The results of two clinical trials in NEJM show that new gene therapy may be available to treat sickle cell anemia

14, 2020 // -- In two recent studies published in the international journal New England Journal of Medicine, scientists from the United States, Germany, Canada and France have developed new gene therapies that target the treatment of sickle-cell anemia.
the first study, researchers used crispr-Cas9 gene editing systems to enhance fetal hemoglobin production in the body of patients with sickle cell anemia.
In a second study, researchers tried to find a way to promote fetal hemoglobin production in patients with sickle cell anemia, using a different technique that mainly introduces RNA through viral vectors to alter the expression of the fetal hemoglobin gene.
file photo: CC0 Public Domain sickle cell anemia is an inherited blood disorder that occurs mainly in people of African descent, and is induced by a genetic mutation that encodes hemoglobin, which causes red blood cells to harden and drive red blood cells to turn into sickle-like cells, which then clog blood vessels, causing painful symptoms in the patient's body and sometimes organ damage or stroke.
researchers say both new therapy options are part of a clinical trial aimed at altering the pathogenic gene that mainly induces sickle cell anemia; in both cases, clinicians remove blood stem cells from a portion of the patient's body and try to insulate the patient's body's genetic switch, which is then given chemotherapy to destroy the wrong cells in the body, which can be re-infused into the patient.
over time, stem cells that enter the patient's body grow into normal blood cells and free the patient from the disease.
Both groups of researchers have been successful in clinical trials, and in the first trial, they used CRISPR-Cas9 about 17 months ago to test patients who had so far shown no symptoms of pain associated with sickle cell anemia.
other patients who have been studied since then have received similar results.
In addition, researchers have tried similar techniques to treat patients with β-thalassemia, a hereditary disease that produces little or no hemoglobin in patients with β β-thalassemia because of the appearance of genetic mutations that are roughly the same as sickle cell anemia.
group of researchers has studied six patients over the past few years and so far there have been no cases of treatment failure.
() Original source: Erica B. Esrick, M.D., Leslie E. Lehmann, M.D., Alessandra Biffi, M.D., et al. Post-Transcriptional Genetic Silencing of BCL11A to Treat Sickle Cell Disease, New England Journal of Medicine (2020). DOI:10.1056/NEJMoa2029392【2】Haydar Frangoul, M.D., David Altshuler, M.D., Ph.D., M. Domenica Cappellini, M.D., et al. CRISPR-Cas9 Gene Editing for Sickle Cell Disease and β-Thalassemia, New England Journal of Medicine (2020). DOI:10.1056/NEJMoa2031054。