Budget impact analysis of pembrolizumab versus the novel PD-1 inhibitor toripalimab in locally advanced or metastatic nonsquamous non-small cell lung cancer

To estimate the budget impact of adding a toripalimab regimen to the existing treatment mix of pembrolizumab, both with pemetrexed and carboplatin, in patients with locally advanced or metastatic nonsquamous NSCLC within two price inputs (wholesale acquisition cost (WAC) and average sales price (ASP)). Budget impact analysis comparing a treatment mix “without” versus “with” the toripalimab regimen in the annual US nonsquamous NSCLC population treated with a PD-1 inhibitor, a 3-year time horizon, toripalimab market share of 1% in 2024, increasing to 4% (2025) and 5% (2026), and medication use adjustments for discontinuation or progression to estimate fully-treated-patient-equivalents. Cost inputs included drugs, administration, and grade 3/4 adverse event (AE) management. The models were replicated in a 1-million-member plan to estimate costs per-member-per-month (PMPM) and per-member-per-year (PMPY). One-way (OWSA) and probabilistic sensitivity analyses (PSA) as well as two scenario analyses were performed. In the “without” scenario, the 3-year WAC costs for the pembrolizumab regimen total $40,750,234,637 ($39,024,548,745 for treatment and $1,725,685,894 for managing AEs). In the “with” scenario, these costs decline to $39,341,379,081. Corresponding “with” costs for toripalimab are $1,186,027,704 (treatment) and $99,454,471 (AE management) for a total of $1,285,482,175. This yields annual net savings of between $10,779,362 (at 1% market share) in 2024 and $64,858,298 (5% market share) in 2026, for 3-year savings of $123,373,381. The associated savings in a 1-million-member plan are $0.030 PMPM and $0.363 PMPY. The ASP model shows similar patterns. Savings were demonstrated in 68% of PSA simulations; OWSAs and scenario analyses reveal how parameter variability impacts results. Significant savings are likely achievable from treating between 1% (year 1) to 5% (year 3) of nonsquamous NSCLC patients with the toripalimab regimen. Projected 3-year savings range from $122 million (ASP) to $123 million (WAC); corresponding to savings of $0.030 PMPM and $0.363 PMPY. Toripalimab is a biological agent of the PD-1 inhibitor class approved in the US for the treatment of nasopharyngeal carcinoma and approved in China, in combination with pemetrexed and platinum, for the treatment of advanced or metastatic nonsquamous non-small cell lung cancer. In this simulation analysis, we evaluated how much it would cost a US payer to cover the toripalimab plus pemetrexed and platinum regimen as a treatment alternative to a similar pembrolizumab regimen. Our model adopted a 3-year time horizon; included two US cost inputs (wholesale acquisition cost and average sales price); and assumed a market share of 1% in 2024, increasing to 4% in 2025 and 5% in 2026. Using data from published clinical trials, we adjusted for patients whose cancer progressed or who discontinued treatment to determine the number of fully-treated-patient-equivalents. We found that, by treating 1% of nonsquamous non-small cell lung cancer patients in year one and increasing to 4% in year two and 5% in year three, the 3-year savings range from $122 million (using average sales price) to $123 million (using wholesale acquisition cost) for the entire adjusted patient population.