This study tests a new cancer drug called THE-0504 in adults with solid tumors, like lung or breast cancer. The main goal is to find out the safest dose to use in future studies. The drug is given through a vein twice in a 21-day cycle. After a patient is treated, there's a pause to see how they react before the next patient starts. The study checks if the drug is safe and how it acts in the body. Participants must have tried all other treatments and be in good health besides their cancer.
- Study involves 21-day cycles with treatment on Day 1 and Day 8.
- Participants must attend all planned visits and follow-up exams.
- Participants must use contraception if they can have children.