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)

OS is defined as the time from randomization to death due to any cause.

PFS is defined as the time from randomization to the first documented progressive disease (PD) per RECIST 1.1 based on BICR or death due to any cause, whichever occurs first. PD is defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of ≥5 mm. The appearance of one or more new lesions is also considered PD.

ORR is defined as the percentage of participants with Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 30% decrease in the sum of diameters of target lesions) per RECIST 1.1 based on BICR.

For participants who demonstrate a confirmed Complete Response (CR: disappearance of all target lesions) or Partial Response (PR: at least a 30% decrease in the sum of diameters of target lesions) per RECIST 1.1 based on BICR, DOR is defined as the time from first documented evidence of CR or PR until progressive disease (PD) or death, whichever occurs first. Per RECIST 1.1, PD is defined as at least a 20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. The appearance of one or more new lesions is also considered PD.

The EORTC QLQ-C30 is a 30-item questionnaire to assess the overall quality of life of cancer patients. Participant responses to the questions "How would you rate your overall health during the past week?" and "How would you rate your overall quality of life during the past week?" are scored on a 7-point scale (1= Very poor to 7=Excellent). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. A higher score indicates a better overall health status.

The EORTC QLQ-C30 is a 30-item questionnaire to assess the overall quality of life of cancer patients. Participant responses to questions about their physical functioning are scored on a 4-point scale (1=Not at All to 4=Very Much). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. A higher score indicates a better level of physical functioning.

The EORTC QLQ-C30 is a 30-item questionnaire to assess the overall quality of life of cancer patients. Participant responses to questions about their emotional functioning are scored on a 4-point scale (1=Not at All to 4=Very Much). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. A higher score indicates a better level of emotional functioning.

The EORTC QLQ-C30 is a 30-item questionnaire to assess the overall quality of life of cancer patients. Participant responses to questions about their fatigue are scored on a 4-point scale (1=Not at All to 4=Very Much). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. A lower score indicates a better level of function.

The EORTC QLQ-C30 is a 30-item questionnaire to assess the overall quality of life of cancer patients. Participant responses to the question "Have you had diarrhea?" are scored on a 4-point scale (1=Not at All to 4=Very Much). Using linear transformation, raw scores are standardized, so that scores range from 0 to 100. A lower score indicates a better level of function.

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.

An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.