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A potential cure for two inherited blood diseases using gene therapy has been authorised by Britain’s medicine regulator in a world first.
The treatment, Casgevy, for sickle cell disease and beta thalassemia, is the first to be licensed using the gene-editing tool known as Crispr – which earned its inventors a Nobel Prize in 2020.
The Medicines and Healthcare products Regulatory Agency (MHRA) has found the treatment to be safe and effective and granted authorisation for use in patients over the age of 12.
It is estimated the treatment could cost about £1million per patient and, following MHRA approval, it will be available privately in the UK.
The National Institute for Health and Care Excellence (Nice) will now evaluate the financial viability of the drug and assess its cost-effectiveness. If approved, it will then be available on the NHS but a decision on this is expected to take several months, The Telegraph understands.
Nice will assess the treatment separately for both conditions. A committee is set to meet to discuss thalassemia in December and sickle cell in February, with draft guidance published as soon as April.
However, one source said it was “unlikely” to be approved that quickly, subject to the price set by Vertex Pharmaceuticals, the manufacturer of Casgevy.
Britain is the first in the world to authorise Crispr therapy for use in patients. The technology is based on a bacterial mechanism that can precisely snip out and replace specific chunks of DNA.
The technology has the potential to cure a patient for life but will not prevent people from potentially passing on their condition to their children.
Gene therapies are the most expensive treatments in the world and there is not yet a set price for Casgevy. Other similar therapies can cost about £3 million a time.
Both sickle cell disease and beta thalassemia are conditions caused by errors in the genetic code of haemoglobin, the iron-containing protein which makes blood red and transports oxygen around the body.
Sickle cell disease is particularly common in people of African or Caribbean descent while beta thalassemia is a hereditary condition that is common in people of Mediterranean, south Asian, south-east Asian and Middle Eastern origin.
There are about 15,000 people in the UK with sickle cell anaemia and about 1,000 with beta thalassemia. There are an estimated 2,000 patients eligible for Casgevy in the UK, Vertex said.
‘Painful, life-long conditions’
Symptoms of sickle cell disease can include very severe pain, serious and life-threatening infections, and anaemia.
People with beta thalassemia can have severe anaemia. Patients often need a blood transfusion every three to five weeks, alongside regular injections and medicines.
A sickle cell patient costs the NHS hundreds of thousands of pounds over a lifetime through transfusions, medication, A&E visits and other appointments, with those most severely ill and requiring the most hospital care likely to cost more than £1 million.
One study of thalassemia patients published in the Transfusion Journal found that each one cost the NHS almost £500,000 over 50 years - less than two thirds were likely to live longer than that.
The clinical trial using Crispr gene editing technology saw almost 100 participants have stem cells from their bone marrow removed from their bodies before scientists in a lab used Crispr to fix the defective gene, called BCL11A. These now fully functioning cells are then put back into the patient’s body.
The patients spend about a month in hospital for the procedure and over this time the stem cells settle back into the bone marrow and begin making improved haemoglobin.
In the sickle cell anaemia study 97 per cent of patients were pain-free after a year. For the beta thalassemia tranche of the study 93 per cent did not need a blood transfusion within 12 months.
‘A positive moment in history’
Scientists at Imperial College London led the UK arm of the trial and Prof Josu de la Fuente, principal investigator, said the MHRA approval “offers a new option for eligible patients”.
“I look forward to patients having access to this therapy as quickly as possible,” said Prof de la Fuente, a consultant haematologist at Imperial College Healthcare NHS Trust.
Julian Beach, interim executive director of healthcare quality and access at the MHRA, said both conditions “are painful, life-long conditions that in some cases can be fatal”.
He added: “To date, a bone marrow transplant – which must come from a closely matched donor and carries a risk of rejection – has been the only permanent treatment option.”
John James, chief executive of the Sickle Cell Society, said current options were “limited” and this “has the potential to significantly improve the quality of life for so many”.
“Sickle cell disorder is an incredibly debilitating condition, causing significant pain for the people who live with it and potentially leading to early mortality,” he added.
“There are limited medicines currently available to patients, so I welcome today’s news that a new treatment has been judged safe and effective, which has the potential to significantly improve the quality of life for so many.”
Simon Waddington, professor of Gene Therapy at UCL hailed the authorisation of the Crispr treatment as a “tremendous advance” in the way these debilitating conditions are treated.
Dr Helen O’Neill, programme director of reproductive science and women’s health at UCL, added that Crispr holds the key to “the future of life-changing cures”.
“Genome editing has the potential to transform medicine but is currently typically applicable to blood-based disorders due to the ability to transfuse blood,” she said.
“The use of the word “cure” in relation to Sickle cell disease or β-thalassemia has, up until now, been incompatible. The move by the MHRA to approve this therapy signals a positive moment in history.”
Reshma Kewalramani, president of Vertex, which launched the drug together with Crispr Therapeutics, said: “Today is a historic day in science and medicine: this authorisation of Casgevy in Great Britain is the first regulatory authorisation of a Crispr-based therapy in the world.”