This is the first of several CRISPR clinical trials that are planned in China and in the US, all aimed at treating various cancers. The US trial, which will be funded by Facebook billionaire Sean Parker, is due to begin in 2017 at the University of Pennsylvania (see BioNews 857).
'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,' Professor Carl June, who will lead the US trial, told Nature News.
The team from China extracted immune T cells from the patient's blood, and used CRISPR/Cas9 to delete the gene that produces PD-1, a protein that keeps the immune response in check. PD-1 inadvertently helps cancerous cells as it tempers the response of T cells that would otherwise attack them. The modified cells were cultured and then injected back into the patient.
Oncologist Dr Lu You, who is leading the trial, said that the treatment went smoothly and the patient has been given a second injection. Each participant will receive between two and four injections in total. The focus of the clinical trial is to establish the safety of the technique, and all ten participants will be monitored closely.
Trials involving PD-1 antibodies, which would operate in the same way to take the brakes off the immune system have shown some promise. Dr Naiyer Rizvi of Columbia University Medical Centre, says he doubts whether the CRISPR-modified cells will work any better than the antibodies, which can be produced in unlimited numbers.He told Nature News: 'It's an exciting strategy. The rationale is strong.' But he added that process of extracting, genetically modifying and multiplying cells is 'a huge undertaking and not very scalable'. 'Unless it shows a large gain in efficacy, it will be hard to justify moving forward,' he concluded.
On Wednesday 7 December 2017, genome editing and embryo research will be debated at the Progress Educational Trust's public conference 'Rethinking the Ethics of Embryo Research: Genome Editing, 14 Days and Beyond'.