Editas Medicine Shares New Data from RUBY Trial on Reni-cel for Severe Sickle Cell Disease at ASH Meeting

Editas Medicine, Inc., a prominent gene editing company, is set to present new safety and efficacy data concerning 28 patients with severe sickle cell disease (SCD) treated with their innovative gene-editing therapy, renizgamglogene autogedtemcel (reni-cel; formerly EDIT-301). This update will be shared by Dr. Rabi Hanna from Cleveland Clinic Children’s during a poster presentation at the American Society of Hematology (ASH) Annual Meeting in San Diego on December 9, 2024, at 6:00 p.m. PT.

The RUBY clinical trial, assessing reni-cel, showed positive results as of the data cutoff date of October 29, 2024. Reni-cel demonstrated tolerability and a safety profile consistent with myeloablative conditioning using busulfan and autologous hematopoietic stem cell transplant. The 28 treated patients had undergone reni-cel infusion with a median follow-up of 9.5 months, and 11 patients had surpassed the one-year follow-up mark. Remarkably, 27 out of the 28 patients experienced no vaso-occlusive events (VOEs) post-treatment. Hemoglobin levels in patients normalized early, with the average total hemoglobin increasing from 9.8 g/dL at the start to 13.8 g/dL after six months. There were notable improvements in fetal hemoglobin (HbF) levels and the mean corpuscular hemoglobin concentration (MCH-F) in HbF-containing cells.

Detailed efficacy data revealed that patients, on average, were 9.5 months post-infusion, with 11 patients monitored for over a year. Of the 28 patients, 27 remained free from VOEs following reni-cel treatment. By the six-month mark, average total hemoglobin levels reached 13.8 g/dL, and the mean HbF percentage was 48.1%. The percentage of HbF-containing cells (F-cells) remained high, exceeding 90% from the fourth month through the last follow-up. MCH-F levels also increased, maintaining a mean value of 16.3 pg per F-cell, above the 10 pg per F-cell threshold known to prevent sickling. Hemolysis markers, such as reticulocyte count, bilirubin, lactate dehydrogenase, and haptoglobin, showed significant improvement or normalization by the six-month follow-up, with these improvements generally maintained.

Patients reported substantial and sustained quality-of-life enhancements regarding pain, physical function, and social activities following reni-cel treatment.

In terms of safety, reni-cel was well-tolerated across the 28 evaluated patients, with a safety profile aligned with myeloablative busulfan conditioning and autologous hematopoietic stem cell transplant. All evaluable patients (27 out of 28) achieved successful engraftment, with a median neutrophil engraftment time of 23 days and platelet engraftment at 25 days, crucial for reducing infection and bleeding risk. The trial recorded two serious adverse events (SAEs) potentially related to reni-cel treatment.

The detailed poster presentation at the ASH meeting, titled "Reni-Cel, an Investigational AsCas12a Gene-Edited Cell Medicine, Led to Sustained Hemoglobin Normalization and Increased Fetal Hemoglobin in Patients with Severe Sickle Cell Disease Treated in the RUBY Trial," will be delivered by Dr. Rabi Hanna. Attendees can access the poster in the poster and presentations section on the Editas Medicine website.

Reni-cel is an experimental gene editing therapy designed to treat severe SCD and transfusion-dependent beta-thalassemia (TDT). It involves editing patient-derived CD34+ hematopoietic stem cells at the gamma globin gene promoters, leading to increased production of fetal hemoglobin. This therapy has the potential to provide a one-time, durable treatment for these conditions.

The RUBY trial is an open-label, multi-center study aimed at evaluating the safety and efficacy of reni-cel in severe SCD patients and is registered under NCT04853576 on clinicaltrials.gov.