The Innovation-Affordability Trade-off of Exagamglogene Autotemcel (Casgevy) for Severe Sickle Cell Disease in NHS England

Severe sickle cell disease is often accompanied by pain and multiorgan damage, thus placing a heavy burden on the patients, their families and the National Health Service (NHS). Exagamglogene autotemcel (exa-cel; Casgevy) offers a new option: a single, autologous CRISPR-Cas9-edited cell therapy that aims to reactivate fetal haemoglobin and prevent severe vaso-occlusive crises. However, the £1.651 million list price, resource-intensive treatment path and uncertain lifetime benefit are problems for a tax-funded healthcare system. This paper conducts a focused narrative review and a case study of the NICE technology appraisal TA1044 to explore why exa-cel was recommended via managed access rather than for routine NHS use. Evidence from the CLIMB SCD-121 trial shows a promising short-term clinical response, but its single-arm design, limited follow-up, and the risks of myeloablative conditioning remain important sources of uncertainty. NICE's decision does not rule out innovation; rather, it is concerned that the modelled cost-effectiveness relies too heavily on assumptions about durability, mortality, quality of life and future healthcare consumption. Therefore, managed access is a reasonable temporary compromise to provide access for eligible patients while further evidence is gathered.