A Study to Test Combination Treatments in Participants With Advanced Gastric Cancer

The PFSR at 24 weeks is defined as the proportion of treated participants remaining progression free and surviving at 24 weeks since the first dosing date. Progressive Disease (PD) is at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Point estimates are derived from Kaplan-Meier analyses, the 95% CIs are derived from Greenwood formula.

Time frame: 24 weeks after first dose

Population: All treated participants

Duration of Response (DOR) is the time between the date of first response and the date of first documented disease progression as determined by RECIST 1.1 or death due to any cause, whichever occurred first. Complete Response (CR) is the disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Partial Response (PR) is at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. Median computed using Kaplan -Meier method.

Time frame: From first dose to date of first documented tumor progression or death due to any cause, whichever occurred first (up to approximately 65 months)

Population: All treated participants with a complete response (CR) or partial response (PR)

ORR is the percent of participants whose best overall response (BOR) is complete response (CR) or partial response (PR). BOR is the best response from the start of the study treatment until objectively documented progression per RECIST v1.1 or subsequent anticancer therapy, whichever occurs first. CR is the disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) have reduction in short axis to \<10 mm. PR is at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. The Response Evaluation Criteria in Solid Tumors (RECIST) is a standard way to measure the response of a tumor to treatment. CR+PR, confidence interval based on Clopper and Pearson method.

Time frame: From first dose of study treatment until progression or subsequent anticancer therapy, whichever occurs first (up to approximately 65 months)

Population: All treated participants

An Adverse Event (AE) is defined as any new untoward medical occurrence or worsening of a preexisting medical condition in a clinical investigation participant administered study treatment and that does not necessarily have a causal relationship with this treatment. Serious Adverse Event (SAE) is defined as any untoward medical occurrence that, at any dose results in death, is life-threatening (defined as an event in which the participant was at risk of death at the time of the event; it does not refer to an event which hypothetically might have caused death if it were more severe), requires inpatient hospitalization or causes prolongation of existing hospitalization.

Time frame: From first dose to 100 days after last dose of study therapy (assessed up to approximately 30 months)

Population: All treated participants

The number of participants with laboratory abnormalities in specific liver tests based on US conventional units. ALT = Alanine Aminotransferase AST = Aspartate Aminotransferase ULN = Upper Limit of Normal

Time frame: From first dose to 100 days after last dose of study therapy (approximately 30 months)

Population: All treated participants with at least one on-treatment AST, ALT and/or bilirubin test measurement

The number of participants with laboratory abnormalities in specific thyroid tests based on US conventional units. TSH = Thyroid Stimulating Hormone LLN = Lower Limit of Normal ULN = Upper Limit of Normal.

Time frame: From first dose to 100 days after last dose of study therapy (approximately 30 months)

Population: All treated participants with at least one on-treatment TSH measurement