FDA slaps a clinical hold on sickle cell IND filed for a new gene therapy from Vertex and CRISPR Therapeutics
The two biotechs announced an alliance on sickle cell disease late last year, co-developing CTX001, which was made with CRISPR/Cas9 tech. The drug is designed to produce high levels of fetal hemoglobin (HbF; hemoglobin F) in red blood cells.
In their statement, the companies neglected to provide much detail, saying only that the hold was put in place “pending the resolution of certain questions that will be provided by the FDA as part of its review of the IND.”
At the same time, researchers for the partners plan to proceed with a European study. CRISPR, which had been buoyed in recent days, saw its shares plunge 20% on the news.
The two companies’ collaboration using CRISPR/Cas9 gene editing tools dates back to 2015, when Vertex handed over $105 million to get the pact started, with an initial focus on cystic fibrosis. Hemoglobinopathies like sickle cell disease were a secondary spotlight in the deal.
Gene therapies have been gaining steady traction in the US, with Spark Therapeutics picking up a pioneering FDA OK for Luxturna last year. The FDA, though, recently put a gene therapy program at Solid Biosciences on hold after Penn’s James Wilson abruptly resigned from their scientific advisory group, warning about the risks associated with “high systemic dosing of AAV [adeno-associated virus].”
We’ll keep you posted on the reasons for this latest hold as we learn more about it.