Genome editing will be tested in humans. China has approved a first lung cancer trial using the CRISPR-Cas9 technique.
China, a pioneer in gene editing? The communist country will in any case be the first to experiment with the CRISPR-Cas9 technique in humans. From August, West China Hospital in Chengdu, Sichuan Province, is launching a clinical trial in lung cancer. The treatment will consist of removing a key gene using these “molecular scissors”.
The ethical agreement, obtained on July 6, opens the possibility for the Lu You team to recruit patients with lung tumors. Their profile is limited to say the least: only people suffering from metastatic non-small cell cancer, and for whom all treatment options have failed, will have the right to experiment with gene editing treatment. “The treatment options are very limited,” as the Chinese oncologist points out.
Act on the immune response
Within the establishment, several stages will be accomplished. The experts will first extract T lymphocytes, responsible for the immune system, from the blood of patients. Then begins the editing phase: using the CRISPR-Cas9 method, the gene which encodes the PD-1 protein will be removed. This protein, which regulates the immune response, prevents the body from attacking healthy cells. But tumors take advantage of this trick and pass for healthy tissue.
Once edited, the cells will be multiplied in the laboratory and then injected again into the bloodstream. They should, if the reaction is as expected, travel to the tumor and attack it.
The Cino-American struggle
The principle of this approach is similar to that requested by immunotherapies: acting on the PD-1 protein and boosting the immune response against tumors. The researchers hope, however, that their method will prove to be more effective. Indeed, only 20 to 30% of patients respond to treatment with immunotherapy. “This technique is really promising: it could bring benefits to patients, especially those we treat every day for cancer”, enthuses Lu You.
But as with immunotherapies, T cells are not specific to tumors. Autoimmune reactions can therefore occur. This is why the trial will initially consist of ensuring that patient safety is ensured. Only 10 people will be recruited and three different dosages will be evaluated, with a gradual increase in load.
This clinical trial is reminiscent of the one recently announced in the United States. And it seems that a new medical-scientific battle is now engaged between Chinese and American researchers. The latter obtained an agreement from the National Institutes of Health (NIH) for a clinical trial also aimed at removing the PD-1 gene and another gene, before inserting another. American research should start by the end of 2016.
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