Ascendis Pharma Reports Positive Phase 2 Results For Weekly TransCon hGH In Turner Syndrome

Ascendis Pharma A/S announced positive Week 52 topline results from its Phase 2 New InsiGHTS trial conducted in the United States. The randomized, open-label, active-controlled study evaluated the safety, tolerability, and efficacy of once-weekly TransCon hGH compared with daily somatropin in prepubertal children with Turner syndrome. TransCon hGH is already approved by the U.S. Food and Drug Administration for pediatric and adult growth hormone deficiency and for pediatric GHD in several other regions.

The New InsiGHTS study enrolled and treated 49 children between one and ten years of age diagnosed with Turner syndrome. Participants were randomized to receive either once-weekly TransCon hGH or daily somatropin, with dosing later individualized based on insulin-like growth factor-1 (IGF-1) levels to optimize therapy.

At Week 52, children treated with TransCon hGH achieved annualized height velocity (AHV) improvements comparable to those receiving daily somatropin, regardless of their starting dose. The least-squares mean AHV was 9.05 cm per year for the TransCon hGH group versus 9.04 cm per year in the daily somatropin arm, indicating similar growth outcomes between the two regimens.

“These new results demonstrated safety and efficacy comparable to daily growth hormone with up to 143 weeks of follow-up, and support the potential of TransCon hGH as a differentiated therapy for short stature in the setting of growth hormone sufficiency and is being further studied in our recently initiated Phase 3 HighLiGHts basket trial to support label expansion,” said Jan Mikkelsen, Ascendis Pharma’s President and Chief Executive Officer.

Average dosing differed between treatment groups. Patients receiving TransCon hGH had a mean dose of 0.22 mg/kg per week, while those on daily somatropin received a mean dose of 0.29 mg/kg per week. Safety and tolerability findings were also comparable. Across follow-up periods extending up to 143 weeks, adverse events were mostly mild to moderate, and no participants discontinued therapy due to side effects. No cases of slipped capital femoral epiphysis were reported, aligning with the low incidence observed in long-term somatropin safety data.

Turner syndrome is the most common congenital sex chromosome condition affecting females, occurring in approximately one in every 2,000 to 2,500 live female births. Short stature, often linked to SHOX gene haploinsufficiency, is the most prominent clinical feature. The disorder can affect multiple organ systems and is associated with serious health risks including cardiovascular complications, ovarian dysfunction, endocrine disorders, kidney and liver abnormalities, hearing loss, and neuropsychological challenges.