Editas Medicine Unveils Promising In Vivo Gene Editing Data for Sickle Cell Disease and Beta Thalassemia, Highlighting HSC-Targeted tLNP Delivery

CAMBRIDGE, Mass. – June 12, 2025 – Editas Medicine, Inc. (Nasdaq: EDIT), a pioneering gene editing company, today announced compelling new in vivo data demonstrating therapeutically relevant levels of HBG1/2 promoter editing in hematopoietic stem cells (HSCs) using a single dose of its proprietary targeted lipid nanoparticle (tLNP) in non-human primates (NHPs). This advanced approach, designed to upregulate fetal hemoglobin (HbF) by targeting HBG1/2 promoters, is under preclinical development as a potential transformative in vivo gene editing medicine for sickle cell disease (SCD) and beta thalassemia.

The company shared these data in a presentation released today and will provide further details in a poster session on Saturday, June 14th, at the European Hematology Association (EHA) 2025 Congress in Milan, Italy.

In the ongoing NHP study, Editas’ proprietary tLNP formulation successfully delivered HBG1/2 promoter editing cargo to HSCs. Latest data at five months post-administration showed that a single intravenous dose of Editas’ tLNP resulted in mean on-target editing levels of 58% in the HBG1/2 promoter region within HSCs. This significantly exceeds the predicted editing threshold of $\ge$25% considered necessary for therapeutic benefit.

Furthermore, biodistribution data from the NHP study continue to demonstrate significant de-targeting of the liver with Editas’ tLNP, a notable improvement compared to standard LNPs. This suggests a more precise delivery to the intended HSC targets while minimizing off-target effects in the liver.

“These data from our in vivo HSC program confirm our ability to achieve high efficiency delivery, therapeutically relevant editing levels and favorable biodistribution in NHPs,” said Linda C. Burkly, Ph.D., Executive Vice President and Chief Scientific Officer, Editas Medicine. “These data validate the further development of Editas’ proprietary HSC-tLNP for editing of the HBG1/2 promoters for the treatment of sickle cell disease and beta thalassemia.”

Editas Medicine’s in vivo HSC program is designed to mimic naturally occurring mechanisms of hereditary persistence of fetal hemoglobin (HPFH) by targeting HBG1/2 promoters. The investigational medicine utilizes proprietary AsCas12a technology to achieve high-efficiency editing while minimizing off-target effects. Previous clinical trials with reni-cel (an investigational medicine also based on editing HBG1/2 promoters with AsCas12a) have already shown robust increases in HbF and total hemoglobin (Hb), further supporting the clinical validity of this gene editing strategy.

The positive NHP data represent a crucial step forward in advancing an in vivo gene editing solution that could offer a less invasive and potentially transformative treatment option for patients with SCD and beta thalassemia.