Cost-Effectiveness of Adjuvant Nivolumab in Patients With Stage II/III Carcinoma of the Esophagus or Gastroesophageal Junction and Residual Disease After Neoadjuvant Chemo-Radiotherapy Following Complete Resection in Austria

OBJECTIVES: Esophageal carcinoma (EC) is a malignant esophagus tumor accounting for approximately 1% of all malignant cancers. In addition, gastroesophageal junction (GEJC) (which connects the throat and the stomach) is also a potential carcinoma site. Few symptoms in early disease stages (stage I or II) often lead to late diagnosis of both cancer types (at stage III or IV), which is associated with a poor prognosis. The aim of this analysis was to evaluate the cost-effectiveness of adjuvant nivolumab versus observation in adult patients with stage II/III EC or GEJC with residual disease after neoadjuvant chemo-radiotherapy after being surgically rendered disease-free in Austria.

METHODS: A discrete-time three-state Markov cohort model (pre-recurrence, post-recurrence, and death) was constructed with a lifetime horizon (30 years) and a cycle length of one month. Clinical data stems from the phase 3 “CheckMate 577” trial. Resource utilization was identified by clinical experts and direct costs (2024 €) from an Austrian payer’s perspective were taken from published sources. A willingness-to-pay threshold of 40,000€ per QALY gained was used. One-way and probabilistic sensitivity analyses (PSA) were performed. A discount rate of 5% for costs and 3% for quality-adjusted life-years (QALYs) and LYs was applied.

RESULTS: Over a lifetime horizon, base case costs of nivolumab and observation are 77,877€ and 13,724€ respectively. Compared to observation, nivolumab is associated with an incremental QALY gain of 2.25 QALYs (6.38 versus 4.14). This leads to an incremental cost-utility ratio of 28,519€. In a Monte Carlo PSA with 1,000 second-order simulations, nivolumab versus observation is cost-effective in approximately 100% of all cases.

CONCLUSIONS: In Austria, adjuvant nivolumab in adult patients with stage II/III EC or GEJC who have residual disease after neoadjuvant chemo-radiotherapy followed by complete resection is a cost-effective therapy which significantly improves disease-free survival compared to observation.