DOR was defined as time between date of first documented response (CR/PR) and date of first documented progression or death, whichever occurred first. CR was defined as disappearance of target and non-target lesions and normalization of tumor markers. Pathological lymph nodes short axis measures <10 mm. PR was defined as >=30% decrease in sum of measures (tumor lesions-longest diameter and nodes-short axis) of target lesions, taking as reference baseline sum of diameters. Non-target lesions must be non-PD. For non-target lesions, PD: unequivocal progression of existing non-target lesions. The appearance of one or more new lesions was also considered progression. There was no participant who had event (CR/PR) in Phase 2a EC higher dose cohort, hence data could not be collected and analyzed for this cohort.

TTR was defined as time from date of first amivantamab administration to date of achieving objective response (CR/PR) as assessed by investigator per RECIST v1.1 among participants who achieved objective response. Per RECIST v1.1, CR: disappearance of target and non-target lesions and normalization of tumor markers. Pathological lymph nodes must have short axis measures <10 mm. PR: >=30% decrease in sum of measures (longest diameter for tumor lesions and short axis measure for nodes) of target lesions, taking as reference baseline sum of diameters. Non-target lesions must be non-PD. For non-target lesions, PD: unequivocal progression of existing non-target lesions. The appearance of one or more new lesions was also considered progression. There was no participant who had event (CR/PR) in Phase 2a EC higher dose cohort, hence data could not be collected and analyzed for this cohort.

PFS was defined as the time from the date of first dose of study drug until the date of objective disease progression or death (by any cause in the absence of progression), whichever comes first, based on investigator assessment using RECIST Version 1.1.

An adverse event (AE) was any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the intervention. TEAEs was defined as AEs occurring at or after first dose of study drug up to 30 days after last dose or until the start of new anticancer therapy, whichever occurred first. TEAEs were graded according to NCI-CTCAE v5.0. Grade 1- Mild; Grade 2- Moderate; Grade 3- Severe or medically significant but not immediately life-threatening; Grade 4- Life-threatening consequences; Grade 5- Death related to AE. All TEAEs including serious and non-serious events are reported in this outcome measure.

Cmax was defined as the maximum observed serum concentration of amivantamab. The concentrations of amivantamab were measured using a validated, specific, and sensitive enzyme-linked immunosorbent assay (ELISA) method. Data for this outcome measure was planned to be collected and analyzed for each cancer type (GC and EC) and overall participants (GC and EC combined cohorts: Amivantamab [1050/1400 mg]). As planned, data for Cmax was not collected and analyzed for Phase 2a EC higher dose cohort.

Tmax was defined as the time to reach maximum observed serum concentration of amivantamab. The concentrations of amivantamab were measured using a validated, specific, and sensitive ELISA method. Data for this outcome measure was planned to be collected and analyzed for each cancer type (GC and EC) and overall participants (GC and EC combined cohorts: Amivantamab [1050/1400 mg]). As planned, data for Tmax was not collected and analyzed for Phase 2a EC higher dose cohort.

AUC (0-168h) was defined as area under the serum concentration time-curve from time zero to the time point 168 hours. The concentrations of amivantamab were measured using a validated, specific, and sensitive ELISA method. Data for this outcome measure was planned to be collected and analyzed for each cancer type (GC and EC) and overall participants (GC and EC combined cohorts: Amivantamab [1050/1400 mg]). As planned, data for AUC (0-168h) was not collected and analyzed for Phase 2a EC higher dose cohort.

Area under the serum concentration curve from time 0 to end of dosing interval (AUCtau), where dosing interval was 336 hours was reported. The concentrations of amivantamab were measured using a validated, specific, and sensitive ELISA method. Data for this outcome measure was planned to be collected and analyzed for each cancer type (GC and EC) and overall participants (GC and EC combined cohorts: Amivantamab [1050/1400 mg]). As planned, data for AUCtau was not collected and analyzed for Phase 2a EC higher dose cohort.

Ctrough of amivantamab in GC and EC cohorts were reported. Ctrough was defined as pre-dose serum drug concentration. The concentrations of amivantamab were measured using a validated, specific, and sensitive ELISA method. Data for this outcome measure was planned to be collected and analyzed for each cancer type (GC and EC) and overall participants (GC and EC combined cohorts: Amivantamab [1050/1400 mg]).

Ctrough of amivantamab in phase 2a EC higher dose cohort was reported. Ctrough was defined as pre-dose serum drug concentration. The concentrations of amivantamab were measured using a validated, specific, and sensitive ELISA method.

Terminal elimination half-life (t1/2) was the time measured for the serum concentration of a drug to decrease by half of its initial concentration. The concentrations of amivantamab were measured using a validated, specific, and sensitive ELISA method.

Terminal elimination half-life (t1/2) was the time measured for the serum concentration of a drug to decrease by half of its initial concentration. The concentrations of amivantamab were measured using a validated, specific, and sensitive ELISA method. Data for this outcome measure was planned to be collected and analyzed for EC cohort and overall participants (GC and EC combined cohorts: Amivantamab [1050/1400 mg]). As planned, data for t1/2 was not collected and analyzed for Phase 2a EC higher dose cohort.

Clearance was a measure of the rate at which a drug was metabolized or eliminated by normal biological processes. The concentrations of amivantamab were measured using a validated, specific, and sensitive ELISA method. Data for this outcome measure was planned to be collected and analyzed for each cancer type (GC and EC) and overall participants (GC and EC combined cohorts: Amivantamab [1050/1400 mg]). As planned, data for CLss was not collected and analyzed for Phase 2a EC higher dose cohort.

Volume of distribution was defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired serum concentration of a drug. The concentrations of amivantamab were measured using a validated, specific, and sensitive ELISA method. Data for this outcome measure was planned to be collected and analyzed for each cancer type (GC and EC) and overall participants (GC and EC combined cohorts: Amivantamab [1050/1400 mg]). As planned, data for Vss was not collected and analyzed for Phase 2a EC higher dose cohort.

Accumulation ratio for AUC was calculated as AUC (0-336h) for Cycle 2 Day 1 divided by AUC (0-168h) for Cycle 1 Day 1. The concentrations of amivantamab were measured using a validated, specific, and sensitive ELISA method. Data for this outcome measure was planned to be collected and analyzed for each cancer type (GC and EC) and overall participants (GC and EC combined cohorts: Amivantamab [1050/1400 mg]). As planned, data for AR of AUCtau was not collected and analyzed for Phase 2a EC higher dose cohort.

Number of participants with anti-amivantamab antibodies were reported. Serum samples were assessed for anti-drug antibodies.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic GC and EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic GC and EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic GC and EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic GC and EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic GC and EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic GC and EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic GC and EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic GC and EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic esophageal cancer (EC) exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic GC and EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1050 mg for body weight <80 kg or 1400 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (700 mg for body weight <80 kg or 1050 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.

Participants with previously treated advanced or metastatic EC exhibiting varying degrees of EGFR, MET, or both as determined by IHC received amivantamab 1750 mg for body weight <80 kg or 2100 mg for body weight >=80 kg as an IV infusion in each 28-day cycles. During Cycle 1, amivantamab was administered once weekly on Days 1, 8, 15 and 22 with the first dose split over Day 1 (350 mg) and Day 2 (1400 mg for body weight <80 kg or 1750 mg for body weight >=80 kg). From Cycle 2 onwards, amivantamab was administered on Days 1 and 15 until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, lost to follow-up or death whichever comes first. Participants were followed up for safety up to 30 days after the last dose.