The Mucolipidosis Type IV (ML4) Foundation announced that the FDA cleared an Investigational New Drug application for an experimental gene therapy program targeting mucolipidosis type IV, the first U.S. clinical trial for ML4. The therapy is designed for an ultra-rare inherited neurological disease with fewer than 100 known children worldwide. The IND clearance provides a regulatory gate for moving into U.S. clinical evaluation, setting up early study initiation plans and trial conduct under FDA oversight. For rare-disease stakeholders, the milestone is a concrete step from preclinical or existing development toward clinical translation. As the first U.S. trial, the decision may also influence future gene-therapy submissions in other ultra-rare lysosomal storage disorders, where enrollment and natural-history evidence often shape trial feasibility.