Budget impact analysis of the novel PD-1 inhibitor toripalimab versus pembrolizumab in recurrent or metastatic nasopharyngeal carcinoma.

Aim: To estimate the budget impact of adding a toripalimab regimen as a treatment option to the existing pembrolizumab regimen, both including gemcitabine and cisplatin, in untreated recurrent/metastatic nasopharyngeal carcinoma (R/M NPC) using the published wholesale acquisition cost (WAC) and average sales price (ASP).

Methods: Budget impact analysis comparing a treatment mix "without" versus "with" the toripalimab regimen in the US eligible annual incident R/M NPC population, a 3-year time horizon, toripalimab/pembrolizumab market splits of 60/40 (Y1) and 80/20 (Y2/3), and medication adjustments for discontinuation or progression. Cost inputs included drugs, administration, and adverse event (AE) management. The models were replicated for a hypothetical 1-million-member health plan in which costs per-member-per-month (PMPM) and per-member-per-year (PMPY) were estimated. One-way (OWSA) and probabilistic sensitivity analyses (PSA) as well as scenario analyses were performed.

Results: In the "without" scenario, the 3-year WAC-based costs for the pembrolizumab regimen total $1,449,695,333 ($1,305,632,448 for treatment and $144,062,885 for managing AEs). In the "with" scenario, total 3-year costs for pembrolizumab decline to $380,012,135 with toripalimab adding $885,505,900 ($779,206,567 for treatment and $106,299,333 for AE management). Annual net savings range from $46,526,152 in 2024 to $71,194,214 in 2026, for 3-year savings of $184,177,298. Associated net savings in a 1-million-member health plan are $543,068 over 3 years with savings of $0.045 PMPM and $0.543 PMPY. The ASP-based model shows similar patterns with 3-year net savings of $174,235,983 in the US incident population and savings of $0.043 PMPM and $0.514 PMPY in a 1-million-member health plan. The PSA support base case findings; OWSA and scenario analyses reveal how parameter variability impacts results.

Conclusion: Savings between $174 million and $184 million can be achieved from treating 60% of R/M NPC patients in year 1 and 80% in years 2 and 3 with the toripalimab regimen over a similar pembrolizumab regimen.