This study is for people with a type of breast cancer called *triple-negative breast cancer* (TNBC). TNBC is a form of cancer that does not have three common traits (receptors) usually found in breast cancer. The study compares two treatments: one using a combination of two drugs called sacituzumab tirumotecan (sac-TMT) and pembrolizumab, and the other is a treatment of the doctor's choice.

This study is for those who did not achieve a *pathological complete response* (pCR), meaning the cancer was not completely gone after initial treatment and surgery. The main goal is to see if the combination of sac-TMT and pembrolizumab helps patients live longer without the cancer coming back, compared to other treatments.

• Participants must have had prior specific treatments and surgery.
• The study involves random assignment to one of the treatment groups within 12 weeks after surgery.
• Participants must not have certain medical conditions or be taking certain medications.

This study may offer a new treatment option, but it's important to consider potential risks and eligibility criteria before joining.