LONDON: Britain has authorised a gene therapy that aims to cure sickle-cell disease and another type of inherited blood disorder for patients aged 12 and over, the country's medical regulator said on Thursday, becoming the first in the world to do so.

Casgevy is the first medicine to be licensed that uses the gene-editing tool CRISPR, which won its inventors the Nobel Prize in 2020, Britain's Medicines and Healthcare products Regulatory Agency (MHRA) said.

Sickle cell disease and β-thalassemia are genetic conditions caused by errors in the genes for haemoglobin, which is used by red blood cells to carry oxygen around the body.

"Both sickle cell disease and β-thalassemia are painful, life-long conditions that in some cases can be fatal," MHRA Interim Director Julian Beach said in the statement.

In clinical trials Casgevy has been found to restore healthy haemoglobin production in the majority of participants with sickle-cell disease and transfusion-dependent β -thalassaemia, relieving the symptoms of disease, Beach added.

The MHRA said no significant safety concerns were identified during the trials, adding that it was closely monitoring the safety of the medicine.

The medicine is administered by taking stem cells out of a patient’s bone marrow and editing a gene in the cells in a laboratory, with the modified cells then infused back into the patient after conditioning treatment to prepare the bone marrow.

U.S.-based companies Vertex Pharmaceuticals and CRISPR Therapeutics welcomed the approval in a separate statement.

"I hope this represents the first of many applications of this Nobel Prize winning technology to benefit eligible patients with serious diseases," said CRISPR CEO Samarth Kulkarni said.