Novartis investigational checkpoint inhibitor tislelizumab met primary endpoint of overall survival in pivotal Phase III trial of esophageal cancer after systemic therapy

  • Tislelizumab demonstrated a 30% reduction in the risk of death and extended median overall survival by 2.3 months compared to chemotherapy in advanced or metastatic esophageal squamous cell carcinoma after prior systemic therapy1
  • Additional Phase II data presented at ASCO showed tislelizumab demonstrated durable anti-tumor activity in patients with microsatellite instability-high, or mismatch-repair-deficient, solid tumors2


Basel, June 4, 2021 - Novartis announced today results from the pivotal Phase III RATIONALE 302 trial showing the investigational anti-PD-1 immune checkpoint inhibitor tislelizumab improved overall survival (OS) versus chemotherapy (median 8.6 months vs. 6.3 months, p=0.0001).1 The study evaluated tislelizumab in patients with unresectable recurrent locally advanced or metastatic esophageal squamous cell carcinoma (ESCC) who had received prior systemic therapy. Results were presented at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting.

Results from RATIONALE 302 in ESCC showed tislelizumab extended median OS by 2.3 months compared to chemotherapy with a 30% reduction in the risk of death (HR=0.70, 95% CI: 0.57-0.85, p=0.0001).1 In PD-L1 positive patients, tislelizumab extended median OS by 3.5 months with a 46% reduction in the risk of death (HR=0.54, 95% CI: 0.36-0.79, p=0.0006).1

"These data show that tislelizumab has the potential to help patients with esophageal squamous cell carcinoma - one of the deadliest types of cancers - live longer," said Jeff Legos, Ph.D., MBA, Senior Vice President and Head of Oncology Drug Development. "We are excited about these results from the newest asset in our portfolio of transformational medicines and look forward to sharing these data with regulatory authorities, as we continue to explore the full potential of this uniquely designed anti-PD-1 antibody."

Treatment with tislelizumab demonstrated median progression-free survival (PFS) of 1.6 months compared to 2.1 months (HR=0.83, 95% CI: 0.67-1.01). Tislelizumab demonstrated a higher and more durable anti-tumor activity than chemotherapy (objective response rate [ORR], 20.3% vs. 9.8%; median duration of response [DoR], 7.1 months vs. 4.0 months).1

The discontinuation rate due to treatment-related adverse events (TRAEs) was lower in patients who received tislelizumab (6.7%) compared to chemotherapy (13.8%). The most common all-grade TRAEs (