The Investigational New Drug Application for the experimental drug CTX001 for treating sickle cell disease has been put on clinical hold, announced Vertex Pharmaceuticals Incorporated and CRISPR Therapeutics. This hold was ordered by the US Food and Drug Administration (FDA), who need to resolve certain questions before the application can be reviewed. The full article can be read at Vertex’s website.
An Investigational New Drug Application (IND) is an important step in the development of a drug for medical use. According to the FDA’s website, when developers have tested a drug in animals for safety and its effects, and want to move on to a trial involving humans, the legal status of the experimental drug changes and it becomes subject to new regulations. Approval from the FDA of an IND for the drug is often required at this stage. Usually, the FDA reviews the IND within thirty days, but in the case of CTX001 the FDA has placed the drug on clinical hold while they resolve further questions about the drug. Clinical hold is the delay or suspension of a clinical trial. CRISPR and Vertex, the developers, are expecting to learn more about the FDA’s questions shortly, and plan to resolve them rapidly.
CTX001 is an investigational therapy for the treatment of β-thalassemia and sickle cell disease. It uses CRISPR gene-editing technology and leads to a higher production of foetal haemoglobin in red blood cells. Foetal haemoglobin is present in babies and carries oxygen around the body. As children grow up, their foetal haemoglobin is replaced by adult haemoglobin. By raising the levels of foetal haemoglobin in the bodies of adults, CTX001 may be able to alleviate sickle cell crises in patients with sickle cell disease and transfusion requirements for patients with β-thalassemia.