• Posted January 17, 2024

FDA Clears Sickle Cell Drug to Treat Another Blood Disorder

Casgevy, a groundbreaking treatment that was approved to treat sickle cell disease in December, was given the U.S. Food and Drug Administration's blessing on Tuesday to treat another inherited blood disorder.

Casgevy is the first CRISPR-based medicine, where gene editing is used to develop the treatment, to be approved for use in the United States.

The one-time dose permanently changes DNA in a patient's blood cells, but experts note the relief will not come cheap. The treatment list price is $2.2 million for its use in both sickle cell disease and beta thalassemia, CNN reported.

This latest approval allows Casgevy to be used in patients over the age of 12 with transfusion-dependent beta-thalassemia. With this disorder, the body doesn't make enough of the oxygen-carrying molecule in blood known as hemoglobin.

"Today's approval is an important step in the advancement of an additional treatment option for individuals with beta-thalassemia, a debilitating disease that places individuals at risk of many serious health problems,"Dr. Nicole Verdun, director of the Office of Therapeutic Products within the FDA's Center for Biologics Evaluation and Research, said in an agency news release.

"The approval of a cell-based gene therapy for this condition using CRISPR/Cas9 technology reflects FDA's continued commitment to supporting safe and effective treatments that leverage the most promising and cutting-edge medical technologies,"she added.

In December, the FDA approved Casgevy to treat sickle cell disease, an inherited blood disorder that typically strikes Black people.

"Gene therapy holds the promise of delivering more targeted and effective treatments, especially for individuals with rare diseases where the current treatment options are limited," Verdun noted at the time of that approval.

The FDA's latest decision was expected, but it comes about two months earlier than the agency's deadline for acting, CNN reported.

To make Casgevy, a person's stem cells are removed and modified using a gene-editing technique called CRISPR/Cas9. The altered cells are then transplanted back into the patient's body, where they multiply and increase the production of hemoglobin, which eases symptoms.

The most common side effects with Casgevy were mouth sores, fever associated with a low level of certain white blood cells and decreased appetite, according to the FDA.

With beta thalassemia, a person can become anemic, which makes them feel weak, tired and out of breath. It can shorten a person's life, and the only treatment in the past has been frequent blood transfusions.

Unfortunately, repeated transfusions can trigger another problem called iron overload syndrome, which then has to be managed with other treatments. There are at least 1,200 people in the United States with thalassemia severe enough that it must be managed with blood transfusions, according to Boston Children's Hospital.

More information

Johns Hopkins Medicine has more on beta thalassemia.

SOURCE: U.S. Food and Drug Administration, news release, Jan. 16, 2024; CNN