More than two years after FDA approval, Vertex’s CRISPR‑based sickle‑cell therapy Casgevy has treated only about 60 patients globally, with centers reporting difficulty collecting sufficient cells to manufacture individualized doses. The shortfall in cell collection is impeding broader rollout and highlights operational bottlenecks in autologous gene‑editing therapies. Clinicians and industry watchers say the constraint affects not only Casgevy but also industry plans for personalized cell and gene therapies that require robust donor collection and manufacturing throughput. Vertex is working with treatment centers to resolve collection and logistics challenges while balancing competition from other emerging curative approaches.