NOV 19, 2016

CRISPR Tested in Humans for the First Time

WRITTEN BY: Xuan Pham

In a historic, landmark clinical trial, Chinese researchers injected a patient with a shot of CRISPR-edited white blood cells in an effort to treat cancer.
 


During the past few years, the CRISPR craze has taken hold of the scientific community, and it shows no signs of letting go. Due to its relatively low cost and high efficiency, CRISPR is revolutionizing the gene-editing game. Many of the breakthroughs using this technology are aimed at improving human health and curing diseases. But none so far has gone as far as using the technology in a human clinical trial.
 
The Chinese trial enrolled 10 participants who are diagnosed with metastatic non-small cell lung cancer. Because their cancer is advanced and has spread to other parts of the body, the patients have shown no signs of positive response to current available treatments. Their life expectancy is grim at only 6 months. In this context, the CRISPR technique may be the only tool left that can give these patients some hope.
 
To help these patients, Chinese researchers exploited the cut-and-paste mechanism of CRISPR to modify the patient’s own immune response cells. In particular, the team isolated the patients’ T cells – a type of white blood cell – to which they modified with CRISPR. The modification turns off a gene responsible for programmed cell death (PD-1). Scientists hope that with this switch off, the T cells can be unleashed to destroy cancer cells in the patients.
 


In essence, it’s a modernized version of immunotherapy – using the patient’s own immune system to combat the cancer invasion. The hope is that the patient’s cells will be much more adept at killing cancer than foreign drug compounds. Furthermore, this method should also minimize the risks to the patient’s healthy cells.
 
The injection was given to the patient as part of a Phase 1 trial, which means that scientists are trying to answer the question of the treatment’s safety. Results from this trial should inform us on how human bodies actually received CRISPR-edited cells and whether there are any unwanted side effects from this treatment. Whether the CRISPR-modified treatment will cure cancer will probably not be answered until years from now.
 
For now, the scientific community may receive this news with mixed reactions. While some may hail this as an exciting step towards genome engineering for human diseases, others are concerned that CRISPR will open the door for unethical tampering of the human genome (think designer babies). However, CRISPR seems unstoppable, and the US is also expected to approve its own medical trials with this technology soon too. 
 


Additional sources: Popular Science, Nature