NC605

NC605 is a novel monoclonal antibody developed by NextCure that targets Siglec-15 (Sialic acid-binding Ig-like lectin 15). Its primary mechanism of action is the inhibition of Siglec-15, which plays a role in osteoclast maturation and bone resorption. In preclinical models, NC605 has demonstrated the ability to prevent bone loss by inhibiting osteoclast activity while simultaneously enhancing osteoblast recruitment and new bone formation. This dual action distinguishes it from current anti-resorptive therapies that inhibit both bone loss and formation, often resulting in increased density but poor overall bone quality. Preclinical studies have shown that treatment with NC605 leads to improved bone mineral density, enhanced trabecular and cortical tissue mineralization, reduced fracture incidence, and better mechanical properties of bones in animal models of Osteogenesis Imperfecta (OI) and immobilization-induced osteoporosis following spinal cord injury[3][4][5][6][7][8]. The drug was initially developed for potential use in rare skeletal disorders such as OI ("brittle bone disease") where there are currently no curative treatments.