Clervonafusp alfa (VAL-1221) is a fusion protein targeting both cytosolic and lysosomal glycogen, addressing the mechanisms of Pompe disease. It combines the Fab segment of a cell-penetrating antibody with recombinant human acid alpha-glucosidase (rhGAA). The Fab portion utilizes the nucleoside transporter ENT-2 for cytosolic entry, while rhGAA accesses lysosomes via mannose-6-phosphate receptors (M6PRs). This dual-targeting approach suggests Clervonafusp alfa as a potential therapeutic research candidate for late-onset Pompe disease [1].