The US Food and Drug Administration (FDA) has approved Vertex Pharmaceuticals and CRISPR Therapeutics’ Casgevy (exagamglogene autotemcel) to treat transfusion-dependent beta thalassaemia (TDT) in patients aged 12 years and older.
Beta thalassaemia is an inherited blood disorder that affects the red blood cells, which are essential for carrying oxygen to all organs and tissues of the body.
Patients with the most severe form of the disease develop life-threatening anaemia and have to undergo regular blood transfusions and iron chelation therapy throughout their lives.
Vertex and CRISPR estimate that approximately 1,000 patients in the US are now eligible for Casgevy, a one-time treatment designed to work by editing the faulty gene in a patient’s own bone marrow stem cells so that the body produces functioning haemoglobin.
The FDA’s decision on the therapy, which is two months earlier than the expected action date of 30 March, was supported by clinical trial results showing it improved the proportion of patients who were transfusion-independent for at least 12 consecutive months.
Nicole Verdun, director of the office of therapeutic products within the FDA’s Center for Biologics Evaluation and Research, described the approval as “an important step in the advancement of an additional treatment option for individuals with beta thalassaemia”.
The authorisation comes just over one month after the FDA first approved Casgevy to treat sickle cell disease, also in patients aged 12 years and older.
The decision made Casgevy the first US-approved treatment to use the gene-editing tool CRISPR, for which its inventors were awarded the Nobel Prize in 2020.
Reshma Kewalramani, chief executive officer and president of Vertex, said: “On the heels of the historic FDA approval of Casgevy for sickle cell disease, it is exciting to now secure approval for TDT well ahead of the Prescription Drug User Fee Act date.
“TDT patients deserve new, potentially curative treatment options, and we look forward to bringing Casgevy to eligible patients who are waiting.”
Casgevy is the first treatment to emerge from Vertex and CRISPR Therapeutics’ strategic partnership, which was originally announced in 2015. Vertex now leads the global development, manufacturing and commercialisation of Casgevy and splits programme costs and profits worldwide with CRISPR.