FDA approves Vertex-CRISPR gene-edited therapy for sickle cell

Vertex Pharmaceuticals and CRISPR Therapeutics announced on Friday that the U.S. FDA has approved their CRISPR/Cas9 genome-edited cell therapy, marking the first gene-edited cell therapy to treat patients with sickle cell disease (SCD). 

Exa-cel, branded Casgevy, is a first-in-class treatment that offers the potential of a one-time transformative therapy for SCD patients 12 years and older with recurrent vaso-occlusive crises (VOCs).

According to Vertex, the approval means that for the first time, approximately 16,000 patients with SCD may be eligible for a durable one-time therapy that offers the potential of a functional cure for their disease by eliminating severe VOCs and hospitalizations caused by severe VOCs.

Back in mid-November, the U.K.’s Medicines and Healthcare products Regulatory Agency (MHRA) became the first in the world to grant regulatory authorization of a CRISPR-based gene-editing therapy when it signed off on Casgevy for patients with SCD and transfusion-dependent beta thalassemia, a rare blood disorder that leads to chronic anemia. According to Vertex, there are an estimated 2,000 patients eligible for Casgevy in the U.K.

The FDA's Cellular, Tissue and Gene Therapies Advisory Committee held a non-voting meeting to discuss the treatment in early November, where members focused on the data concerning off-target risks, and eventually expressed reservations about Vertex's capacity to evaluate risk across a wide population. However, when it came to efficacy, there were fewer concerns.

The drug is the first therapeutic product arising from a 2015 collaboration between CRISPR Therapeutics and Vertex. It is currently still under review by the European Medicines Agency and the Saudi Food and Drug Authority and has an FDA PDUFA target action date of March 30, 2024 for approval in transfusion-dependent beta thalassemia.