven out of 10 new infections are occurring. “We really need to be looking for therapies that can benefit the millions of individuals with HIV, not just a select few who might be able to afford cellular therapies.”