FDA lifts hold on Fulcrum sickle-cell disease drug

Aug. 23, 2023

The FDA has lifted the clinical hold on Fulcrum Therapeutics' IND application for FTX-6058, a potential treatment for sickle-cell disease (SCD). 

Back in February, the FDA placed a hold on the Massachusetts-based rare disease specialist's application, citing concerns about hematological malignancies associated with similar compounds. Fulcrum halted dosing during this period and collaborated with the FDA to address the concerns. 

FTX-6058 is an investigational oral small-molecule inhibitor of Embryonic Ectoderm Development that was discovered using Fulcrum’s proprietary discovery engine. The drug has received FDA Fast Track and Orphan Drug designations for SCD treatment. 

SCD is a genetic disorder caused by a mutation in the HBB gene, responsible for a vital hemoglobin component that carries oxygen. This mutation leads to impaired oxygen transport, causing red blood cells to adopt a sickle shape. These inflexible cells can obstruct vessels, triggering severe issues like anemia, pain, infections, stroke, heart and lung problems, kidney and liver disorders, and shortened lifespan.

With the hold now lifted, Fulcrum expressed optimism about the potential of FTX-6058 based on phase 1b trial data, which showed increased levels of HbF with each dose escalation.