CRISPR Shows Promise in Gene-Editing Therapy During Clinical Trial

Scientists at UCL National Amyloidosis Centre at the Royal Free Hospital, London are hoping their gene editing therapy using CRISPR will be a breakthrough for patients suffering from hereditary transthyretin (ATTR) amyloidosis. In a phase 1 clinical trial, the first six patients have shown positive interim results for gene-editing treatment.

The CRISPR breakthrough comes in treating transthyretin amyloidosis, a mutation in the transthyretin (TTR) gene. Those with this mutation produce an abnormal protein, which gradually builds up in the heart and nerves. Symptoms can include numbness in the hands and feet, loss of control of the bowel and bladder, and loss of mobility.

Hereditary transthyretin amyloidosis gets progressively worse and is fatal. Up until this point, most of the treatment options available to patients have included management of the symptoms and prevention of progression.

Those taking part in the trial have received a molecule knows as CRISPR/Cas9 via one-off infusion. The purpose of this is to deactivate the incorrect gene within the liver cell.

“With the gene no longer active in the liver, it is expected that the patient will only produce negligible levels of the harmful transthyretin protein,” UCL stated in a press release. 

Scientists saw in the first six patients a reduced production of the harmful transthyretin protein by up to 96 percent, 28 days after the treatment. Additionally, there were no serious adverse effects witnessed. This data was published in the New England Journal of Medicine.

“As the trial progresses, patients will be given higher doses of the gene editing therapy with the hope that will drive the levels of toxic protein even lower,” UCL explained. 

CRISPR/Cas9, a Nobel Prize-winning technology, has been used to edit cells outside the body in the past. However, UCL is presenting the first clinical data which CRISPR/Cas9 is being used as medicine itself for a potential therapy.

“This is wonderful news for patients with this condition. If this trial continues to be successful, the treatment may permit patients who are diagnosed early in the course of the disease to lead completely normal lives without the need for ongoing therapy,” Professor Julian Gillmore, the trial lead, of the UCL National Amyloidosis Centre, part of the UCL Centre for Amyloidosis and Acute Phase Proteins said in a press release.

“Until very recently, the majority of treatments we have been able to offer patients with this condition have had limited success. If this trial continues to go well, it will mean we can offer real hope and the prospect of meaningful clinical improvement to patients who suffer from this condition,” Gillmore continued.

The global trial includes patients from the Royal Free London and a hospital located in Auckland, New Zealand. The investigational therapy, designated NTLA-2001, is being developed by Intellia Therapeutics; a biotechnology company based in the United States.

 This could be a big step forward in using CRISPR as gene therapy. Typically, the therapy is injected into the site of illness. However, this newest approach injects CRISPR directly into the bloodstream, which could revolutionize how clinicians treat certain illnesses.