ARU-2801

**ARU-2801** is an investigational one-time adeno-associated virus (AAV) type 8 gene therapy for hypophosphatasia (HPP), a rare genetic disorder caused by mutations in the *ALPL* gene leading to deficient tissue-nonspecific alkaline phosphatase (TNAP) activity and impaired bone mineralization. It expresses a modified TNAP enzyme (TNAP-D10) with enhanced bone affinity via a D10 peptide fused to the catalytic domain, enabling sustained systemic TNAP production after intramuscular injection to restore enzymatic activity, improve bone maturation, alveolar bone formation, survival, and disease biomarkers in preclinical HPP mouse models without ectopic calcification or major toxicities. Preclinical studies in non-human primates confirmed durable high plasma ALP levels, muscle-restricted biodistribution, and no liver toxicity or abnormal calcification; manufacturing and IND-enabling studies are underway toward clinical trials.[1][3][5][8]