Tislelizumab Demonstrates Superior Overall Survival Compared With Chemotherapy

Tislelizumab (BeiGene) demonstrated superior overall survival (OS) compared with chemotherapy for individuals with advanced unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma, regardless of programmed death-ligand 1 (PD-L1) status.

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Tislelizumab is a humanized immunoglobulin G4, anti-PD-1 monoclonal antibody specifically designed to minimize binding to the Fc-gamma receptors on macrophages.

“At the recent [American Society of Clinical Oncology] GI meeting, we presented results from an interim analysis demonstrating a statistically significant and clinically meaningful improvement in overall survival in the high PD-L1 expression group in RATIONALE 305 [(NCT03777657]), and we are pleased that the final analysis demonstrated a significant survival benefit and consistent safety profile in the entire study population,” Mark Lanasa, MD, PhD, chief medical officer of Solid Tumors at BeiGene, said in a statement. “These data support tislelizumab combined with chemotherapy as a potential first-line treatment option for patients with locally advanced, unresectable or metastatic gastric, or gastroesophageal junction cancer.”

In the analysis, the OS for tislelizumab showed a mean of 17.2 months compared with 12.6 months for the placebo arm.

BeiGene previously announced superior OS for the combination compared with chemotherapy in the PD-L1 high group at a planned interim analysis, with the trial continued according to pre-specified statistical hierarchy testing.

Investigators compared the efficacy and safety of tislelizumab combined with platinum and fluoropyrimidine chemotherapy and the placebo combined with platinum fluoropyrimidine chemotherapy as a first-line treatment. There was a total of 997 individuals from 13 countries and regions included in the study who were randomized 1:1 to either tislelizumab or the placebo.

The OS analysis took place after the OS analysis in the PD-L1 high population proved to be statistically significant, favoring the tislelizumab arm. The secondary endpoints included duration of response, overall response rate, progression-free survival, and safety.

The company reported that no new safety signals were identified for tislelizumab.

Study results will be submitted for presentation at an upcoming medical conference.

The European Medicines Agency (EMA) and the FDA are reviewing tislelizumab for advanced or metastatic esophageal squamous cell carcinoma after prior chemotherapy.

Additionally, the EMA will also review tislelizumab for advanced or metastatic non–small cell lung cancer (NSCLC) after prior chemotherapy and in combination with chemotherapy for previously untreated advanced or metastatic NSCLC.

Tislelizumab has been approved for 10 indications in China, which includes a recent approval for use in combination with fluoropyrimidine and platinum chemotherapy for the first-line treatment of individuals with locally advanced unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma with high PD-L1 expression.

In China, the National Healthcare Security Administration issued a 2023 update to the National Reimbursement Drug List, which included tislelizumab for 9 reimbursed indications.

Tislelizumab is not approved outside of China.

An expansive global clinical trial program supported the development of tislelizumab, including 21 registration-enabling clinical trials with more than 11,800 individuals enrolled across the world.

Reference

BeiGene announces positive phase 3 tislelizumab trial in advanced gastric or gastroesophageal junction adenocarcinoma. News release. BeiGene. April 20, 2023. Accessed April 21, 2023. https://ir.beigene.com/news/beigene-announces-positive-phase-3-tislelizumab-trial-in-advanced-gastric-or-gastroesophageal-junction-adenocarcinoma/dc7ae8df-dbbb-4de2-834f-0f74feaaa519/