Ever since it was introduced in 2013, CRISPR has been touted as a promising technology for treating inherited disorders, cancer, and other diseases with no current treatment options. Teams of researchers had been hoping to begin human trials in 2018, but none of those trials have taken place yet with the exception of China, where researchers have been working on CRISPR in humans since 2016. No results from these trials have been published yet. In the United States, the FDA placed a ‘clinical hold’ on the first proposed CRISPR gene editing human trial. But why?
Two new studies found that when CRISPR performs its hallmark trick and cuts DNA, that damage can kill the cell, or make it stop growing. CRISPR modifications are also less likely to kill cells that have a defective version of a gene called p53. P53 plays a role in preventing the onset of cancer by regulating a cell’s life cycle, so by leaving more of the defective cells alive than healthy ones, CRISPR may be inadvertently raising the risk of cancer in that patient.