A cost-effectiveness analysis of avelumab plus best supportive care versus best supportive care alone as first-line maintenance treatment for patients with locally advanced or metastatic urothelial carcinoma in Taiwan

Abstract

Background: Patients with locally advanced or metastatic urothelial carcinoma have limited treatment options and a poor prognosis. The JAVELIN Bladder 100 trial showed that avelumab as first-line maintenance plus best supportive care significantly prolonged overall survival and progression-free survival versus best supportive care alone in patients with locally advanced or metastatic urothelial carcinoma that had not progressed with first-line platinum-containing chemotherapy.

Aims: We assessed whether avelumab plus best supportive care is a cost-effective treatment option versus best supportive care alone in this patient group in Taiwan.

Methods and results: A partitioned survival model was used to estimate the costs and effects of avelumab plus best supportive care versus best supportive care alone over a 20-year time horizon from the perspective of Taiwan's National Health Insurance Administration. Patient-level data from JAVELIN Bladder 100 on efficacy, safety, utility, and time on treatment were analyzed to provide parameters for the model. Log-normal and Weibull distributions were used for overall survival and progression-free survival, respectively. Costs of healthcare resources, drug acquisition, adverse events, and progression were identified through publicly available data sources and clinician interviews. The model estimated total costs, life years, and quality-adjusted life years. In the modeled base case, avelumab plus best supportive care increased survival versus best supportive care alone by 0.79 life years (2.93 vs. 2.14) and 0.61 quality-adjusted life years (2.15 vs. 1.54). The incremental cost-effectiveness ratio for avelumab plus best supportive care versus best supportive care alone was NT$1 827 680. Most (78%) of the probabilistic sensitivity analyses fell below three times the gross domestic product per capita. Scenario analysis indicated that life year and quality-adjusted life year gains were most sensitive to alternative survival extrapolations for both avelumab plus best supportive care and best supportive care alone.

Conclusion: Avelumab first-line maintenance therapy combined with best supportive care was determined as a cost-effective treatment strategy for patients in Taiwan diagnosed with locally advanced or metastatic urothelial carcinoma that had not progressed with platinum-containing chemotherapy.

Keywords: JAVELIN Bladder 100 study; Taiwan; avelumab; economic model; health technology assessment; urothelial carcinoma.

FIGURE 1

First‐line maintenance treatment in patients with locally advanced/metastatic urothelial carcinoma: Partitioned survival model structure. Arrows indicate transitions from one state to another. Arrows that curve back to the same state indicate that the patient remains in the same state. 1L, first line; CR, complete response; PFS, progression‐free survival; PPS, post‐progression survival; PR, partial response; SD, stable disease.

FIGURE 2

Projected time to treatment discontinuation for avelumab plus best supportive care versus best supportive care alone. The exponential distribution was chosen for avelumab. 1LM, first‐line maintenance; BSC, best supportive care; KM, Kaplan–Meier; TTD, time to treatment discontinuation.

FIGURE 3

Cost‐effectiveness for avelumab plus best supportive care versus best supportive care alone: (A) acceptability curve; (B) plane. 3 × GDP = NT$2 533 962; 2 × GDP = NT$1 689 308; current Taiwan GDP = NT$844 654. 1LM, first‐line maintenance; BSC, best supportive care; GDP, gross domestic product.

FIGURE 4

Tornado diagram of the incremental net monetary benefit of avelumab plus best supportive care versus best supportive care alone. The vertical line in the center indicates the incremental net monetary benefit of the base‐case scenario. The darker bar indicates the incremental net monetary benefit result when the minimum input value is used, while the pink bar indicates the incremental net monetary benefit result when the maximum input value is used. 1LM, first‐line maintenance; BSC, best supportive care; ICER, incremental cost‐effectiveness ratio; ICI, immune checkpoint inhibitor; INMB, incremental net monetary benefit; Pop2, first‐line maintenance population.