A therapy is granted Orphan Drug designation if the FDA believes that this therapy will treat, prevent, or diagnose rare conditions. Rare conditions, in the United States, are those affecting fewer than 200,000 people nationwide. This therapy comes alongside numerous benefits for drug developers: think 7 years of market exclusivity upon drug approval, increased regulatory assistance and FDA communication, fee waivers, tax credits, and more. Ultimately, this is designed to incentivize drug development within the rare disease space. In late April 2023, the FDA granted Orphan Drug designation to EDIT-301 for the treatment of patients with sickle cell disease (SCD). 

A Brief Overview of EDIT-301

According to Pharmaceutical Technology, this is the drug’s second Orphan Drug designation. The first was granted to the treatment one year ago this month for the treatment of patients with beta thalassemia, a rare blood disorder characterized by low hemoglobin levels. A press release from clinical-stage genome editing company Editas Medicine (“Editis”) explains that EDIT-301 is: 

an experimental cell therapy medicine [that] consists of patient-derived CD34+ hematopoietic stem and progenitor cells edited at the gamma globin gene promoters, where naturally occurring fetal hemoglobin mutations reside, by a highly specific and efficient proprietary engineered AsCas12a nuclease. Red blood cells derived from EDIT-301 CD34+ cells demonstrate a sustained increase in fetal hemoglobin production.

Currently, researchers are evaluating the safety and efficacy of a single dose of EDIT-301 in the Phase 1/2 RUBY trial. As of right now, EDIT-301 has been safe and well-tolerated. Additionally, data from the study highlights the treatment’s ability to increase hemoglobin levels and reduce characteristic SCD symptoms. 

What is Sickle Cell Disease (SCD)?

Sickle cell disease consists of a group of rare, inherited red blood cell disorders. It is caused when a gene mutation prevents the body from producing functional hemoglobin. Normally, hemoglobin carries oxygen throughout the body. But in SCD, the red blood cells become sickle-shaped and stiff. They get caught along the walls of blood vessels and capillaries, restricting blood flow and causing pain. Many people also experience hemolysis, or red blood cell destruction. People of African-American descent and those with a family history of SCD are at the highest risk of having it. Symptoms, which often appear within the first six months of life, may include:

• Fatigue and fussiness (in infants)
• Priapism (in males) 
• Pain crisis
• Swelling of the hands and feet
• Hematuria (blood in the urine) 
• Dizziness
• Frequent infections
• Anemia (low red blood cell count)
• Jaundice (yellowing of the skin, eyes, and mucous membranes) 
• Acute chest syndrome
• Stroke
• Organ damage 

Right now, there are no cures for sickle cell disease. Most treatments aim to manage and control symptoms.