NEW YORK - HIV patients given gene therapy more than a decade ago are healthy and the altered DNA they received remains stable in their bodies, according to a study that scientists say proves the treatment may safely be tested as a way to attack other illnesses.
All except two of 43 people treated with genetically altered versions of their own infection-fighting T cells were healthy as many as 11 years later, according to the study reported Thursday in the journal Science Translational Medicine.
Previous uses of gene therapy in experiments have suggested that leukemia caused by the viruses that transfer the genes to the cells might be a risk.
Thursday’s finding allays that concern, enabling researchers to move beyond immediately life-threatening illnesses, such as HIV and cancer, said Bruce Levine, a study author and researcher at the University of Pennsylvania.
“We turned those cells into heat-seeking missiles directed against HIV-infected cells,’’ said Levine, head of the Clinical Cell and Vaccine Production Facility at the Philadelphia university’s Perelman School of Medicine. “What really surprised us was when we got those samples, not only could we detect the gene-modified cells but they appeared to be present at relatively stable levels.’’
Because the therapy has been found to work safely over a significant period of time, the designer cells should be considered a platform technology that can also be used by scientists researching other diseases besides HIV, Levine said in a telephone interview.
Each patient in the new study received at least one transfusion of their own immune cells between 1998 and 2005. The T cells were designed to look for an HIV protein and kill any infected cells they encountered, before the virus has a chance to mature.
“It’s like a controlled burn,’’ Levine said.
The Food and Drug Administration required the patients be followed for 15 years to see if any late-developing side effects, such as cancer, might arise from the therapy.
The patients were followed every year after their initial dose.
No gene therapy has been approved by the FDA. The field almost halted in 1999, when 18-year-old Jesse Gelsinger died within hours of being injected. Earlier, in a French trial, two of 10 patients acquired leukemia following gene therapy for “bubble boy disease,’’ or severe combined immunodeficiency.