Global Blood Therapeutics, Inc. (GBT) (GBT) announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation (BTD) to voxelotor (previously called GBT440) for the treatment of sickle cell disease (SCD). Voxelotor is being developed as a disease-modifying therapy for SCD and previously received European Medicines Agency (EMA) Priority Medicines (PRIME) designation for the treatment of SCD.

“The FDA’s decision to grant voxelotor the first Breakthrough Therapy designation for the treatment of sickle cell disease reflects a recognition of the promising efficacy and safety data we have collected to date for this investigational drug, as well as an acknowledgement of the overwhelming need for major advances over available therapies in the treatment of SCD patients,” said Ted W. Love, president and chief executive officer of GBT. “This designation is another significant milestone for GBT as we work to expedite the development of voxelotor.”

The FDA selectively grants BTD to expedite the development and review of drugs that have demonstrated preliminary clinical evidence indicating the potential for substantial improvement over available therapy. The BTD decision 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)

About Sickle Cell Disease (SCD)

SCD is a lifelong inherited blood disorder caused by a genetic mutation in the beta-chain of hemoglobin, which leads to the formation of abnormal hemoglobin known as sickle hemoglobin (HbS). In its deoxygenated state, HbS has a propensity to polymerize, or bind together, forming long, rigid rods within a red blood cell (RBC). The polymer rods deform RBCs to assume a sickled shape and to become inflexible, which can cause blockage in capillaries and small blood vessels. Beginning in childhood, SCD patients suffer unpredictable and recurrent episodes or crises of severe pain due to blocked blood flow to organs, which often lead to psychosocial and physical disabilities. This blocked blood flow, combined with hemolytic anemia (the destruction of RBCs), can eventually lead to multi-organ damage and early death.