A gene-editing therapy that offers a “functional cure” for some sickle cell patients has been approved for use on the NHS in England, in a move heralded as a positive “leap” forward.

The National Institute for Health and Care Excellence (NICE) has approved exagamglogene autotemcel (exa-cel) for the treatment of severe sickle cell disease, a life-limiting blood disorder, in older children and adults.

“The significance of this milestone for the sickle cell community cannot be understated"

John James

The one-time therapy uses clustered regularly interspaced short palindromic repeat (CRISPR) technology, which allows the editing of a gene inside bone marrow stem cells, to allow the patient’s body to produce functioning haemoglobin.

It will be offered to eligible patients aged 12 and over who experience recurrent sickle cell crises, a symptom of the disease characterised by severe pain caused by blood vessels becoming blocked.

NHS England said around 50 people per year would receive exa-cel.

In clinical trials for exa-cel, sold under the brand name Casgevy, 96.6% of participants were functionally cured of sickle cell disease, which is the UK’s fastest-growing genetic condition.

Patients will be eligible if they would qualify for a stem cell transplant, but a donor is not available.

Dee Thiruchelvam, chief nursing officer for NHS Blood and Transplant, said: “The approval of exa-cel… to treat sickle cell disease is extremely positive.

“Sickle cell severely impacts a patient’s quality of life, with painful side effects and regular blood transfusions and can result in serious or even fatal complications.

“[Exa-cel] effectively provides a cure, which is life-changing for those living with the disease. It is reassuring that it will now be available to those who may not have had many other treatment options.”

Ms Thiruchelvam explained that, while the news was welcome, there was still a massive need for blood donations to the NHS to provide transfusions for sickle cell patients ineligible for exa-cel.

“There continues to be a need for more people of Black heritage to come forward as blood donors – a single sickle cell patient receiving regular full blood exchanges can require blood from up to 100 donors each year,” she added.

According to the NHS, around 32,000 people were admitted to hospital in England in 2023-24 due to sickle cell disorders, of which 14,000 were due to sickle cell crises.

Amanda Pritchard, NHS England chief executive, said following the announcement: “More than a step, this is a leap in the right direction for people with sickle cell disease – which can be an extremely debilitating and painful condition.

“This innovative, gene-editing therapy offers hope of a cure for people facing a severe form of the disease and could be absolutely transformative – it could enable patients to live free from the fear of sickle cell crises hanging over them.”

John James, chief executive of the Sickle Cell Society, described the approval of exa-cel as a major milestone for people with the disease.

“We are absolutely thrilled to see this groundbreaking gene therapy treatment available on the NHS from today,” he said.

“The significance of this milestone for the sickle cell community cannot be understated – today’s result will give hope to many and is the result of determined campaigning.

“We extend our heartfelt thanks to the incredible individuals who shared their personal stories, challenges, and experiences of sickle cell as part of the campaign”

Exa-cel is the second novel treatment for sickle cell which has been approved for use in the NHS by NICE in the last year.

In 2024, the sickle cell disease community described the approval of  voxelotor, a drug which can treat haemolytic anaemia, as a "landmark victory".