Trial Purpose

The purpose of this study is to evaluate the efficacy and safety of pembrolizumab (MK-3475) plus chemotherapy vs. placebo plus chemotherapy as neoadjuvant therapy and pembrolizumab vs. placebo as adjuvant therapy in participants who have triple negative breast cancer (TNBC). After a screening phase of approximately 28 days, each participant will receive neoadjuvant study treatment (Pembrolizumab + Chemotherapy OR Placebo + Chemotherapy) based on the randomisation schedule for approximately 24 weeks (8 cycles). Each participant will then undergo definitive surgery 3-6 weeks after conclusion of the last cycle of the neoadjuvant study treatment. After definitive surgery, each participant will receive adjuvant study treatment (Pembrolizumab OR Placebo) for approximately 27 weeks (9 cycles). Following adjuvant study treatment, each participant will be monitored for safety, survival and disease recurrence. The primary study hypothesis is that pembrolizumab when combined with chemotherapy is superior to placebo with chemotherapy in the treatment of participants with locally advanced TNBC.

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About The Trial

All patients who enroll in the trial will receive medication while on the study.

67% will receive pembrolizumab along with chemotherapy before surgery, and pembrolizumab alone after surgery

33% will receive placebo along with chemotherapy before surgery, and placebo alone after surgery

*You will be assigned by chance (a process called randomization) to receive one of the above treatments.

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Phase 3

Tests the medicine or vaccine in approximately 1,000 to 5,000 volunteers. For medicines, volunteers have the disease or condition the medicine is designed to treat. In vaccine studies, the volunteers may be healthy or have diseases or conditions. Phase 3 trials take place in hospitals, clinics or physician offices.

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  • Actual study start date March 7, 2017
  • Estimated primary completion date September 30, 2025
  • Estimated study completion date September 30, 2025


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Triple Negative Breast Neoplasms

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Age Range

18 - No Age Maximum

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Trial locations

What Can You Do Next?

If you think this trial might be a fit and are interested in participating, take the next step to see if you are eligible.

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Discuss With Your Doctor

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When speaking to your doctor, please have the trial identifier number available.

Participating in a clinical trial is an important decision.

Anyone participating in a trial should know as much as possible about what is being studied, what risks are involved and what potential benefits may be gained before deciding to enroll. If you are interested in participating in a clinical trial, please talk to your doctor first.