When the shades of stigma often overshadow advancements in medical science, we must embrace new treatments and tools that make our lives and our patients’ lives easier. Following our exploration of the stigma surrounding sickle cell disease, we will shed light on what is quickly emerging as a game-changer treatment option for sickle cell disease: gene therapy. Dr. Sunny Singh, oncologist and hematologist at the University of Arkansas for Medical Sciences in Little Rock, is excited about the bright future for gene therapy.
IN THIS BLOG:
What causes sickle cell disease, and how does gene therapy address it?
Sickle cell disease is caused by inheriting faulty hemoglobin genes from one's parents, leading to the production of sickle-shaped red blood cells that can block blood vessels and cause various health issues. Gene therapy aims to correct or replace these faulty genes, allowing the body to produce healthy red blood cells and alleviate symptoms.
How does the gene therapy process work for sickle cell disease?
The process involves collecting a patient's stem cells, sending them to a facility for gene editing, and then reintroducing the corrected cells back into the patient. Before reintroduction, the patient's existing bone marrow is cleared using chemotherapy to make room for the new, healthy cells.
What are the different approaches being studied in gene therapy for sickle cell disease?
Researchers are exploring various methods, including gene editing, fetal hemoglobin induction, and gene addition. These approaches aim to either correct the faulty gene directly or promote the production of alternative forms of hemoglobin that can compensate for the defective ones.
Is gene therapy considered a cure for sickle cell disease?
While gene therapy shows promise in significantly reducing symptoms and improving quality of life, the scientific community is cautious about labeling it a definitive cure until long-term data is available. Some approaches, like fetal hemoglobin induction, may not correct the faulty gene but still offer substantial benefits.
What are the potential benefits and limitations of gene therapy for sickle cell patients?
Gene therapy has been shown to reduce symptoms, minimize pain, and decrease the need for blood transfusions or emergency visits. However, as it's a relatively new treatment, long-term effects are still being studied, and initial availability may be limited to select patients.
When is gene therapy expected to be available for patients?
Gene therapy has been shown to reduce symptoms, minimize pain, and decrease the need for blood transfusions or emergency visits. However, as it's a relatively new treatment, long-term effects are still being studied, and initial availability may be limited to select patients.
When is gene therapy expected to be available for patients?
Experts anticipate that gene therapy for sickle cell disease will receive FDA approval and become available to patients within the next one to two years, initially targeting those with severe symptoms.
Dr. Singh is confident that gene therapy will soon be approved by the FDA and available to patients in the next one to two years. “We already offer stem cell transplants at UAMS, but I think the hot topic and game changer for patients will be gene therapy,” Dr. Singh says. “Once approved, we can offer this treatment to patients who have severe symptoms.”
How does gene therapy work?
Sickle cell disease is caused by a faulty gene that a person inherits from their mother or father (or both) that creates mutated proteins. These proteins control the production of red blood cells. When a person inherits a faulty hemoglobin gene, the protein produces sickle-shaped blood cells that stick to the walls of blood vessels more easily, causing blood clots to form throughout the body.
“There are several approaches being studied in gene therapy, such as gene editing, fetal hemoglobin induction, and gene addition,” Dr. Singh explains. “The idea is to wipe out the existing bone marrow containing the faulty gene with chemotherapy, start with a clean slate, and then repopulate the bone marrow with blood cells which have the corrected gene.”
During gene therapy treatment, a specialist will collect the patient’s stem cells and send them off to a company that does gene editing before being injected back into the patient.
We don't have enough donors to find a match for everyone. For those populations with an increased likelihood of inhereting sickle cell disease, finding a match can be very difficult.
“In the scientific community, unless the gene is corrected/replaced, we don’t like to call this a cure, but even with gene therapy approaches where the faulty gene is not being corrected per se (like in fetal hemoglobin induction), it is still nearly a cure."
An Effective Treatment
Recent available data indicates that gene therapy reduces symptoms, minimizes pain, and prevents patients from undergoing multiple blood transfusions or emergency department visits. “The limitation here is that we don’t have 20- or 30-year-old data on patients who have already undergone gene therapy. We cannot fully know if an issue will occur down the road until we have followed these patients for a much longer time,” Dr. Singh states. “Having said that, overall, the results have been very encouraging so far.”
Even after FDA approval, Dr. Singh says gene therapy will likely be used on selected patients to begin with. “Patients who have uncontrolled disease, or those who have tried several medicines with little to no improvement will be prioritized initially for gene therapy.”
Allogeneic stem cell transplantation carries risks
Until gene therapy is fully approved by the FDA, patients who have sickle cell anemia and are experiencing severe symptoms despite trying the medications may benefit from an Allogeneic stem cell transplant. The process can be arduous and stressful for patients, but it offers the chance of a “cure.”
“We don’t have enough donors to find a match for everyone. For those populations with an increased likelihood of inheriting sickle cell disease, finding a match can be very difficult,” Dr. Singh says. “The issue with Allogeneic transplant is graft versus host disease (GVHD), which can happen once the transplant is done and can be difficult to manage at times.”
Gene therapy, given the absence of GVHD when compared to transplant, will be the best option for patients with severe symptoms in the future.
I think the hot topic and game changer for patients will be gene therapy. Once approved, we can offer this treatment to paients who have severe symptoms.
“There are patients I see right now who I feel should get gene therapy, but it hasn’t been approved yet. While some of these could go for an Allogeneic stem cell transplant, I am waiting for gene therapy to be approved so they can undergo that process instead.”
The stigma that has long shrouded sickle cell anemia is gradually giving way to the promise of innovative treatments that hold the potential to transform lives. If gene therapy is approved, we will inch closer to a future where sickle cell disease is no longer a source of suffering for the nearly 100,000 people who are diagnosed every year. Health care professionals stand at the forefront of this change, armed with the knowledge, compassion, and power to inspire change and improve health outcomes for individuals who live their lives in pain.
Read more about the stigma surrounding sickle cell disease.
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Meet Dr. Sunny Singh
Dr. Sunny Singh, a hematologist/oncologist with the UAMS Winthrop P. Rockefeller Cancer Institute, is director of the Adult Sickle Cell Program and also oversees operations at the satellite cancer center in North Little Rock owned by the UAMS Winthrop P. Rockefeller Cancer Institute and Baptist Health. Fellowship-trained in hematology and oncology at UAMS and Henry Ford Hospital in Detroit and UAMS in Little Rock, Dr. Singh has expertise in treating various cancers and blood disorders. He was the chief resident at John H. Stroger, Jr. Hospital of Cook County, Chicago. Dr. Singh received his medical degree from King George's Medical University in India.
Among his many professional honors and associations, he is also a member of the American Medical Society of Clinical Oncology, the American Society of Hematology, and the International Association for the Study of Lung Cancer. He is also a co-author of a textbook chapter and multiple peer-reviewed scientific journal articles on cancer research.
