The European Medicines Agency’s (EMA) Committee for Medicinal Products for Human Use (CHMP) has recommended approval of Vertex Pharmaceuticals and CRISPR Therapeutics’ Casgevy (exagamglogene autotemcel) to treat transfusion-dependent beta thalassemia (TDT) and severe sickle cell disease (SCD).
SCD and beta thalassemia are genetic conditions caused by errors in the gene for haemoglobin, which is used by red blood cells to deliver oxygen around the body.
The cell-based gene therapy is the first medicine to use CRISPR/Cas9 to edit the faulty gene in patients’ bone marrow stem cells to allow the body to produce functioning haemoglobin.
If approved, Casgevy would be the only genetic therapy available to EU patients aged 12 and older with either severe SCD with recurrent vaco-occlusive crises (VOC) or TDT for whom hematopoietic stem cell transplantation is appropriate and a suitable donor is not valid.
The recommendation follows the announcement from EMA’s Committee for Advanced Therapies that the benefits of Casgevy outweighed the possible risks in patients with TDT and SCD.
The decision was based on two ongoing, single-arm trials evaluating the safety and efficacy of the gene therapy, along with a long-term follow-up study involving 97 adolescent and adult patients with TDT and SCD who were treated with the therapy.
The first trial demonstrated that 39 of 42 patients with TDT were transfusion-free for at least one year and 28 of 29 patients in the second trial were free of vaso-occlusive crises (VOC) episodes for at least 12 months.
Final results obtained from the trials will need to be submitted by Vertex and CRISPR by August 2026, confirming the efficacy and safety of Casgevy, as well as the results from a long-term follow-up study based on data from a patient registry.
Described as a “durable and potentially curative treatment option”, Casgevy could “pave the way for… the next-generation of gene-editing treatments for a range of diseases, from other rare disorders to cancers”, said Tim Hunt, chief executive officer, Alliance for Regenerative Medicine.
The gene therapy has already received authorisation from the Medicines and Healthcare products Regulatory Agency for patients living with SCD and TDT and was recently approved by the US Food and Drug Administration for SCD patients who experience recurrent VOCs, aged 12 and over.