(ORLANDO, Dec. 6, 2025) The first study assessing the real-world commercial roll-out of gene therapies for sickle cell disease and beta thalassemia offers lessons learned to inform best practices as manufacturers and medical centers prepare to meet growing demand for gene therapies in the coming years.
“Gene therapy requires system-level coordination and close collaboration across patients, treatment centers, payers, and manufacturers,” said study author Joanne Lager, MD, chief medical officer at Genetix Biotherapeutics Inc. “The demand for these one-time durable gene therapies is growing, and we’re learning how to deliver treatment more efficiently as we gain more experience.”
Sickle cell disease and beta thalassemia are both inherited disorders that affect the hemoglobin in red blood cells. In beta thalassemia, not enough functional hemoglobin is produced, which impacts the ability of red blood cells to carry oxygen, leading to debilitating symptoms and cumulative organ damage. In sickle cell disease, abnormal hemoglobin production causes the red blood cells to become rigid and sickle-shaped, leading to blood vessel blockages and subsequent pain and organ damage.
Betibeglogene autotemcel (beti-cel) and lovotibeglogene autotemcel (lovo-cel) are autologous ex vivo gene therapies in which a patient’s own stem cells are collected, manufactured to add functional copies of a modified gene, and then infused back into the patient to engraft in the bone marrow and begin producing red blood cells with functional hemoglobin. The U.S. Food and Drug Administration (FDA) approved beti-cel for transfusion dependent beta thalassemia in 2022 under the name Zynteglo, and lovo-cel for sickle cell disease in 2023 under the name Lyfgenia.
To study the process and timing of real-world commercial implementation of these therapies, researchers analyzed data from 392 U.S. patients who enrolled to receive either beti-cel or lovo-cel between 2022 and 2025. To date, 29% (115) of these patients have received treatment, with 72% of beti-cel patients and 76% of lovo-cel patients having done so within a year of enrollment.
According to the findings, the median time elapsed from the decision to enroll and the one-time infusion of drug product was 9.8 months for beti-cel and 7.9 months for lovo-cel. Time for enrollment, scheduling, and cell collection varied across patients, with the most variability seen in the time elapsed between the decision to enroll in gene therapy and the collection of stem cells. The median time to complete this step – during which centers prepare patients for therapy medically and financially – was 4.4 months.
Most patients required only one cell collection for both beti-cel (79%) and lovo-cel (63%), consistent with experience from clinical trials. The number of stem cell collection procedures played a role in the overall treatment timeline, with about 80 days added per collection cycle. Once stem cells were collected, the median time it took to manufacture, test, and deliver the gene therapy drug product to a treatment center was 3.2 months for beti-cel and 3.5 months for lovo-cel.
“We’ve identified areas of opportunity to enhance the treatment journey for patients and providers,” said Dr. Lager. “We recognize the importance of delivering our therapies to patients as soon as possible and remain committed to improving the treatment experience.”
The results showed some operational differences between the two gene therapies. The time between FDA approval and first commercial patient enrollment was about half as long for lovo-cel as for beti-cel. Since beti-cel was approved about 16 months before lovo-cel, the researchers suggest that early experience implementing beti-cel meant that more centers were prepared to begin treating patients with lovo-cel.
Researchers said that operational factors such as insurance approvals, the number of cell collections required, and manufacturing capacity play an important role in influencing treatment timelines. Finding opportunities for greater efficiency across these areas remains a key focus.
“Demand for our gene therapies continue to build. We are actively working toward ensuring that we have the manufacturing capacity to deliver gene therapy to all patients seeking a path to a cure,” said Dr. Lager.
The researchers noted that insurance coverage for these treatments has continued to expand. To facilitate further progress in overcoming barriers and increasing efficiency, they plan continued process improvements and collaboration with medical centers to share lessons learned and develop best practices.
Anjulika Chawla, MD, of Genetix Biotherapeutics Inc., will present this study on Monday, December 8, 2025, at 4:00 p.m. Eastern time in W311A-D of the Orange County Convention Center.
###
The American Society of Hematology (ASH) (hematology.org) is the world’s largest professional society of hematologists dedicated to furthering the understanding, diagnosis, treatment, and prevention of disorders affecting the blood. Since 1958, the Society has led the development of hematology as a discipline by promoting research, patient care, education, training, and advocacy in hematology. Join the #Fight4Hematology by visiting hematology.org/fight4hematology.
The Blood journals (https://ashpublications.org/journals) are the premier source for basic, translational, and clinical hematologic research. The Blood journals publish more peer-reviewed hematology research than any other academic journals worldwide.
The ASH Center for Sickle Cell Disease Initiatives (hematology.org/ash-center-for-sickle-cell-disease-initiatives) is committed to progressing research in sickle cell disease by targeting critical needs and generating powerful, real-world evidence to create impact and change.