A study published in July 2021 in the Journal of Clinical Oncology has shown that the overall survival (OS) in patients who had previously treated esophageal cancer improved significantly with the humanized monoclonal antibody drug tislelizumab when compared to chemotherapy (J Clin Oncol. 2021 39:15_suppl, 4012-4012; the study was sponsored by BeiGene, Ltd.).
In the global phase 3 RATIONALE-302 trial (NCT03430843), 512 adult patients from 132 sites in 10 countries in Asia (n=404 patients) and in Europe and North America (n=108 patients) were randomized to either tislelizumab (n=256) or investigator-chosen standard chemotherapy (n=256). Patients had histologically confirmed advanced/unresectable or metastatic esophageal squamous cell carcinoma that progressed following prior systemic therapy with ≥1 evaluable lesion per RECIST v1.1 and an Eastern Cooperative Oncology Group performance score of ≤1. Of the 512 patients, 157 had visually estimated combined positive score (vCPS) of ≥10%.
Tislelizumab was given to the tislelizumab group on day one and then every 
21 days; the chemotherapy group received a combination of drugs: paclitaxel on day one and then every 21 days or on a weekly schedule, docetaxel on day one and then every 21 days, and irinotecan on days one and eight and then every 21 days. The study’s primary endpoint was overall survival in all randomized patients. Patients in both groups were treated with these protocols until their disease progressed, they showed unacceptable toxicity levels of any of the drugs, or they withdrew from the study.
Results showed that tislelizumab clinically and significantly improved overall survival compared to chemotherapy in the intent-to-treat population (8.6 vs 6.3 months). Tislelizumab also showed significant improvement in overall survival compared to chemotherapy in patients with a vCPS of ≥10% (10.3 vs 6.8 months), as well as a higher overall response rate (20.3% vs 9.8%) and a more durable response (7.1 vs 4.0 months)