New Drug Combats Leading Cause of Dwarfism

FRIDAY, June 21, 2019 (HealthDay News) -- An experimental drug increased growth rates in children with dwarfism, according to a new study.

The four-year phase 2 trial was conducted at centers in the United States, France, United Kingdom and Australia, and included 35 children, ages 5-14, with the genetic bone disorder achondroplasia, the most common type of dwarfism.

The children were divided into four groups that received daily injections of the drug vosoritide, which helps regulate bone development, in increasing amounts.

The average increase in height among the children was about 2.4 inches a year, which is close to growth rates among children of average stature, according to the study published June 18 in the New England Journal of Medicine.

On average, the children's growth rate increased by 50%, said the authors of the study, which was designed and funded by drug maker BioMarin Pharmaceutical, which also analyzed the data.

The side effects of the drug were mostly mild, according to the researchers.

Vosoritide is now being tested in a phase 3 trial in a larger group of patients ages 5-18.

Achondroplasia is caused by overactivity of a signal that stops growth, which can be compared to overwatering a plant, explained study lead author Ravi Savarirayan, a clinical geneticist at Murdoch Children's Research Institute in Melbourne, Australia.

"This drug basically kinks the hose so that the plant gets the right amount of water and can resume regular growth," Savarirayan said in an institute news release.

Achondroplasia, which affects about 1 in every 25,000 infants, is caused by a mutation in the FGFR3 gene that impairs the growth of bones in the limbs, the spine and base of the skull.

Common complications among children with achondroplasia include spinal cord compression, spinal curvature and bowed legs. About half require spinal or other surgery.

"This study is the very first report of a possible disruptive, precision therapy for children with achondroplasia, which we hope will improve their health outcomes and functioning, as well as increase their height and access to their environment," Savarirayan said.

More information

The U.S. National Library of Medicine has more on achondroplasia.