Objectives: ORIENT-16, a phase III clinical trial conducted at 62 hospitals in China, reported that add-on sintilimab (Sin) to chemotherapy (Chemo) had favorable efficacy (p < 0.05) for patients with advanced HER2-negative gastric or gastroesophageal junction cancer (GC/GEJC). This study aimed to evaluate the cost-utility of the Sin+Chemo based on results of ORIENT-16 from the perspective of Chinese healthcare payers.
Methods: A three-state partitioned survival model was developed to simulate the 10-year life expectancy and total healthcare costs for patients with advanced HER2-negative GC/GEJC. Primary measure outcomes were: cost, quality-adjusted life-years (QALYs), and incremental cost-utility ratios (ICURs). Sensitivity/scenario analyses were conducted to assess the model robustness.
Results: In all patients, Sin+Chemo vs Chemo increased costs by $6,472, additionally providing 0.61 QALYs, resulting in an ICUR of $10,610/QALY. While, in PD-L1 combined positive score ≥ 5 cohort, the ICUR was $9,738/QALYs. The ICUR was most sensitive to the utility of progression-free survival. The probabilistic sensitivity analysis showed that add-on Sin had a 100% probability of being cost-effective at a willingness-to-pay threshold of $18,625/QALY gained.
Conclusions: Sin+Chemo is a cost-effective first-line treatment option for advanced HER2-negative GC/GEJC in China.
Clinical trial registration: ORIENT-16, www.clinicaltrials.gov, identifier is NCT03745170.
Keywords: China; GC/GEJC; ORIENT-16; cost-utility analysis; immunotherapy; sintilimab.