medwireNews: Children with growth hormone deficiency (GHD) maintain their growth trajectories if they switch from a daily recombinant human growth hormone (rhGH) to weekly lonapegsomatropin, and the vast majority prefer the less frequent injections, show the results of the fliGHt trial.

After 13 weeks of the new treatment, 83.8% of the children surveyed (99 of 143 trial participants) and 90.1% of parents said they preferred lonapegsomatropin to their previous rhGH, with the top three reasons given all relating to the advantages of once-weekly versus daily injections.

This was despite almost all the children having previously used injection pens for rhGH administration, whereas they had to use a syringe and vial for lonapegsomatropin. Notably, the nine children who preferred their previous rhGH did so primarily because of less pain and injection-site reactions with the old treatment.

“This supports the relatively high importance of the frequency of treatment in determining treatment preference”, write Aimee Shu (Ascendis Pharma Inc, Palo Alto, California, USA) and study co-authors in Hormone Research in Paediatrics.

Treatment burden also decreased after switching to weekly injections, as reflected in a significant reduction of average Child Sheehan Disability Score as reported by the children, from 2.5 at week 1 to 1.4 at week 26. The researchers believe the “relatively low” baseline treatment burden reflects the treatment-experienced study population.

The 143 trial participants were aged between 2.0 and 17.4 years at enrolment and had a height standard deviation score (SDS) that was on average 1.11 short of their mid-parental height SDS. They had been taking somatropin for an average of 1.14 years (range 0.25–3.97 years) at an average dose of 0.29 mg/kg per week (range 0.13–0.49 mg/kg per week).

Shu and team say that this broad range of patients in fliGHt “was intended to complement the design and data obtained from the heiGHt trial in treatment-naïve, prepubertal children.” The positive results of heiGHt, published last year, resulted in the approval of lonapegsomatropin for children with GHD.

The fliGHt trial participants continued to experience the growth benefits of rhGH treatment after switching to lonapegsomatropin, achieving an average annualised height velocity of 8.72 cm/year at week 26 and an increase in height SDS averaging 0.25.

As anticipated, children who gained the greatest benefit were younger or with a less advanced Tanner stage, more GH-deficient and had a shorter duration of previous treatment. However, the researchers stress that children in all subgroups continued to grow.

The majority of adverse events were “typical ailments in a pediatric population” and just six events were believed to relate to the study drug, none of which were serious or led to discontinuation. Three percent of patients developed low-titre anti-GH antibodies, which “did not appear to affect safety or efficacy”, say the researchers.

The average insulin-like growth factor (IGF-1) SDS increased from 0.91 before switching to lonapegsomatropin to 1.65 after 26 weeks of treatment. “This incremental increase in IGF-1 SDS is consistent with the heiGHt trial”, note Shu and team.

By Eleanor McDermid

medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2022 Springer Healthcare Ltd, part of the Springer Nature Group

Horm Res Paediatr 2022; doi:10.1159/000524003

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