A Study to Investigate the Effects of AZD0901 Monotherapy in Adult Participants With 2L+ Advanced or Metastatic Gastric or GEJ Adenocarcinoma Expressing CLDN18.2

Progression Free Survival (PFS)

PFS is defined as time from date of first dose until progression per RECIST 1.1 as assessed by the investigator, or death due to any cause

Time frame: From the date of assignment until the date of first documented progression or date of death from any cause, whichever comes first, assessed up to 30 months

Overall Survival (OS)

OS is defined as the time from date of first dose of IMP until the date of death due to any cause. The analysis will include all dosed participants. All deaths will be included, regardless of whether the participant withdraws from therapy or receives another anticancer therapy

Time frame: From the date of assignment until the date of death from any cause, assessed up to 30 months

Disease control rate (DCR) at 12 weeks

DCR at 12 weeks is defined as the percentage of participants who have at least 1 visit response of confirmed CR or PR or who have stable disease (SD) per RECIST 1.1 for at least 11 weeks as assessed by the investigator to all dosed participants

Time frame: At 12 weeks after date of first dose

Duration of Response (DoR)

DoR is defined as the time from the date of first documented confirmed response until date of documented progression or death due to any cause. Analysis will include all dosed participants, with measurable disease at baseline who have a response, regardless of whether the participant withdraws from therapy, receives another anticancer treatment, or clinically progresses prior to PD.