Go-ahead given to genetically modify humans for the first time
Biotech firm wins approval for European trials of ‘molecular scissors’ to fight devastating blood disorder
HUMANS will be genetically engineered in Europe for the first time this year, using a groundbreaking genesplicing therapy after regulators approved trials.
The biotech company Crispr Therapeutics is hoping to cure the disease beta thalassaemia, a devastating blood disorder that reduces the production of haemoglobin, the protein which carries oxygen to cells.
Without sufficient oxygen, sufferers can be left with bone deformities, severe anaemia, slow growth, fatigue and shortness of breath.
The disease is caused by a genetic mutation in the HBB gene, but scientists are confident that they can alter the body’s code to fix the problem and restore healthy levels of haemoglobin.
It will be the first human disease to be treated using the technology in the West. China has already begun similar trials, but does not have the same strict regulation as Europe or the US. The company has yet to decide where the first trial will take place.
British experts hailed the new treatments as “very promising”.
Prof Robin Lovell-Badge, Group Leader at London’s Francis Crick Institute, said: “We will look back and think that this is the real beginning of gene therapy.”
Genome therapy has been around in a basic form for around 30 years, with scientists administering missing DNA to damaged cells so they are able to work more effectively. Doctors have also used genetically engineered immune cells to keep patients alive until a donor is found.
But Crispr, which stands for Clustered, Regularly Interspaced, Short Palindromic Repeat, could be a cheap and permanent solution. It is based on a natural defence mechanism used by bacteria, which carry in their DNA strands of genetic code belonging to deadly viruses so that they can recognise them. When they spot a virus they release an enzyme which attacks it, snipping away this area of code.
Scientists have harnessed this mechanism to create “molecular scissors” which remove mutated areas of DNA.
During the new trial the gene editing will take place outside of the body, with stem cells harvested from patients and then engineered in the lab.
Although some therapies involve inserting the correct gene, the company has taken a different option, seeking to boost foetal haemoglobin – the high levels of the protein which babies have – by removing a gene that represses its production in adults.
The engineered cells are then transfused back into the patient’s bone marrow, where they start producing high levels of haemoglobin, allowing oxygen to once again flood cells.
Darren Griffith, professor of genetics at the University of Kent, said: “Everything I have seen suggests it’s very safe and effective. I think the [trial] results will be positive. And then we will be able to say, this is where it all began.”
Several other companies are hoping to develop similar therapies, while the University of Pennsylvania has begun recruiting for a new trial which seeks to use Crispr to treat people suffering from various forms of cancer.
Chinese universities began using Crispr for cancer in 2016. Dr Simon Waddington, reader in Gene Transfer Technology at University College London, said: “I get the feeling that public sentiment has changed, in that genetic therapies are now more acceptable.”