The patient in question – a 27-year-old male citizen of China – was diagnosed with AIDS back in 2016, and two weeks later found out he also had lymphoblastic leukaemia.
With prospects bleak, the patient was offered to receive a bone marrow transplant engineered with CRISPR-Cas9 to be free of the CCR5 gene known to produce a protein which the virus uses to gain access to an infected person’s cells.
After 19 months following the experimental treatment, performed in the summer of 2017, the patient achieved complete remission with regards to leukaemia, but was found to harbour the CCR5 edit in merely 5% to 8% of his bone marrow cells.
“In the future, further improving the efficiency of gene-editing and optimising the transplantation procedure should accelerate the transition to clinical applications,” said Deng Hongkui, lead researcher on a study published in The New England Journal of Medicine.
Despite the relatively slight efficacy of the treatment, Deng considers it a success, pointing out that it’s primary focus was to test the waters, namely – to find out if the procedure is feasible and safe, which, according to him, it almost certainly is.
The research team did not find any adverse effects associated with the intervention, yet longer-term and more in-depth studies remain indicated to identify potential “off-target effects” and to conduct “other safety assessments”.
The present study builds on research conducted in the past, such as the team’s – largely successful – experiment in transplanting edited CCR5 humans cells into mice with HIV, as well as similar experiments performed by other American research groups using an older gene-editing tool called zinc finger nuclease.
Hongkui's and his team's efforts form a part of China’s Five Year Plan announced in 2016, which lays out, among other things, the central government’s plan to invest heavily into biotech to generate a number of scientific breakthroughs and thereby maintain the country's prestige within the scientific community.
Hongkui believes that not only does CRISPR brings the goal of a functional cure for AIDS that much closer, but could also “bring a new dawn” to the treatment of blood-related diseases, such as sickle cell anaemia, haemophilia, and beta thalassemia.