Genetic Edits Still Has Long Way to Go

So it begins. Nobody thought it would happen this fast, and now we are preparing to take a leap into the unknown. Not Brexit but Crispr gene-editing, a DNA-changing technology that can supposedly cure mice of liver disease and muscular dystrophy, render human cells resistant to HIV and create fungus-resistant wheat.

It has also been touted as a means of remaking humanity — and now it is about to progress from Petri dishes into people. An influential advisory panel at the US National Institutes of Health has unanimously approved the first clinical trial to use Crispr genome-editing (also known as gene-editing) on humans, to reboot immune cells in cancer patients. Researchers at the University of Pennsylvania will target patients with multiple myeloma, melanoma or sarcoma. The team will remove a class of immune cells called T-cells from patients, edit the genes of those T-cells so they are better able to “lock on” to tumour cells, and then restore the altered T-cells back into the bloodstream.

With luck, the genetic edits should boost the patient’s immune system. The study, now expected to receive the blessing of federal regulators, will be funded by a cancer institute founded by Sean Parker of Napster and Facebook fame.

The aim of this first in-human trial of Crispr is not to enhance therapeutic outcomes but to prove its safety. Other genetic technologies of great pro-mise cast long shadows. Gene therapy, which involves inserting copies of missing or defective genes into a patient, usually using a virus as a carrier, was nearly derailed at the turn of the millennium , when a child with a severe immune disorder developed leukaemia as a direct result of the treatment.

The viruses chosen as carriers in some early trials wrought unforeseen damage. As a result the first European treatment using gene therapy, which has been around since 1990, was licensed only in 2012.

With gene-editing, the unintended consequence that most terrifies genetic researchers is “off-target effects”, in which untargeted genes are inadvertently snipped, deleted or altered. The technology uses enzymes to search for particular sequences of DNA — but, just as it is possible for a search facility in word-processing software to pick out a string of letters in an unexpected place, the enzymes might similarly latch on to the wrong stretch of DNA.

The risk, at least in this trial, is minimised by the gene-editing being done outside the body, allowing researchers to check the T-cells have been appropriately amended before being put back into the patient. Still, once the cutting enzyme is unleashed, there is a possibility it could continue operating inside the body to uncertain end.

By next year we should have a hint of whether gene-editing really can fix deficient DNA in people. And that is when things get serious: why stop at correcting the human genome? Why not beautify it? That thought is preoccupying those in the field, who raised concerns at a Washington summit in December, organised by scientists from the UK, China and the US. Among those attending was Yale University’s Daniel Kevles, a historian of the eugenics movement.

The thing about Crispr genome-editing is this: it is fast, cheap and easy to do. Many countries, especially those that see themselves as future torchbearers for technology, such as China, are forging ahead; China holds the first claim to creating a (non-viable) gene-edited embryo. Regulation is patchy.

No country endorses a genome-edited human embryo being implanted and being brought to term. Even so, gene-editing technology makes the prospect of a homo perfectus just slightly more probable — and, as a species; we have yet to fully grasp the implications of this brave and perfectly edited new world.