Comprehensive Sickle Cell Center provides life changing Gene Therapy

MOBILE, Ala. (WALA) – Gene therapy for sickle cell disease (SCD) is a cutting-edge treatment that targets the root cause of the disorder—a genetic mutation in the HBB gene, which leads to the production of abnormal hemoglobin (HbS). This faulty hemoglobin causes red blood cells to become sickle-shaped, leading to severe pain, organ damage, and a shortened life expectancy.

Unlike traditional treatments (like pain management, transfusions, or hydroxyurea), gene therapy offers a potential one-time, curative solution. The process begins by collecting the patient’s own hematopoietic stem cells (HSCs), which are then genetically modified in a lab. The modification can either:

· Correct the mutation in the HBB gene, or

· Increase fetal hemoglobin (HbF) production, which prevents sickling.

Afterward, the patient receives high-dose chemotherapy to remove the abnormal cells, followed by an infusion of the modified stem cells. These new cells produce healthy red blood cells that do not sickle.

In 2023, the FDA approved two gene therapies—Casgevy and Lyfgenia—for patients aged 12 and older. Clinical trials have shown that patients experienced dramatic improvements, including reduced pain crises and independence from blood transfusions. However, long-term monitoring is essential, especially due to a black-box warning for potential blood cancer with Lyfgenia.

The Johnson Haynes Jr. M.D. Comprehensive Sickle Cell Center is part of the journey of Addilee Mason, a 13-year-old girl who received gene therapy in 2024 after exhausting other treatment options and lacking a matched donor for stem cell transplant.

Addilee, who was born with sickle cell disease, has had a tough course, starting with her first painful episode in infancy. Despite the family being very compliant with medications, Hydroxyurea therapy with dose escalations, and regular checkups, she had multiple hospitalizations for pain episodes, sickling in the lungs, bone infections, and blood clots.

After several years of complications and despite optimization of medical and transfusion therapy, the center discussed curative options with family during a pediatric sickle cell clinic appointment and then a consultation with the transplant center took place. Unfortunately, she did not have a suitable matched donor. But the transplant center shared information on gene therapy clinical trial participation once she turns 12 years.

Fortunately, Vertex Pharmaceuticals Inc., had a spot for her at their research center in Sarah Cannon Research Institute in Nashville, TN. Addilee qualified for the gene editing trial CTX-151 after a year’s wait to meet strict eligibility criteria. Participants in this research study received a single intravenous infusion of CTX001, consisting of cells collected from a patient’s bone marrow and modified to produce fetal hemoglobin. She traveled to TriStar Centennial Children’s Hospital, also in Nashville, to receive care.

She is the center’s first gene therapy patient, and she participated in a clinical trial at age 12. Eleven months post-treatment, she remains pain-free with normal hemoglobin levels—an inspiring milestone for SCD care.

The Johnson Haynes Jr. M.D. Comprehensive Sickle Cell Center provides consultation for the diagnosis, management, and treatment of children and adults with sickle cell disease. The center cares and advocates for a large number of individuals and their caregivers affected by SCD.

Addilee joined us on Studio10 along with her mom Vangila Arrington and Hamayun Imran, M.D., Pediatric Hematologist/Oncologist at USA Health to tell her story.

University of South Alabama Johnson Haynes Jr., M.D., Comprehensive Sickle Cell Center:

www.southalabama.edu/colleges/com/research/sicklecell.html

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