The approval of Casgevy by regulators in the United Kingdom and United States in late 2023 marked a transition that many scientists had spent two decades working toward: gene editing moving from research tool to approved medical treatment.
The therapy works by reactivating foetal haemoglobin in patients with sickle cell disease or beta-thalassaemia — effectively giving the body a second haemoglobin system that the disease cannot disrupt. Early results show more than 90 percent of patients free of severe pain crises after treatment.
The limitations are significant. The procedure is technically demanding, requires specialised centres, and costs approximately $2 million per patient. The infrastructure question will determine whether the technology fulfils its promise or remains available only to the wealthiest patients in the wealthiest countries.
