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.
For the most part, gene-editing has been frowned upon in the US and Europe, with many ethicists stating that it is well, unethical. However, 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. 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 trials were given the green light in 2016 by the National Institutes of Health and aims to recruit at least 18 participants to test just how effective the Crispr therapy is against three specific cancers. 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 of the immune system and allowing the cells to fight off the cancer. Once the edits are made in the lab, the patient's cells are then introduced back into their body.
"This is just the beginning of the use of Crispr for somatic editing," says Gaétan Burgio, a geneticist at Australian National University who was not directly associated with the trial. "We need some time to assess the safety and efficiency of the Crispr editing versus other available options."
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 restriction on human embryo editing. The critical difference in He's work and the studies that are currently taking place in the US is the exact point in which 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. Therefore, the edited genes can not become hereditary and that seems to appease the ethicists.
