Tislelizumab regimen extends OS in advanced esophageal cancer
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The addition of tislelizumab to first-line chemotherapy extended OS among patients with advanced esophageal cancer, according to study results presented at European Society for Medical Oncology World Congress on Gastrointestinal Cancer.
The combination conferred a significant survival benefit regardless of PD-L1 status, results of the randomized phase 3 RATIONALE 306 study showed.
Tislelizumab (BGB-A317, BeiGene) is a humanized immunoglobulin G4 monoclonal antibody designed to minimize binding to Fc gamma receptors on macrophages, which may result in anti-PD-1 resistance.
The double-blind RATIONALE 306 study included 649 patients with unresectable, locally advanced recurrent or metastatic esophageal squamous cell carcinoma. Researchers randomly assigned study participants to chemotherapy plus either tislelizumab or placebo.
OS in the intent-to-treat population served as the primary endpoint. Secondary endpoints included OS among patients with PD-L1 score of 10% or higher, PFS, objective response rate, duration of response, health-related quality of life and safety.
Results showed significantly longer median OS among tislelizumab-treated patients (17.2 months vs. 10.6 months; HR = 0.66; 95% CI, 0.54-0.8). The OS benefit persisted in the subgroup of study participants with PD-L1 scores of 10% or higher (16.6 months vs. 10 months; HR = 0.62; 95% CI, 0.44-0.86), and an exploratory analysis of study participants with PD-L1 scores less than 10% also favored tislelizumab (16.7 months vs. 10.4 months; HR = 0.72; 95% CI, 0.55-0.94).
The tislelizumab-chemotherapy combination also appeared associated with longer median PFS (7.3 months vs. 5.6 months; HR=0.62; 95% CI, 0.52-0.75) and a higher ORR (63.5% vs. 42.4%; OR = 2.38; P < 0.0001).
Incidence of treatment-related adverse events appeared comparable between treatment groups.
The most common treatment-related adverse events in the tislelizumab-chemotherapy group included anemia (68% for tislelizumab-chemotherapy vs. 61% for placebo-chemotherapy), decreased neutrophils (78% vs. 80%), decreased white blood cell count (55% vs. 65%), decreased appetite (39% vs. 38%), nausea (37% vs. 42%) and peripheral sensory neuropathy (26% vs. 21%).
“The prognosis for [esophageal squamous cell carcinoma] remains poor, with a 5-year survival rate of just 5%, and patients are in need of more treatment options, especially in earlier lines of therapy,” Jeff Legos, executive vice president and global head of oncology and hematology development for Novartis — which has the rights to develop, manufacture and commercialize tislelizumab in North America, Europe and Japan — said in a company-issued press release. “These results add to the growing body of evidence demonstrating the potential for tislelizumab to help patients with esophageal cancer, and reinforce our commitment to studying tislelizumab alone and in synergistic combinations across additional tumor types that may benefit from an immunotherapy.”