The investigational therapy is also currently being evaluated in a clinical trial for sickle cell disease.
Editas Medicine has announced that the FDA has granted orphan drug designation to EDIT-301, its investigational gene-edited cell therapy which is currently being evaluated in severe sickle cell disease, with a phase 1/2 trial in transfusion-dependent beta thalassemia upcoming later in the year.
“Receiving orphan drug designation for EDIT-301 for beta thalassemia highlights the urgent need for new treatment options for patients,” said James C. Mullen, chairman, president, and chief executive officer, Editas Medicine, in a statement. “Preparations to initiate the Phase 1/2 clinical trial of EDIT-301, a potentially transformative medicine for people living with beta thalassemia, are underway, and we look forward to dosing the first patient in the clinical trial this year.”
The FDA previously granted EDIT-301 rare pediatric disease designation for both beta thalassemia and sickle cell disease.
The one-time treatment consists of autologous CD34+ hematopoietic stem and progenitor cells that are edited at the gamma globin gene (HBG1, HBG2) promoters via a specific and proprietary engineered AsCas12a nuclease. Therapy-derived red blood cells in turn produce a sustained increase in fetal hemoglobin.
The ongoing phase 1/2 RUBY trial (NCT04853576) is evaluating the safety, tolerability, and efficacy of a single dose unit of EDIT-301 in adults age 18 to 50 with severe sickle cell disease. Up to 40 participants will receive a 1-time intravenous infusion after undergoing myeloablative conditioning with busulfan.
The primary end point is difference in rates of severe vaso-occlusive events (VOE) that require medical attention, as measured over 2 years post-infusion. Secondary end points include the proportion of participants with mean fetal hemoglobin (HbF) >20% compared with baseline and mean Hb ≥10 g/dL starting at least 60 days after last packed red blood cell transfusion compared with baseline, both up to 2 years post-infusion. Additional secondar outcomes include annual number of packed red blood cell transfused for sickle cell-related events; change from baseline in annualized rate of hospitalization for severe VOEs; change from baseline in rates of severe VOEs by at least 75% and 90%; and complete resolution of severe VOEs, all evaluated up to 2 years post-infusion.