Study of Pembrolizumab (MK-3475) Plus Chemotherapy vs Placebo Plus Chemotherapy as Neoadjuvant Therapy and Pembrolizumab vs Placebo as Adjuvant Therapy in Participants With Triple Negative Breast Cancer (TNBC) (MK-3475-522/KEYNOTE-522)

Conditions

• Triple Negative Breast Neoplasms

Eligibility Criteria

Sex

ALL

Age

18 Years - N/A

Healthy Volunteers

Not accepted

Interventions

• Pembrolizumab — BIOLOGICAL
  On Day 1 of each cycle in the neoadjuvant and adjuvant phases of the study for a total of 17 cycles; intravenous (IV) infusion.
• Carboplatin — DRUG
  On Day 1 of Cycles 1-4 of the neoadjuvant phase of the study OR on Days 1, 8, 15 of Cycles 1-4 of the neoadjuvant phase of the study; IV infusion.
• Paclitaxel — DRUG
  On Days 1, 8 and 15 of Cycles 1-4 in the neoadjuvant phase of the study; IV infusion.
• Doxorubicin — DRUG
  On Day 1 of Cycles 5-8 of the neoadjuvant phase of the study; IV injection.
• Epirubicin — DRUG
  On Day 1 of Cycles 5-8 of the neoadjuvant phase of the study; IV injection.
• Cyclophosphamide — DRUG
  On Day 1 of Cycles 5-8 of the neoadjuvant phase of the study; IV infusion.
• Placebo — DRUG
  normal saline solution or dextrose: On Day 1 of each cycle in the neoadjuvant and adjuvant phases of the study for a total of 17 cycles; IV infusion
• Granulocyte colony stimulating factor: Filgrastim or Pegfilgastrim — BIOLOGICAL
  For prevention of neutropenia, filgrastim 5 μg/kg/day via subcutaneous (SC) injection administered per standard of care after chemotherapy OR pegfilgastrim 100 µg/kg (individualized) or 6 mg (general approach) via SC injection administered per standard of care.

Study Details

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 randomization 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 is superior to placebo, in combination with chemotherapy, as measured by the rate of Pathological Complete Response (pCR) and/or Event-free Survival (EFS), in participants with locally advanced TNBC.

Key Dates

Start date

Mar 7, 2017

Status verified

Oct 2025

Primary completion

Oct 14, 2025

Completion

Oct 14, 2025

Study Design

Enrollment

1,174 participants (actual)

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Arms

• Experimental: Pembrolizumab + Chemotherapy
  Participants receive pembrolizumab every 3 weeks (Q3W) + paclitaxel weekly + carboplatin (weekly or Q3W) x 4 cycles, followed by pembrolizumab Q3W + (doxorubicin OR epirubicin) + cyclophosphamide Q3W x 4 cycles as neoadjuvant therapy prior to surgery; followed by 9 cycles of pembrolizumab Q3W as adjuvant therapy post-surgery. Each cycle is 21 days.
• Active Comparator: Placebo + Chemotherapy
  Participants receive placebo (normal saline solution) Q3W + paclitaxel weekly + carboplatin (weekly or Q3W) x 4 cycles, followed by placebo + (doxorubicin OR epirubicin) + cyclophosphamide Q3W x 4 cycles as neoadjuvant therapy prior to surgery; followed by 9 cycles of placebo Q3W as adjuvant therapy post-surgery. Each cycle is 21 days.

Primary Outcome Measure

Pathological complete response (pCR) rate using the definition of ypT0/Tis ypN0 (i.e., no invasive residual in breast or nodes; noninvasive breast residuals allowed) at the time of definitive surgery [ Time Frame: Up to approximately 27-30 weeks ]

Locations (47)

Related coverage on Hipa.ai

• Pembrolizumab KEYNOTE-522 Phase 3 Trial for TNBC to Reach Primary Completion…
  Pembrolizumab · Oct 14, 2025 · ClinicalTrials.gov

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