Zion (Solid Tumors)

We are doing this study to find out what the safest and most effective dose of the study drug (ZN-A-1041) is when given alone or in combination with capecitabine.

People with HER2-Positive Advanced Solid Tumors

• Phase 1a - Adults with HER2-positive advanced solid tumors
• Phase 1b - Adults with HER2-positive breast cancer
• Phase 1c - Adults with HER2-positive unresectable or metastatic breast cancer with brain metastases

This study will consist of three groups: Group 1a, Group 1b, and Group 1c.

• Group 1a is for people with HER2-positive advanced solid tumors. Participants in this group will get the study drug, ZN-A-1041.
• Group 1b is for people with HER2-positive breast cancer. Participants in this group will get the study drug in combination with capecitabine
• Group 1c is for people with HER2-positive unresectable or metastatic breast cancer with brain metastases. Participants in this group will get the study drug in combination with capecitabine.

If you choose to join this study, you will:

• Complete a 28 day screening period
• Complete a 21 day period where you take the study drug twice a day
• Have physical exams, blood and urine tests
• Have an eye exam
• Have imaging scans (CT and/or MRI)
• Complete a follow-up 28 days after finishing the study drug

You will be in the study until your disease progresses or you're unable to tolerate the study drug(s).