A Study of Sacituzumab Tirumotecan (Sac-TMT, MK-2870) as Monotherapy and in Combination With Pembrolizumab (MK-3475) in Participants With Triple-Negative Breast Cancer (MK-2870-011/TroFuse-011)

To join this study, you must be at least 18 years old and have triple-negative breast cancer that has come back in the local area or spread to other parts of your body, and can't be cured by surgery. You can't have received previous treatment for this advanced stage of breast cancer, though if you were treated for early-stage breast cancer, that's okay, as long as it was at least 6 months ago.

You should also generally be fit enough for treatment with pembrolizumab and standard chemotherapy options like paclitaxel. If you've had side effects from previous cancer treatments, these must have mostly cleared up. If you have hepatitis B or C, you might still be able to join if your virus levels are very low or undetectable with treatment.

However, you can't join if your breast cancer could still be cured with surgery. You also can't have certain other conditions, such as severe nerve damage (peripheral neuropathy), severe dry eyes or corneal issues, or active inflammatory bowel disease. If you've already received systemic treatment for your advanced breast cancer, you won't be eligible for this study.

If you decide to join this study, you would receive either sacituzumab tirumotecan alone, sacituzumab tirumotecan with pembrolizumab, or standard chemotherapy (such as paclitaxel or a combination of gemcitabine and carboplatin). The treatment will involve regular visits to the clinic for your medications and check-ups. Doctors and nurses will closely monitor your health, perform tests, and assess how well the treatment is working and if you're experiencing any side effects. You will also have regular follow-up appointments after your main treatment period. The exact duration of your participation will depend on the treatment assigned and your response, and your study team will provide you with a detailed schedule.