HIV gene therapy breakthrough
Immune system boost may mean patients no longer need to take daily meds to control infection
Thursday, 06 March 2014
While doctors are stressing caution due to the size of the study, they have boosted the immune systems of 12 patients with HIV using gene therapy.
They say that it raises the long-term prospect of patients no longer needing to take expensive daily medication to control their infection.
In the study, published in the New England Journal of Medicine, patients' white blood cells were taken out of the body, given HIV resistance and then re-injected.
Doctors say some patients have a rare mutation that changes the structure of their T-cells so that the virus cannot get inside and multiply. The researchers from the University of Pennsylvania took millions of T-cells from the blood and grew them in the laboratory and then edited the DNA inside the cells to give them the shielding mutation - known as CCR5-delta-32. About 10 billion cells were then infused back in, although only around 20% were successfully modified.
When patients were taken off their medication for four weeks, the number of unprotected T-cells still in the body fell dramatically, whereas the modified T-cells seemed to be protected and could still be found in the blood several months later.
Researchers stressed that the trial was designed to test only the safety and feasibility of the method, not whether it could replace drug treatment in the long term.
Prof Bruce Levine, the director of the Clinical Cell and Vaccine Production Facility at the University of Pennsylvania, who led the research, said: "This is a first - gene editing has not to date been used in a human trial [for HIV].
"We've been able to use this technology in HIV and show it is safe and feasible, so it is an evolution in the treatment of HIV from daily antiretroviral therapy."
He says the aim is to develop a therapy that gets people away from expensive daily medication. "What if we can now take the leap to an upfront treatment that can last for years?"
Such a treatment will be expensive so any benefit will depend on how long people could be freed from drugs and how long that protection would last. Prof Levine argues this could be several years, which might save money in the long term.
Commenting on the findings, Prof Sharon Lewin from Monash University in Australia, told BBC News: "The idea of modifying a T-cell to make it resistant and showing it is feasible and they survive - that's exciting in itself.
"What most people are aiming for in HIV is a way you take treatment for a short period of time and that keeps the virus under control."
She said drug treatment would not be replaced by this, especially in the early stages of the infection. But it might lead to people eventually replacing drugs with an immune upgrade, but "it's still a long way off".