NextCure announces presentation of preclinical data on NC605

NextCure announced the presentation of new preclinical data demonstrating that treatment with NC605, a novel anti-Siglec-15 antibody, reduced bone loss and enhanced bone quality in mice with osteogenesis imperfecta, OI, at the 2023 American Society for Bone and Mineral Research, ASBMR, annual meeting. These results support development of NC605 as a potential highly effective treatment for osteogenesis imperfecta, a rare disease in which bones easily fracture. The number of new bone fractures and bone quality were assessed and compared to control animals and to female OI mice from a prior study. Key findings include: Treatment with the surrogate antibody, NP159 prevented new bone fractures in 90% of male oim compared to 85% of female oim seen earlier. All control mice had one or more new bone fractures. High resolution microCT showed decreased trabecular bone separation with NP159 treatment in both oim males and females. Cortical bone porosity, a measure of mechanical strength of bone, was normal in the treated male mice, in contrast with females who showed increased porosity. There were no changes in the overall bone mineral density for male or female mice. Bone stiffness increased in both male and female oim. Fourier Transform Infrared readouts, a measure of bone quality, in treated females showed a normalization of mineral: matrix ratio, increased acid phosphate and decreased collagen maturity. Interestingly and in contrast, the males showed no similar changes.