Novel Gastric Cancer Drug Under FDA Review Improves Survival

The FDA is reviewing tislelizumab for advanced unresectable or metastatic gastric or gastroesophageal junction.

A treatment currently under review by the Food and Drug Administration (FDA) for the treatment of patients with advanced unresectable or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma has been shown to improve patients’ overall survival, according to an announcement from the biotechnology company behind the treatment.

Interim results of the RATIONALE 305 study showed that tislelizumab in combination with chemotherapy resulted in a median overall survival time (from the start of the trial until death of any cause) of 17.2 months, compared to 12.6 months for patients who received chemotherapy and a placebo, according to an announcement from drug’s manufacturer, BeiGene.

A 997-participant, phase 3 clinical study started in late 2018, interim results from RATIONALE 305 were shared in an oral presentation at the 2023 ASCO Gastrointestinal Cancers Symposium in January.

“At the recent ASCO 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 and we are pleased that the final analysis demonstrated a significant survival benefit and consistent safety profile in the entire study population,” said Dr. Mark Lanasa, chief medical officer, solid tumors at BeiGene, in the press release.

“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,” Lanasa said.

Tislelizumab, BeiGene explained in its press release, is “an anti-PD-1 monoclonal antibody specifically designed to minimize binding to Fc-gamma (Fcγ) receptors on macrophages. In pre-clinical studies, binding to Fcγ receptors on macrophages has been shown to compromise the anti-tumor activity of PD-1 antibodies through activation of antibody-dependent macrophage-mediated killing of T effector cells.”

Overall survival was the primary outcome measure of RARTIONALE 305; secondary measures include progression-free survival (time from treatment until when the disease worsens or spreads), overall response rate and duration of response.

BeiGene said that results from the study will be submitted for presentation at an upcoming medical conference, and that no new side effects for tislelizumab have been identified, other than those that have been previously seen in patients taking the drug.

Currently approved for use in China, tislelizumab is under review by both the FDA and the European Medicines Agency (EMA) for advanced or metastatic esophageal squamous cell carcinoma after prior chemotherapy. In the United States, the drug is also showing promise for patients with non-small cell lung cancer.

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