Most children born small for gestational age (SGA) experience catch-up growth in the first few years of life. However, at least 10% do not, and thus experience reduced longitudinal growth compared to their peers, reports Healio.
In recent clinical trials, children receiving the once-weekly injectable growth hormone therapy somapacitan had a mean height velocity increase of 6.6 cm to 7.7 cm at four-years-old, with the research team reporting that no new safety signals were observed, and few severe adverse events occurred during the trial.
Short children born SGA maintained increases in height velocity and height standard deviation scores at 208 weeks with the therapy, according to data from the REAL5 extension trial.
In the findings published in the European Journal of Endocrinology, children born small for gestational age who did not experience spontaneous catch-up growth who were receiving somapacitan-beco (Sogroya, Novo Nordisk) continued to have increases in height velocity and height standard deviation score over four years of treatment follow-up.
Additionally, the safety profile of somapacitan was consistent with what was observed in the primary 52-week study, according to Philippe Backeljauw, MD, paediatric endocrinologist in the division of diabetes and endocrinology at Cincinnati Children’s Hospital Medical Centre and University of Cincinnati College of Medicine.
Backeljauw said it was important to assess somapacitan in short children born small for gestational age, as that population tends to experience less improvement in growth with daily growth hormone (GH) therapy compared with those with GH deficiency.
“The fact that (children born small for gestational age) have to take daily GH injections may be a hurdle that they don’t want to jump over at the beginning,” Backeljauw told Healio. “It may be an impediment to starting treatment. Then, giving daily injections for multiple years to get a better treatment outcome is not as attractive to many families. Non-adherence, non-compliance and lack of treatment persistence are key with the currently approved treatments.”
The phase 2 REAL5 trial enrolled 62 children born small for gestational age who had not yet reached puberty and were not treating with GH therapy before the study (64.5% male).
Participants were randomly assigned to once-weekly 0.16 mg/kg, 0.2 mg/kg or 0.24 mg/kg somapacitan, or once-daily 0.035 mg/kg or 0.067 mg/kg GH therapy. After a 26-week main study period and 26-week extension, all participants still enrolled in the trial switched to 0.24 mg/kg somapacitan for the four-year safety extension.
Researchers measured height velocity, change in height standard deviation score, height velocity standard deviation score and bone age vs. chronological age. Insulin-like growth factor I standard deviation score was calculated from blood samples.
Height improvements
Sixty of the trial’s original 62 participants enrolled in the safety extension, with 48 children switching to 0.24 mg/kg somapacitan from their original group and 12 children continuing receiving 0.24 mg/kg somapacitan. Of the participants, 55 completed the four-year safety extension.
Participants in all five of the initial dosing groups maintained growth increases from baseline to four years. Mean height velocity at four years ranged from 6.6 cm per year among children who were originally assigned to 0.24 mg/kg somapacitan to 7.7 cm per year for those originally assigned to 0.035 mg/kg of daily GH.
Mean height standard deviation scores continued to increase through the end of the extension trial. Increases in IGF-I standard deviation score were maintained up to four years in all groups.
Safety data
The safety profile with somapacitan was similar to daily GH therapy. After the daily GH groups switched to somapacitan, adverse event reporting rates were 277.3 per 100 patient-years of exposure for those originally receiving somapacitan 0.16 mg/kg per week, 241.6 per 100 patient-years of exposure for children originally receiving 0.2 mg/kg per week of somapacitan, 139.3 per 100 patient-years of exposure for participants originally receiving 0.035 mg/kg per day of GH, and 130.5 per 100 patient-years of exposure for children originally receiving GH 0.067 mg/kg per day.
Three serious adverse events occurred before the study groups switched to somapacitan 0.24 mg/kg. After switching, one serious adverse event occurred. One event also occurred in the somapacitan 0.24 mg/kg per week group.
The most frequently reported adverse events were events common in the paediatric population and occurred at a similar rate between the somapacitan and GH groups, according to the paper. Rates of possible and probable treatment-related adverse events were low for all groups prior to switching to somapacitan 0.24 mg/kg per week, and remained low after switching.
“There weren’t really any surprises from this perspective,” Backeljauw said of the safety findings. “We have now several years of experience with long-acting GH products, including somapacitan, and it seems to be tolerated in a similar way to daily GH, which in our community is considered pretty benign treatment from a long-term safety perspective.”
Patient preference
In a patient questionnaire completed by 23 children who switched from daily GH to somapacitan, 87% said they preferred the once-weekly drug. The most common reasons for preferring somapacitan included fewer injections, feeling less worried or annoyed about receiving injections, feeling less worried about remembering to take therapy and less injection-related pain.
Of the 20 children who preferred somapacitan, 80% said they thought they would be more adherent to a once-weekly drug than a once-daily drug.
Backeljauw said parents of short children born small for gestational age sometimes struggle with the decision of whether to commit their child to long-term daily GH therapy. He said having a potential once-weekly option could help encourage these families to pursue treatment.
“This is what we’ve seen in all the other trials with long-acting GH preparations,” Backeljauw said. “You can imagine if there are fewer injections annually, that you expect adherence to be better. You expect the treatment burden to be better. You expect that the apprehension there is to start treatment will be lowered.
But such assumptions still need to be determined with long-term follow-up and real-world data.”
Backeljauw added that there was a need for studies examining how somapacitan affects adult height for people born small for gestational age.
Study details
Somapacitan in children born small for gestational age: 4-year results from phase 2
Anders Juul, Michael Højby, Philippe Backeljauw et al.
Published in EJE on 30 January 2026
Abstract
Objective
Evaluate long-term efficacy, safety, and tolerability of once-weekly somapacitan, a long-acting growth hormone (GH) derivative, in children born small for gestational age (SGA) with short stature, including after switching from daily GH.
Design
REAL5 (NCT03878446) is a global, randomised, open-label, controlled phase 2 study comprising a 26-week main phase, 26-week extension I, and an ongoing 4-year extension II.
Methods
Sixty-two children born SGA with short stature were recruited at 38 clinics across 12 countries and randomised (1:1:1:1:1) to somapacitan (0.16, 0.20, or 0.24 mg/kg/week) or daily GH (0.035 or 0.067 mg/kg/day) until week 52 (inclusive main phase and extension I). Sixty participants entered extension II. Forty-eight participants switched to somapacitan 0.24 mg/kg/week from cohorts randomized to daily GH or lower somapacitan doses. Fifty-five children completed 208 weeks of treatment. Novel safety and efficacy results from week 52 to 208 are presented here.
Results
Across all treatment arms, continuous increases in height standard deviation scores were observed from week 52 to week 208, including after switch to somapacitan 0.24 mg/kg/week. The safety and tolerability profile for somapacitan 0.24 mg/kg/week was similar to the well-established safety and tolerability profile for daily GH in SGA. Patient preference questionnaire results indicate that most respondents (87%) prefer somapacitan over daily GH. Most respondents (80%) answered that they expect to be more adherent to treatment with somapacitan.
Conclusions
These results support long-term continuous efficacy, safety, and tolerability of GH therapy with somapacitan 0.24 mg/kg/week for up to 4 years in children born SGA, including after switching from daily GH.
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