TOPLINE

A phase 3 trial found that once-weekly somapacitan was noninferior to daily growth hormone (GH) in improving height velocity after 52 weeks among treatment-naive girls with Turner syndrome, with a comparable safety profile.

METHODOLOGY

• Daily GH can promote growth in girls with Turner syndrome but imposes a high treatment burden; long-acting GH such as once-weekly somapacitan may reduce this burden, although direct comparisons are lacking.
• Researchers conducted a phase 3 trial to compare the efficacy and safety of once-weekly somapacitan vs daily GH therapy in promoting linear growth among 105 treatment-naive girls with Turner syndrome.
• The participants were randomly assigned to receive either 0.24 mg/kg once-weekly subcutaneous somapacitan (n = 68; mean age, 6.17 years) or 0.050 mg/kg daily subcutaneous GH (Norditropin; n = 37; mean age, 6.18 years), with doses adjusted according to body weight at each visit during the 52-week study period.
• The primary endpoint was the between-group difference in height velocity (cm/y) at week 52, with a noninferiority margin set at -1.6 cm/y.
• Secondary outcomes included changes from baseline to week 52 in the height SD score, height velocity SD score, insulin-like growth factor 1 (IGF-1) SD score, and bone age; safety was evaluated based on adverse events.

TAKEAWAY

• At week 52, the estimated mean annualized height velocity was 8.9 cm/y in the somapacitan group vs 9.7 cm/y in the daily GH group, with an estimated treatment difference of -0.8 (95% CI, -1.57 to -0.11), confirming noninferiority.
• The height SD score, IGF-1 SD score, and ratio of bone age to chronological age increased comparably from baseline to week 52 in the somapacitan and daily GH group.
• The mean BMI SD score increased in the somapacitan group from +0.17 at baseline to +0.65 at week 52 and decreased slightly in the daily GH group from +0.15 to -0.06; however, no significant difference was found between the groups.
• Safety profiles were similar between the two groups; most adverse events were mild or moderate, except for one case of severe chronic otitis media in the somapacitan group, and no patients discontinued treatment due to adverse events.

IN PRACTICE

“With demonstrated noninferiority, somapacitan presents an attractive choice for families who wish to lessen the therapeutic burden especially in [Turner syndrome] which is a population who often have multiple interactions with the healthcare system,” the study authors wrote.

SOURCE

This study was led by Nelly Mauras, MD, Nemours Children’s Health, Jacksonville, Florida. It was published online in The Journal of Clinical Endocrinology & Metabolism.

LIMITATIONS

The main limitation was the 52-week duration, which limited assessment of longer-term growth, near-adult height, and safety outcomes.

DISCLOSURES

This study received financial support from Novo Nordisk A/S. Two authors declared being employees and shareholders of Novo Nordisk. Several other authors reported receiving speaker fees, consulting fees, research grants, or honoraria or serving as investigators or consultants and having other ties with pharmaceutical companies, including the funding agency.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.