General Information

Voxzogo (vosoritide) is a C type natriuretic peptide (CNP) analog.

Voxzogo is specifically indicated to increase linear growth in pediatric patients with achondroplasia of all ages with open epiphyses.

Voxzogo is supplied as an injection for subcutaneous use.

To reduce the risk of low blood pressure and its associated signs and symptoms, instruct the caregiver and patient that the patient should 1) have adequate food intake prior to Voxzogo administration, and 2) drink approximately 240-300 mL of fluid in the hour prior to Voxzogo administration.

The recommended dosage of Voxzogo is based on the patient’s actual body weight. Voxzogo is administered by subcutaneous injection once daily. Inject Voxzogo at approximately the same time each day, if possible. The volume of Voxzogo to be administered (injection volume) is based on the patient's actual body weight and the concentration of reconstituted Voxzogo (0.8 mg/mL or 2 mg/mL.

See the drug label for the weight based dosing chart.

Mechanism of Action

Voxzogo (vosoritide) is a C type natriuretic peptide (CNP) analog. n patients with achondroplasia, endochondral bone growth is negatively regulated due to a gain of function mutation in fibroblast growth factor receptor 3 (FGFR3). Binding of vosoritide to natriuretic peptide receptor-B (NPR-B) antagonizes FGFR3 downstream signaling by inhibiting the extracellular signal-regulated kinases 1 and 2 (ERK1/2) in the mitogen-activated protein kinase (MAPK) pathway at the level of rapidly accelerating fibrosarcoma serine/threonine protein kinase (RAF-1). As a result, vosoritide, like CNP, acts as a positive regulator of endochondral bone growth as it promotes chondrocyte proliferation and differentiation.

Clinical Trial Results

This indication is approved under accelerated approval based on an improvement in annualized growth velocity. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trial(s).

The approval was based on a global randomized, double-blind, placebo-controlled Phase 3 study evaluating the efficacy and safety of Voxzogo and the open-label extension of this Phase 3 study. The study enrolled 121 children aged 5 to 14.9 with achondroplasia. Baseline mean AGV in the placebo and Voxzogo groups was 4.06 cm/year and 4.26 cm/year, respectively. At week 52, the change from baseline in AGV was -0.17 cm/year for the placebo treated patients and 1.40 cm/year for the Voxzogo treated patients, resulting in a statistically significant improvement in AGV of 1.57 cm/year in favor of Voxzogo. After the 52 week double blind, placebo–controlled, phase 3 study, 58 subjects initially randomized to Voxzogo enrolled into an open–label extension. Among the subjects who had two years of follow–up since randomization, the improvement in AGV was maintained.