Scientists in China are about to become the first to use the game-changing gene-editing technology Crispr-Cas9 on humans.
Last week, Nature reported that researchers at Sichuan University’s West China Hospital have received the green-light from the hospital’s review board to begin a trial using the technology to try to cure cancer. The scientists will use CRISPR to edit immune-system T cells, reprogramming them to destroy cancerous cells. The trial is slated to begin in August, putting it ahead of a similar American trial led by researchers at the University of Pennsylvania that recently received the okay from a federal biosafety panel. The U.S. study, however, faced additional regulatory hurdles, and was expected to begin at the end of 2016 at the earliest.
CRISPR allows scientists to easily add in or delete small bits of DNA in order to either remove troubling traits or alter a gene to particular specifications. Similar to the U.S. study, the China study aims to use CRISPR to delete a gene that plays a role in allowing cancer to spread. The researchers plan to remove T cells from the blood of lung cancer patients whose disease has aggressively spread, then delete a particular gene for a molecule called PD-1. The PD-1 molecule helps cancer spread by acting as a receptor for molecules from tumors that allows the cancerous genes to slop into a T-cell and turn it off—effectively killing the cell's ability to fight off cancer.
The researchers will edit the PD-1 gene in the lab, and then, once certain that only the PD-1 genes had been affected by the CRISPRing process, they will infuse the edited cells back into the patients' blood streams, hopefully transformed into cancer-fighting machines. The initial trial will include 10 patients, receiving different doses of the edited cells.
Drugs that produce a similar effect suggest that turning the body's immune system into weapons that attack tumors may very well work. Last year, the Food and Drug Administration approved two drugs for the same type of lung cancer that researchers plan to treat based on studies showing that blocking PD-1 can indeed effectively allow T-cells to attack tumors.
In the U.S. study, scientists plan to instead treat patients diagnosed with myeloma, melanoma, and sarcoma, removing patients’ T cells from their bodies and using CRISPR to snip out two genes in the cells that they hope will allow them to more effectively attack and kill tumor cells. Another U.S. study slated for 2017 plans to use the gene-editing technique to treat a rare form of blindness.
But gene-editing research has moved at a much faster pace in China, where there are fewer regulations to interfere. Last year, in a controversial experiment, scientists there became the first to use CRISPR to edit human embryos.
The human trials will not just provide answers to the question of whether this gene editing technology might be used to cure certain kinds of cancer. Scientists also seek to find answers to how safe and useful CRISPR is for treating humans in general. CRISPR offers incredible power to change the very makeup of our genetics. But it is also unknown what consequences might come with such genetic cutting and pasting.