This study is testing a drug called DB-1310 on people with advanced solid tumors. A tumor is a lump of cells that can be cancerous, and advanced solid tumors mean the cancer has spread or is hard to treat. This is a Phase 1/2a trial, meaning it's in the early stages to see if the drug is safe and how well it works. The study is being done in multiple places and will test different doses of the drug.

• Participants must be 18 or older and have tried other cancer treatments that didn’t work.
• They need to visit the trial center for tests and treatment, and the study will check their health closely.
• Participants can't join if they have certain heart problems, infections, or are pregnant.

This study involves taking DB-1310 alone or with other cancer drugs like trastuzumab or Osimertinib. The goal is to find the right dose and see if it helps people with these tough cancers. Participants will be monitored for safety and side effects.