Liu, Sumei

TPS462 Background: Esophageal squamous cell carcinoma (ESCC) is the predominant histological subtype of esophageal cancer, particularly in Asian countries. Inhibition of the PD-1/PD-L1 axis has demonstrated antitumor activity in patients with advanced unresectable or metastatic ESCC. Tislelizumab, an investigational humanized IgG4 monoclonal antibody with high affinity and binding specificity for PD-1, was engineered to minimize binding to FcγR on macrophages in order to abrogate antibody-dependent phagocytosis, a mechanism of T-cell clearance and potential resistance to anti-PD-1 therapy. Results from early phase clinical studies suggest tislelizumab, as a single agent or in combination with chemotherapy, was generally well tolerated and had antitumor activity in patients with solid tumors, including ESCC. Methods: This global, phase 3, randomized, placebo-controlled, double-blind study (NCT03783442) is designed to evaluate the efficacy and safety of tislelizumab plus chemotherapy as first-line treatment of unresectable, locally advanced recurrent or metastatic ESCC. Adult patients with histologically confirmed unresectable ESCC, or locally advanced recurrent/metastatic disease with a ≥6 month treatment-free interval, are eligible; palliative radiation administered > 4 weeks from study initiation is allowed. Patients who received prior anti-PD-(L)1, anti-PD-L2, or first-line therapy are ineligible. Patients (n≈480) will be randomized 1:1 to receive tislelizumab 200 mg IV every 3 weeks (Q3W) plus investigator-chosen chemotherapy (ICC) or placebo plus ICC. ICC options include: platinum (plat; cisplatin 60-80 mg/m2 or oxaliplatin 130 mg/m2 IV Q3W) + 5-FU 750-800 mg/m2 by continuous IV infusion over 24 hours for 5d Q3W; or plat + capecitabine 1000 mg/m2 orally BID for 14d Q3W; or plat + paclitaxel 175 mg/m2 IV Q3W. Progression-free and overall survival are primary endpoints; secondary endpoints include objective response rate, duration of response, and health-related quality of life. Safety will be assessed by monitoring adverse events, physical examinations, vital signs, and electrocardiograms. This study is actively enrolling. Clinical trial information: NCT03783442.

TPS2656 Background: ESCC remains the predominant histological subtype of, and accounts for most deaths from, esophageal cancer. PD-1 inhibition has demonstrated antitumor activity and was generally well tolerated in patients (pts) with advanced unresectable or metastatic ESCC. Tislelizumab, an investigational anti-PD-1 antibody, was engineered to minimize binding to FcγR on macrophages to abrogate antibody-dependent phagocytosis, a mechanism of T-cell clearance and potential resistance to anti-PD-1 therapy. Results from early phase clinical studies suggest single-agent tislelizumab was generally well tolerated and had antitumor activity in pts with solid tumors, including ESCC. Methods: This phase 3, randomized, placebo-controlled, double-blind study (NCT03783442) is designed to evaluate the efficacy and safety of tislelizumab plus chemotherapy as first-line treatment of unresectable, locally advanced recurrent or metastatic ESCC. Adult pts with histologically confirmed ESCC that had metastatic disease either at first diagnosis or with a ≥6 month treatment-free interval will be eligible. Additional eligibility criteria include measurable/evaluable disease, ECOG performance score ≤1, and no prior anti-PD-(L)-1, PD-L2, or other first-line therapy or palliative radiation treatment ≤4 weeks before treatment. Approximately 480 pts will be randomized 1:1 to receive investigator-chosen chemotherapy (ICC) plus tislelizumab 200 mg IV Q3W or ICC plus placebo. Chemotherapy options include: platinum (cisplatin 60–80 mg/m2 or oxaliplatin 130 mg/m2 IV Q3W) plus 5-FU 750–800 mg/m2 IV daily for 5 days Q3W; or platinum plus capecitabine 1000 mg/m2 orally BID for 14 days Q3W; or platinum + paclitaxel 175 mg/m2 IV Q3W. Progression-free survival and overall survival are coprimary endpoints; secondary endpoints include objective response rate, duration of response, and health-related quality-of-life. Safety will be assessed by monitoring adverse events, physical examinations, vital signs, and electrocardiograms. This study is actively enrolling. Clinical trial information: NCT03783442.