BeiGene says Phase 3 RATIONALE 315 trial met primary endpoints

BeiGene announced that the Phase 3 RATIONALE 315 study met its dual primary endpoints of major pathological response (MPR) by Blinded Independent Pathology Review (BIPR) and event-free survival (EFS) by Blinded Independent Central Review (BICR), demonstrating statistically significant and clinically meaningful improvements in patients with resectable Stage II or IIIA NSCLC treated with tislelizumab in combination with chemotherapy before surgery and as a single agent after surgery versus neoadjuvant chemotherapy plus placebo followed by placebo after surgery. The tislelizumab plus chemotherapy regimen also showed a statistically significant improvement in pathological complete response (pCR), the key secondary endpoint, after neoadjuvant therapy versus chemotherapy. The MPR and pCR data will be featured as a late-breaking mini oral presentation on October 23 at 2:55 p.m. CEST at the European Society for Medical Oncology (ESMO) Congress 2023 (Abstract #LBA58). In the study, 56.2% of NSCLC patients treated with tislelizumab in combination with chemotherapy before surgery achieved MPR, compared to 15.0% of patients treated with chemotherapy alone (difference: 41.1%; 95% CI: 33.2-49.1, pless than0.0001). MPR is defined as less than 10% residual viable tumor after neoadjuvant therapy. Additionally, 40.7% of patients on the tislelizumab-based regimen achieved pCR, defined as no viable residual tumor after neoadjuvant therapy, compared to 5.7% of patients treated with chemotherapy alone (difference: 35.0%; 95% CI: 27.9-42.1, pless than0.0001). Tislelizumab plus chemotherapy was generally well tolerated, with no new safety signals identified.