FDA placed hold on Fulcrum's sickle cell therapy over hematological malignancy concerns

The FDA’s ongoing clinical hold on Fulcrum’s sickle cell disease therapy was sparked by concerns about potential hematological malignancies, the biotech has revealed.

The agency placed the candidate, dubbed FDX-6058, on hold on February 23. Details were sparse while the company waited for the FDA’s hold letter, with Fulcrum only saying that the decision related to preclinical data. At the time, interim CEO Robert Gould, Ph.D., suggested the hold was linked to “modulation of the PRC2 complex,” a system involved in gene expression.