This was an open-label, multicenter, nonrandomized Phase 1 and 2 clinical trial evaluating various combinations of surzebiclimab (BGB-A425) and/or alcestobart (LBL-007) with tislelizumab.
Blocking antibodies targeting programmed cell death protein-1 (PD-1) have achieved remarkable results in the treatment of many types of tumors. However, based upon the rate of primary and secondary resistance to PD-1 blockade, it was apparent that additional immuno-regulatory mechanism(s) underlie tumor immune escape. Indeed, research shows that the T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) pathway cooperates with PD-1 to maximize the suppression of effector tumor infiltrating lymphocytes (TILs) as well as promote resistance to anti-PD-1 therapy. Therefore, TIM-3 represents an ideal target with the potential to significantly improve and/or extend the therapeutic benefit of anti-PD-1 therapy to a greater number of participants. TIM-3, Lymphocyte activation gene-3 (LAG-3), and PD-1 function as immune checkpoint receptors in the overlapping regulation of immune tolerance and have been shown to be co-overexpressed on the TILs from the participant samples of various solid tumors. Furthermore, emerging clinical data and preclinical data demonstrate co-expression of TIM-3, LAG-3, PD-1 often yield T cells exhausted immunophenotype (i.e., cytokine expression, proliferation etc.). Cancer cells take advantage of PD-1, TIM-3, and LAG-3 in inhibiting immune cells' function, and escape the immune surveillance. Based upon the overlapping expression profiles and immuno-regulatory functions, TIM-3 and LAG-3 mediated adaptive resistance, there was strong scientific rationale that simultaneous targeting of these checkpoint blockers, could potentially increase therapeutic benefit and might help to overcome the resistance arising due to anti-PD-(L)-1 therapy. Hence, this study evaluated the safety and preliminary efficacy of surzebiclimab (anti TIM-3), alcestobart (Anti-LAG-3) in combination with tislelizumab (anti PD-1) in patients with advanced solid tumors. This was an open-label, multicenter, nonrandomized Phase 1 and Phase 2 clinical trial. Phase 1 determined the recommended phase 2 dose (RP2D) for the combination of surzebiclimab and tislelizumab. Phase 2 safety lead-in determined the RP2D for the combination of surzebiclimab, tislelizumab and/or alcestobart. Phase 2 dose expansion continued to evaluate the safety but also focus on the efficacy of the doublet or triplet treatment combination in select tumor types.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
147
Humanized immunoglobulin G1 (IgG1)-variant monoclonal antibody against TIM-3
Humanized, IgG4-variant monoclonal antibody against PD-1
Human anti LAG-3 antibody
Phase 1: Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
An Adverse Event (AE) was defined as any unfavorable and unintended sign, symptom, or disease associated with the use of study drugs, whether considered related to study drugs or not. TEAE was an AE that has an onset date or a worsening in severity from baseline on or after the first dose of study drug up to 30 days following study drug discontinuation or initiation of the first new systemic anticancer therapy, whichever occurred first. An SAE was any untoward medical occurrence that, at any dose, resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability, was a congenital anomaly or was considered a medically significant. Severity of AEs was assessed according to National Cancer Institute Common Toxicity Criteria for Adverse Events (NCI-CTCAE) v.5.0, which consists of: Grade 1 Mild; Grade 2 Moderate; Grade 3: Severe; Grade 4: Life-threatening; Grade 5: Death due to AE.
Time frame: Up to 30 days after last dose of study drug (maximum treatment duration: up to 32.7 months)
Phase 1: Maximum Tolerated Dose (MTD) or Maximum Administered Dose (MAD) of Surzebiclimab in Combination With Tislelizumab
The MAD was defined as the highest dose administered, where all dose levels were tolerated during dose escalation. The MTD was not reached in Phase 1, therefore the MAD was reported.
Time frame: Up to 28 days
Phase 1: Recommended Phase 2 Dose (RP2D) of Surzebiclimab in Combination With Tislelizumab
The RP2D or recommended dose for expansion of the combination treatment was determined based upon the MTD or MAD, and also considered the long-term tolerability, PK, efficacy, and any other relevant data as available.
Time frame: Up to 28 days
Phase 2 (Safety Lead-In): Number of Participants With TEAEs and SAEs
An AE was defined as any unfavorable and unintended sign, symptom, or disease associated with the use of study drugs, whether considered related to study drugs or not. TEAE was an AE that has an onset date or a worsening in severity from baseline on or after the first dose of study drug up to 30 days following study drug discontinuation or initiation of the first new systemic anticancer therapy, whichever occurred first. An SAE was any untoward medical occurrence that, at any dose, resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability, was a congenital anomaly or was considered a medically significant. Severity of AEs was assessed according to NCI-CTCAE v.5.0, which consists of: Grade 1 Mild; Grade 2 Moderate; Grade 3: Severe; Grade 4: Life-threatening; Grade 5: Death due to AE.
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Chao Family Comprehensive Cancer Center
Orange, California, United States
University of Colorado Cancer Center
Aurora, Colorado, United States
University of Chicago Medical Center
Chicago, Illinois, United States
University of Kentucky Markey Cancer Center
Lexington, Kentucky, United States
Weill Cornell Medical College Newyork Presbyterian Hospital
New York, New York, United States
University of North Carolina At Chapel Hill
Chapel Hill, North Carolina, United States
Fox Chase Cancer Center
Philadelphia, Pennsylvania, United States
The University of Texas Md Anderson Cancer Center
Houston, Texas, United States
Ut Health San Antonio Mays Cancer Center
San Antonio, Texas, United States
University of Virginia
Charlottesville, Virginia, United States
...and 30 more locations
Time frame: Up to 30 days after last dose of study drug (maximum duration of treatment: up to 19.6 months in Cohort A and up to 21.5 months in Cohort B)
Phase 2 (Safety Lead-In): MTD or MAD of Alcestobart in Combination With Tislelizumab
The MAD was defined as the highest dose administered, where all dose levels were tolerated during dose escalation. The MTD was not reached in Phase 2, therefore the MAD was reported.
Time frame: Up to 21 days
Phase 2 (Safety Lead-In): MTD or MAD of Alcestobart in Combination With Surzebiclimab and Tislelizumab
The MAD was defined as the highest dose administered, where all dose levels were tolerated during dose escalation. The MTD was not reached in Phase 2, therefore the MAD was reported.
Time frame: Up to 21 days
Phase 2 (Safety Lead-In): RP2D of Alcestobart in Combination With Surzebiclimab and Tislelizumab
The RP2D or recommended dose for expansion of the combination treatment was determined based upon the MTD or MAD, and also considered the long-term tolerability, PK, efficacy, and any other relevant data as available.
Time frame: Up to 21 days
Phase 2 (Dose Expansion): Overall Response Rate (ORR)
ORR was defined as the percentage of participants who had complete response (CR) or partial response (PR). Per Response Evaluation Criteria in Solid Tumors (RECIST) version (v)1.1., CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (\<) 10 millimeters (mm). PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.
Time frame: Maximum time on study: Cohort 1: up to 31.3 months, Cohort 2: up to 32.0 months, Cohort 4: up to11.3 months, Cohort 5: up to 15.9 months
Phase 1: Overall Response Rate (ORR)
ORR was defined as the percentage of participants who had CR or PR. Per RECIST v.1.1, CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \< 10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.
Time frame: Maximum time on study: up to 57.5 months
Phase 2 (Safety Lead- In): Overall Response Rate (ORR)
ORR was defined as the percentage of participants who had CR or PR. Per RECIST v.1.1, CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \< 10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters.
Time frame: Maximum time on study: Cohort A: up to 22.1 months; Cohort B: up to 21.5 months
Phase 1: Disease Control Rate (DCR)
DCR was defined as the percentage of participants with a best overall response (BOR) of CR, PR, or stable disease (SD), per RECIST v.1.1. CR was defined as the disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \< 10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. Stable Disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease (PD), taking as reference the smallest sum diameters while on study.
Time frame: Maximum time on study: up to 57.5 months
Phase 2 (Safety Lead-In): Disease Control Rate (DCR)
DCR was defined as the percentage of participants with a BOR of CR, PR, or SD, per RECIST v.1.1. CR was defined as the disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \< 10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. SD: Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study.
Time frame: Maximum time on study: Cohort A: up to 22.1 months; Cohort B: up to 21.5 months
Phase 2 (Dose Expansion): Disease Control Rate (DCR)
DCR was defined as the percentage of participants with a BOR of CR, PR, or SD, per RECIST v.1.1. CR was defined as the disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \< 10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. SD: Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study.
Time frame: Maximum time on study: Cohort 1: up to 31.3 months, Cohort 2: up to 32.0 months, Cohort 4: up to 11.3 months, Cohort 5: up to 15.9 months
Phase 2 (Dose Expansion): Duration of Response (DOR)
DOR was defined as the time from the first determination of an overall response per RECIST v1.1 until the first documentation of progression or death, whichever came first. DOR was estimated using the Kaplan-Meier method. Per RECIST v.1.1., CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \< 10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. Progressive disease was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study.
Time frame: From the first determination of an overall response until PD or death, whichever came first (Maximum time on study [Cohort 1: up to 31.3 months, Cohort 2: up to 32.0 months, Cohort 4: up to 11.3 months, Cohort 5: up to 15.9 months])
Phase 2 (Dose Expansion): Progression Free Survival (PFS)
Progression free survival was defined as the time from the date of the first dose of study drug(s) to the date of the first documentation of disease progression assessed by investigator or death, whichever occurred first as determined from investigator derived tumor assessments per RECIST 1.1. Per RECIST v1.1, PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study.
Time frame: Maximum time on study: Cohort 1: up to 31.3 months, Cohort 2: up to 32.0 months, Cohort 4: up to 11.3 months, Cohort 5: up to 15.9 months
Phase 1: Maximum Observed Plasma Concentration (Cmax) of Surzebiclimab
The maximum observed plasma concentration of surzebiclimab was measured in Cycle 1 and Cycle 5.
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI; within 30 minutes), 6 hours, 1, 3, 7, 14, 21, and 28 (cycle 1 only) days after EOI. Cycle 1 was 28 days and Cycle 5 was 21 days.
Phase 2 (Dose Expansion): Cmax of Surzebiclimab
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI (each cycle was 21 days)
Phase 1: Minimum Observed Plasma Concentration (Cmin) of Surzebiclimab
Cmin of surzebiclimab was determined.
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, 21, and 28 (cycle 1 only) days after EOI (Cycle 1 was 28 days; Cycle 2 and thereafter were 21 days)
Phase 2 (Dose Expansion): Cmin of Surzebiclimab
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI
Phase 1: Time to Maximum Observed Plasma Concentration (Tmax) of Surzebiclimab
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, 21, and 28 (cycle 1 only) days after EOI (Cycle 1 was28 days; Cycle 2 and thereafter were 21 days)
Phase 2 (Dose Expansion): Tmax of Surzebiclimab
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI (each cycle was 21 days)
Phase 1: Half-Life (t1/2) of Surzebiclimab
Time frame: Cycle 1 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, 21, and 28 days after EOI (Cycle 1 was 28 days)
Phase 2 (Dose Expansion): T1/2 of Surzebiclimab
Time frame: Cycle 1 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI (each cycle was 21 days)
Phase 1: Area Under Curve From 0 to 21 Days (AUC0-21d) of Surzebiclimab
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI (Cycle 1 was 28 days; Cycle 2 and thereafter were 21 days)
Phase 2 (Dose Expansion): AUC0-21d of Surzebiclimab
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI (each cycle duration= 21 days)
Phase 1: Clearance (CL/F) of Surzebiclimab
Time frame: Cycle 1 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, 21, and 28 days after EOI (Cycle 1 was 28 days)
Phase 2 (Dose Expansion): CL/F of Surzebiclimab
Time frame: Cycle 1 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI
Phase 1: Volume of Distribution (Vz/F) of Surzebiclimab
Time frame: Cycle 1 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, 21, and 28 days after EOI (Cycle 1 was 28 days)
Phase 2 (Dose Expansion): Vz/F of Surzebiclimab
Vz/F of surzebiclimab was determined.
Time frame: Cycle 1 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI
Phase 2 (Safety Lead-In): Cmax of Alcestobart
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI (each cycle was 21 days)
Phase 2 (Safety Lead-In): Cmin of Alcestobart
Cmin of alcestobart was determined.
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI (each cycle was 21 days)
Phase 2 (Safety Lead-In): Tmax of Alcestobart
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI (each cycle was 21 days)
Phase 2 (Safety Lead-In): t1/2 of Alcestobart
Time frame: Cycle 1 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI (each cycle was 21 days)
Phase 2 (Safety Lead-In): AUC0-21d of Alcestobart
Time frame: Cycle 1 Day 1 and Cycle 5 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI (each cycle was 21 days)
Phase 2 (Safety Lead-In): CL/F of Alcestobart
Time frame: Cycle 1 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI
Phase 2 (Safety Lead-In): Vz/F of Alcestobart
Time frame: Cycle 1 Day 1 at pre-dose, end of infusion (EOI), 6 hours, 1, 3, 7, 14, and 21 days after EOI
Phase 1: Serum Concentrations of Tislelizumab
Serum concentrations of tislelizumab were measured using an enzyme-linked immunosorbent assay (ELISA).
Time frame: Pre-dose and EOI (within 30 minutes) on Cycle 1 Day 8 and Cycle 5 Day 1, and pre-dose on Day 1 of Cycles 2, 3, 6, 9, 13, 17, and 25 (Cycle 1 was 28 days, Cycle 2 and thereafter were 21 days)
Phase 2 (Dose Expansion): Serum Concentrations of Tislelizumab
Serum concentrations of tislelizumab were measured using an enzyme-linked immunosorbent assay (ELISA).
Time frame: Pre-dose on Day 1 of Cycles 1, 2, 5, 6, 9, 13, 17, 25 and at EOI (within 30 minutes) on Day 1 of Cycles 1 and 5 (each cycle was 21 days)
Phase 1: Number of Participants With Anti-Drug Antibodies (ADA) to Surzebiclimab
Immunogenic responses to surzebiclimab included: treatment emergent, treatment-induced and treatment boosted anti-drug antibodies (ADA) and neutralizing antibody (NAb) positive assessments. Treatment-emergent ADA was defined as the sum of treatment-boosted ADA and treatment-induced ADA participants. Treatment-induced ADA was defined as ADA-evaluable participants that were ADA-negative at baseline and ADA-positive after drug administration during the treatment or follow-up observation period. Treatment-boosted ADA was defined as the Baseline-positive ADA-evaluable participants with significant increases (4-fold or higher) in ADA titer after drug administration during the treatment or follow-up observation period. NAb positive was defined as ADA-evaluable participants with positive Nab at any time including baseline and/or after drug administration.
Time frame: Maximum time on study: up to 57.5 months
Phase 2 (Safety Lead-In) Cohort B: Number of Participants With Anti-Drug Antibodies to Surzebiclimab
Immunogenic responses to surzebiclimab included: treatment-emergent, treatment-induced and treatment-boosted ADA and NAb positive assessments. Treatment-emergent ADA was defined as the sum of treatment-boosted ADA and treatment-induced ADA participants. Treatment-induced ADA was defined as ADA-evaluable participants that were ADA-negative at baseline and ADA-positive after drug administration during the treatment or follow-up observation period. Treatment-boosted ADA was defined as the baseline-positive ADA-evaluable participants with significant increases (4-fold or higher) in ADA titer after drug administration during the treatment or follow-up observation period. NAb positive was defined as ADA-evaluable participants with positive NAb at any time including baseline and/or after drug administration.
Time frame: Maximum time on study in Cohort B: up to 21.5 months
Phase 2 (Dose Expansion): Number of Participants With Anti-Drug Antibodies to Surzebiclimab
Immunogenic responses to surzebiclimab included: treatment-emergent, treatment-induced and treatment-boosted ADA and NAb positive assessments. Treatment-emergent ADA was defined as the sum of treatment-boosted ADA and treatment-induced ADA participants. Treatment-induced ADA was defined as ADA-evaluable participants that were ADA-negative at baseline and ADA-positive after drug administration during the treatment or follow-up observation period. Treatment-boosted ADA was defined as the baseline-positive ADA-evaluable participants with significant increases (4-fold or higher) in ADA titer after drug administration during the treatment or follow-up observation period. NAb positive was defined as ADA-evaluable participants with positive NAb at any time including baseline and/or after drug administration.
Time frame: Maximum time on study: Cohort 1: up to 31.3 months, Cohort 2: up to 32.0 months, Cohort 4: up to 11.3 months, Cohort 5: up to 15.9 months
Phase 2 (Safety Lead-In): Number of Participants With Anti-Drug Antibodies to Alcestobart
Immunogenic responses to alcestobart included: treatment-emergent, treatment-induced and treatment-boosted ADA and NAb positive assessments. Treatment-emergent ADA was defined as the sum of treatment-boosted ADA and treatment-induced ADA participants. Treatment-induced ADA was defined as ADA-evaluable participants that were ADA-negative at baseline and ADA-positive after drug administration during the treatment or follow-up observation period. Treatment-boosted ADA was defined as the baseline-positive ADA-evaluable participants with significant increases (4-fold or higher) in ADA titer after drug administration during the treatment or follow-up observation period. NAb positive was defined as ADA-evaluable participants with positive NAb at any time including baseline and/or after drug administration.
Time frame: Maximum time on study: Cohort A: up to 22.1 months; Cohort B: up to 21.5 months
Phase 2 (Dose Expansion) Cohorts 4 and 5: Number of Participants With Anti-Drug Antibodies to Alcestobart
Immunogenic responses to alcestobart included: treatment-emergent, treatment-induced and treatment-boosted ADA and NAb positive assessments. Treatment-emergent ADA was defined as the sum of treatment-boosted ADA and treatment-induced ADA participants. Treatment-induced ADA was defined as ADA-evaluable participants that were ADA-negative at baseline and ADA-positive after drug administration during the treatment or follow-up observation period. Treatment-boosted ADA was defined as the baseline-positive ADA-evaluable participants with significant increases (4-fold or higher) in ADA titer after drug administration during the treatment or follow-up observation period. NAb positive was defined as ADA-evaluable participants with positive NAb at any time including baseline and/or after drug administration.
Time frame: Maximum time on study: Cohort 4: up to 11.3 months, Cohort 5: up to 15.9 months
Phase 1: Number of Participants With Anti-Drug Antibodies to Tislelizumab
Immunogenic responses to tislelizumab included: treatment-emergent, treatment-induced and treatment-boosted ADA and NAb positive assessments. Treatment-emergent ADA was defined as the sum of treatment-boosted ADA and treatment-induced ADA participants. Treatment-induced ADA was defined as ADA-evaluable participants that were ADA-negative at baseline and ADA-positive after drug administration during the treatment or follow-up observation period. Treatment-boosted ADA was defined as the baseline-positive ADA-evaluable participants with significant increases (4-fold or higher) in ADA titer after drug administration during the treatment or follow-up observation period. NAb positive was defined as ADA-evaluable participants with positive NAb at any time including baseline and/or after drug administration.
Time frame: Maximum time on study: up to 57.5 months
Phase 2 (Safety Lead-In): Number of Participants With Anti-Drug Antibodies to Tislelizumab
Immunogenic responses to alcestobart included: treatment-emergent, treatment-induced and treatment-boosted ADA and NAb positive assessments. Treatment-emergent ADA was defined as the sum of treatment-boosted ADA and treatment-induced ADA participants. Treatment-induced ADA was defined as ADA-evaluable participants that were ADA-negative at baseline and ADA-positive after drug administration during the treatment or follow-up observation period. Treatment-boosted ADA was defined as the baseline-positive ADA-evaluable participants with significant increases (4-fold or higher) in ADA titer after drug administration during the treatment or follow-up observation period. NAb positive was defined as ADA-evaluable participants with positive NAb at any time including baseline and/or after drug administration.
Time frame: Maximum time on study: Cohort A: up to 22.1 months; Cohort B: up to 21.5 months
Phase 2 (Dose Expansion): Number of Participants With Anti-Drug Antibodies to Tislelizumab
Immunogenic responses to tislelizumab included: treatment-emergent, treatment-induced and treatment-boosted ADA and NAb positive assessments. Treatment-emergent ADA was defined as the sum of treatment-boosted ADA and treatment-induced ADA participants. Treatment-induced ADA was defined as ADA-evaluable participants that were ADA-negative at baseline and ADA-positive after drug administration during the treatment or follow-up observation period. Treatment-boosted ADA was defined as the baseline-positive ADA-evaluable participants with significant increases (4-fold or higher) in ADA titer after drug administration during the treatment or follow-up observation period. NAb positive was defined as ADA-evaluable participants with positive NAb at any time including baseline and/or after drug administration.
Time frame: Maximum time on study: Cohort 1: up to 31.3 months, Cohort 2: up to 32.0 months, Cohort 4: up to 11.3 months, Cohort 5: up to 15.9 months
Phase 2 (Dose Expansion): Number of Participants With TEAEs and SAEs
An AE was defined as any unfavorable and unintended sign, symptom, or disease associated with the use of study drugs, whether considered related to study drugs or not. An SAE was any untoward medical occurrence that, at any dose, resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability, was a congenital anomaly or was considered a medically significant. TEAE was an AE that has an onset date or a worsening in severity from baseline on or after the first dose of study drug up to 30 days following study drug discontinuation or initiation of the first new systemic anticancer therapy, whichever occurred first. Severity of AEs was assessed according to NCI-CTCAE v.5.0, which consists of: Grade 1 Mild; Grade 2 Moderate; Grade 3: Severe; Grade 4: Life-threatening; Grade 5: Death due to AE.
Time frame: Up to 30 days after last dose of study drug (maximum treatment duration: Cohort 1: up to 6.9 months, Cohort 2: up to 23.5 months, Cohort 4: up to 9.6 months, Cohort 5: up to 15.4 months)