Currently, the European Hematology Association (EHA) is holding its 2021 Virtual Congress through June 17, 2021. During the event, researchers are expounding on new insights and research within the hematological sphere. In one news release, biopharmaceutical company Global Blood Therapeutics, Inc. (“GBT”) shared that it will present data from the Phase 2a HOPE-KIDS 1 clinical trial during the conference. Altogether, the data centers around the use of Oxbryta (voxelotor) tablets in pediatric patients (4-11) with sickle cell disease (SCD).

Oxbryta

According to the FDA, Oxbryta is:

a hemoglobin S polymerization inhibitor.

GBT describes Oxbryta as the first FDA-approved therapy which stops sickle hemoglobin polymerization, or the process in which red blood cells (RBCs) become sickled and deformed. Overall, Oxbryta does this by increasing hemoglobin’s attraction to oxygen. As a result, sickle hemoglobin becomes oxygenated and fails to go through the polymerization process. The treatment, administered once daily, is taken orally. While Oxbryta is relatively safe and well-tolerated, patients may experience some side effects, such as fever, rash, abdominal pain, diarrhea, fatigue, nausea, rash, and headaches. Thus far, Oxbryta has received Fast Track, Orphan Drug / Orphan Medicinal Product, PRIME, Breakthrough Therapy, and Rare Pediatric disease designations.

Clinical Trial Data

During the EHA Virtual Congress, the oral abstract #S260 focuses on data from the Phase 2a HOPE-KIDS 1 clinical trial. Altogether, 45 pediatric patients enrolled. Patients received either 1500mg Oxbryta or a weight-dependent dose. Data from the trial shows that:

• Oxbryta was safe and well-tolerated. Common side effects included diarrhea, nausea and vomiting, and rashes.
• Overall, Oxbryta treatment raised hemoglobin levels in 47% of patients within 2 weeks of treatment. Additionally, the increased hemoglobin levels were sustained over a 24-week (5.5 month) period.
• Patients also saw lower amounts of hemolysis (RBC destruction or rupturing), a characteristic of SCD.

Additionally, GBT will present data from two real-world analyses which saw similar results to the Phase 3 HOPE clinical trial. This data shows:

• One analysis (#EP1209) comprised of 77 patients with SCD. After Oxbryta treatment, patients saw improved hemoglobin levels and lower amounts of hemolysis. Additionally, 62% of patients saw hemoglobin rises more than 1g/dL, which rose to 87% when Oxbryta was used in conjunction with hydroxyurea. Oxbryta was deemed to be relatively safe and well-tolerated.
• The secondary analysis (#EP1206) focused on the RETRO study design. Altogether, RETRO will include real-world patient outcomes of approximately 300 patients (adult and pediatric) with sickle cell disease. So far, researchers have initial data from 20 patients. Of these, 10 patients saw hemoglobin rises of more than 1g/dL.

Sickle Cell Disease (SCD)

Sickle cell disease (SCD), a group of inherited disorders caused by beta-globin gene defects, causes the development of malformed, sickle-shaped red blood cells. Normally, this gene produces hemoglobin, which carries oxygen throughout the body. Normal red blood cells are also circular shaped and easily moveable. But in patients with SCD, the malformed RBCs become caught along blood vessel walls, causing blockages and inhibiting blood flow. Patients of African American heritage are more likely to have SCD. Symptoms typically appear within the first few months of life. These symptoms include:

• Jaundice (yellowing of the skin and eyes)
• Pain crisis
• Anemia (low red blood cell count)
• Organ damage
• Excessive irritability
• Delayed growth
• Swelling of the hands and feet
• Fatigue
• Pulmonary hypertension