The federal authorities approved on Friday two gene therapies for sickle cell anemia, which is welcome news for tens of thousands of people suffering from this genetic disease that causes painful crises and early death.
What is sickle cell anemia?
Sickle cell anemia, also known as sickle cell disease, which is the most severe form, is a genetic disorder that affects the ability of red blood cells to carry oxygen to every part of the body.
Everyday normal activities, such as climbing stairs or running during gym class in elementary school or rough play with friends, can lead to a painful crisis due to the inability of the misshapen red blood cells to transport oxygen efficiently.
Choosing gene therapy
Gray had been hospitalized seven times during each of the two years prior to her gene therapy.
When she turned 32, she told her doctor that she was too exhausted to go on. “I told him I can’t live like this anymore.”
She considered getting a bone marrow transplant—the only treatment considered to provide long-term relief from the painful crises and damage caused by sickle cell anemia.
But only about 15% of patients have siblings who are a good match for the bone marrow donation required for the transplant, and even then, there is a risk that it might not work.
Stevenson, who also considered the procedure, noted that she has three older siblings, but none of them matched her. Gray’s brother offered a half-match. This would make her marrow susceptible to what is known as graft-versus-host disease, meaning she would need to take immunosuppressive medications for a year.
Despite facing mistreatment from other doctors, Dr. Hadar Frangoul, who runs the pediatric hematology and oncology program at Sarah Cannon Research Institute in Nashville, treated her with dignity and care. When he offered her a spot in the gene therapy trial, Gray agreed.
The life-changing price
It is still unclear how many patients will enroll in gene therapy or who will be most suitable for treatment.
Some will depend on the specified price of the therapy and whether the government and private insurance will cover the cost and extras such as housing during monitoring. Gene therapy for other rare diseases has been priced as high as $3.5 million.
There are two different approaches that were approved on Friday. The first, named CASGEVY, from Vertex and CRISPR Therapeutics, is the first to use CRISPR gene editing technology, which won the Nobel Prize in 2020. It is priced at $2.2 million. The second, named LYFGENIA, from bluebird bio, uses a slightly different technique to achieve the same goal. It is priced at $3.1 million.
Azar does not have a preference between the two at this point. It is unclear which of the sickle cell patients will be most suitable for gene therapy. He wants one or two patients to receive the treatment to see who improves better: whether those who struggle the most with their disease, those who are getting the least benefit from current treatment, or those who are still young and healthy.
Gene therapy can prevent future damage to the body, but it cannot reverse the problems already created by the disease, which is why it’s important to treat patients while they are young, according to Frangoul, who also works at HCA Healthcare’s The Children’s Hospital At TriStar Centennial. He is currently testing the treatment in children ages 5 and may soon begin offering it to younger children.
Frangoul said, “Sickle cell disease is like a hammer hitting the wall,” causing a dent in the wall. “I can take away the hammer, but I can’t fix the wall.”
Hope
In the Future
Dr. Stuart Orkin at Boston Children’s Hospital hopes that the lessons learned from gene therapy can be used to develop effective treatments that are less challenging and less expensive, so that they can be made available to more sickle cell anemia patients in the United States and around the world.
Many researchers are working on ways to deliver gene therapy using less toxic drugs than chemotherapy or to perform all genetic manipulation within the body, eliminating the need for advanced labs and expertise.
Orkin, who spoke with reporters on a conference call Tuesday organized by the Doris Duke Foundation, which funds some of his early work on gene therapy for sickle cell anemia, hopes to develop pills that could achieve most of the same benefits, although he does not yet know if that is possible.
Azar said that gene therapy has raised public awareness about sickle cell disease. “It allows sickle cell disease to come into social awareness,” he said. “It’s a huge win for the community.”
Stevenson said she has not suffered from a single pain crisis or hospitalization in the six years since her gene therapy. She has been able to complete her studies and now works as a behavior analyst, helping many people on the autism spectrum.
She said, “When I live the life that I lived and was ordered to, my career choice aligns with that,” adding that her work brings her happiness. “I do my best to give my children what they deserve in patience, empathy, and a program specifically designed to meet them where they are.”
Gray, now thirty-eight, is finally able to work full-time after completing her clinical nursing degree. She wants to give hope to others in the same way that her treatment provided for her, which is gene therapy and other less expensive, more accessible treatments.
Relieving the pain from high-dose medications was difficult, but “after that, my life really changed,” she said. “I live life as a normal person.”
One morning, eight months after her treatment, Gray woke up and thought her entire body had lost sensation because she felt no pain. She began to touch her face and thigh before realizing that the absence of pain was evidence of her treatment’s success.
She said, “I can dream again,” adding, “I had stopped dreaming and hoping for anything. Now I have big dreams and big plans.”
Karen Weintraub can be reached at kweintraub@usatoday.com.
Source: https://www.aol.com/fda-approves-gene-therapy-sickle-162200118.html
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