On Friday, regulators gave their approval for two gene therapies that aim to cure sickle cell disease, a painful and hereditary blood disorder prevalent among Black individuals in the U.S.

The FDA announced that individuals 12 years and older with severe forms of the illness can receive one-time treatments. One treatment, produced by Vertex Pharmaceuticals and CRISPR Therapeutics, is the initial therapy utilizing CRISPR, the Nobel Prize-winning gene editing tool in 2020. The second treatment, created by Bluebird Bio, has a different method of action.

Dr. Nicole Verdun of the FDA stated in a release that sickle cell disease, a serious and potentially fatal blood disorder, is uncommon and causes great suffering for those affected. The agency is pleased to make progress in this area, particularly for those whose lives have been significantly impacted by the illness.

The FDA has given approval for two gene therapies to treat sickle cell, making them the first of their kind in the United States. The FDA has also granted approval for 15 other gene therapies for various conditions in the past. Many of these treatments have a high list price, often reaching millions of dollars, and the sickle cell therapies will be no exception.

Approximately 100,000 individuals in the United States are estimated to have sickle cell, with 20% of them experiencing the severe form. This disease is most prevalent among individuals of Black ethnicity, with 1 in every 365 Black babies being born with it in the country. It is believed by scientists that carrying the sickle cell trait provides protection against severe malaria, resulting in a higher occurrence of the disease in regions with a high mosquito population, such as Africa, or in individuals whose ancestors resided in these regions.

The illness impacts hemoglobin, which is the protein responsible for carrying oxygen in red blood cells. A mutation in genes results in the cells taking on a sickle or crescent shape, potentially obstructing blood flow and leading to intense pain, harm to organs, stroke, and other complications.

Options for treatment currently consist of prescribed drugs and the transfusion of blood. The sole lasting remedy is a transplant of bone marrow, which necessitates a donor with a close match and carries the possibility of being rejected.

The gene therapies, known as Casgevy, do not require a donor and have the ability to permanently alter DNA in the patient’s blood cells. The aim of this Vertex therapy is to restore the production of fetal hemoglobin, present at birth, rather than the defective adult form found in individuals with sickle cell disease. The CRISPR technology is utilized to remove a gene from stem cells harvested from the patient.

Lyfgenia, a treatment developed by Bluebird, involves introducing modified copies of a gene that aids in the production of “anti-sickling” hemoglobin in red blood cells, thereby preventing or reversing the formation of abnormal cells.

After receiving treatment, patients have their blood drawn to extract stem cells, which are then transported to a laboratory. As a necessary step before the reintroduction of the modified cells, patients must undergo chemotherapy. This procedure typically involves two hospital stays, with the first lasting four to six weeks.

However, numerous patients express that they would contemplate gene therapy due to the severity of the illness.

Jalen Matthews, a resident of Louisville, Kentucky, was identified with sickle cell disease from birth and experienced her initial episode of pain at the age of 9. At the age of 12, the illness resulted in a spinal cord stroke, causing partial paralysis in her left arm and leg.

Matthews, now 26, stated that he had to relearn how to walk, feed himself, and dress himself. Essentially, he had to start from scratch and learn everything all over again.

Currently, she manages her sickle cell disease by receiving transfusions every other month. During these transfusions, five units of her blood are replaced with healthy cells. She intends to inquire with her doctor about the potential of gene therapy as a more effective treatment.

Matthews stated that this singular remedy is crucially necessary.

Bluebird’s treatment has received the first approval from the FDA, while Vertex has been previously authorized in the UK and Bahrain.

Research on these treatments indicates that they are effective. Out of 31 individuals who received treatment in the crucial Vertex study and were closely monitored, 29 did not experience any pain episodes for at least one year. Similarly, in the Bluebird study, 28 out of 32 patients did not experience severe pain or damage to their organs within six to 18 months after undergoing the therapy.

However, medical professionals emphasize that there may be potential adverse reactions and the future effects are uncertain. In both cases, the required chemotherapy carries potential hazards, including the possibility of infertility, hair loss, and increased susceptibility to severe infection.

The FDA has announced that the label for Bluebird therapy will now include a “black box warning” due to the risk of blood cancer. However, there are concerns among scientists about potential “off-target effects” from the use of CRISPR in Vertex therapy, which could result in unexpected changes to a person’s genome.

Dr. Benjamin Watkins, director of the pediatric stem cell and cell therapy program at Children’s Hospital New Orleans, stressed the importance of being both cautious and optimistic about this treatment. However, it should also be noted that there is still limited knowledge and experience with it.

Medical professionals predict that not all healthcare facilities will be able to provide gene therapies due to the complex equipment and coordination needed among different specialists. They also anticipate that there will not be a high demand for these therapies immediately. Watkins suggests that some individuals may choose to delay seeking treatment until it becomes more widely available.

Specialists cautioned that the price could present a challenge. Bluebird Bio’s cost is $3.1 million, while Vertex’s is $2.2 million. The amount patients would have to pay will vary based on their insurance coverage and other variables. In order to assist with the expense, the U.S. Centers for Medicare and Medicaid Services proposed a strategy to form partnerships with state Medicaid agencies and pharmaceutical companies.

However, in the future, gene therapy may have the potential to significantly alter the current state of sickle cell disease, according to Dr. Monica Bhatia, a physician at NewYork-Presbyterian who specializes in treating children with this condition.

Matthews, a volunteer for The Sickle Cell Association of Kentuckiana, expressed optimism about the potential impact of the treatments.

She expressed gratitude, stating that it would greatly help everyone in the sickle cell community.

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