CRISPR gene-edited cells are injected into a patient with lung cancer as part of a Chinese Phase I clinical trial to investigate the safety of the technology in humans.
CRISPR, or clustered regularly interspaced palindromic repeats, is a revolutionary gene-editing tool that can precisely cut and paste DNA into any genome. CRISPR can be used to modify more than one gene at a time and has been used in biomedical research to improve the development of animal models and target specific genes in cell lines.
CRISPR has undeniable potential as a medical treatment. Many research groups across the globe have plans to test CRISPR technology in humans, particularly in patients with cancer so that a more effective immunotherapy can be developed. In June, the National Institutes of Health in the U.S. approved a study to determine whether CRISPR technology is safe to use in humans, and more details can be found in a previous article. The study would use CRISPR to alter the genes of human immune cells so that they can more effectively fight cancer, prior to their injection in patients.
However, it seems that China, and not the U.S., is the first country to actually inject CRISPR-edited cells into a person. As reported in a news article from the journal Nature, researchers from Sichuan University modified T cells – specialized white blood cells of the immune system that can destroy tumours – and injected them into a patient with aggressive lung cancer on October 28. This patient is one of up to ten who will be part of a Phase I clinical trial (NCT02793856) to test the safety of CRISPR-edited cells in patients with metastatic lung cancer.
The use of CRISPR technology in patients is a complex procedure, involving three major steps: 1) extracting the target cells, 2) genetically modifying them using CRISPR, and 3) growing them up in greater numbers. In this trial, T-cells were isolated from a blood sample from the patient. The genes which code for PD-1, a protein that normally suppresses the cell’s immune response, were disabled using CRISPR. The edited T-cells were then grown in vitro to increase their numbers before being injected back into the patient. Without PD-1, the T-cells will hopefully attack and destroy the cancer.
According to the lead researcher of the trial, the first treatment went well and a second is planned. The patient will be monitored over the course of the trial for serious adverse effects, and also if they are benefitting from the treatment. Additional participants will receive two, three, or four injections to get a better idea of the safety and dosing limits associated CRISPR-edited cells in the treatment of lung cancer.
It will be very exciting to see what results this first-ever CRISPR clinical trial brings, and whether the technology can live up to its huge potential in medicine.
Written By: Fiona Wong, PhD