--Lead type V editor program in SCD demonstrates industry leading delivery and repeat dosing with a passive LNP--

--Results reveal unprecedented improvement of editing rates from single digits to nearly 80% in primary HSPCs--

WATERTOWN, Mass., Oct. 22, 2024 /PRNewswire/ -- Orna Therapeutics, a biotechnology company dedicated to designing and delivering a new class of circular RNA medicines and unprecedented lipid nanoparticle (LNP) delivery solutions for oncology and autoimmune diseases, today presented a poster highlighting preclinical data from its SiTu Editing in the Marrow (STEM) in vivo CRISPR editing platform at the European Society of Gene & Cell Therapy Annual Congress taking place October 22-25 in Rome.

The data show dramatically improved editing rates from single digits to roughly 80% in primary hematopoietic stem progenitor cells (HSPCs) from healthy donors. Orna's STEM technology is geared to address beta-hemoglobinopathies including sickle cell disease (SCD) and transfusion-dependent beta thalassemia (TDT).

While significant progress has been made with two recent U.S. Food and Drug Administration approvals for SCD and TDT using ex vivo approaches, patient journeys involve lengthy wait times for treatment at specialized centers and harsh therapeutic regimens that come with serious safety risks that can limit eligibility. By contrast, in vivo delivery of gene editing therapies offers a simple, off-the-shelf treatment that can be administered in an outpatient setting.

"Our results are highly promising and demonstrate the powerful potential of Orna's type V editors when combined with HSPC-targeted RNA delivery to enable in vivo delivery without the need for a targeting ligand or antibody fragment," said Robert Mabry, Chief Scientific Officer for Orna. "Orna Therapeutics is pioneering an entirely new approach to genome engineering through the development of our gene editing and in vivo delivery platforms, which could offer more patients access to less toxic and complicated cell-based therapies."

Utilizing a high-throughput barcoding screening approach in non-human primates (NHPs), the company identified a series of LNPs that demonstrated tropism to a rare population of CD34+ HSPCs that reside in the bone marrow. The technology allows for repeat dosing, which is not currently feasible for viral-based delivery approaches.

The lead HSPC-tropic LNP candidate was found to have greater than 70% reporter-positive bulk CD34+ cells and greater than 95% reporter positive long-term HSCs in humanized mice. Furthermore, when tested individually in NHPs, the LNP candidate showed robust delivery to the bone marrow – revealing an average of 24% reporter positive HSPCs, while multiple doses achieved up to 30% editing.

The company plans to share additional data for its type V editor program at a conference in 2025.

About Orna Therapeutics

Orna Therapeutics is dedicated to designing and delivering a new class of fully engineered circular RNA (oRNA) therapeutics to unlock the potential of RNA medicine to treat diseases anywhere in the body. Orna's circular RNA transcripts have advantages over traditional mRNA approaches, including simplified production, improved formulation into lipid nanoparticles, and superior protein expression. Its industry-leading LNP-based delivery systems and comprehensive editing programs position Orna to advance novel RNA medicines with vast potential to transform patient care. To learn more, visit and follow Orna Therapeutics on X and LinkedIn.

SOURCE Orna Therapeutics