This study is testing a new drug called SAIL66 for adults with advanced solid tumors that are CLDN6-positive. CLDN6 is a protein found in some cancer cells. The study checks how safe and effective the drug is, and how the body processes it. The study is in Phase 1, which means it's an early stage to see if the drug can be used safely in humans.

Eligibility: You can participate if you are 18 or older, have a solid tumor with CLDN6, and are in good overall health (ECOG PS 0 or 1). You cannot join if you plan to get pregnant or are breastfeeding during and 3 months after the study, have certain brain diseases, or have uncontrolled pain or fluid build-up from the tumor.

• The study involves taking SAIL66 and having regular check-ups to monitor safety and effects.
• Participants should not have certain brain conditions or uncontrolled symptoms.
• Before joining, consider the commitment and possible side effects.