Summary: Among 77 treatment-naive prepubertal children with Noonan syndrome, weekly somapacitan produced greater estimated annualised height velocity than daily growth hormone at 52 weeks: 10.4 versus 9.2 cm/year, a difference of 1.2 cm/year (95% CI 0.32-2.03). These first-year results do not establish final adult height.
PICO Summary
| Element | Detail |
|---|---|
| Population | 77 growth-hormone-treatment-naive prepubertal children with Noonan syndrome. Boys were aged 2.5-11 years and girls 2.5-10 years. This was the Noonan syndrome substudy within the multinational REAL8 programme. |
| Intervention | Subcutaneous somapacitan 0.24 mg/kg once weekly, allocated in a 2:1 ratio against daily growth hormone. These are the study doses, not patient-specific prescribing instructions. |
| Comparator | Subcutaneous daily growth hormone 0.050 mg/kg/day. The primary comparison covered 52 weeks; the protocol also included a 104-week extension. |
| Outcomes | Primary estimated annualised height velocity at week 52: 10.4 versus 9.2 cm/year; estimated treatment difference 1.2 cm/year (95% CI 0.32-2.03), supporting reported noninferiority and superiority (P<0.01). Height standard-deviation score increased by 1.07 versus 0.75; difference 0.32 (95% CI 0.16-0.48). The abstract reports similar overall safety and tolerability, but does not provide numerical adverse-event counts; equivalence for uncommon or delayed harms cannot be inferred. |
| Study Design | Randomised, open-label, active-comparator phase 3 substudy, 52-week main phase; REAL8 registration NCT05330325. Manufacturer employees and shareholders were among the authors. This population should not be conflated with other REAL8 growth-disorder substudies. |
Expert Commentary
I view these results as encouraging evidence for a less frequent growth-hormone regimen in children with Noonan syndrome. The first-year growth response exceeded that of the daily comparator, and the confidence interval did not cross zero. However, faster growth over one year is not the same as a demonstrated improvement in final adult height or long-term quality of life. Can I use this with my patients? The evidence can inform specialist discussions with families whose children resemble those enrolled, alongside current indication-specific authorisation and established surveillance requirements. It should not be extrapolated to every child with short stature or to other Noonan syndrome age groups without qualification. The open-label design particularly affects interpretation of convenience, burden and subjective tolerability, even though measured height is comparatively objective. Manufacturer involvement should also remain visible in the appraisal. I would avoid saying that the regimens are equally safe on the basis of a small one-year substudy and an abstract-level safety summary. Rare events and longer-term effects require substantially more observation. The practical attraction is fewer injections, but improved adherence was not established by the numerical efficacy results quoted here. Follow-up should determine sustained growth, final height, treatment burden and safety before the first-year advantage is presented as a complete clinical benefit.
References
Jorge AAL, Albanese A, Højby M, et al. Once-weekly somapacitan in children with Noonan syndrome: randomized controlled phase 3 trial. Eur J Endocrinol. 2026;194(3):393-403. doi:10.1093/ejendo/lvag041. PMID: 41774755.
