3D-printed model of CAS9, a DNA-cutting enzyme that features in the CRISPR gene editing system. Photo by NIH Image Gallery

First human treated with CRISPR gene-edited cells in China, report says

For the first time, a cancer patient is being treated with cells altered using a gene editing technique called CRISPR-Cas9, according to a news exclusive in Nature. The cells, which have been programmed to attack the patient’s metastatic lung cancer, could signal a new chapter in medicine.

The Chinese team behind this clinical trial, led by oncologist Lu You at Sichuan University in Chengdu, collected immune cells from the patient’s blood. They used CRISPR-Cas9 – an enzyme that precisely cuts and edits DNA – to disable a protein called PD-1. Normally, cells in the immune system use PD-1 as an off-switch to keep from attacking the rest of the body.

But cancer cells manipulate this protein in order to evade detection and rapidly multiply. The gene-edited cells have removed the PD-1, hopefully leading immune cells to fight the cancer.

CRISPR has drawn mixed reviews from the public and those in the bioethics community. In April 2015, scientists used CRISPR to alter human embryos, sparking an outcry about the ethics of possible “designer babies” through gene alteration. Some nations, including China and the U.S., have banned or restricted gene-editing on embryos, and an international committee of scientists condemned gene editing on embryos until the process is deemed safe.

There are 10 patients in total participating in Lu’s clinical trial, receiving up to four injections of the gene-edited cells. They will be monitored for the next six months to note any side effects and beyond that time to see if the treatment works to repel cancer.