Cost-effectiveness of tislelizumab plus chemotherapy vs chemotherapy as first-line treatment of PD-L1 positive advanced gastric or gastroesophageal junction adenocarcinoma from a Chinese perspective.

Background: This work was designed to assess the cost-effectiveness of front-line tislelizumab plus chemotherapy (TIS+Chemo) in advanced gastric cancer (GC) or gastroesophageal junction cancer (GEJC) with positive expression of programmed cell death ligand 1 (PD-L1) from the perspective of Chinese healthcare system.

Research design and methods: A 10-year partitioned survival model was undertaken utilizing clinical data from RATIONALE 305. Costs and utilities were both discounted at an annual rate of 5%. The primary outcome was incremental cost-effectiveness ratios (ICERs) and calculated as the cost per quality-adjusted life years (QALYs). The willingness-to-pay (WTP) threshold was set as $18,625/QALY. Only direct medical costs were considered. Sensitivity analyses and subgroup analyses were performed to evaluate the robustness of the model.

Results: In the base-case analysis, the incremental cost and effectiveness associated with TIS+Chemo vs Chemo was 7,361 and 0.38 QALYs, respectively, leading to an ICER of 19,371/QALY. At the WTP threshold of $18,625/QALY, the TIS+Chemo was not a cost-effective first-line treatment option. The model outcomes were robust.

Conclusions: TIS+Chemo did not provide a cost-effective approach for PD-L1 positive advanced GC/GEJC in China setting. However, TIS+Chemo might be cost-effective in provinces with higher WTP threshold.

Clinical trial registration: RATIONALE 305, www.clinicaltrials.gov, identifier is NCT03777657.