When CRISPR-Cas9, the genome editing technology, was first reported, the speculation was about whether it would lead to designer babies. It did, though not in the sense that dominates popular imagination. A Chinese researcher used the tool to edit genes in human embryos illegally, and now has been jailed by the authorities. But, the interest CRISPR-Cas9 has generated over the years is primarily because of the promise it holds for treatment of genetic diseases. Nature reports that some of that promise is being realised now as the tool is being tweaked to deliver ever newer successes. In 2016, Chinese researchers announced that they used CRISPR-Cas9 in a therapy to treat cancer—they used the tool to switch off a gene that codes for a protein called PD-1, which has an immunoregulatory function that shields cancer cells in the process. By 2019, a US database listed over a dozen active studies that are testing CRISPR-Cas9 as a treatment option for a range of diseases, from cancer to HIV.
Of course, the experiments and the subjects are still too few to comment with certainty on the safety or efficacy of CRISPR-Cas9 therapies. Preliminary results from two trials—one involving an HIV patient and the other involving three cancer patients—showed no signs of clinical improvement, Nature reports. However, there are early signs that another trial meets more success. US-based CRISPR Therapeutics and Vertex Pharmaceuticals have treated two people with sickle-cell anaemia and ß-thalassaemia. Early results show some success, but a more definite call on the therapy can only be taken after a longer time has elapsed. A future where genetic diseases could become a thing of the past is certainly a worthy vision—and CRISPR success could ensure just that.