Pioneering trial for treating genetic disease before birth nears reality

UCSF team are in advanced talks with the FDA about first-in-human study of in utero gene therapy

In the early 2000s, Tippi MacKenzie, then a postdoctoral fellow, and her colleagues explored the potential of gene replacement therapy to address inherited disorders in mice before birth. Their efforts repeatedly demonstrated success, achieving cures for conditions such as hemophilia and tyrosinemia. Throughout this journey, they were met with assertions that gene therapy for human fetuses was imminent—just five years away.

Now, 25 years later, this vision has yet to be fully realized. Nevertheless, following constructive discussions with the Food and Drug Administration, MacKenzie and her team are on the brink of a significant breakthrough.

They have submitted an investigational new drug (IND) application to the FDA, seeking authorization for a clinical trial aimed at treating five fetal patients affected by a rare lysosomal storage disorder. Encouragingly, the FDA has indicated that the team can forgo the customary animal testing, citing the well-established safety profile of the vector they intend to use, which has been thoroughly characterized by other researchers and companies developing gene therapies for both children and adults.