People suffering from a rare genetic blood disorder in England are being offered a “life-changing” new treatment through the NHS, in a moment which has been described as historic.

Casgevy, a one-time gene therapy, has been approved by the NHS for use in people with a severe form of thalassemia.

The treatment was approved by the National Institute for Health and Care Excellence (Nice) on Wednesday, meaning around 460 patients currently living with transfusion-dependent beta thalassemia could be eligible for the treatment.

Thalassemia is the name given to a group of inherited blood disorders in which the body produces too little haemoglobin. It affects around 2,300 people in the UK, mostly from Mediterranean, Asian or Middle Eastern backgrounds. Many people with beta thalassemia are not expected to live past the age of 50.

Casgevy works by editing a gene in a recipient’s bone marrow stem cells so that the body produces functioning hemoglobin.

It is hoped that the therapy will result in a lifelong cure. In international clinical studies, 93% of patients with beta thalassemia did not require a blood transfusion for at least a year after treatment.

Amanda Pritchard, chief executive of the NHS, said: “This is a historic moment for people living with beta thalassemia. The NHS is now offering these people a potential cure for this debilitating disease.

“Typically, patients suffer painful side effects and have to undergo regular blood transfusions, which severely impact their quality of life. However, this therapy offers people a life without these side effects as well as the hope of living longer, which is truly amazing news.

“This is the latest in a series of revolutionary gene therapies secured by NHS England over the past five years that bring significant benefits to patients. And thanks to funding from our Innovative Medicines Fund, this first-of-its-kind therapy can be made available more quickly to patients who can benefit from the new life it promises.”

Prof Bola Owolabi, Director of the National Healthcare Inequalities Improvement Programme at NHS England, said: “This is an incredibly exciting advance in the treatment of thalassemia and could dramatically change the lives of people living with this sometimes extremely painful disease.

“We are committed to reducing health inequalities by introducing new and groundbreaking treatments in the NHS for diseases such as thalassemia, which disproportionately affects people from certain ethnic minorities.”

Romaine Maharaj, chief executive of the British Thalassemia Society, said: “With Nice’s approval of gene therapy for transfusion-dependent thalassemia under the NHS Managed Access Scheme, we are on the verge of a revolutionary breakthrough.

“This groundbreaking treatment offers patients a life-changing opportunity, allowing them to repair their own cells and face a future free from the challenges of their disease.

“It is a glimmer of hope that underscores the power of innovation in medicine and paves the way for cures that can truly improve the quality of life of all affected.”