New Dwarfism Drug Approved

The newly approved drug is Yuviwel (navepegritide), developed by Ascendis Pharma. It's a once-weekly injection for children aged two and older with achondroplasia, the most common form of dwarfism, whose growth plates are still open. This offers a new treatment schedule compared to existing options. Yuviwel works by providing a continuous exposure to a C-type natriuretic peptide (CNP) analog. In achondroplasia, a genetic mutation makes the FGFR3 gene overactive, which hinders normal bone growth. Yuviwel helps to counteract this by stimulating a pathway that promotes bone growth. This approval marks the end of a market monopoly for the first approved targeted therapy for achondroplasia, Voxzogo (vosoritide) by BioMarin Pharmaceutical. Voxzogo, which also targets the CNP pathway, was approved in 2021 but requires a daily injection. Prior to these targeted therapies, treatment for achondroplasia primarily focused on managing symptoms and complications. This often involved surgeries to address issues like spinal stenosis or limb lengthening, as well as growth hormone therapy, which had limited effectiveness for achondroplasia. The approval of Yuviwel was granted under the FDA's accelerated approval pathway, based on its ability to increase annualized growth velocity in clinical trials. In one key study, children receiving Yuviwel grew an average of 1.49 cm/year more than those on a placebo. The treatment landscape for achondroplasia continues to evolve. In addition to these two approved injectable drugs, an oral medication is also in late-stage development. BridgeBio's infigratinib, an FGFR3 inhibitor, has shown positive results in its Phase 3 trial.