America's First CRISPR Trial is Still Nearly 100% Effective 3 Years On

Incredible new data presented recently at the European Hematology Association Congress has revealed an experimental CRISPR gene editing therapy is both safe and effective up to three years after treatment. The follow-up results come from one of the longest-running human trials using CRISPR technology to treat a pair of rare genetic blood diseases. From a report: The first human trial in the United States to test CRISPR gene editing technology started back in 2019. The trial focused on two rare blood diseases: beta-thalassemia and sickle cell disease. The treatment involves first gathering stem cells from a patient's blood. Using CRISPR technology a single genetic change is made, designed to raise levels of fetal hemoglobin in red blood cells. The stem cells are then re-administered into the patients. Initial results were extraordinarily promising. The first two patients treated were essentially cured within months, but questions over long-term efficacy remained. A follow-up announcement last year continued the impressive results with 22 patients treated and all demonstrating 100 percent success. Importantly, seven of those patients were 12 months past the initial treatment with no waning of efficacy. Now, a new data release is offering results from 75 patients treated with the groundbreaking CRISPR therapy, now dubbed exa-cel (exagamglogene autotemcel). Of those 75 patients treated, 44 were suffering transfusion-dependent beta thalassemia (TDT) and 31 had severe sickle cell disease (SCD). All but two of the 44 patients with TDT were essentially cured of their disease, needing no more blood transfusions. The two TDT patients still requiring blood transfusions had 75 percent and 89 percent reductions in transfusion volumes respectively. All 31 SCD patients were also free of disease symptoms at long-term follow-up.

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