The first clinical trials using CRISPR-edited cells have begun in the US, with researchers at the University of Pennsylvania treating cancer patients with an experimental therapy, according to a report by NPR.
CRISPR is a revolutionary gene-editing tool that can cut DNA with great precision, allowing genes to be turned off, new genes added or their functions changed. The gene editing technology is so powerful it could be used to wipe out entire species or solve long-standing agricultural problems, such as the annual culling of male chicks.
Two patients, one with multiple myeloma and one with sarcoma, have received the treatment which uses an edited version of the patient's white blood cells. It involves the US-first example of using CRISPR to edit a specific type of immune cell "ex-vivo" -- outside the body.
The trial was first greenlit in 2016 by the National Institutes of Health (NIH) and aims to recruit at least 18 participants to test how effective the CRISPR therapy is against three specific cancers.
The human immune system is a remarkable evolutionary adaptation that fights off all manner of invaders. In the battle against cancer, it doesn't always fare so well -- and one of the reasons is cancer is particularly good at evading destruction and slamming on the immune system's "brakes".
In the trial, the immune cells are removed from a patient and three edits are made to the DNA by CRISPR. The edits allow for the cells to more readily attack a tumor, inhibiting the brakes and allowing the cells to fight off the cancer. Once the edits are made in the lab, the patient's cells are infused back into their body.
This is not the first time CRISPR has been used to edit human immune cells. A team of researchers from Sichuan University in China have also been working with CRISPR-edited immune cells to treat patients with non-small cell lung cancer. Preliminary results from that study suggest the therapy is safe, but further study and larger sample sizes will be necessary to explore its effectiveness.
"This is just the beginning of the use of CRISPR for somatic editing," says Gaétan Burgio, a geneticist at Australian National University not associated with the trial. "We need sometime to assess the safety and efficiency of the CRISPR editing versus other available options."
It's been a wild six months for CRISPR in humans. After the revelations in November 2018 that Chinese scientist He Jiankui used CRISPR to edit the embryos of human babies, the scientific community called for a moratorium on human embryo editing ("germline editing") last March.
The critical difference in He's work and the studies currently taking place in the US is when CRISPR makes the edit. In He's case, CRISPR was introduced into the genes of an embryo, which will carry the genes throughout life. The clinical studies described here make edits to a set of cells that will eventually die, taking their CRISPR edits with them. He's work was highly controversial and resulted in termination of his employment, with a Chinese investigation labeling his actions unethical and unlawful.
Time magazine recently listed He as a pioneer in its list of 2019's 100 most influential people. He's profile was penned by CRISPR pioneer Jennifer Doudna, who said his work "shattered scientific, medical and ethical norms" and "will likely be remembered as one of the most shocking misapplications of any scientific tool in our history."