[Gln6,14]CNP-38

**[Gln6,14]CNP-38** is a synthetic 38-amino acid peptide analog of C-type natriuretic peptide (CNP), engineered by substituting glutamine (Gln) for asparagine at positions 6 and 14 to enhance resistance to deamidation and improve chemical stability. It maintains potent and selective agonism at natriuretic peptide receptor B (NPR-B), exhibiting similar efficacy and potency to vosoritide and native CNP-38 in cellular and animal models. The analog is designed for use in long-acting formulations for the treatment of achondroplasia and potentially other growth disorders, with demonstrated promotion of longitudinal bone growth in preclinical models. Long-acting delivery is achieved via covalent attachment to hydrogel microspheres using β-eliminative releasable linkers, enabling controlled, sustained subcutaneous release designed for weekly or monthly administration.