FDA Grants Breakthrough Therapy Designation to Voxelotor for Sickle Cell Disease

The drug also has fast-track, orphan drug, and rare pediatric disease status

The FDA has granted a breakthrough therapy designation to voxelotor (previously called GBT440, Global Blood Therapeutics) for the treatment of sickle cell disease (SCD). Voxelotor is being developed as a disease-modifying therapy for SCD.

The breakthrough therapy designation for voxelotor was based on clinical data submitted from the following studies:

  • Preliminary efficacy and safety data from part A of the phase 3 HOPE study (GBT440-031)
  • Phase 1/2 study and open-label extension in adults (GBT440-001/024)
  • Ongoing phase 2 HOPE-KIDS 1 study in children age 6 to 17 (GBT440-007)
  • Compassionate Access experience in adults with severe SCD (not eligible for the HOPE study)

Voxelotor is being developed as an oral, once-daily therapy for patients with SCD. Voxelotor works by increasing hemoglobin's affinity for oxygen. Because oxygenated sickle hemoglobin does not polymerize, the developer believes voxelotor blocks polymerization and the resultant sickling of red blood cells. With the potential to restore normal hemoglobin function and improve oxygen delivery, the company believes that voxelotor may potentially modify the course of SCD.

In recognition of the critical need for new SCD treatments, the FDA has granted voxelotor fast-track, orphan drug, and rare pediatric disease designations for the treatment of patients with SCD.

Voxelotor is currently being evaluated in the HOPE (Hemoglobin Oxygen Affinity Modulation to Inhibit HbS Polymerization) study, a phase 3 clinical study in patients 12 years of age and older with SCD. In addition, voxelotor is being studied in the ongoing phase 2a HOPE-KIDS 1 study, an open-label, single- and multiple-dose study in pediatric patients (ages 6 to 17 years) with SCD. HOPE-KIDS 1 is assessing the safety, tolerability, pharmacokinetics, and exploratory treatment effect of voxelotor.

Source: Global Blood Therapeutics; January 9, 2018.