The first sickle cell disease (SCD) patient has been successfully dosed with EDIT-301 in the phase 1/2 RUBY trial (NCT04853576), according to a new release. The successful engraftment of the patient’s neutrophils and platelets by the treatment has also been confirmed by the developer, Editas Medicine.

This study marks the first clinical use of Editas’s proprietary, engineered AsCas12a nuclease. Edit-301 is created through the editing of patient-derived CD34+ hematopoietic stem and progenitor cells by AsCas12a. The nuclease targets the gamma-globin genes (HBG1 and HBG2) promoters in order to induce the production of naturally occurring fetal hemoglobin (HbF).

Additional patients between the ages of 18 and 50 years are being recruited and enrolled at multiple sites across the US and Canada. Editas has already edited CD34+ cells for several patients in preparation for reinfusion. Top-line results of the trial are expected by the end of the year.

Read more about other SCD experimental therapies.

Editas also announced that the US Food and Drug Administration (FDA) has removed a partial clinical hold placed on the RUBY trial. The removal enables Editas to use efficacy data from the trial in its future marketing applications.

EDIT-301 is also being investigated for the treatment of patients with transfusion-dependent beta-thalassemia. The company is on track to dose their first patient in their phase 1/2 EDITHAL trial (NCT05444894) before the end of 2022.


Editas Medical announces clinical achievements in the development of EDIT-301 for sickle cell disease. News release. Editas Medical; July 27, 2022.