OBJECTIVES: The health-related quality-of-life (HRQoL) measurement is important for patients with advanced gastric or gastroesophageal junction (G/GEJ) adenocarcinoma. This study aimed to assess the health outcome and clinical benefit of patients with advanced G/GEJ adenocarcinoma receiving sintilimab in combination with chemotherapy (oxaliplatin and capecitabine) compared with chemotherapy alone in China.

METHODS: The individual HRQoL data was obtained from the ORIENT-16 trial and officially authorized by the Innovent Biologics, Inc^©. company. Health utility values of progression-free survival (PFS) and post-progression (PP) were calculated using Chinese EQ-5D-5L value set. Quality-adjusted life-year (QALY) was estimated as health outcome. For short-term analysis, during the clinical trial period (January 3, 2019 to June 20, 2021), the QALYs of patients received sintilimab in combination with chemotherapy and chemotherapy alone were calculated. For long-term analysis, a lifetime simulation three-state (PFS, PP, and Death) partitioned survival model (PSM) was developed based on the ORIENT-16 extrapolated survival data to compare the QALYs of the two groups.

RESULTS: A total of 641 individual patient data were included in the analysis. Short-term analysis showed that during the follow-up period of ORIENT-16, the health outcome of sintilimab group and the control group were 0.63 QALYs and 0.53 QALYs respectively. Patients on sintilimab plus chemotherapy resulted in an incremental gain of 0.09 QALYs over the chemotherapy alone. The mean utility value of study group and control group were 0.896 and 0.897 in PF state, 0.822 and 0.833 in PP state, respectively. Long-term analysis showed that the lifetime simulation of sintilimab group had higher QALYs than chemotherapy alone group (1.88 QALYs vs. 1.39 QALYs). There were 0.44 QALYs and 0.06 QALYs gained in PFS and PP states, respectively.

CONCLUSIONS: Compared with chemotherapy alone, sintilimab combined with chemotherapy improves the HRQoL of Chinese patients with advanced G/GEL adenocarcinoma as a first-line treatment strategy.