Photo Credit: Penn Medicine

The U.S. are the closest they’ve ever been to using gene-editing tool, CRISPR for the first time in a human test in a bid to tackle deadly cancers. 

Doctors at the University of Pennsylvania have revealed that they will use CRISPR to modify human immune cells so that they become expert cancer killers, writes MIT Technology Review. The study in question will enroll up to 18 patients fighting three different types of cancer, multiple myeloma, sarcoma, and melanoma. It would become the first medical use of CRISPR outside China, where similar studies have been taking place. 

Although the National Institutes of Health gave the Penn researchers the go-ahead back in June 2016, but until now it was not known whether the trial would proceed. 

“We are in the final steps of preparing for the trial, but cannot provide a specific projected start date,” explained a spokesperson for Penn Medicine. 

The trial, led by doctor Edward Stadtmauer, involves reprogramming a person’s immune cells to find and attack tumours. In order to enhance the treatment, the scientists intend to use CRISPR to delete two genes in patients’ T cells to make them better cancer fighters. One of the genes to be removed makes a “checkpoint” molecule, PD-1, which cancer cells exploit to put brakes on the immune system.

Another edit will delete the receptor that immune cells normally use to sense danger, like germs or sick tissue. An engineered receptor, added in its place, will instead steer them toward particular tumours. 

Doctors plan to remove people’s blood cells, modify them with CRISPR in the lab, and then infuse them back into the patients. This outside-the-body-approach, called ex-vivo gene therapy, is considered less risky than injecting CRISPR directly into a person’s bloodstream, which could cause immune reactions. 

There is talks of a second CRISPR trial that could take place in Europe later this year which would also explore the ex vivo approach. Biotech, CRISPR Therapeutics asked European regulatory authorities in December for permission to try to cure beta thalassemia, a blood disorder, by making a genetic tweak to people’s blood cells.