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The United Kingdom has become the first country to give regulatory approval to a medical treatment involving the revolutionary CRISPR gene editing tool.
The country’s Medicines and Healthcare products Regulatory Agency said Thursday it had given a greenlight to a treatment known as Casgevy, which will be used to treat sickle cell disease and beta thalassemia. Both genetic conditions are caused by errors in the genes for hemoglobin, which is used by red blood cells to carry oxygen around the body. There is no known universally successful treatment for either disorder.
Sickle cell disease, which can result in attacks of debilitating pain, is more common in people with an African or Caribbean family background. Beta thalassemia mainly affects people of Mediterranean, South Asian, Southeast Asian and Middle Eastern origin, the statement said.
“Both sickle cell disease and β-thalassemia are painful, life-long conditions that in some cases can be fatal. 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,” said Julian Beach, the interim executive director of healthcare quality and access at the MHRA, in a statement.
“I am pleased to announce that we have authorised an innovative and first-of-its-kind gene-editing treatment called Casgevy, which in trials 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.”
The promise of CRISPR-Cas9
The CRISPR-Cas9 gene editing technique allows scientists to make very precise changes to DNA. Its inventors — Emmanuelle Charpentier and Jennifer A. Doudna — won a Nobel Prize in chemistry in 2020.
Casgevy isn’t a simple pill or injection. The treatment, made by Vertex Pharmaceuticals, is administered by taking stem cells out of a patient’s bone marrow and editing a gene in the cells in a lab. Patients then must undergo a “conditioning treatment,” which can involve an immunosuppressing drug, radiotherapy or chemotherapy, to prepare the bone marrow before the modified cells are infused back into the patient, according to the MHRA.
“After that, patients may need to spend at least a month in a hospital facility while the treated cells take up residence in the bone marrow and start to make red blood cells with the stable form of haemoglobin,” according to the statement.
The US Food and Drug Administration is evaluating the same treatment and is expected to make a decision on whether to greenlight it by December 8.
“This is a great step in the advancement of medical approaches to tackle genetic diseases we never thought would be possible to cure,” said Alena Pance, a senior lecturer in genetics at the University of Hertfordshire, in a statement released by the Science Media Centre, which provides information to journalists.
“Modifying the stem cells from the bone marrow of the patient avoids the problems associated with immune compatibility, i.e. searching for donors that match the patient and following immunosuppression, and constituting a real cure of the disease rather than a treatment,” Pance added.
The release from the MHRA did not say how much the treatment would cost, but it’s likely to be expensive.
CRISPR-Cas9 has had a major impact on biomedical research, clinical medicine and agriculture and is widely used in labs around the world.
The cutting-edge technology was tainted with controversy after Chinese scientist He Jiankui announced in 2018 he had created the world’s first gene-edited babies. Scientists say the powerful technique should not be used to manipulate human genes that will be passed down from one generation to the next.