Clinical-stage biotech company CorrectSequence Therapeutics (Correctseq) announced on Tuesday that new research published online in the journal Cell Stem Cell demonstrates that CS-101/CS-206 base-editing therapy, developed with the transformer Base Editor (tBE), achieved consistent efficacy and safety in beta-hemoglobinopathy patients of diverse genetic origins.

This follows the team's prior clinical report published in Nature on five Chinese transfusion-dependent beta-thalassemia (TDT) patients treated with CS-101, all achieving transfusion independence.

The new study extends treatment to four additional patients from Nigeria, Laos, Malaysia, and Pakistan: one with sickle cell disease (SCD) and three with TDT. All achieved rapid hematopoietic reconstitution, sustained high-level pan-cellular HbF expression, complete transfusion independence or freedom from vaso-occlusive crises (VOCs), with no detectable off-target edits, or product-related adverse events.

This confirms that tBE is equally safe and effective for African SCD patients and TDT patients from South/Southeast Asia, Correctseq said.

To date, CS-101 and CS-206 have treated more than 30 patients across China, Africa, Southeast Asia, and South Asia, with 100% of patients achieving transfusion independence or freedom from VOCs, accompanied by sustained, high-level hemoglobin expression. CS-101, the world's first ongoing base-editing therapy candidate to enter clinical development, with the first patient dosed in October 2023, has completed Phase I and is now being evaluated in pivotal trials.

According to the company, all patients treated in Phase I have maintained transfusion independence for more than one year, with the longest duration approaching almost three years.