Anti-PD-1 Monoclonal Antibody Tislelizumab (BGB-A317) Combined With or Without Anti-TIGIT Monoclonal Antibody Ociperlimab (BGB-A1217) in Participants With Recurrent or Metastatic Esophageal Squamous Cell Carcinoma

Overall survival (OS) is defined as the time from the date of randomization until the date of death due to any cause.

Median overall survival was estimated using the Kaplan-Meier method. For participants who were still alive at the end of the trial, OS was censored at the last known alive date or the date of data cutoff, whichever was earlier.

Objective response rate is defined as the percentage of participants who had a best overall response of confirmed complete response (CR) or partial response (PR) assessed by the Independent Review Committee (IRC) according to RECIST v1.1.

Response evaluations were performed using computed tomography or MRI approximately every 6 weeks for the first 54 weeks and then every 12 weeks thereafter.

CR: Disappearance of all target and non-target lesions; any pathological lymph nodes (whether target or non-target) < 10 mm, and no new lesions.

PR: At least a 30% decrease in the size of target lesions, with no progression of non-target lesions and no new lesions, or disappearance of target lesions with persistence of 1 or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits, and no new lesions.

Response (CR or PR) must have been confirmed 4 weeks or later after the first response was observed.

Progression-free survival is defined as the time from the date of randomization to the date of first documentation of progressive disease assessed by the Independent Review Committee per RECIST v1.1, or death, whichever occurred first.

Median PFS was estimated using the Kaplan-Meier method.

Progressive Disease (PD): At least a 20% increase in the size of target lesions with an absolute increase of at least 5 mm, or unequivocal progression of existing non-target lesions, or the appearance of any new lesions.

Progression-free survival is defined as the time from the date of randomization to the date of first documentation of progressive disease assessed by the Investigator per RECIST v1.1, or death, whichever occurred first.

Median PFS was estimated using the Kaplan-Meier method.

Progressive Disease (PD): At least a 20% increase in the size of target lesions with an absolute increase of at least 5 mm, or unequivocal progression of existing non-target lesions, or the appearance of any new lesions.

Duration of response is defined as the time from the first determination of an objective response (CR or PR) until the first documentation of progressive disease as assessed by the Independent Review Committee per RECIST v1.1, or death, whichever occurred first.

Median DOR was estimated using the Kaplan-Meier method.

Duration of response is defined as the time from the first determination of an objective response (CR or PR) until the first documentation of progressive disease as assessed by the Investigator per RECIST v1.1, or death, whichever occurred first.

Median DOR was estimated using the Kaplan-Meier method.

Disease Control Rate is defined as the percentage of participants who had confirmed CR, PR, or stable disease (SD) assessed by the IRC and the investigator per RECIST v1.1. Response evaluations were performed using computed tomography or MRI approximately every 6 weeks for the first 54 weeks and then every 12 weeks thereafter.

CR: Disappearance of all target and non-target lesions; any pathological lymph nodes (whether target or non-target) < 10 mm, and no new lesions.

PR: At least a 30% decrease in the size of target lesions, with no progression of non-target lesions and no new lesions, or disappearance of target lesions with persistence of 1 or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits, and no new lesions.

SD: Neither sufficient shrinkage in size of lesions to qualify for PR nor sufficient increase to qualify for PD, and no new lesions.

Response (CR or PR) must have been confirmed 4 weeks or later after the first response.

Clinical benefit rate is defined as the percentage of participants who achieved a confirmed complete response, partial response, or durable stable disease assessed by the IRC and the Investigator per RECIST v1.1. Response evaluations were performed using computed tomography or MRI approximately every 6 weeks for the first 54 weeks and then every 12 weeks thereafter.

CR: Disappearance of all target and non-target lesions; any pathological lymph nodes (whether target or non-target) < 10 mm, and no new lesions.

PR: At least a 30% decrease in the size of target lesions, with no progression of non-target lesions and no new lesions, or disappearance of target lesions with persistence of 1 or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits, and no new lesions.

Durable SD: Stable disease for ≥ 24 weeks. Response (CR or PR) must have been confirmed 4 weeks or later after the first response.

The EORTC QLQ-30 contains 30 questions that incorporate 5 functional scales (physical functioning, role functioning, emotional functioning, cognitive functioning, and social functioning), 1 global health status scale, 3 symptom scales (fatigue, nausea and vomiting, and pain), and 6 single items (dyspnea, insomnia, appetite loss, constipation, diarrhea, and financial difficulties). The participant answers questions about their health during the past week. There are 28 questions answered on a 4-point scale where 1 = Not at all (best) and 4 = Very Much (worst) and 2 global health quality of life (QOL) questions answered on a 7-point scale where 1 = Very poor and 7 = Excellent. Raw scores are transformed into a 0 to 100 scale via linear transformation. Higher scores in GHS and functional scales indicate better quality of life.

The EORTC-QLQ-OES18 is the specific esophageal symptoms module of the QLQ-C30. QLQ-OES18 is comprised of 18 questions grouped into 4 multi-item subscales: Dysphagia (3 items), Eating (4 items), Reflux (2 items), and Pain (3 items) and 6 single item subscales (saliva swallowing, choking, dry mouth, taste, coughing, and talking). Participants indicate the extent to which they have experienced symptoms on a scale from 1 (Not at all) to 4 (Very much). Scores are calculated and transformed to a scale from 0 to 100; higher scores indicate a higher level of symptomatology or problems.

An AE is defined as any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of study drugs, whether related to study drugs or not.

An SAE is any untoward medical occurrence that, at any dose:

• Resulted in death
• Was life-threatening
• Required hospitalization or prolongation of existing hospitalization
• Resulted in disability/incapacity
• Was a congenital anomaly/birth defect
• Was considered a significant medical AE by the Investigator based on medical judgement.

AEs were considered "related" to study drugs if there was evidence to suggest a causal relationship.

The investigator assessed the severity of each AE reported based upon National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) v5.0, where ≥ 3 includes severe or medically significant, life-threatening events or death related to AE.

Immune-mediated AEs were diagnosed by the investigator.