Global Blood Therapeutics (GBT), a biopharmaceutical company developing novel therapeutics for the treatment of grievous blood-based disorders with significant unmet needs, announced that the US Food and Drug Administration (FDA) has granted Fast Track designation to GBT440 for the treatment of sickle cell disease (SCD).

“By granting Fast Track designation to GBT440, the FDA is acknowledging that SCD is a serious health problem that needs new treatment options. This gives us the opportunity to work closely with the FDA to accelerate development of GBT440 for this important unmet medical need,” said Ted W. Love, M.D., chief executive officer of GBT.

“We believe the unique ability of GBT440 to target the underlying mechanism of red blood cell sickling underscores its potential to modify the disease, rather than only treat its symptoms.”

GBT440 is an oral, once daily therapy for the treatment of SCD that works by increasing haemoglobin’s affinity for oxygen. Since oxygenated sickle haemoglobin does not polymerize, GBT440 blocks polymerization and the resultant sickling of red blood cells (RBCs). With the potential to restore normal haemoglobin function, GBT440 may be capable of modifying the progression of SCD. Currently, GBT440 is being investigated in an ongoing phase 1/2 clinical trial in both healthy subjects and SCD patients.


The FDA’s Fast Track process is designed to expedite the clinical development and submission of a New Drug Application (NDA) for medicines with the potential to treat serious or life-threatening conditions and address an unmet medical need (i.e., a condition whose treatment or diagnosis is not addressed adequately by available therapy). A drug programme with Fast Track designation enables the company to have early and frequent communication with the FDA in the development and review of the product candidate, often leading to faster drug approval and access by patients.

SCD is an inherited blood disorder caused by a genetic mutation in the beta-chain of hemoglobin, leading to formation of abnormal hemoglobin known as sickle haemoglobin, or 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 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.