Lonapegosmatropin For Treatment of Pediatric GHD Reduces Overall US Health Plan Costs

Including lonapegsomatropin (SKYTROFA) – a once-weekly prodrug of somatropin for the treatment of pediatric growth hormone deficiency (pGHD) – in the formulary of a US health plan can bring about a substantial reduction in total costs for the plan.1

The “Growth Hormone Research Society” recommends using recombinant human growth hormone for the treatment of GHD in children and adolescents. Given its long history of efficacy and safety in both trials and clinical practice, this has been the standard treatment for patients with GHD for decades. However, the requirement of a daily injection generally results in poorer compliance, limiting the treatment outcome.2

“The objective of this study was to develop a health economic model to estimate the budget impact of introducing lonapegsomatropin to a market with existing daily and weekly growth hormone (GH) treatments from the perspective of a US payer and to identify potential cost savings associated with its use,” wrote Emily Boller, MPH, health economics and outcomes researcher at Maple Health Group, LLC, and colleagues.1

The budget impact model (BIM) used in the study was designed to compare the costs associated with 2 hypothetical scenarios for pGHD: one in which daily and weekly GHs are available as treatment options and lonapegsomatropin does not exist and another where lonapegsomatropin is introduced to the market with daily and weekly GHs. The model combines per-patient costs with expected market shares for GHs to estimate the total financial expenditure for both scenarios. Because health plans typically include up to 3 brands of growth hormones, the analysis included daily GH, somatropin, and weekly GHs (somatrogon and somapacitan) as comparators.1

Investigators included a hypothetical population of 1 million covered individuals, based on data derived from the heiGHt trial and real-world evidence. The modeled age followed a beta distribution with a mean of 11.1 years, a minimum of 3, and a maximum of 18. Mean bodyweight was 30.8 kg (68 lbs) in the first year, and the bodyweight by age was based on growth predictions for patients with GHD treated with daily GH.1

The team used a stepwise approach to identify the eligible population. The prevalence of GHD (0.029%) was applied to the number of covered individuals <18 years to determine the number of pGHD patients. Annual GHD incidence (0.002%) was used to calculate the number of new patients annually, who were added to the cohort each year.1

The total costs before lonapegsomatropin’s introduction were estimated to be $19,431,530 over 5 years, with somatropin ($7,433,864) and somatrogon ($7,894,782) incurring the highest total costs. With lonapegsomatropin, the total costs were estimated at $18,471,902, with somatropin accounting for the highest costs ($7,433,864), followed by somapacitan ($3,947,391), lonapegsomatropin ($3,671,576), and somatrogon ($3,419,070).1

Investigators also found that the introduction of lonapegosmatropin’s introduction resulted in a cumulative total budget saving of $959,629 over the 5-year time horizon, with cost savings of $40,314 in year 1 and $373,258 in year 5. Estimated average cost savings was $39,392 per patient per year. Primary drivers of this cost reduction were the decreased acquisition costs for daily somatropin and the avoidance of wastage for weekly GHs.1

Ultimately, this hypothetical study suggests a substantial cumulative total savings over 5 years after the introduction of lonapegsomatropin. Through scenario analysis, investigators tested alternative assumptions, providing insight into other situations – all of these further supported the significance of cost savings associated with lonapegomatropin.1

“Overall, results from this budget impact analysis show that the introduction of lonapegsomatropin for pGHD can lead to significant cost savings over time, reduce medication wastage due to its efficient auto-injector, and provide a competitive advantage by offering a more convenient and lower-cost weekly GH treatment option,” Boller and colleagues wrote. “As a result, the inclusion of lonapegsomatropin in the formulary of a US health plan can result in significant reduction in total costs for the plan.”1

References

1. Boller E, Raveendran S, Smith A, Noori W, Miner P, Kleintjens J. Budget impact analysis of Skytrofa for the treatment of pediatric growth hormone deficiency in a US health plan. J Med Econ. Published online September 12, 2025. doi:10.1080/13696998.2025.2561472

2. Zhu J, Yuan K, Rana S, et al. Long-acting growth hormone in the treatment of growth hormone deficiency in children: a systematic literature review and network meta-analysis. Sci Rep. 2024;14(1):8061. Published 2024 Apr 5. doi:10.1038/s41598-024-58616-4