Health economics researchers report that introducing lonapegsomatropin (Skytrofa) into US health plan formularies for treating pediatric growth hormone deficiency (pGHD) could deliver meaningful cost savings over five years. The drug, which is administered once weekly, may also curb wastage and improve patient satisfaction when compared with existing daily and weekly growth hormone therapies. The findings are based on a recent budget‐impact model and related studies.
Key Findings: Cost Savings and Budget Impact
- A recent peer‐reviewed budget impact analysis estimates that for a health plan covering 1 million members, the total cost over five years without lonapegsomatropin would be about US$19,431,530. With lonapegsomatropin added to the mix, that five-year cost drops to US$18,471,902, yielding a cumulative savings of US$959,629. (Taylor & Francis Online)
- Per patient savings average about US$39,392 per year under scenarios modelled. (Taylor & Francis Online)
- The cost savings increase over time: in year 1, the saving is modest but by year 5, the potential savings grow more substantial—driven by reduced drug acquisition costs for somatropin (daily GH) and less wastage among weekly GH therapies. (Taylor & Francis Online)
How the Model Was Built
To estimate these impacts, the model undertook several steps:
- Population estimation:
- In a hypothetical 1 million covered individuals, only those under 18 were considered.
- Prevalence of pGHD was set at 0.029%, and incident cases (new diagnoses) at 0.002% annually. (Taylor & Francis Online)
- Average age of patients modelled: ~11.1 years; average body weight ~30.8 kg in first year. (Taylor & Francis Online)
- Treatment mix:
- Comparators included daily GH (somatropin) and two weekly GHs (somatrogon, somapacitan). Skytrofa (weekly lonapegsomatropin) was introduced into that mix. (Taylor & Francis Online)
- Cost inputs:
- Drug acquisition costs.
- Wastage reduction (Skytrofa auto-injector design reduces waste) was taken into account. (Taylor & Francis Online)
- Temporal horizon:
- Five years. This allows capturing increasing uptake, accumulating savings, and trends in treatment costs. (Taylor & Francis Online)
- Scenarios and sensitivity analyses:
- Alternative uptake rates, market share shifts, and assumptions about wastage etc. were tested. All supported cost savings. (Taylor & Francis Online)
Comparing with Other Analyses
One related abstract (ISPOR / Value in Health) looked at cost offset and budget impact of adding Skytrofa to formulary and estimated:
- An increase in budget of US$475,147 over five years, which corresponds to about US$0.04 per member per month. This increase is largely offset by US$2,876,449 in savings due to reduced GH usage. (ISPOR.org)
- The net result in that study is that while the health plan would spend more up front on adopting Skytrofa, much of that cost is balanced by reduced consumption of other GH therapies. (ISPOR.org)
What Drives the Savings
The budget model identifies several levers behind cost reductions:
- Lower daily GH acquisition costs: Since somatropin (daily GH) is expensive, shifting patients to a once-weekly treatment reduces the dose frequency and associated costs. (Taylor & Francis Online)
- Reduced drug wastage: Skytrofa’s auto-injector design reportedly limits or eliminates waste, a factor often overlooked in cost estimations. (Taylor & Francis Online)
- Market share shifts: As Skytrofa is adopted, some use of other weekly GHs (somatrogon, somapacitan) decreases, resulting in savings due to efficiency gains. (Taylor & Francis Online)
Caveats and Uncertainties
To provide full context, the model and related studies have limitations:
- Hypothetical modelling: These are projections based on assumptions. Real-world uptake, patient adherence, reimbursement and payer policies may differ.
- Sensitivity to pricing and use patterns: If Skytrofa is priced significantly higher, or if uptake is slower, savings could shrink.
- Exclusion of some costs: The model may not fully account for monitoring, administration overheads, or long-term outcomes beyond the 5-year horizon.
Implications for Payers & Clinicians: What You Can Do Now
For health plans, policymakers and providers interested in adopting or optimizing use of Skytrofa:
- Review current formulary options: Compare acquisition costs of daily vs weekly GH therapies. Model expected savings using your own population data (age, weight, incidence) to assess whether Skytrofa would yield similar savings.
- Monitor real-world adherence and wastage: Track how much GH product is being wasted under current therapy; get data on adherence / missed doses. These metrics can significantly affect realized savings.
- Negotiate pricing & rebates: Leverage volume, outcomes, and usage patterns to negotiate favorable terms for Skytrofa versus competing GH products.
- Educate clinicians and patients: Once weekly injections are often more acceptable, especially among pediatric populations. Improving adherence can multiply benefits.
- Plan for budget phasing: Even if long-term savings are evident, short term costs may rise. Budget holders should prepare for upfront investment, then monitor offsets over time.
Bottom Line
Introducing once-weekly lonapegsomatropin (Skytrofa) into the treatment mix for pediatric growth hormone deficiency can offer US health plans tangible savings over a five-year horizon. The main gains come from reducing the expensive daily GH burden and cutting down wastage. While real-world factors will shape the scale of savings, the economic modelling supports formulary inclusion of Skytrofa as a sensible pathway toward cost-efficient and patient-friendly GH therapy.
