Vosoritide

Achondroplasia is a congenital disease resulting from a missense mutation in the fibroblast growth factor receptor 3 (FGFR3) gene, resulting in a gain-of-function that negatively regulates endochondral bone growth. Under normal conditions, FGFR3 is expressed during both embryonic and postnatal development, but serves a different role in each. During initial development, FGFR3 signaling promotes proliferation of chondrocytes (i.e. growth), whereas postnatal skeletal growth is actually inhibited by FGFR3 - as a result, the pathologic activation of FGFR3 observed in patients with achondroplasia leads to suppressed pre-pubertal skeletal growth.

Vosoritide is an analog of C-type natriuretic peptide (CNP), a signaling molecule that appears primarily responsible for the stimulation of chondrocytes and the growth of long bones. The binding of CNP (or vosoritide) with its corresponding receptor, NPR-B, results in a signaling cascade that ultimately inhibits the MAPK/ERK pathway via inhibition of RAF-1 and stimulates the proliferation and differentiation of chondrocytes. This activity serves to antagonize the downstream signaling resulting from FGFR3 and its resultant effects on bone growth.