BeiGene has reported that its Phase lll RATIONALE 305 trial of tislelizumab plus chemotherapy against chemotherapy alone, to treat patients with advanced unresectable or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma, irrespective of PD-L1 status, met its primary endpoint.

The international trial met its endpoint of overall survival (OS), with no new safety signals observed for tislelizumab.

Progression-free survival, overall response rate, duration of response and safety are included as the secondary endpoints.

The randomised, double-blind, placebo-controlled trial enrolled 997 patients from 13 countries and regions worldwide.

During the trial, the patients were randomised into a 1:1 ratio to receive either tislelizumab or a placebo combined with chemotherapy.

Tislelizumab, a humanised IgG4 anti-PD-1 monoclonal antibody, is currently under evaluation by the US Food and Drug Administration and the European Medicines Agency (EMA) for the treatment of advanced or metastatic oesophagal squamous cell carcinoma following previous chemotherapy.

The EMA is also reviewing the antibody for advanced or metastatic non-small cell lung cancer (NSCLC) after prior chemotherapy along with chemotherapy for advanced or metastatic NSCLC formerly untreated.

Tislelizumab has already received approval for use in ten indications in China.

Earlier, BeiGene reported better OS for the therapy combination than chemotherapy in the PD-L1 high group at an interim analysis.

In the final analysis, tislelizumab plus chemotherapy showed superior OS compared with chemotherapy in the intent-to-treat (ITT) group.

BeiGene Solid Tumors chief medical officer Mark Lanasa said: “Gastric cancer is the fifth most common cancer globally, and the prognosis for patients with advanced or metastatic conditions remains inadequate; 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.”