A Phase 2, Open-label, Multicenter Study to Evaluate Efficacy and Safety of Zanidatamab for the Treatment of Participants With Previously Treated HER2-expressing Solid Tumors (DiscovHER PAN-206)
The purpose of this study is to evaluate the efficacy and safety of zanidatamab for the treatment of participants with previously treated solid tumors that have Human Epidermal Growth Factor Receptor 2 (HER2) Immunohistochemistry (IHC) 3+ overexpression.
• Is at least 18 years of age inclusive at the time of signing the informed consent
• Participants with locally advanced, unresectable, or metastatic solid tumors (except Biliary Tract Cancer (BTC), defined as gallbladder cancer or cholangiocarcinoma) who have progressed following at least 1 prior systemic treatment for metastatic or advanced disease and have no available treatment options that have confirmed benefit. Prior treatment with HER2-targeted therapy is not permitted (Cohort 1 only). For participants with breast cancer (Cohort 2) or GEA (Cohort 3), prior HER2-targeted therapy is permitted and prior therapy with trastuzumab deruxtecan (T-DXd) is required.
• HER2 overexpression (IHC 3+) must be determined by a sponsor designated central laboratory.
• All participants must have adequate tumor sample for submission to allow central HER2 testing.
• Presence of at least 1 measurable lesion as assessed by Independent Central Review (ICR) based on Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1)
• Has Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
• Has a life expectancy of at least 3 months, in the opinion of the investigator.
• Participants with history of treated and stable CNS metastases are eligible, provided the following criteria are met:
∙ Participants also have measurable metastatic disease with HER2 overexpression (IHC 3+) outside the CNS.
‣ Participants with treated CNS metastases that are no longer symptomatic may be included in the study if they recovered to \< Grade 1 (CTCAE Version 5.0 or higher) or baseline from the acute toxic effect associated with the treatment \> 7 days prior to Cycle 1 Day 1.
‣ Prior stereotactic radiosurgery or stereotactic radiotherapy should be completed at least 7 days (≥ 7 days) before the first dose of study intervention.
• Adequate organ functions.
⁃ Females of childbearing potential must have a negative pregnancy test result.
⁃ Females of childbearing potential and males with a partner of childbearing potential must be willing to use 2 methods of birth control.