BeiGene says Phase 3 RATIONALE 305 trial data show improved overall survival

BeiGene announced results from the final analysis of the Phase 3 RATIONALE 305 trial showing tislelizumab plus chemotherapy significantly improved overall survival (OS) in the intent-to-treat (ITT) population as a first-line treatment for patients with advanced gastric or gastroesophageal junction adenocarcinoma (GC/GEJC). No new safety signals were identified. Study results will be featured as a late-breaking oral presentation on October 21 at 5:25 p.m. CEST at the European Society for Medical Oncology (ESMO) Congress 2023 (Abstract #LBA80). “Gastric cancer is a devastating disease that affects millions of people worldwide. Unfortunately, patients with advanced or metastatic conditions have a poor prognosis and urgently need more treatment options in the first-line setting,” said Mark Lanasa, M.D., Ph.D., Chief Medical Officer, Solid Tumors at BeiGene. “These data show that tislelizumab plus chemotherapy resulted in significant overall survival improvement compared with chemotherapy alone in the intent-to-treat patient group. These results and positive findings build upon the data presented earlier this year in the high PD-L1 expression group and add to the growing body of evidence demonstrating the potential for tislelizumab to help patients with advanced gastric cancer or gastroesophageal junction cancer.” In the final analysis of 997 intent-to-treat patients from the Phase 3 RATIONALE 305 trial, tislelizumab plus chemotherapy (oxaliplatin 130 mg/m2 IV Q3W (day 1) and oral capecitabine 1000 mg/m2 twice daily (days 1-14) Q3W (XELOX), or cisplatin 80 mg/m IV Q3W (day 1) and 5-fluorouracil 800 mg/m2/day IV (days 1-5) Q3W (FP)) showed a median OS of 15.0 months compared with an OS of 12.9 months for chemotherapy alone (HR: 0.80 (95% CI: 0.70, 0.92); P = 0.0011) in first line advanced GC/GEJC.