CASGEVY | 1st Gene-Editing Therapy for Thalassaemia and SCD Approved in UK
A new treatment for transfusion-dependent β-thalassaemia (TDT) and sickle cell disease (SCD) has been authorised by UK’s Medicines and Healthcare products Regulatory Agency (MHRA) for patients aged 12 and over after a rigorous assessment of its safety, quality and effectiveness.
Casgevy is the first medicine to be licensed that uses the innovative gene-editing tool CRISPR, for which its inventors were awarded the Nobel Prize in 2020.
The therapy, developed by Vertex Pharmaceuticals and CRISPR Therapeutics, works by editing the faulty gene in a patient’s bone marrow stem cells so that the body produces functioning haemoglobin. To do this, stem cells are taken out of bone marrow, edited in a laboratory and then infused back into the patient, after which the results have the potential to be lifelong.
“I am pleased to announce that we have authorized an innovative and first-of-its-kind gene-editing treatment called Casgevy, which in trials has been found to restore healthy hemoglobin production in the majority of participants with [SCD] and [TDT], relieving the symptoms of disease,” Julian Beach, interim executive director of MHRA’s Healthcare Quality and Access, said in a press release.
The Thalassaemia International Federation (TIF) praised the groundbreaking announcement from UK regulators, declaring that it “marks the beginning of a new era in genetic medicine and science.”
“This is a historic decision for people suffering from thalassaemia and sickle cell anaemia that opens new avenues for the radical treatment of these serious inherited diseases,” said TIF Executive Director, Dr. Androulla Eleftheriou.
“We congratulate the UK for recognising the therapeutic benefit of the treatment and proceeding with its approval, while we are sure that the regulatory organisations in Europe and America will soon follow this example. As a Federation, we will work with all our strength to promote the access of as many patients as possible to such innovative treatments and ensure them the best quality of life they deserve,” she added.
Exa-cel is under review in the U.S., European Union, and Saudi Arabia. In the U.S., the therapy was granted priority review for SCD, with an expected decision by Dec. 8. A decision on its use for TDT is set for March 30, 2024.
Trial results
In the clinical trial for sickle-cell disease, 45 patients have currently received Casgevy but only 29 patients have been in the trial long enough to be eligible for the primary efficacy interim analysis. Of these eligible patients, 28 (97%) were free of severe pain crises for at least 12 months after treatment.
In the clinical trial for transfusion-dependent β-thalassemia, 54 patients have currently received Casgevy but only 42 patients have been in the trial long enough to be eligible for the primary efficacy interim analysis. Of these, 39 (93%) did not need a red blood cell transfusion for at least 12 months after treatment. The remaining three had more than a 70% reduction in the need for red cell transfusions.
Side effects from treatment were similar to those associated with autologous (from a person’s own cells) stem cell transplants, including (but not limited to) nausea, fatigue, fever, and increased risk of infection.
No significant safety concerns were identified during the trials. Both trials are ongoing, and further results will be made available in due course.
