A First-in-human Study to Learn How Safe the Study Drug BAY3375968, an Anti-CCR8 Antibody, is, When Given Alone or in Combination With Pembrolizumab, How it Affects the Body, How it Moves Into, Through, and Out of the Body, and to Find the Best Dose in Participants With Advanced Solid Tumors

This study is looking for adults aged 18 or over who have advanced solid tumours. This means your cancer has spread or is difficult to treat with current options. You should have already tried, been unable to tolerate, or been unsuitable for standard treatments.

To join, your cancer must be measurable, and your general health, including your kidney and liver function, needs to be good. You'll need to be willing to use contraception if you are a woman of childbearing potential or a sexually active man. Also, you must be able and willing to have tumour biopsies (small tissue samples taken from your cancer).

You won't be able to join if you have another ongoing cancer, a brain tumour, or have had major surgery recently. You also can't have any significant side effects from previous cancer treatments that haven't cleared up (unless it's hair loss or skin darkening), or uncontrolled medical conditions. You also can't be pregnant or breastfeeding.

If you join this study, you will first have two visits to the study clinic before starting treatment. Once treatment begins, you'll have frequent visits – five times in the first week, then generally one to three times a month. You'll have another visit within 30 days after your last treatment.

Throughout the study, the team will take blood and urine samples, check your vital signs and overall health, and monitor your heart using ECGs and echocardiograms. They will also use imaging scans to see how your cancer is responding and if it has grown or spread. You may also be asked to have tumour samples taken. You will be asked questions about how your health is affecting your daily life and general well-being.

The study lasts for about 4 years and 7 months in total. After you finish your treatment and leave the study, doctors will check on your health around 90 days later. For a longer period, the study team will keep track of your cancer status roughly every 12 weeks, and for up to two years after the last participant has left the study, they will check on your survival and any other cancer treatments you may have received, usually by phone.