British regulators on Thursday approved the first treatment derived from CRISPR, the revolutionary gene editing method. Called Casgevy, the treatment aims to cure sickle cell disease and a related disease, beta thalassemia.
The makers, Boston-based Vertex Pharmaceuticals and Switzerland-based CRISPR Therapeutics, say about 2,000 British patients with sickle cell disease or beta thalassemia should be eligible for the treatment.
The companies anticipate that the Food and Drug Administration will approve Casgevy for sickle cell patients in the United States in early December. The agency will decide whether to approve beta thalassemia next year.
At the end of December, the FDA is expected to approve another sickle cell gene therapy made by Bluebird Bio of Somerville, Massachusetts. This treatment does not rely on gene editing, but rather on a method that inserts new DNA into the genome.
Sickle cell disease is caused by a defective gene that results in the creation of abnormal hemoglobin, the component that carries oxygen in red blood cells. The cells themselves become malformed, causing episodes of extreme pain. About 100,000 Americans, mostly black and Hispanic, are estimated to have the disease.
In beta thalassemia, the defective gene causes low hemoglobin levels in red blood cells. The condition is rare.
Casgevy relies on CRISPR to cut DNA, thereby activating a gene that produces an alternative form of hemoglobin. To receive the sickle cell treatment, UK patients must be at least 12 years old and have experienced repeated episodes of extreme pain.
There is no upper age limit, nor are patients excluded because they have suffered too much organ damage from sickle cell disease, said Dr. David Altshuler, Vertex’s chief scientific officer.
But patients should not have other options. Sickle cell disease can be cured with a bone marrow transplant, but few patients have matching donors.
For those battling the disease, Vertex and Bluebird treatments have been slow to arrive. Pain isn’t the only complication: People with sickle cell disease also suffer from bone and organ damage and strokes. The distorted blood cells do not survive long, leading to anemia.
Still, CRISPR and Bluebird treatments are expensive and will require expertise that most hospitals lack.
Patients must receive intense chemotherapy to rid their bone marrow of abnormal stem cells and make way for the genetically modified cells. Then, patients must stay a month or more in the hospital while their marrow grows back.
And gene editing is expensive. Vertex and CRISPR Therapeutics have not yet set a price in Britain – that will depend on conversations with those who will pay for it, said Stuart Arbuckle, executive vice president and chief operating officer at Vertex.
In the United States, however, the price is expected to be several million dollars per patient. However, sickle cell disease itself is expensive, costing the U.S. healthcare system approximately $3 billion per year.
In the United States, Bluebird already has an approved gene therapy for beta thalassemia. This costs $2.8 million per patient.
Dr. Altshuler said Vertex is testing its sickle cell treatment in children ages 5 to 11, hoping to prevent irreversible organ damage that occurs over time.
The company’s first sickle cell patient, Victoria Gray, said Thursday the treatment changed her life.
Ms. Gray, a Walmart associate in Forest, Miss., was diagnosed with sickle cell anemia when she was 3 months old and had a pain attack. These episodes became an integral part of his life, leading to frequent hospitalizations.
“A lot of my dreams, I couldn’t make them come true,” she said. “The smallest things – the cold and the weather changing – I would end up in the hospital. »
She underwent the gene editing treatment in 2019, when she was 33 years old. Today, she says, all her symptoms are gone.
“It meant a new beginning,” Ms. Gray said. “It’s way more than I dreamed of it all disappearing.”