Study of Pembrolizumab (MK-3475) Versus Placebo in Participants With Esophageal Carcinoma Who Are Receiving Chemotherapy and Radiation Therapy (MK-3475-975/KEYNOTE-975)
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ClinicalTrials.gov Identifier: NCT04210115 |
Recruitment Status :
Recruiting
First Posted : December 24, 2019
Last Update Posted : May 30, 2023
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The purpose of this study is to assess the efficacy and safety of treatment with definitive chemoradiotherapy (dCRT) + pembrolizumab (MK-3475) compared to treatment with dCRT + placebo with respect to Event-free Survival (EFS) and Overall Survival (OS) in:
- participants whose tumors express Programmed Death-Ligand 1 (PD-L1) Combined Positive Score (CPS) ≥10
- participants whose tumors express PD-L1 CPS ≥1
- all participants
The primary study hypotheses are that dCRT+ pembrolizumab is better than dCRT + placebo with respect to:
- EFS in participants whose tumors express PD-L1 CPS ≥10
- EFS in participants whose tumors express PD-L1 CPS ≥1
- EFS in all participants
- OS in participants whose tumors express PD-L1 CPS ≥10
- OS in participants whose tumors express PD-L1 CPS ≥1
- OS in all participants
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Esophageal Squamous Cell Carcinoma (ESCC) Gastroesophageal Junction Carcinoma (GEJC) Esophageal Adenocarcinoma (EAC) | Biological: pembrolizumab Drug: placebo Drug: cisplatin Drug: 5-FU Radiation: radiotherapy Drug: leucovorin Drug: levoleucovorin Drug: oxaliplatin | Phase 3 |
Participants receive pembrolizumab or placebo PLUS one of two chemotherapy regimens PLUS radiation therapy for up to approximately one year. The chemotherapy regimens are either:
- FP (5-fluorouracil [5-FU] + cisplatin) or
- FOLFOX (5-FU + oxaliplatin + leucovorin or levoleucovorin).
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 700 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Triple (Participant, Investigator, Outcomes Assessor) |
Primary Purpose: | Treatment |
Official Title: | A Randomized, Double-blind, Placebo-controlled Phase 3 Trial of Pembrolizumab (MK-3475) Versus Placebo in Participants With Esophageal Carcinoma Receiving Concurrent Definitive Chemoradiotherapy (KEYNOTE 975) |
Actual Study Start Date : | February 28, 2020 |
Estimated Primary Completion Date : | February 11, 2027 |
Estimated Study Completion Date : | February 11, 2027 |

Arm | Intervention/treatment |
---|---|
Experimental: Pembrolizumab+FP or FOLFOX Therapy+Radiotherapy
Participants receive pembrolizumab 200 mg on Day 1 of each 3-week cycle for 8 cycles followed by pembrolizumab 400 mg on Day 1 of each 6-week cycle for 5 cycles PLUS either:
All treatments except radiotherapy are given by intravenous (IV) infusion. Total treatment duration is approximately 1 year. |
Biological: pembrolizumab
IV infusion
Other Names:
Drug: cisplatin IV infusion
Other Name: PLATINOL® Drug: 5-FU IV infusion
Other Name: ADRUCIL® Radiation: radiotherapy external radiation Drug: leucovorin IV infusion
Other Names:
Drug: levoleucovorin IV infusion
Other Names:
Drug: oxaliplatin IV infusion
Other Name: ELOXATIN® |
Placebo Comparator: Placebo+FP or FOLFOX Therapy+Radiotherapy
Participants receive placebo on Day 1 of each 3-week cycle for 8 cycles followed by placebo on Day 1 of each 6-week cycle for 5 cycles PLUS either:
All treatments except radiotherapy are given by IV infusion. Total treatment duration is approximately 1 year. |
Drug: placebo
IV infusion
Other Name: Normal saline solution Drug: cisplatin IV infusion
Other Name: PLATINOL® Drug: 5-FU IV infusion
Other Name: ADRUCIL® Radiation: radiotherapy external radiation Drug: leucovorin IV infusion
Other Names:
Drug: levoleucovorin IV infusion
Other Names:
Drug: oxaliplatin IV infusion
Other Name: ELOXATIN® |
- Event-free Survival (EFS) [ Time Frame: Up to ~60 months ]EFS is defined as the time from randomization to an event defined as local, regional, or distant radiological recurrence as assessed by the investigator; clinical recurrence as assessed by the investigator with histopathologic confirmation (in the absence of radiological disease recurrence by investigator assessment); or death from any cause, whichever occurs first.
- Overall Survival (OS) [ Time Frame: Up to ~72 months ]OS is defined as the time from randomization to death from any cause.
- Number of participants with an adverse event (AE) [ Time Frame: Up to ~15 months ]An AE is any untoward medical occurrence in a participant that is temporally associated with the use of study treatment, whether or not considered related to the study treatment.
- Number of participants discontinuing study treatment due to an adverse event (AE) [ Time Frame: Up to ~12 months ]An AE is any untoward medical occurrence in a participant that is temporally associated with the use of study treatment, whether or not considered related to the study treatment.

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Has histologically or cytologically confirmed diagnosis of CTX N+ M0 or cT2-T4a NX M0 ESCC, GEJC, EAC, or histologically or cytologically confirmed diagnosis of cTX N+ M1 cervical or upper thoracic esophageal carcinoma with supraclavicular lymph node metastases only
- Is deemed suitable for dCRT
- Is ineligible for curative surgery based on the documented opinion of a qualified medical/surgical/radiation oncologist.
- Is not expected to require tumor resection during the course of the study
- Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1 within 3 days of the first dose of study treatment.
- Has adequate organ function.
- Male participants must use adequate contraception (a male condom plus partner use of an additional contraceptive method) unless confirmed to be azoospermic (vasectomized or secondary to medical cause) and refrain from donating sperm during the study treatment period and through 90 days after the last dose of chemotherapy.
- Female participants who are a Woman of Childbearing Potential (WOCBP) must use contraception that is highly effective (with a failure rate of <1% per year), with low user dependency, or be abstinent from heterosexual intercourse as their preferred and usual lifestyle, during the study treatment period through 180 days after the last dose of chemotherapy or 120 days after the last dose of pembrolizumab, whichever is greater, and agree not to donate eggs to others or freeze/store for her own use for the purpose of reproduction during this period
- Female participants must not be pregnant or breastfeeding
Exclusion Criteria:
- Has direct invasion of tumor into adjacent organs such as the aorta or trachea or has radiographic evidence of >90 degree encasement or invasion of a major blood vessel, or of intratumoral cavitation.
- Has had major surgery other than for insertion of a feeding tube, open biopsy, or significant traumatic injury within 28 days prior to randomization, or anticipates the need for major surgery during study treatment; participants with gastric or esophageal fistulae are excluded
- Has had weight loss of >20% in the previous 3 months
- Has had prior chemotherapy or radiotherapy for esophageal cancer
- Has had a myocardial infarction within the past 6 months
- Has symptomatic congestive heart failure
- Has received prior therapy with an anti-programmed cell death-1 (anti PD-1), anti-programmed cell death-ligand 1 (anti-PD-L1), or anti-programmed cell death-ligand 2 (anti-PD-L2) agent or with an agent directed to another stimulatory or coinhibitory T-cell receptor (e.g. cytotoxic T-lymphocyte-associated protein 4 [CTLA-4], OX-40, CD137)
- Has received a live or live-attenuated vaccine within 30 days prior to the first dose of study intervention; administration of killed vaccines is allowed
- Has received any prior systemic anticancer therapy for esophageal cancer including investigational agents
- Has not recovered from all adverse events (AEs) due to previous non-anticancer therapies to ≤Grade 1 or Baseline
- Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior the first dose of study treatment
- Has a known additional malignancy that is progressing or has required active treatment within the past 3 years. Note: Participants with basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or carcinoma in situ (e.g. breast carcinoma, cervical cancer in situ) that have undergone potentially curative therapy are not excluded from the study. Participants with localized prostate cancer that has undergone potentially curative treatment can be enrolled in the study.
- Has severe hypersensitivity (≥Grade 3) to pembrolizumab, any of the study chemotherapy agents, or their excipients
- Has an active autoimmune disease that has required systemic treatment in past 2 years
- Has a history of (non-infectious) pneumonitis that required steroids or has current pneumonitis
- Has an active infection requiring systemic therapy
- Has a known history of human immunodeficiency virus (HIV) infection
- Has a known history of Hepatitis B or known active Hepatitis C virus infection
- Has a known history of active tuberculosis (TB; Bacillus tuberculosis)
- Is pregnant or 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 (180 days for participants receiving cisplatin who are breastfeeding)
- Has had an allogenic tissue/solid organ transplant

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04210115
Contact: Toll Free Number | 1-888-577-8839 | Trialsites@merck.com |

Study Director: | Medical Director | Merck Sharp & Dohme LLC |
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: | Merck Sharp & Dohme LLC |
ClinicalTrials.gov Identifier: | NCT04210115 |
Other Study ID Numbers: |
3475-975 MK-3475-975 ( Other Identifier: Merck ) KEYNOTE-975 ( Other Identifier: Merck ) PHRR200210-002490 ( Registry Identifier: PHRR ) 205261 ( Registry Identifier: Japic-CTI ) 2019-002006-51 ( EudraCT Number ) |
First Posted: | December 24, 2019 Key Record Dates |
Last Update Posted: | May 30, 2023 |
Last Verified: | May 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | http://engagezone.msd.com/doc/ProcedureAccessClinicalTrialData.pdf |
URL: | http://engagezone.msd.com/ds_documentation.php |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Programmed Cell Death-1 (PD1, PD-1) Programmed Death-Ligand 1 (PDL1, PD-L1) Programmed Death-Ligand 2 (PDL2, PD-L2) |
Carcinoma Esophageal Squamous Cell Carcinoma Esophageal Neoplasms Neoplasms, Glandular and Epithelial Neoplasms by Histologic Type Neoplasms Carcinoma, Squamous Cell Neoplasms, Squamous Cell Gastrointestinal Neoplasms Digestive System Neoplasms Neoplasms by Site Head and Neck Neoplasms Digestive System Diseases Esophageal Diseases Gastrointestinal Diseases |
Calcium, Dietary Leucovorin Pembrolizumab Oxaliplatin Calcium Levoleucovorin Antineoplastic Agents Antineoplastic Agents, Immunological Immune Checkpoint Inhibitors Molecular Mechanisms of Pharmacological Action Calcium-Regulating Hormones and Agents Physiological Effects of Drugs Bone Density Conservation Agents Antidotes Protective Agents |