The FDA approved Casgevy and Lyfgenia in 2023 as the first two gene therapies for patients with severe forms of sickle cell disease.
High costs, a complex treatment process, provider availability and access to specialized treatment centers have slowed use.
By the end of 2025, uptake remained limited, with 64 patients worldwide receiving Casgevy infusions and 115 U.S. patients treated with Lyfgenia since its approval.