Researchers at Children’s Hospital of Philadelphia (CHOP) contributed to updated safety data in U.S. children treated with Exagamglogene Autotemcel (Exa-cel), a one-time gene-editing cell therapy for sickle cell disease with recurrent painful vaso-occlusive crises (VOCs) and for transfusion-dependent beta thalassemia (TDT), which requires regular blood transfusions. The findings, published earlier this month in the New England Journal of Medicine, contributed to the FDA’s recent decision to expand use to children ages 2 and up, broadening access and approval beyond the prior approval for patients 12 and older.
Exa-cel uses a patient’s own blood-forming stem cells, which are edited outside the body using CRISPR/Cas9. The goal is to raise fetal hemoglobin, a form of hemoglobin that can help red blood cells work more normally, then the edited cells are infused back after chemotherapy-style conditioning.
Researchers gave exa-cel to 15 children with transfusion-dependent beta thalassemia and 11 children with sickle cell disease and followed them for approximately 17 months. Among the children who were followed at least 16 months, all 8 in the beta thalassemia group were able to go at least a year without needing blood transfusions, and all 8 in the sickle cell group had at least a year without severe pain crises. The remaining children in each group hadn’t been followed long enough yet to know if they would meet that same benchmark.
“The FDA’s decision marks a lifesaving, paradigm-shifting step for children with sickle cell disease and transfusion‑dependent beta thalassemia,” said Stephan A. Grupp, MD, PhD, a co-senior study author and Section Chief of the Cellular Therapy and Transplant Section, and Inaugural Director of the Kelly Center for Cancer Immunotherapy at CHOP. “Access at younger ages gives families and care teams the chance to consider a one-time, potentially transformative treatment before years of irreversible, life‑shortening damage accumulates.”
The researchers expect to conduct long-term follow-up on patients to support the best possible approach and outcomes.
The research was funded by Vertex Pharmaceuticals and CRISPR Therapeutics.
Frangoul et al. “Exa-cel in Children with Transfusion-Dependent β-Thalassemia or Sickle Cell Disease.” NEJM. Online June 10, 2026. DOI: 10.1056/NEJMoa2603387.
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Researchers at Children’s Hospital of Philadelphia (CHOP) contributed to updated safety data in U.S. children treated with Exagamglogene Autotemcel (Exa-cel), a one-time gene-editing cell therapy for sickle cell disease with recurrent painful vaso-occlusive crises (VOCs) and for transfusion-dependent beta thalassemia (TDT), which requires regular blood transfusions. The findings, published earlier this month in the New England Journal of Medicine, contributed to the FDA’s recent decision to expand use to children ages 2 and up, broadening access and approval beyond the prior approval for patients 12 and older.
Exa-cel uses a patient’s own blood-forming stem cells, which are edited outside the body using CRISPR/Cas9. The goal is to raise fetal hemoglobin, a form of hemoglobin that can help red blood cells work more normally, then the edited cells are infused back after chemotherapy-style conditioning.
Researchers gave exa-cel to 15 children with transfusion-dependent beta thalassemia and 11 children with sickle cell disease and followed them for approximately 17 months. Among the children who were followed at least 16 months, all 8 in the beta thalassemia group were able to go at least a year without needing blood transfusions, and all 8 in the sickle cell group had at least a year without severe pain crises. The remaining children in each group hadn’t been followed long enough yet to know if they would meet that same benchmark.
“The FDA’s decision marks a lifesaving, paradigm-shifting step for children with sickle cell disease and transfusion‑dependent beta thalassemia,” said Stephan A. Grupp, MD, PhD, a co-senior study author and Section Chief of the Cellular Therapy and Transplant Section, and Inaugural Director of the Kelly Center for Cancer Immunotherapy at CHOP. “Access at younger ages gives families and care teams the chance to consider a one-time, potentially transformative treatment before years of irreversible, life‑shortening damage accumulates.”
The researchers expect to conduct long-term follow-up on patients to support the best possible approach and outcomes.
The research was funded by Vertex Pharmaceuticals and CRISPR Therapeutics.
Frangoul et al. “Exa-cel in Children with Transfusion-Dependent β-Thalassemia or Sickle Cell Disease.” NEJM. Online June 10, 2026. DOI: 10.1056/NEJMoa2603387.
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