Gene editing tool CRISPR gets clearance for human trials

The genetic editing tool known as CRISPR has been described as a game changer, and in response to the groundbreaking results is has produced; the National Institutes of Health (NIH) has approved it for the first human clinical trial.

The approved trial is focused on improving cancer treatments that use the patient’s own immune cells to fight off the disease.

“Cell therapies [for cancer] are so promising but the majority of people who get these therapies have a disease that relapses,” lead researcher Edward Stadtmauer, a physician at the University of Pennsylvania, told Nature News.

Using gene editing for immune system treatment

Designed to more see if CRISPR is safe for use in humans, the trial will involve using CRISPR to make edited T-cells from the immune systems of 18 patients with melanoma, sarcoma or myeloma.

One change will place a gene for a protein designed to recognize cancer cells and teach the T cells to target them. A second genetic change will eliminate a normal T-cell protein that may restrict the initial edit. A third edit will take out the gene for a protein that recognizes the T cells as immune cells and stop the cancer cells from shutting them down. The scientists will then place the edited cells into the same patient from which they originally came.

“Last year’s excitement over CRISPR was in anticipation of this,” said Dean Anthony Lee, a member of the NIH’s Recombinant DNA Research Advisory Committee (RAC), which reviewed the proposal.

CRISPR has garnered most interest due to its simplicity. However, the T-cell trial will not be the first test of the effectiveness of using gene editing to battle diseases.

In 2014, a trial used another gene-editing system known as zinc-finger nuclease. This trial took blood from 12 individuals with HIV and eliminated the gene that encodes a protein on T cells that is attacked by the virus. The team said they hoped that this would stop infection of the cells. The outcomes were encouraging, and the process is now being used in clinical trials for many other applications.

Despite the fact that CRISPR is easier to use than other means and better at editing numerous genes at once, a major challenge will be overcoming CRISPR’s inclination for ‘off-target’ edits. These are situations involving the unintentional edits to the genome. In spite of precautions, the immune system could still assault the edited cells, trial researchers said.

—–

Image credit: Steve Gschmeissner/SPL