Black physicians are excited about a groundbreaking gene-editing treatment for sickle cell disease that a federal advisory panel deemed safe enough for clinical use this week — but they also worry about access.
“It offers a lot of potential,” Dr. Oyebimpe Adesina, a hematologist at the University of California Davis, told Capital B Tuesday. “But it’s not fully accessible to everyone.”
She recommends patients talk to trusted health care providers about what they have access to and consider registering for clinical trials to evaluate their options. She has found that self-advocacy has helped a few patients she knows be considered for treatment they might not have otherwise had access to, and also understands jumping toward gene therapy might not be for everyone.
A lot of patients are hesitant, she said, because it’s a lot of new information to navigate.
The federal advisory panel’s move means the U.S. Food and Drug Administration is likely to approve the gene-editing treatment’s use by the end of the year, which is a revolutionary step toward a cure for a disease that disproportionately affects Black Americans. Several companies have been pursuing gene therapies to treat sickle cell, and the panel reviewed the first of those proposals in an all-day meeting Tuesday.
To date, the only other cure has been bone marrow transplants. If approved, this Nobel Prize-winning therapy, called CRISPR, would address the disease at its source — sick patient’s genes.
Adesina and Dr. Yasmin Tyler-Hill, former chair of pediatrics for the National Medical Association, broke down what this revolutionary development in treatment could mean for patients.
How does sickle cell affect the body?
Sickle cell disease is an inherited gene mutation that makes red blood cells resemble more of a crescent, or “sickle” shape than a healthy, round disk. Those misshapen cells do not move easily through blood vessels, restricting blood flow through the body. That can cause strokes, organ damage, and agonizing pain for those living with the illness.
In the U.S., the disease mostly affects Black Americans. Because the sickle cell trait is thought to be protective against malaria, it’s common within regions where that disease is endemic, such as sub-Saharan Africa. Through slavery, it made its way to the United States, said Tyler-Hill.
Disparities also exist in funding and research related to sickle cell, experts say. Although sickle cell affects three times as many people as cystic fibrosis, it’s received only a fraction of the advocacy, awareness, funding, and advancements in treatment, said Adesina.
What treatments already exist for sickle cell?
Working in pediatrics, Tyler-Hill often found that sickle cell disease consistently fell within that section. Back when she started her residency, many children with the illness were not living until adulthood, but since then, treatments have come a long way. Giving penicillin to babies to protect against the infections they were prone to, helped them live past age 5.
As patients live longer, treatments include pain management, blood transfusion, and bone marrow transplants. Those transplants can come with a lot of complications, experts say, from finding a match to removing bone marrow and hoping for a successful transfer. And if those patients already have organ damage — which many do by the age of 20, Adesina said — it’s often not reversible.
Blood transfusions keep the amount of misshapen red blood cells down, but also require good donor matches and a consistent supply of healthy blood donations. Often, sickle cell patients are treated with medications to manage their pain, Tyler-Hill said.
No treatment to date has addressed the disease’s root cause. That’s where the new gene therapy comes in.
How does this new treatment expand options for patients?
Unlike blood transfusions and bone marrow transplants, no donor is required for the gene-editing treatment. During treatment, the CRISPR technique edits the patient’s own stem cells to help the body produce a more healthy form of blood. In the process, the DNA of the patient’s blood cells is permanently altered.
It’s not a complete cure for all the complications sickle cell patients are dealing with, Adesina said. She has patients who have undergone bone marrow transplants and still deal with chronic pain and infertility. The slate is not wiped clean. If there’s damage already caused to the body, it’s likely not reversible. That’s why she advocates for gene therapy, especially for young patients, before the disease takes a devastating toll throughout the body. But she worries about how costly the treatment could be, and how much social, emotional, and medical support is required to complete the therapy effectively. It’s expected to cost millions per patient. So far, it’s only been used in clinical trials, she said.
The full treatment requires about two months of blood transfusions, then the removal of bone marrow stem cells to be treated and altered. Patients will go through chemotherapy, then the edited cells will be infused back into their bodies. They will have to stay in the hospitals for weeks while new blood cells repopulate.