Vertex Pharmaceuticals and CRISPR Therapeutics’ gene therapy CTX001 has been granted a Priority Medicines (PRIME) designation from the European Medicines Agency (EMA).

CTX001 is an investigational CRISPR/Cas9 gene-edited therapy for the treatment of transfusion-dependent beta thalassemia (TDT). Previously, the gene therapy was also granted a PRIME designation for the treatment of sickle cell disease (SCD).

A PRIME designation provides early support to the developers of ‘promising medicines’ in a bid to optimise development plans and accelerate evaluations to improve patient access.

The most recent PRIME designation for CTX001 is based on clinical data from an ongoing Phase I/II trial of the gene therapy in patients with TDT.

Patients enrolled in this trial have their hematopoietic stem and progenitor cells collected from peripheral blood.

These cells are then edited using CRISPR/Cas9 technology to produce high levels of fetal haemoglobin (HbF) in red blood cells, after which they are infused back into the patient as part of a stem cell transplant.

The elevation of HbF has the potential to rid TDT patients of transfusion requirements and reduce painful sickle crises for SCD patients, according to Vertex and CRISPR Therapeutics.

Currently, CTX001 has been granted Regenerative Medicine Advanced Therapy (RMAT), Fast Track, Orphan Drug and Rare Paediatric Disease designations from the US Food and Drug Administration (FDA) for TDT and SCD.

The EMA has also granted CTX001 Orphan Drug Designations for both TDT and SCD.