A team of Chinese scientists will soon pioneer the use of a breakthrough gene-editing technique to inject modified cells on humans during clinical trials.
The team, which received ethical approval on July 6 from the review board of the West China Hospital in Chengdu, will begin testing genetically altered cells on lung cancer patients in August.
Led by oncologist Lu You from the Sichuan University, scientists will modify the cells using CRISPR-Cas9, a form of "genetic engineering scissors" that allows experts to edit DNA with precision.
"I hope we are the first," Lu tells the scientific journal Nature. "And more importantly, I hope we can get positive data from the trial."
How The Clinical Trial Will Work
Lu and colleagues will enroll patients diagnosed with metastatic non-small lung cancer, as well as patients for whom radiation therapy, chemotherapy and other forms of treatment have failed.
According to Lu, current treatment options are very limited, but the CRISPR-Cas9 technique holds great promise in bringing benefits to patients, particularly to cancer patients.
The research team will extract T-cells from the blood of patients and use the gene editing technique to knock out a gene in these cells.
The gene will encode a protein known as PD-1 which acts as a check on the T-cells' capacity to trigger an immune response, preventing it from targeting healthy cells.
The modified T-cells will be multiplied in a laboratory and injected into the bloodstream of the patient. The team hopes the modified cells will circulate and directly target the cancer.
Possible Dangers
Previous research has shown that CRISPR can result in gene edits at the wrong place in the genome.
Because of this, biotechnology company Chengdu MedGencell will validate the modified cells in the Chinese trial to make sure that the correct genes are removed.
Meanwhile, Timothy Chan from the Memorial Sloan Kettering Cancer Center is worried that the approach might trigger an excessive autoimmune response — the cells might start attacking the gut, the adrenaline glands or other healthy tissues.
"All the T-cells - everything will be active," says Chan. "That will be a concern."
Chan suggests that the Chinese team take the T-cells from the site of the tumor, because they would already be specialized for targeting cancer.
However, oncologist Lei Deng, who is one of the researchers in the Chinese study, says the lung cancer tumors targeted in the clinical trial cannot be accessed easily.
Deng says the project is reassured by antibody therapies approved by the FDA. These therapies did not display a high level of autoimmune response.
Trials In The United States?
Clinical researcher Carl June from the University of Pennsylvania, who has led a human clinical trial using another gene-editing technique, believes the Chinese team's plans are a step forward.
June's previous research has helped patients fight against HIV. He is also a scientific adviser on a proposed trial that would use CRISPR-Cas9 to modify cells for cancer treatment.
Last month, the project with June received approval from the U.S. National Institutes of Health, but scientists require the greenlight of the Food and Drug Administration and a university review board to proceed.
This U.S. trial also plans to knock out the gene for PD-1 and a second gene, and then insert a third gene before the modified cells are injected to the patient.
