Please assess the completion status of the following clinical trial:

Trial Title: Study of Pembrolizumab (MK-3475) Monotherapy for Metastatic Triple-Negative Breast Cancer (MK-3475-086/KEYNOTE-086)

Study Design Characteristics:
- Allocation: NON_RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: NONE
- Phase: PHASE2
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~For the purposes of this study, neoadjuvant and/or adjuvant chemotherapy regimens do not count as a prior line of therapy.~For second line plus monotherapy (Parts 1 and 2):~* Has received at least one systemic treatment for metastatic breast cancer~* Has documented disease progression on or after the most recent therapy~* Prior treatment must include an anthracycline and a taxane in the neoadjuvant, adjuvant, or metastatic setting~For first line monotherapy (Part 1):~* Has received no prior systemic treatment for metastatic breast cancer~* Has PD-L1-positive mTNBC.~For second line plus monotherapy (Part 2):~- Has PD-L1 strong positive mTNBC~For all parts:~* Has mTNBC confirmed by a central laboratory~* For biomarker analysis, adequate newly obtained core or excisional biopsy of a not-previously-irradiated metastatic tumor lesion (mandatory)~* Has measurable metastatic disease~* Has Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1~* Female participants of childbearing potential should be willing to use 2 methods of birth control or be surgically sterile, or abstain from heterosexual activity for the course of the study through 120 days after the last dose of study treatment~* Male participants should agree to use an adequate method of contraception starting with the first dose of study treatment through 120 days after the last dose of study treatment~* Has adequate organ function~Exclusion Criteria:~* Is currently participating and receiving study treatment, or has participated in a study of an investigational agent and received study therapy or used an investigational device within 4 weeks prior to study Day 1~* Has received prior anti-cancer monoclonal antibody (mAb) therapy for direct anti-neoplastic treatment within 4 weeks prior to study Day 1~* Has received prior chemotherapy, targeted small molecule therapy, or radiation therapy within at least 2 weeks prior to study Day 1~* Has not recovered (i.e., ≤ Grade 1 or at baseline) from adverse events due to agents administered within at least 2 weeks prior to study Day 1~* Has an active autoimmune disease requiring systemic treatment in past 2 years~* Has a diagnosis of immunodeficiency or receiving systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to the first dose of study treatment~* Has known additional malignancy that progressed or required active treatment within the last 5 years. Exceptions include basal cell carcinoma of the skin, squamous cell carcinoma of the skin that has undergone potentially curative therapy, or in situ cervical cancer~* Has radiographically-detectable central nervous system (CNS) metastases and/or carcinomatous meningitis~* Has a history of (non-infectious) pneumonitis that required steroids or current pneumonitis or a history of interstitial lung disease~* Has an active infection requiring systemic therapy~* Has known psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the study~* Is pregnant, breastfeeding, or expecting to conceive or father children within the projected duration of the study, starting with the screening visit through 120 days after the last dose of study treatment~* Has received prior therapy with an anti-programmed cell death protein-1 (anti-PD-1), anti-PD-L1, anti-PD-L2 agent or with an agent directed to another co-inhibitory T-cell receptor (e.g. cytotoxic T-lymphocyte-associated protein-4 \[CTLA-4\], OX-40, CD137) or has participated in Merck MK-3475 (pembrolizumab) study~* Has a known history of human immunodeficiency virus (HIV)~* Has known active Hepatitis B or C~* Has received a live vaccine within 30 days of planned start of study treatment

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Cohort A: Pembrolizumab (Type: EXPERIMENTAL): Participants in Cohort A previously received at least one prior systemic treatment for metastatic breast cancer. Participants will be administered pembrolizumab 200 mg intravenously (IV) on Day 1 of each 3-week cycle (Q3W) for up to 35 cycles (up to \~ 2 years).
- Cohort B: Pembrolizumab (Type: EXPERIMENTAL): Participants in Cohort B previously received no prior systemic treatment for metastatic breast cancer AND had a programmed cell death-ligand 1 (PD-L1) positive tumor expression. Participants will be administered pembrolizumab 200 mg IV on Day 1 of each 3-week cycle (Q3W) for up to 35 cycles (up to \~ 2 years).

Based on this trial design, predict the completion outcome and termination type (if applicable).