Scientists and clinicians behind the custom CRISPR therapy for 'Baby KJ' published their interactions with the FDA, offering a de‑facto roadmap for tailored gene‑editing treatments for ultra‑rare patients. The documentation describes regulatory touchpoints, submission strategies, and safety monitoring that guided the six‑month sprint to produce a one‑off therapeutic intervention, and it outlines steps other academic centers and small biotechs can use to navigate a unique approval process. The Baby KJ team is also engaging regulators to scale the approach from a single compassionate‑use case toward a reproducible pathway that might support future bespoke therapies, while stakeholders debate how to balance individualized medicine with evidentiary and reimbursement standards.