A University of Pennsylvania and Children’s Hospital of Philadelphia report that an mRNA-based CRISPR base editing therapy delivered to infant “Baby KJ” with CPS1 deficiency produced meaningful clinical benefits, including the ability to eat a normal protein-filled diet. The case was previously described as a historic milestone for in vivo delivery, but Penn professor Kiran Musunuru emphasized the intervention was not a clinical trial. Musunuru told audiences that the effort was an expanded access IND for a single patient and “unambiguously not a cure,” while still serving as a demonstration of what’s possible as companies like Verve and YolTech pursue base editing therapies. The statement frames the next regulatory and clinical expectations for genome editing programs—where regulators and sponsors will need to translate single-patient outcomes into scalable trial evidence.