How effective is vosoritide?

Voxzogo (vosoritide) is a drug used to treat patients with achondroplasia older than 4 months whose bones are still growing. Achondroplasia is a genetic disorder caused by mutations (changes) in a gene called fibroblast growth factor receptor 3 (FGFR3). The mutation affects the growth of nearly all bones in the body, including the skull, spine, arms and legs, resulting in very short stature with the characteristic appearance. Achondroplasia is very rare, and Voxzogo has been designated as an "orphan drug" (a drug for rare diseases) by the United States, the European Union and many other countries.

In a study involving121 children aged 5 to 17 years diagnosed with achondroplasia, Voxzogo was more effective than placebo (dummy treatment) in increasing growth rate after 52 weeks of treatment. Children who received Voxzogo grew about 1.57 centimeters longer during treatment than those who received a placebo. Furthermore, the results show that the improvement in growth is maintained.

In a second study,Voxzogo was more effective than placebo in increasing growth rate, which involved 75 children aged 4 months to less than 5 years old with diagnosed achondroplasia. The main measure of effectiveness is the change in height Z-score, a method that compares a patient's height to the average height for their age and sex. After one year of treatment, children taking Voxzogo had greater improvements in their average height Z-scores than those taking a placebo. Children who received Voxzogo also grew about 0.8 centimeters longer during treatment than those who received a placebo.

Voxzogo effectively increases the growth rate of children 4 months and older with achondroplasia. This may increase final height, making it easier for people with achondroplasia to perform daily activities. The side effects of this drug are considered manageable. Safety for children under 5 years old is similar to older children.