Gene Editing Treatment Shows Promise for Children with Blood Disorders

The New England Journal of Medicine (NEJM) has posted details of two phase 3 clinical studies — CLIMB THAL-141 and CLIMB SCD-151 — examining exa-cel (exagamglogene autotemcel) in children living with transfusion-dependent beta-thalassaemia (a condition where the body can’t make enough healthy red blood cells, requiring regular blood transfusions to survive) and sickle cell disease (where red blood cells form an abnormal crescent shape, causing pain, organ damage and anaemia).

Both conditions are caused by faults in the genes that control haemoglobin — the protein in red blood cells that carries oxygen around the body. Children with the most severe forms can need blood transfusions every few weeks throughout their lives. Exa-cel works by editing a patient’s own stem cells using CRISPR-Cas9 gene-editing technology, then returning them to the body.

The NEJM also published an accompanying editorial titled Advancing Gene Editing for Children with Hemoglobinopathies — the medical term for inherited disorders affecting haemoglobin. The editorial addresses the broader questions around applying this technology specifically to paediatric patients.

Exa-cel, marketed as Casgevy, received approval from the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK in November 2023 — making Britain the first country in the world to authorise a CRISPR-based therapy. But access through the NHS has remained subject to ongoing assessment by the National Institute for Health and Care Excellence (NICE).

For families in Kent and Medway affected by these conditions, NHS Kent and Medway Integrated Care Board commissions specialist haematology services through regional and national NHS centres. Any questions about eligibility for new treatments should go through a GP or specialist haematologist rather than self-referral.

If you or your child has been diagnosed with sickle cell disease or beta-thalassaemia and want to understand your treatment options, speak to your GP or contact NHS 111 for guidance on next steps.