FDA approves first once-weekly injection for pediatric GH deficiency
The FDA approved the first once-weekly formulation of somatropin for children with growth hormone deficiency, according to an industry press release.
Lonapegsomatropin-tcgd injection (Skytrofa, Ascendis) is approved for children who weigh at least 11.5 kg and have growth failure due to inadequate secretion of endogenous growth hormone.
Growth hormone deficiency, characterized by the inadequate secretion of GH from the anterior pituitary gland, is a rare disorder among U.S. children, with an estimated prevalence of 1 in 3,500.
“Today’s approval represents an important new choice for children with GH deficiency and their families, who will now have a once-weekly treatment option,” Paul Thornton, MB BCh, MRCPI, a clinical investigator and pediatric endocrinologist in Fort Worth, Texas, said in the release. “In the pivotal head-to-head clinical trial, once-weekly Skytrofa demonstrated higher annualized height velocity at week 52 compared to somatropin. This once-weekly treatment could reduce treatment burden and potentially replace the daily somatropin therapies, which have been the standard of care for over 30 years.”
The approval includes an auto-injector and cartridges which, after first removed from a refrigerator, allow families to store the medicine at room temperature for up to 6 months, according to the release.
“Skytrofa is the first product using our innovative TransCon technology platform that we have developed from design phase through nonclinical and clinical development, manufacturing and device optimization, and out to the patients,” Jan Mikkelsen, president and CEO of Ascendis Pharma, said in the release. “It reflects our commitment and dedication to addressing unmet medical needs by developing a pipeline of highly differentiated proprietary products across multiple therapeutic areas. We are grateful to the patients, caregivers, clinicians, clinical investigators, and our employees, who have all contributed to bringing this new treatment option to children in the U.S. with GH deficiency.”
The FDA approval of Skytrofa was based on results from the phase 3 heiGHt Trial, a 52-week, global, randomized, open-label, active-controlled, parallel-group trial that compared once-weekly Skytrofa with daily somatropin (Genotropin) in 161 treatment-naive children with GH deficiency. The primary endpoint was annualized height velocity at 52 weeks for weekly Skytrofa and daily human GH treatment groups. Other endpoints included adverse events, injection-site reactions, incidence of anti-human GH antibodies, annualized height velocity, change in height SDS, and the proportion of participants with insulin-like growth factor-I SDS.
At week 52, the treatment difference in annualized height velocity was 0.9 cm/year (11.2 cm/year for Skytrofa compared with 10.3 cm/year for daily somatropin). The primary objective of non-inferiority in annualized height velocity was met for Skytrofa and further demonstrated a higher annualized height velocity at week 52 for lonapegsomatropin compared with daily somatropin, with similar safety.
There were no serious adverse events or discontinuations related to Skytrofa reported. The most common adverse reactions in children were infection, cough, nausea and vomiting, hemorrhage, diarrhea, abdominal pain, and arthralgia and arthritis. For both arms of the study, researchers observed low incidences of transient, non-neutralizing anti-human GH binding antibodies and no cases of persistent antibodies.
In an agency press release, the FDA noted that Skytrofa may interact with glucocorticoid treatment, oral estrogen, insulin, and other antihyperglycemic agents.