A lack of specificity in the US Food and Drug Administration’s genome editing draft guidance allowed Vertex Pharmaceuticals Incorporated to set what an advisory committee deemed a sufficiently high bar in its analyses for potential off-target effects with the sickle cell disease gene therapy exagamglogene autotemcel (exa-cel).
Although the FDA’s guidance describes the types of nonclinical studies that are appropriate for analyzing potential off-target edits, it does...