Cost-efficiency and expanded access modeling of toripalimab versus pembrolizumab in locally advanced or metastatic nonsquamous non-small cell lung cancer.

Abstract

e20590 Background: Toripalimab, a novel anti-PD-1 antibody, demonstrated significant PFS and OS benefit in combination with pemetrexed and platinum (toripalimab+PemPlat) in advanced nonsquamous non-small cell lung cancer (nsNSCLC) over placebo+PemPlat in the CHOICE-01 trial (median PFS: 9.7 vs 5.5 months; median OS: NE vs 17.0 months), though not currently approved for this indication. FDA-approved pembrolizumab+PemPlat was similarly found to extend PFS and OS over placebo+PemPlat in metastatic nsNSCLC patients in KEYNOTE-189 (median PFS: 9.0 vs 4.9 months; median OS: 22.0 vs 10.7 months). The current wholesale acquisition cost (WAC) of pembrolizumab is $11,115 per dose. The WAC of toripalimab, recently approved for nasopharyngeal carcinoma, is 80% of pembrolizumab. In this simulation we modeled the cost-efficiency of the toripalimab regimen versus pembrolizumab in nsNSCLC and the budget-neutral expanded access to additional toripalimab enabled by savings. Methods: Utilizing WAC drug costs and treatment administration costs, we estimated the cost-efficiency of the toripalimab regimen for the median PFS 9.7 months observed in CHOICE-01 versus the pembrolizumab regimen for the median PFS 9.0 months observed in KEYNOTE-189. We assumed that 14 cycles of toripalimab+Pem (with carboplatin in cycles 1-4) are administered over 9.7 months and 13 cycles of pembrolizumab+Pem (with carboplatin in cycles 1-4) are administered over 9.0 months. From the differential, we estimated the potential expanded access to additional toripalimab treatment on a budget-neutral basis. The model was replicated utilizing an ex ante toripalimab average sales price (ASP) of 80% of pembrolizumab ASP. Results: The pembrolizumab regimen costs $176,705 over 9.0 months (13 cycles) while the toripalimab regimen costs $159,136 over 9.7 months (14 cycles) at the respective WACs, for savings of $17,569 per patient. This would enable the purchase of 1.6 additional toripalimab+pemetrexed maintenance cycles on a budget-neutral basis for every patient treated. For every 9 patients treated with toripalimab instead of pembrolizumab, one additional patient could be treated with the full toripalimab regimen (all agents) for 9.7 months. Extrapolated to the US incident nsNSCLC population of 49,647 patients, if only 5% of patients are treated with toripalimab instead of pembrolizumab estimated savings of $43,611,849 provide access to 3,849 additional toripalimab+pemetrexed maintenance cycles or 274 full toripalimab regimens (all agents for 9.7 months) budget-neutrally. Similar results were seen in the ex ante ASP model. Conclusions: If approved for use in advanced nsNSCLC, toripalimab is estimated, at its market-entry WAC, to save $17.6 thousand per patient over a median PFS 9.7 months treatment duration compared to the pembrolizumab regimen over a median PFS 9.0 months of treatment.