This may just be the good news lung cancer patients have been waiting for as a team of Chinese researchers from Sichuan University’s West China Hospital prepare for the first ever trial of CRISPR-Cas9 gene-editing technique on humans next month.
Patients who have failed to respond to treatments—who still haven’t gotten well even after undergoing chemotherapy, radiation therapy, and other treatments—were chosen to take part in the CRISPR trial.
After receiving ethical approval from the hospital’s review board last July 6, the scientists plan to take T cells from patients and use the CRISPR-Cas9 technique to edit out the PD-1 gene. PD-1 regulates T cells’ immune response and prevents them from attacking healthy cells.
The team will then multiply the modified samples in the lab before reintroducing them to the patients’ bloodstream, in the hopes that they’ll target parts of the patient’s body affected with cancer.
A biotechnology company will validate the cells before they’re reintroduced into the patient to make sure only PD-1 was edited out.
As a safety precaution, the Chinese research team will start the trial with just 10 people, and they will slowly administer increasing dosages on just one patient. This is so they can monitor the results closely and to look out for side effects.
Chinese scientists were also the first to use CRISPR editing on human embryos to repair a gene that causes fatal blood disorder, but it only worked on half the embryos.
Researchers from the United States are also planning to perform the very first CRISPR-Cas9 gene-editing on humans to fight against melanoma, sarcoma and myeloid cancers. They have received the green light from the US National Institute of Health but still waiting the approval from the US Food and Drugs Administration and a university review board.
CRISPR-Cas9 is based on a gene-editing technique used by bacteria to help them remove sections of DNA introduced by viruses that infect bacteria, known as phages.Small chemical tags are used to get an enzyme to cut DNA in a precise place and ‘snip out’ a small piece of DNA.This can be used to turn off specific genes in an extremely precise manner that has not been available using previously less accurate gene editing techniques.
However, scientists now need to prove the technique can be used safely in patients before it can be used more widely and these initial tests will aim to show it does not harm those being treated. Future trials will then have to assess how effective the technique is compared to other types of treatment.