Study of T-DXd Monotherapy in Patients With HER2-expressing Locally Advanced or Metastatic Gastric or GEJ Adenocarcinoma Who Have Received 2 or More Prior Regimens

Progression-free Survival (PFS) Rate at 6 Months Based on Independent Central Review (ICR)

PFS based on ICR is defined as the time from date of enrolment until the date of objective disease progression or death (by any cause in the absence of progression) regardless of whether the patient withdraws from therapy or receives another anti-cancer therapy prior to progression

Time frame: Tumour assessments every 6 weeks from 1st dose of treatment until Recist 1.1 defined radiological progressive disease. Calculated at 6 months using the Kaplan-Meier technique

Progression-free Survival (PFS) Rate at 9 Months Based on Independent Central Review (ICR)

PFS based on ICR is defined as the time from date of enrolment until the date of objective disease progression or death (by any cause in the absence of progression) regardless of whether the patient withdraws from therapy or receives another anti-cancer therapy prior to progression

Time frame: Tumour assessments every 6 weeks from 1st dose of treatment until Recist 1.1 defined radiological progressive disease. Calculated at 9 months using the Kaplan-Meier technique

Progression-free Survival (PFS) Rate at 12 Months Based on Independent Central Review (ICR)

PFS based on ICR is defined as the time from date of enrolment until the date of objective disease progression or death (by any cause in the absence of progression) regardless of whether the patient withdraws from therapy or receives another anti-cancer therapy prior to progression

Time frame: Tumour assessments every 6 weeks from 1st dose of treatment until Recist 1.1 defined radiological progressive disease. Calculated at 12 months using the Kaplan-Meier technique

Progression-free Survival (PFS) Rate at 15 Months Based on Independent Central Review (ICR)

PFS based on ICR is defined as the time from date of enrolment until the date of objective disease progression or death (by any cause in the absence of progression) regardless of whether the patient withdraws from therapy or receives another anti-cancer therapy prior to progression

Time frame: Tumour assessments every 6 weeks from 1st dose of treatment until Recist 1.1 defined radiological progressive disease. Calculated at 15 months using the Kaplan-Meier technique

Progression-free Survival (PFS) Rate at 18 Months Based on Independent Central Review (ICR)

PFS based on ICR is defined as the time from date of enrolment until the date of objective disease progression or death (by any cause in the absence of progression) regardless of whether the patient withdraws from therapy or receives another anti-cancer therapy prior to progression

Time frame: Tumour assessments every 6 weeks from 1st dose of treatment until Recist 1.1 defined radiological progressive disease. Calculated at 18 months using the Kaplan-Meier technique

Progression-free Survival (PFS) Rate at 21 Months Based on Independent Central Review (ICR)

PFS based on ICR is defined as the time from date of enrolment until the date of objective disease progression or death (by any cause in the absence of progression) regardless of whether the patient withdraws from therapy or receives another anti-cancer therapy prior to progression

Time frame: Tumour assessments every 6 weeks from 1st dose of treatment until Recist 1.1 defined radiological progressive disease. Calculated at 21 months using the Kaplan-Meier technique

Disease Control Rate (DCR) Based on Independent Central Review (ICR)

Disease control rate based on ICR according to RECIST version 1.1 was defined as the rate of best objective response of complete response (CR), partial response (PR) or stable disease (SD)

Time frame: Tumour assessments every 6 weeks from 1st dose of treatment until Recist 1.1 defined radiological progressive disease. Assessed up to a maximum of 22 months

Disease Control Rate (DCR) Based on Independent Central Review (ICR) at Week 12

Disease control rate based on ICR according to RECIST version 1.1 was defined as the rate of best objective response of complete response (CR), partial response (PR) or stable disease (SD) for at least 11 weeks (ie 12 weeks - 1 week to allow for an early assessment within the assessment window)

Time frame: Tumour assessments every 6 weeks from 1st dose of treatment until Recist 1.1 defined radiological progressive disease. DCR assessed at Week 12

Duration of Response (DoR) Based on Independent Central Review (ICR)

DoR defined as the time from the date of first documented OR (confirmed CR or confirmed PR) until date of documented progression (PD) or death in the absence of progression based on investigator assessments by using RECIST version 1.1

Time frame: Tumour assessments every 6 weeks from 1st dose of treatment until Recist 1.1 defined radiological progressive disease. Assessed up to a maximum of 22 months

Overall Survival (OS) Based on Independent Central Review (ICR)

OS based on ICR is defined as the time from date of enrolment until the date of death due to any cause

Time frame: From date of enrolment until death due to any cause. Assessed up to approximately 30 months (from date of first subject in to data cut-off 28February2024)

Best Percentage Change in Sum of Diameters of Measurable Tumours Based on Independent Central Review (ICR)

Best percentage change based on ICR is defined as the best change in target lesion tumour size from baseline (maximum reduction or minimum increase from baseline in the absence of a reduction)

Time frame: Tumour assessments every 6 weeks from 1st dose of treatment until Recist 1.1 defined radiological progressive disease. Assessed up to a maximum of 22 months