The FDA has not approved a clinical trial request for CTX001, an experimental drug that uses CRISPR technology. This drug is ex-vivo gene therapy which would be used as first-line treatment in the management of sickle cell anaemia. It is being developed jointly by CRISPR Therapeutics and Vertex Pharmaceuticals. The first laboratory results have proved "promising".
In 2016, China became the first country to carry out a clinical trial in humans using CRISPR-based treatment. For CTX001, the next step is to conduct an early trial in adult volunteers but the FDA has "refused to approve the study" arguing "that a certain number of questions remain unanswered". Brian Skorney, a biotechnologist in Wisconsin explains: "There's so much promise with this technology, but it's such early days. It's a permanent alteration of a patient's genetic code so I think the FDA is going to be cautious".
Sickle cell anaemia is a genetic blood disorder in which the red blood cells are deformed. This has a harmful effect on carrying oxygen through the body and can cause numerous health problems, chronic pain, blindness and stroke, etc. CTX001 can modify the stem cells harvested from a patient to stimulate foetal haemoglobin. This will have a significant effect on subjects with sickle cell anaemia by reducing the symptoms of the disease.
 FDA, US Food and Drug Administration
 Ex-vivo therapy: therapy via which target cells are harvested from the body, treated in a laboratory and then returned to the body.
Bionews, Christie Whitehouse (11/06/2018)