The scientific team leading the first CRISPR human trial in Chengdu has injected the first patient with cells edited using CRISPR-Cas9
While cells that have been gene edited have been infused into patients before, in a trial on HIV patients, this was achieved using an alternative editing system called zinc finger nucleases. The famous CRISPR-Cas9 editing system has many advantages, namely being cheaper and much easier to work with. There has therefore been a great deal of excitement around the first human trial in Chengdu, in which patients with aggressive lung cancer will be treated with modified cells to fight the disease.
"I think this is going to trigger ‘Sputnik 2.0’, a biomedical duel on progress between China and the United States, which is important since competition usually improves the end product”
A landmark moment
Both American and Chinese teams are vying for clinical translation. In early 2017 an American immunotherapy trial involving CRISPR has the go ahead, and Peking University plans to begin 3 additional trials against bladder, prostate and renal-cell cancers.
What has the Chengdu team done?
The trial involves the removal of immune cells from a patient, before editing a gene called PD-1. PD-1 acts as an inhibitory signal, preventing the immune system from effectively targeting and removing cancer cells. By essentially disabling this gene, the scientists hope to stimulate a response more elegantly and effectively than through drugs that mimic this effect. The trial will involve 10 people, each of which will receive a series of injections. They will then undergo 6 months of observation, to confirm whether the strategy is likely safe or not. The first patient is apparently doing well after the first infusion.
The trial is thrilling, but it remains to be seen whether it represents a real step up in immunotherapy tactics. Lung cancer patients treated with antibodies to PD-1 have indeed seen therapeutic benefit, but while this strategy is more potent it's considerably more expensive than its alternatives, which could be a barrier to adoption.
“The technology is a huge undertaking and not very scalable. Unless it shows a large gain in efficacy, it will be hard to justify moving forward”
Read more at Nature