A newly developed single-treatment approach, uses autologous gene therapy and CD34 stem cells to improve erythrocyte function in SSD patients.
Sickle cell disease (SSD) refers to a group of inherited erythrocyte disorders. Hemoglobin in people with SSD becomes defective leading to abnormal shaping of erythrocytes. The defective hemoglobin form, hemoglobin S, replaces the normal hemoglobin A. The abnormally crescent or sickle-shaped erythrocytes cause a number of illnesses associated with the clogging of vessels, poor oxygen flow to organs, and associated damage.
Currently studied or available treatment approaches involve the use of drugs to reduce oxidative stress, inhibit blood cell adhesion, and enhance blood flow dynamics. Stem cell transplantation has led to some treatment success, but not all patients are candidates for this approach, and it is usually reserved for those patients who have suffered recurring serious cardiovascular events. Furthermore, stem cell transplantation almost always depends on myeloablative conditioning.
Aruvant/Roivant Sciences is developing a single-treatment approach, ARU-1801, for SDD and β-thalassemia. This treatment is an autologous gene therapy using CD34 stem cells, and was granted both Rare Pediatric Disease and Orphan Drug status by the US FDA. The objective of the treatment is to improve erythrocyte function by increasing the population of genetically modified fetal hemoglobin, hemoglobin F. It is known that patients with SSD and elevated hemoglobin F levels have less vaso-occlusive crises and events requiring hospitalization than those who only have the adult form of hemoglobin.
The gene encoding for hemoglobin F is inserted into the patients’ CD34 stem cells via a lentiviral vector. Results of early clinical trials show that there was a significant increase in hemoglobin F after infusion of the transfected CD34 stem cells. In addition, there was a reduction in the population of hemoglobin S in the patients, and the hemoglobin oxygen-carrying capacity was enhanced.
Another significant benefit of this therapeutic approach is that it does not depend on high-intensity myeloablative conditioning regimens that are associated with the risk of many adverse effects. Instead, a reduced-intensity conditioning regimen is applied, which lowers the risk of serious complications and length of hospitalization.
HemaCare supplies high-quality human cells and tissues for globally-recognized gene and cell-therapy research.
FDA grants rare pediatric disease designation to gene therapy for sickle cell disease. (2020). Retrieved 14 April 2020, from https://www.healio.com/hematology-oncology/hematology/news/online/%7Ba43f5d66-463f-4454-b561-76f42a36ed2b%7D/fda-grants-rare-pediatric-disease-designation-to-gene-therapy-for-sickle-cell-disease