This study investigates the effectiveness of an investigational medication for treating germ cell tumors that do not respond to platinum-based treatments. Germ cell tumors are a type of cancer that begins in the cells that develop into sperm or eggs. The purpose of the study is to find the best dose for phase 2 and to measure how well the medication works in shrinking tumors.
Participants will receive the investigational medication and undergo various tests to see how their tumors respond. The study will look at different measures of effectiveness, such as how long the response lasts and how the disease progresses. It will also monitor the safety and side effects of the medication, as well as its effects on certain proteins in the blood.
- Who can participate: Eligible participants are men who must use contraception or remain abstinent during the study and for 6 months after. They should also comply with specific requirements if their partner is pregnant or breastfeeding.
- Study details: Participants will receive the investigational medication and will be monitored for changes in their condition. A placebo will not be used in this study. The study will include tests to measure the effects of the medication on blood proteins and tumor response.

