US clears Ascendis' once-weekly paediatric growth hormone injection

Ascendis Pharma said Wednesday that the FDA has approved Skytrofa (lonapegsomatropin-tcgd) as a once-weekly treatment for paediatric patients aged one year and older who have growth failure due to inadequate secretion of endogenous growth hormone. The company noted that Skytrofa, a long-acting prodrug of somatropin, is the first FDA-approved product that delivers somatropin by sustained release over one week.

The filing was based on results from the Phase III heiGHt trial comparing once-weekly Skytrofa to daily injections with Pfizer's Genotropin (somatropin) in 161 treatment-naïve children with growth hormone deficiency. Skytrofa met the primary endpoint of annualised height velocity (AHV), demonstrating an AHV of 11.2 cm/year at 52 weeks, compared to 10.3 cm/year for daily Genotropin.

Moreover, no serious adverse events or discontinuations related to Skytrofa were reported in the study, with the most common side effects being viral infections, pyrexia, cough, nausea and vomiting. Ascendis noted that both arms of the study reported low incidences of transient, non-neutralising anti-hGH binding antibodies and no cases of persistent antibodies.

Cuts number of injections days by 86%

The FDA approval, which boosted Ascendis shares about 27% after-hours, also includes the new Skytrofa auto-injector and cartridges that allow the medicine to be stored at room temperature for up to six months. "With a weekly injection, patients switching from injections every day can experience up to 86% fewer injection days per year," the company said. It added that the treatment would be made available "shortly" in the US.

"Skytrofa is the first product using our innovative TransCon technology platform that we have developed from design phase through non-clinical and clinical development, manufacturing and device optimisation, and out to the patients," remarked CEO Jan Mikkelsen. The platform is meant to help "optimise" the therapeutic effect of new treatments, including efficacy, safety and dosing frequency. The company says its TransCon technology can be "applied broadly to a protein, peptide or small molecule in multiple therapeutic areas, and can be used systemically or locally."