Editas Medicine, Inc. announced new safety and efficacy data in 17 patients treated with EDIT-301, now known as renizgamglogene autogedtemcel (reni-cel), in the RUBY trial for severe sickle cell disease (SCD) (n=11) and in the EdiTHAL trial for transfusion-dependent beta thalassemia (TDT) (n=6). The total dataset of 17 treated patients includes 12 additional patients since the data presentation at the European Hematology Association (EHA) Annual Congress and in a Company-sponsored webinar this past June. Reni-cel is being investigated in the RUBY and EdiTHAL clinical trials as a potential one-time, durable gene editing medicine for people living with severe SCD and TDT.

Editas Medicine will present the RUBY and EdiTHAL trial data on December 11, 2023 at 1 p.m. ET in a Company-sponsored webinar. The data will also be presented in a poster presentation at the American Society of Hematology (ASH) Annual Meeting in San Diego, CA, at 6:00 p.m. PT (9:00 p.m. ET). In both the RUBY and EdiTHAL trials to date, reni-cel was well-tolerated and continues to demonstrate a safety profile consistent with myeloablative conditioning with busulfan and autologous hematopoietic stem cell transplant by all patients in the two trials (n=17).

Since treatment with reni-cel, all RUBY patients are free of vaso-occlusive events (VOEs) (n=11). All RUBY patients with =5 months follow-up have maintained a normal hemoglobin level and a fetal hemoglobin level of >40%. All EdiTHAL patients had early and robust increase of total hemoglobin, above the transfusion independence threshold of 9 g/dl (n=6).

Safety: Reni-cel was well-tolerated and demonstrated a safety profile consistent with myeloablative conditioning with busulfan and autologous hematopoietic stem cell transplant by all patients in the RUBY and EdiTHAL trials (n=17). After reni-cel infusion, all treated patients with >2 months follow-up demonstrated successful neutrophil engraftment within one month and platelet engraftment within 1.6 months. No serious adverse events (SAEs) related to reni-cel treatment have been reported.

Efficacy: RUBY Trial in Severe Sickle Cell Disease: In the RUBY trial, all treated patients are free of VOEs since reni-cel infusion. Reni-cel treatment drives early, robust increase of total hemoglobin and fetal hemoglobin. The patients with =5 months follow-up have maintained a normal hemoglobin level and a fetal hemoglobin level of >40% (n=6; range 5-18 months follow-up).

All treated RUBY patients with >1 month of follow-up followed a similar trajectory of total hemoglobin and fetal hemoglobin increases (n=10). EdiTHAL Trial in Transfusion-dependent Beta Thalassemia: In the EdiTHAL trial, patients with >1 month follow-up (n=5) demonstrated early and robust total hemoglobin and fetal hemoglobin increases, with total hemoglobin rising above the transfusion independence threshold of 9 g/dL. Reni-cel, formerly known as EDIT-301, is an experimental gene editing medicine under investigation for the treatment of severe sickle cell disease (SCD) and transfusion-dependent beta thalassemia (TDT).

Reni-cel consists of patient-derived CD34+ hematopoietic stem and progenitor cells edited at the gamma globin gene (HBG1 and HBG2) promoters, where naturally occurring fetal hemoglobin (HbF) inducing mutations reside, by AsCas12a, a novel, proprietary, highly efficient, and specific gene editing nuclease. Red blood cells derived from reni-cel CD34+ cells demonstrate a sustained increase in fetal hemoglobin production, which has the potential to provide a one-time, durable treatment benefit for people living with severe SCD and TDT. The RUBY trial is a single-arm, open-label, multi-center Phase 1/2 study designed to assess the safety and efficacy of reni-cel in patients with severe sickle cell disease.

Enrolled patients will receive a single administration of reni-cel. The RUBY trial marks the first time AsCas12a was used to successfully edit human cells in a clinical trial. The EdiTHAL trial is a single-arm, open label, multi-center Phase 1/2 study designed to assess the safety and efficacy of reni-cel in patients with transfusion-dependent beta thalassemia.

Patients will receive a single administration of reni-cel.