Boston — Vertex Pharmaceuticals said new data show clinical benefits from CASGEVY in patients ages 5 and older living with severe sickle cell disease or transfusion-dependent beta thalassemia.
The results, from pivotal studies in children ages 5 to 11, were presented at the European Hematology Association Congress and simultaneously published in the New England Journal of Medicine.
Vertex said the efficacy and safety outcomes in younger children were consistent with the profile previously shown in adults and adolescents.
“The data presented at EHA and published in NEJM underscore the consistent, durable and transformative benefits CASGEVY can provide to people living with sickle cell disease or transfusion-dependent beta thalassemia from early in life,” said Carmen Bozic, M.D., Executive Vice President, Global Medicines Development and Medical Affairs, and Chief Medical Officer at Vertex.
CASGEVY, also known as exagamglogene autotemcel, is currently approved in several countries for eligible patients 12 and older with sickle cell disease with recurrent vaso-occlusive crises or transfusion-dependent beta thalassemia. Its use in children ages 5 to 11 remains investigational.
In the Phase 3 CLIMB-151 study of children with severe sickle cell disease, all 11 patients dosed were free from vaso-occlusive crises. Vertex said all eight patients with sufficient follow-up achieved the primary endpoint of being free from vaso-occlusive crises for at least 12 consecutive months. Among those patients, the mean duration without vaso-occlusive crises was 19 months.
In the Phase 3 CLIMB-141 study of children with transfusion-dependent beta thalassemia, 15 patients were dosed with CASGEVY. All eight patients with sufficient follow-up achieved the primary endpoint of transfusion independence for at least 12 consecutive months while maintaining a weighted average hemoglobin of at least 9 g/dL. Vertex said all children who achieved transfusion independence remained so throughout follow-up, with a mean duration of 23.4 months.
The company said the safety profile in younger patients was consistent with myeloablative conditioning and autologous transplant, as seen in earlier studies of older patients with sickle cell disease and transfusion-dependent beta thalassemia. Vertex noted that, as previously disclosed, there was one death not related to CASGEVY in a child with transfusion-dependent beta thalassemia who developed severe veno-occlusive disease from busulfan conditioning.
“Despite optimized supportive therapy, children living with sickle cell disease and transfusion-dependent beta thalassemia carry a significant disease burden from a very young age, with progressive complications leading to the irreversible and life-shortening consequences of these diseases,” said Franco Locatelli, M.D., Ph.D., Professor of Pediatrics at the Catholic University of the Sacred Heart of Rome, Director of the Department of Pediatric Hematology and Oncology at Bambino Gesù Children’s Hospital, Chair of Vertex’s TDT Program Steering Committee, and presenting author of the 5–11 years old CASGEVY data at EHA. “These data represent a profoundly important step forward, and I look forward to the possibility of providing earlier intervention to prevent complications in children and for families who have had limited potentially curative options to date.”
Vertex said treated children showed durable and clinically relevant increases in fetal hemoglobin and stable allelic editing, consistent with studies in older patients.
The company said regulatory review is underway in the United States to expand use of CASGEVY to younger children after Vertex received the Commissioner’s National Priority Voucher. Vertex has also recently completed submissions in Saudi Arabia and the United Kingdom seeking expanded use in younger children.
The company said activated authorized treatment centers are already in place in those countries to support patients upon availability.
