In a major step forward for the treatment of beta thalassemia, the Food and Drug Administration (FDA) has approved beti-cel (brand name Zynteglo®), the first potentially curative gene therapy for people who require regular red blood cell transfusions to treat the condition. Children’s Hospital of Philadelphia (CHOP) will be one of the Qualified Treatment Centers (QTCs) offering the treatment, which is manufactured by bluebird bio.
“This treatment is a potential game changer for patients who have required regular red blood transfusions to manage their disease, an intense treatment burden that comes with its own risks,” said Janet Kwiatkowski, MD, MSCE, Director of the Thalassemia Center at Children's Hospital of Philadelphia (CHOP), CHOP lead investigator for the three clinical trials that led to beti-cel’s approval, and overall coordinating investigator for one of the studies. “Above all, it is important for patients to have choices about their treatment. This gene therapy offers a potentially curative option that far surpassed what we were expecting in terms of effectiveness. I am thrilled that CHOP’s Thalassemia Center,CuRED team, and Cell Therapy and Transplant Section (CTTS) will be able to provide this treatment to those patients for whom it is the best option.”
“There is a deep unmet need for a potentially curative treatment option for patients with transfusion-dependent beta thalassemia, whose quality of life is profoundly impacted by both the disease and the current standard of care,” said Alexis A. Thompson, MD, MPH, Chief of the Division of Hematology at Children's Hospital of Philadelphia, who was a lead investigator of the phase 3 clinical trials and presented before the FDA Advisory Committee ahead of approval. “As a lead investigator in the clinical trials that led to beti-cel’s approval, I am thrilled that the FDA has approved this treatment, which has the potential to vastly improve patients’ lives.”
Study results show effectiveness of gene therapy for beta thalassemia
Beta thalassemia is an inherited blood disorder that affects the production of normal hemoglobin, a protein in red blood cells that carries oxygen to tissues throughout body. The most severe form of the disease involves mutations on both copies of the hemoglobin beta chain gene, requiring lifelong blood transfusions every two to five weeks and constant monitoring for complications caused by the disease as well as the transfusions themselves.
The FDA approval was based on clinical trial data from multiple study sites, including CHOP. The data showed that 89% of patients treated in the phase three trials no longer needed red blood cell transfusions after receiving gene therapy, while maintaining hemoglobin levels of at least 9 g/dL. The benefits extended across age groups (4 to 34 years) and in those with milder as well as more severe beta globin mutations.
The approval caps off nearly a decade of clinical research of gene therapy for beta thalassemia at CHOP, where screening of the patients and access to the therapy was centralized and streamlined through its Sickle Cell and Red Cell Disorders Curative Therapy Center (CuRED). CuRED is a unique collaboration between Hematology and the CTTS transplant team. The program provides integrated and coordinated care for patients with red blood cell disorders, combining appointments with hematologists, stem cell transplanters, psychologists, social workers, fertility preservationists, and other specialists at a single visit. A key part of CuRED’s role at CHOP will involve counseling patients with beta thalassemia on whether gene therapy is an appropriate treatment option.
As part of this complex and highly collaborative effort, CTTS facilitates collection of patient cells and cell transfer for manufacturing. The cells are then returned to the Cell and Gene Therapy Lab. The patient is admitted to the transplant service to undergo the preparative chemotherapy, administration of the modified cells, and inpatient post-transplant care.