FDA Approves First Gene Therapy using CRISPR-Cas9 to Treat Sickle Cell Disease

The United States Food and Drug Administration (FDA) has approved Casgevy and Lyfgenia, the first cell-based gene therapies to treat sickle cell disease (SCD). Casgevy is the first FDA-approved treatment developed using CRISPR-Cas9 genome editing technology, signaling an innovative advancement in gene therapy.

Casgevy, a cell-based gene therapy, is approved to treat SCD patients 12 years of age and older with recurrent vaso-occlusive crises. Casgevy is the first FDA-approved therapy that uses CRISPR-Cas9 where the patients' blood stem cells are modified using the technology. CRISPR-Cas9 can cut DNA in targeted areas to allow accurate editing (removing, adding, or replacing) of the DNA where it was cut. The modified blood stem cells are transplanted back into the patient where they attach and multiply within the bone marrow and increase the production of fetal hemoglobin (HbF)to prevent the sickling of red blood cells. Casgevy also received approval in the United Kingdom in November.

Lyfgenia, a cell-based gene therapy uses a lentiviral vector (gene delivery vehicle) for genetic modification and is approved for the treatment of patients 12 years of age and older with sickle cell disease and a history of vaso-occlusive events. The patient's blood stem cells are genetically modified to produce HbAT87Q, a gene-therapy-derived hemoglobin to lower the risk of sickling and occluding blood flow.

Sickle cell disease is a group of inherited blood disorders affecting approximately 100,000 people in the U.S. It is most common in African Americans and, while less prevalent, also affects Hispanic Americans.

For more details, read the FDA news release.