CNP Analogs Vosoritide and Navepegritide Safely Boost Linear Growth in Children with Achondroplasia

Achondroplasia is the most common form of skeletal dysplasia, caused by a gain-of-function mutation in the FGFR3 gene. This mutation leads to overactive FGFR3 signaling, which prematurely inhibits chondrocyte proliferation and differentiation in growth plates, resulting in disproportionate short stature. Current standard-of-care primarily involves orthopedic surgeries to address complications, but these do not target the underlying genetic mechanism. C-type natriuretic peptide (CNP) analogs, like vosoritide and navepegritide, are designed to counteract FGFR3 overactivity by activating the NPR-B receptor, promoting chondrocyte growth and offering a targeted therapeutic approach.

This systematic review and meta-analysis evaluated the safety and efficacy of CNP analogs in children (<18 years) with genetically confirmed achondroplasia. Researchers included 11 studies (N = 542), comprising 4 randomized controlled trials (RCTs) (n = 326) and real-world studies. Coprimary outcomes were adverse events (AEs) and changes from baseline in annualized growth velocity (AGV) at trial end. Secondary outcomes included changes in height Z-score, standing height, and upper-to-lower body segment (ULS) ratio. The meta-analysis focused on RCT data, assessing overall risk of bias.

C-type natriuretic peptide analogs demonstrated statistically significant improvements in linear growth. The mean difference in AGV was increased by 1.36 cm/year (95% CI: 1.05-1.68; P < .00001). Similarly, standing height showed a mean increase of 1.24 cm (95% CI: 0.47-2.01; P = .002). No short-term effect was observed on the ULS ratio. Safety analysis revealed that overall and serious AE rates were comparable between CNP analogs and placebo, indicating an acceptable short-term safety profile. However, specific adverse events were more frequent with CNP analogs: injection site reactions (relative risk 1.65), urticaria (relative risk 4.04), and swelling (relative risk 3.57). Real-world data further supported sustained growth benefits with infrequent serious AEs or treatment discontinuations.

CNP analogs significantly increased mean differences in annualized growth velocity by 1.36 cm/year (P < .00001) and standing height by 1.24 cm (P = .002), offering a meaningful therapeutic option.