RIBOMIC, Inc. announced positive interim results from its Phase IIa clinical trial of umedaptanib pegol for pediatric patients (5-14 years old) with achondroplasia (ACH). The low-dose (0.3 mg/kg) subcutaneous injection group, administered once a week, demonstrated a positive impact on patient growth rate.
Height Growth Improvement
In the first cohort, comprising six subjects, five completed the study, excluding one withdrawal due to medication interruption. Among these five, two subjects exhibited a notable increase in height growth rate, with improvements of +4.6 cm and +3.3 cm/year compared to their pre-treatment growth rates observed during an observational study. These findings suggest a significant therapeutic effect, especially when compared to the average height growth rate of +1.7 cm/year reported for Voxzogo (vosoritide), a currently approved treatment for ACH. However, three patients did not respond to the low dose of the drug.
Continued Evaluation and High-Dose Study
Five of the initial subjects have transitioned to a long-term, low-dose administration study to further evaluate the drug's efficacy and safety. Concurrently, enrollment has been completed for a high-dose (0.6 mg/kg) subcutaneous administration study (cohort 2), involving seven patients, with four already receiving treatment. The results from the high-dose cohort are anticipated in September 2025.
Safety Profile
No safety concerns have been reported throughout the ongoing Phase IIa clinical trials.
Potential New Treatment Option
The observed increase in growth rate in a subset of patients receiving low-dose, once-weekly subcutaneous administration of umedaptanib pegol offers a promising new treatment avenue for pediatric patients with achondroplasia. RIBOMIC is exploring the possibility of increasing the dose and extending the dosing interval to optimize the treatment regimen.
About Umedaptanib Pegol
Umedaptanib pegol, previously known as RBM-007, is an aptamer with anti-FGF2 (fibroblast growth factor 2) activity. It is designed to target the underlying cause of achondroplasia.
About Achondroplasia
Achondroplasia results from a genetic mutation in the fibroblast growth factor receptor 3 (FGFR3), leading to excessive activation of FGFR3. This inhibits normal cartilage growth, resulting in short stature and limb shortening. It affects approximately 1 in 25,000 newborns and is considered a rare disease with a high unmet medical need.
