The U.S. National Institutes of Health has just approved a proposal to use the CRISPR-Cas-9 system in a clinical trial to modify human immune cells to attack cancer cells.
CRISPR-Cas9 gene editing technology (CRISPR) has unquestionably changed the face of biomedical research by making it cheaper and easier for scientists to manipulate genomes. CRISPR, or clustered regularly interspaced palindromic repeats, is a collection of DNA sequences that guides the enzyme Cas9 to cut and paste DNA into any genome. For example, CRISPR is much more efficient than traditional techniques used to create genetically-altered mice used in research, reducing the time it would take to generate a genetic model from a year to only a few months. Other gene-editing techniques using restriction enzymes (ZFN and TALENS) have been used to treat disease in people with varying degrees of success, but CRISPR has even greater potential as a medical treatment since it is more effective at modifying more than one gene at a time.
The U.S. National Institutes of Health’s (NIH) Recombinant DNA Research Advisory Committee has just approved a proposal led by the University of Pennsylvania to use CRISPR to edit T-cells, or human immune cells, to attack cancer cells. Researchers will remove T-cells from 18 cancer patients and edit them with CRISPR in three ways. First, they will insert the gene for an engineered protein that can cause the T-cells to target cancer cells. Second, they will also edit a naturally-occurring T-cell protein that could interfere with targeting, and third, they will remove a gene that allows cancer cells to identify T-cells and destroy them. The edited T-cells will then be placed back in the patient.
The primary purpose of this first NIH-approved initial clinical trial will be to determine whether CRISPR technology is safe to use in humans, and not if it can effectively treat cancer. Further approval is still required by the research group’s academic ethics board as well as the U.S. FDA prior to the start of the trial, which will be funded by a $250 million dollar immunotherapy foundation created by the former president of Facebook, Sean Parker. Gene editing required for the trial will be done at the University of Pennsylvania, and patients will be recruited and treated at cancer centres in Texas and California.
Written By: Fiona Wong, PhD