Study of Tislelizumab in Participants With Resectable Esophageal Squamous Cell Carcinoma

This study enrolled participants with esophageal squamous cell carcinoma who were eligible to have their tumor removed by surgery (also called surgical resection). The treatment phase of the study included the following:

• Induction therapy, in which participants received 1 cycle of chemotherapy;
• Neoadjuvant therapy (neoadjuvant refers to treatment that occurs before surgery, which can make the tumor easier to remove). In this study participants received neoadjuvant therapy based on their response to induction therapy. Response to induction therapy was assessed using the maximum standardized uptake value (SUVmax) measured using a Positron Emission Tomography (PET) scan. The SUV number refers to the level of brightness on the PET scan which reflects metabolic activity; increased metabolic activity can indicate cancerous growth.

• Participants with a decrease in SUVmax of 35% or more after induction therapy received neoadjuvant treatment with tislelizumab plus chemotherapy.
• Participants with a decrease in SUVmax less than 35% after induction therapy received neoadjuvant treatment with tislelizumab plus chemotherapy and radiotherapy.
• Surgery to remove the remaining tumor (resection) was to occur 4-6 weeks after completion of neoadjuvant treatment.

After surgery participants were followed until death, lost to follow-up, withdrawal of consent, or until the study was completed

Key Inclusion Criteria:

• Eastern Cooperative Oncology Group Performance Status of 0 or 1.
• Histologically confirmed esophageal squamous cell carcinoma (ESCC).
• Stage cT1-2N+M0 and cT3NanyM0 (per The American Joint Committee on Cancer 8th Edition).
• Evaluation by the investigator to confirm eligibility for an R0 resection with curative intent.
• Adequate hematologic and organ function, defined by protocol-specified laboratory test results obtained within 14 days before first dose.

Key Exclusion Criteria:

• Ineligible for treatment with any of the chemotherapy doublets of protocol-specified chemotherapy.
• Any prior therapy for current ESCC, including investigational agents, chemotherapy, radiotherapy, targeted therapy agents, or prior therapy with an anti-programmed cell death protein-1, anti-programmed cell death protein ligand-1, anti-programmed cell death protein ligand-2, or any other antibody or drug specifically targeting T-Cell co-stimulation or checkpoint pathways.
• History of fistula due to primary tumor invasion.
• Participants with high risk of fistula or sign of perforation evaluated by investigator.
• Any condition requiring systemic treatment with either corticosteroids (> 10 mg daily prednisone or equivalent) or other immunosuppressive medications within 14 days before first dose.

• Adrenal replacement steroid (dose ≤ 10 mg daily of prednisone or equivalent) and topical, ocular, intra-articular, intranasal, or inhaled corticosteroid with minimal systemic absorption, and short course (≤ 7 days) of corticosteroid prescribed prophylactically or for the treatment of a non-autoimmune condition are permitted.
• Active autoimmune diseases or history of autoimmune diseases that may relapse.

• Controlled Type I diabetes, hypothyroidism only requiring hormone replacement, controlled celiac disease, skin diseases (such as vitiligo, psoriasis, or alopecia) not requiring systemic treatment, or conditions not expected to recur in the absence of an external trigger are permitted to enroll.
• History of interstitial lung disease, non-infectious pneumonitis or uncontrolled diseases including pulmonary fibrosis, acute lung diseases.
• With infections requiring systemic antibacterial, antifungal, or antiviral therapy, including tuberculosis infection.

• Severe infections within 4 weeks before first dose, including but not limited to hospitalization for complications of infection, bacteremia, or severe pneumonia.
• Receive therapeutic oral or intravenous antibiotics within 2 weeks before first dose.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.