Tislelizumab Plus Chemotherapy Significantly Improved Overall Survival in First-Line Treatment for Advanced Esophageal Cancer

Positive topline results from an interim analysis of the phase 3 RATIONALE 306 study showed the anti-PD-1 immune checkpoint inhibitor tislelizumab plus chemotherapy significantly improved overall survival (OS) compared to chemotherapy in patients with previously treated unresectable, locally advanced, recurrent, or metastatic esophageal squamous cell carcinoma (ESCC).

Tizlelizumab is a unique anti-PD-1 monoclonal antibody that is being analyzed in 14 pivotal clinical trials across an array of solid tumors, with more than 8800 patients enrolled in studies in 35 countries, according to a Novartis press release. Approximately 649 study participants were randomized in the RATIONALE 306 study to receive either tislelizumab plus chemotherapy or chemotherapy alone.

The primary endpoint was OS, whereas the secondary endpoints include progression-free survival, objective response rate, duration of response, health-related quality of life measures, and safety.

In the global phase 3 RATIONALE 305 trial, tislelizumab in combination with chemotherapy showed positive results versus placebo as a first-line treatment for patients with locally advanced, unresectable, or metastatic gastric or gastroesophageal junction adenocarcinoma.

The primary endpoint of the trial was overall survival (OS), and the secondary endpoints included progression-free survival, overall response rate, duration of response, and safety. In total, 997 patients from 13 countries and regions were enrolled and randomized 1:1 to receive either tislelizumab and chemotherapy or placebo and chemotherapy.

The tislelizumab combination met the primary endpoint of OS in patients with PD-L1 expression, with additional follow-up needed to assess OS benefits in the intention-to-treat population. The safety profile of tislelizumab was consistent with what was observed in previous trials with no safety signals identified with the addition of chemotherapy.

"People living with esophageal cancer experience painful everyday challenges and typically have a poor prognosis, with a 5-year survival rate of around five percent for metastatic cases, underscoring the urgency for more immunotherapy options,” said Jeff Legos, executive vice president, Global Head of Oncology & Hematology Development, in a press release. “We plan to discuss these data with health authorities, and we will continue to expand our tislelizumab clinical development program in pursuit of novel, synergistic combinations with the ultimate goal of extending survival for more patients.”

REFERENCE
Novartis tislelizumab plus chemotherapy significantly improved overall survival as first-line treatment for advanced esophageal cancer in Phase III study. Novartis. April 27, 2022. Accessed April 29, 2022. https://www.novartis.com/news/media-releases/novartis-tislelizumab-plus-chemotherapy-significantly-improved-overall-survival-first-line-treatment-advanced-esophageal-cancer-phase-iii-study