Breakthrough Treatments Targeting Severe Forms of the Disease Set to Transform Lives

In a groundbreaking move, U.S. regulators have granted approval for two gene therapies designed to potentially cure sickle cell disease, a painful and hereditary blood disorder that disproportionately affects Black individuals in the United States.

The Food and Drug Administration (FDA) announced on Friday that these one-time treatments are intended for patients aged 12 and older with severe forms of sickle cell disease. Notably, one of the therapies, developed by Vertex Pharmaceuticals and CRISPR Therapeutics, marks the first FDA-approved therapy based on CRISPR, the revolutionary gene-editing tool honored with the Nobel Prize in 2020. The second therapy, created by Bluebird Bio, employs a different mechanism.

Dr. Nicole Verdun of the FDA expressed enthusiasm about advancing the field, especially for individuals whose lives have been severely impacted by sickle cell disease. The approval marks a significant milestone as the first gene therapies approved in the U.S. specifically for sickle cell disease, with the FDA having previously authorized 15 gene therapies for other conditions.

Approximately 100,000 people in the U.S. live with sickle cell disease, with about one-fifth experiencing the severe form. The disease is most prevalent among Black individuals, with 1 in 365 Black babies born with the condition nationally. The genetic mutation causing sickle cell disease results in misshapen red blood cells that can obstruct blood flow, leading to excruciating pain, organ damage, and other serious complications.

While current treatments include medications, blood transfusions, and the risky bone marrow transplant, the newly approved gene therapies offer a potentially transformative solution. The Vertex therapy, named Casgevy, aims to revert the body to producing a fetal form of hemoglobin, crucial for those with sickle cell disease. CRISPR is utilized to eliminate a gene in stem cells collected from the patient. Bluebird’s treatment, Lyfgenia, seeks to enhance red blood cell production of “anti-sickling” hemoglobin, preventing or reversing misshapen cells.

Despite the promising outcomes observed in studies, doctors emphasize potential side effects and unknown long-term impacts. Both therapies involve chemotherapy, with associated risks such as infertility and vulnerability to infections. The FDA has mandated a “black box warning” for the Bluebird therapy due to the occurrence of blood cancer, while concerns about “off-target effects” are raised with the CRISPR technology in the Vertex therapy.

The significant cost of these gene therapies poses a potential hurdle, with list prices at $3.1 million for Bluebird Bio and $2.2 million for Vertex. However, the U.S. Centers for Medicare and Medicaid Services are devising plans to collaborate with state Medicaid agencies and drug companies to alleviate costs.

Despite challenges, medical experts believe gene therapy could be transformative for sickle cell disease, offering hope for a lasting impact on the lives of those affected. The approval of these groundbreaking treatments marks a significant leap forward in the pursuit of a cure for sickle cell disease.