Pembrolizumab/Placebo Plus Trastuzumab Plus Chemotherapy in Human Epidermal Growth Factor Receptor 2 Positive (HER2+) Advanced Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma (MK-3475-811/KEYNOTE-811)

NCT ID: NCT03615326

Last Updated: 2025-12-11

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE3
• Total Enrollment: 738 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-10-05
• Study Completion Date: 2025-11-12

Brief Summary

The study will compare the efficacy and safety of pembrolizumab plus trastuzumab in combination with standard of care (SOC) chemotherapy versus trastuzumab in combination with SOC chemotherapy in participants with HER2-positive gastric cancer. The primary hypotheses of the study are that pembrolizumab plus trastuzumab in combination with chemotherapy is superior to trastuzumab plus chemotherapy in terms of 1) progression free survival (PFS) per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) as assessed by blinded independent central review (BICR), and 2) overall survival (OS).

Detailed Description

Pembrolizumab (200 mg) or placebo will be administered intravenously [IV] on day 1 of each 3-week cycle. Trastuzumab (8 mg/kg loading dose, 6 mg/kg maintenance dose) will be administered IV on day 1 of each 3-week cycle. SOC chemotherapy for the global cohort will either be FP (80 mg/m^2 cisplatin administered IV on Day 1 of each 3-week cycle and 800 mg/m^2 5-fluorouracil [5-FU] administered IV on Days 1-5 of each 3-week cycle) or CAPOX (1000 mg/m^2 capecitabine administered orally twice daily [BID] on days 1-14 of each 3-week cycle and 130 mg/m^2 oxaliplatin administered IV on Day 1 of each 3-week cycle). A Japan cohort will receive SOX chemotherapy consisting of S-1 (tegafur, 5-chloro-2,4-dihydroxypyridine [CDHP], and potassium oxonate [Oxo]) administered orally BID according to Body Surface Area (BSA) on Days 1-14 of each 3-week cycle and oxaliplatin (130 mg/m^2) administered IV on Day 1 each 3-week cycle.

Conditions

Gastric Neoplasms; Gastroesophageal Junction Adenocarcinoma

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: QUADRUPLE

Study Groups

Global Pembrolizumab + Standard of Care First Course

Participants received 200 mg pembrolizumab IV every 3 weeks (Q3W) plus trastuzumab (8 mg/kg loading dose, 6 mg/kg maintenance thereafter) IV Q3W in combination with investigator's choice of FP or CAPOX chemotherapy.

Group Type: EXPERIMENTAL

Pembrolizumab

Intervention Type: BIOLOGICAL

200 mg on Day 1 of each 3-week cycle as an IV infusion.

Cisplatin

Intervention Type: DRUG

80 mg/m\^2 on Day 1 of each 3-week cycle as an IV infusion, administered as part of FP chemotherapy regimen.

5-FU

Intervention Type: DRUG

800 mg/m\^2/day continuous on Days 1-5 of each 3-week cycle (120 hours or per local standard), administered as part of FP chemotherapy regimen.

Oxaliplatin

Intervention Type: DRUG

130 mg/m\^2 on Day 1 of each 3-week cycle over 2 hours as an IV infusion, administered as part of CAPOX chemotherapy regimen and as part of SOX chemotherapy regimen.

Capecitabine

Intervention Type: DRUG

1000 mg/m\^2 as oral capsules BID on Days 1-14 of each 3-week cycle, administered as part of CAPOX chemotherapy regimen.

Trastuzumab

Intervention Type: BIOLOGICAL

8 mg/kg loading dose and then 6 mg/kg maintenance dose administered IV on day 1 of each 3-week cycle.

Global Standard of Care

Participants received matched placebo to pembrolizumab IV Q3W plus trastuzumab (8mg/kg loading dose, 6mg/kg maintenance thereafter) IV Q3W in combination with investigator's choice of FP or CAPOX chemotherapy.

Group Type: ACTIVE_COMPARATOR

Placebo

Intervention Type: BIOLOGICAL

Solution for IV infusion on Day 1 of each 3-week cycle.

Cisplatin

Intervention Type: DRUG

80 mg/m\^2 on Day 1 of each 3-week cycle as an IV infusion, administered as part of FP chemotherapy regimen.

5-FU

Intervention Type: DRUG

800 mg/m\^2/day continuous on Days 1-5 of each 3-week cycle (120 hours or per local standard), administered as part of FP chemotherapy regimen.

Oxaliplatin

Intervention Type: DRUG

130 mg/m\^2 on Day 1 of each 3-week cycle over 2 hours as an IV infusion, administered as part of CAPOX chemotherapy regimen and as part of SOX chemotherapy regimen.

Capecitabine

Intervention Type: DRUG

1000 mg/m\^2 as oral capsules BID on Days 1-14 of each 3-week cycle, administered as part of CAPOX chemotherapy regimen.

Trastuzumab

Intervention Type: BIOLOGICAL

8 mg/kg loading dose and then 6 mg/kg maintenance dose administered IV on day 1 of each 3-week cycle.

Japan Pembrolizumab + Trastuzumab + S-1 Plus Oxaliplatin

Participants received 200 mg pembrolizumab IV every 3 weeks (Q3W) plus trastuzumab (8 mg/kg loading dose, 6 mg/kg maintenance thereafter) IV Q3W in combination with SOX chemotherapy.

Group Type: EXPERIMENTAL

Pembrolizumab

Intervention Type: BIOLOGICAL

200 mg on Day 1 of each 3-week cycle as an IV infusion.

Oxaliplatin

Intervention Type: DRUG

130 mg/m\^2 on Day 1 of each 3-week cycle over 2 hours as an IV infusion, administered as part of CAPOX chemotherapy regimen and as part of SOX chemotherapy regimen.

S-1

Intervention Type: DRUG

Combination product of tegafur, CDHP, and Oxo. Oral capsules BID on Days 1-14 of each 3-week cycle based on body surface area (BSA): \<1.25 m\^2 BSA =40 mg, 1.25 to \<1.5 m\^2 BSA=50 mg, ≥1.5 m\^2 BSA=60 mg. Administered as part of SOX chemotherapy regimen.

Trastuzumab

Intervention Type: BIOLOGICAL

8 mg/kg loading dose and then 6 mg/kg maintenance dose administered IV on day 1 of each 3-week cycle.

Japan Trastuzumab + S-1 Plus Oxaliplatin

Participants received matched placebo to pembrolizumab IV Q3W plus trastuzumab (8mg/kg loading dose, 6mg/kg maintenance thereafter) IV Q3W in combination with SOX chemotherapy.

Group Type: EXPERIMENTAL

Placebo

Intervention Type: BIOLOGICAL

Solution for IV infusion on Day 1 of each 3-week cycle.

Oxaliplatin

Intervention Type: DRUG

130 mg/m\^2 on Day 1 of each 3-week cycle over 2 hours as an IV infusion, administered as part of CAPOX chemotherapy regimen and as part of SOX chemotherapy regimen.

S-1

Intervention Type: DRUG

Combination product of tegafur, CDHP, and Oxo. Oral capsules BID on Days 1-14 of each 3-week cycle based on body surface area (BSA): \<1.25 m\^2 BSA =40 mg, 1.25 to \<1.5 m\^2 BSA=50 mg, ≥1.5 m\^2 BSA=60 mg. Administered as part of SOX chemotherapy regimen.

Trastuzumab

Intervention Type: BIOLOGICAL

8 mg/kg loading dose and then 6 mg/kg maintenance dose administered IV on day 1 of each 3-week cycle.

Interventions

Pembrolizumab

200 mg on Day 1 of each 3-week cycle as an IV infusion.

Intervention Type: BIOLOGICAL

Placebo

Solution for IV infusion on Day 1 of each 3-week cycle.

Intervention Type: BIOLOGICAL

Cisplatin

80 mg/m\^2 on Day 1 of each 3-week cycle as an IV infusion, administered as part of FP chemotherapy regimen.

Intervention Type: DRUG

5-FU

800 mg/m\^2/day continuous on Days 1-5 of each 3-week cycle (120 hours or per local standard), administered as part of FP chemotherapy regimen.

Intervention Type: DRUG

Oxaliplatin

130 mg/m\^2 on Day 1 of each 3-week cycle over 2 hours as an IV infusion, administered as part of CAPOX chemotherapy regimen and as part of SOX chemotherapy regimen.

Intervention Type: DRUG

Capecitabine

1000 mg/m\^2 as oral capsules BID on Days 1-14 of each 3-week cycle, administered as part of CAPOX chemotherapy regimen.

Intervention Type: DRUG

S-1

Combination product of tegafur, CDHP, and Oxo. Oral capsules BID on Days 1-14 of each 3-week cycle based on body surface area (BSA): \<1.25 m\^2 BSA =40 mg, 1.25 to \<1.5 m\^2 BSA=50 mg, ≥1.5 m\^2 BSA=60 mg. Administered as part of SOX chemotherapy regimen.

Intervention Type: DRUG

Trastuzumab

8 mg/kg loading dose and then 6 mg/kg maintenance dose administered IV on day 1 of each 3-week cycle.

Intervention Type: BIOLOGICAL

Other Intervention Names

Keytruda®; MK-3475; Herceptin®

Eligibility Criteria

Inclusion Criteria

• Histologically or cytologically confirmed diagnosis of previously untreated, locally advanced unresectable or metastatic human epidermal growth factor receptor 2 (HER2) positive gastric or gastroesophageal junction (GEJ) adenocarcinoma
• HER2-positive defined as either immunohistochemistry (IHC) 3+ or IHC 2+ in combination with in-situ hybridization positive (ISH+) or fluorescent in-situ hybridization (FISH), as assessed by central review on primary or metastatic tumor
• Has measurable disease as defined by Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) as determined by the site investigator
• Male participants must agree to use approved contraception
• Female participants who are not pregnant or breastfeeding, and who are either not a woman of childbearing potential (WOCBP), or are a WOCBP who agrees to use approved contraception
• Has a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) Performance Scale within 3 days prior to the first dose of trial treatment
• Has a life expectancy of greater than 6 months
• Has adequate organ function

Exclusion Criteria

• Has had previous therapy for locally advanced unresectable or metastatic gastric/GEJ cancer
• Has had major surgery, open biopsy or significant traumatic injury within 28 days prior to randomization, or anticipation of the need for major surgery during the course of study treatment
• Has had radiotherapy within 14 days of randomization
• Has a known additional malignancy that is progressing or has required active treatment within the past 5 years
• Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis
• Has an active autoimmune disease that has required systemic treatment in past 2 years
• Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy
• Has a history of (non-infectious) pneumonitis that required steroids or current pneumonitis
• Has a known history of active tuberculosis (TB; Mycobacterium tuberculosis)
• Has an active infection requiring systemic therapy
• Has poorly controlled diarrhea
• Accumulation of pleural, ascitic, or pericardial fluid requiring drainage or diuretic drugs within 2 weeks prior to enrollment. If the participant is receiving diuretic drugs for other reasons, it is acceptable
• Has a history or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the trial, interfere with the participant's participation for the full duration of the trial, or is not in the best interest of the participant to participate, in the opinion of the treating investigator
• Has peripheral neuropathy > Grade 1
• Has a known psychiatric or substance abuse disorder that would interfere with cooperation with the requirements of the trial
• A WOCBP who has a positive urine pregnancy test within 24 hours prior to randomization or treatment allocation
• Has active or clinically significant cardiac disease
• Has a known history of Human Immunodeficiency Virus (HIV) (HIV 1/2 antibodies)
• Has a known history of Hepatitis B (defined as Hepatitis B surface antigen [HBsAg] reactive) or known active Hepatitis C virus (defined as HCV RNA [qualitative] is detected) infection
• Has severe hypersensitivity (≥Grade 3) to pembrolizumab, trastuzumab, study chemotherapy agents and/or to any excipients, murine proteins, or platinum-containing products
• Has had an allogeneic tissue/solid organ transplant
• Has received prior therapy with an anti-PD-1, anti-PD-L1, or anti PD L2 agent or with an agent directed to another stimulatory or co-inhibitory T-cell receptor (e.g., cytotoxic T-lymphocyte-associated protein 4 [CTLA-4], OX 40, Cluster of Differentiation 137 [CD137])

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Merck Sharp & Dohme LLC

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Medical Director

Role: STUDY_DIRECTOR

Merck Sharp & Dohme LLC

Locations

UCLA Hematology/Oncology - Westwood (Building 200 Suite 120) ( Site 0045)

Los Angeles, California, United States

Pacific Cancer Care ( Site 0063)

Monterey, California, United States

UC Irvine Medical Center/Chao Family Comprehensive Cancer Center ( Site 0050)

Orange, California, United States

University of Miami Sylvester Comprehensive Cancer Center - Plantation ( Site 0026)

Miami, Florida, United States

Southeastern Regional Medical Center, Inc. ( Site 0058)

Newnan, Georgia, United States

Midwestern Regional Medical Center, Inc. ( Site 0059)

Zion, Illinois, United States

Beth Israel Deaconess Medical Center ( Site 0070)

Boston, Massachusetts, United States

Dana-Farber Cancer Institute [Boston, MA] ( Site 0010)

Boston, Massachusetts, United States

Minnesota Oncology Hematology, PA ( Site 8001)

Minneapolis, Minnesota, United States

Washington University School of Medicine ( Site 0040)

St Louis, Missouri, United States

Memorial Sloan Kettering Cancer Center- Monmouth ( Site 0071)

Middletown, New Jersey, United States

Memorial Sloan-Kettering Cancer Center at West Harrison ( Site 0065)

Harrison, New York, United States

Memorial Sloan-Kettering Cancer Center ( Site 0017)

New York, New York, United States

University of Rochester ( Site 0041)

Rochester, New York, United States

Levine Cancer Institute ( Site 0015)

Charlotte, North Carolina, United States

Duke Cancer Institute ( Site 0042)

Durham, North Carolina, United States

CTCA Southwestern ( Site 0060)

Tulsa, Oklahoma, United States

Cancer Treatment Centers of America-Eastern Regional Medical Center ( Site 0025)

Philadelphia, Pennsylvania, United States

Allegheny General Hospital ( Site 0053)

Pittsburgh, Pennsylvania, United States

Sanford Hematology Oncology-Sioux Falls SD ( Site 0004)

Sioux Falls, South Dakota, United States

University of Texas MD Anderson Cancer Center ( Site 0001)

Houston, Texas, United States

Oncology & Hematology Assoc. SW Virginia, Inc., DBA Blue Ridge Cancer Care ( Site 8000)

Roanoke, Virginia, United States

Seattle Cancer Care Alliance ( Site 0038)

Seattle, Washington, United States

Liverpool Hospital ( Site 2206)

Liverpool, New South Wales, Australia

Westmead Hospital ( Site 2200)

Westmead, New South Wales, Australia

Southern Medical Day Care Centre ( Site 2207)

Wollongong, New South Wales, Australia

Monash Health ( Site 2202)

Clayton, Victoria, Australia

Instituto do Cancer do Ceara ( Site 0208)

Fortaleza, Ceará, Brazil

Hospital Sao Rafael ( Site 0209)

Salvador, Estado de Bahia, Brazil

CIONC - Centro Integrado de Oncologia de Curitiba ( Site 0205)

Curitiba, Paraná, Brazil

Hospital de Caridade de Ijui ( Site 0202)

Ijuí, Rio Grande do Sul, Brazil

Hospital Nossa Senhora da Conceicao ( Site 0203)

Porto Alegre, Rio Grande do Sul, Brazil

CEPON - Centro de Pesquisas Oncologicas ( Site 0200)

Florianópolis, Santa Catarina, Brazil

Instituto Nacional do Cancer Jose Alencar Gomes da Silva INCA ( Site 0201)

Rio de Janeiro, , Brazil

IBCC - Instituto Brasileiro de Controle do Cancer ( Site 0204)

São Paulo, , Brazil

Clinica Universidad Catolica del Maule ( Site 0305)

Talca, Maule Region, Chile

Fundacion Arturo Lopez Perez FALP ( Site 0302)

Santiago, Region M. de Santiago, Chile

Pontificia Universidad Catolica de Chile ( Site 0301)

Santiago, Region M. de Santiago, Chile

Instituto Nacional del Cancer ( Site 0303)

Santiago, Region M. de Santiago, Chile

Centro Investigación del Cáncer James Lind ( Site 0300)

Temuco, Región de la Araucanía, Chile

Shanghai General Hospital ( Site 2404)

Shanghai, Anhui, China

Peking Union Medical College Hospital ( Site 2419)

Beijing, Beijing Municipality, China

Fifth Medical Center of CPLA General Hospital ( Site 2415)

Beijing, Beijing Municipality, China

Beijing Cancer Hospital ( Site 2413)

Beijing, Beijing Municipality, China

Fujian Provincial Cancer Hospital ( Site 2418)

Fuzhou, Fujian, China

900 Hospital of the Joint ( Site 2420)

Fuzhou, Fujian, China

The First Affiliated Hospital of Xiamen University ( Site 2431)

Xiamen, Fujian, China

Guangdong General Hospital ( Site 2433)

Guangzhou, Guangdong, China

Harbin Medical University Cancer Hospital ( Site 2407)

Harbin, Heilongjiang, China

Henan Cancer Hospital ( Site 2400)

Zhengzhou, Henan, China

Xiangya Hospital Central-South University ( Site 2426)

Changsha, Hunan, China

Jiangsu Cancer Hospital ( Site 2432)

Nanjing, Jiangsu, China

The First Hospital Of Jilin University ( Site 2402)

Changchun, Jilin, China

Fudan University Shanghai Cancer Center ( Site 2424)

Shanghai, Shanghai Municipality, China

Zhongshan Hospital affiliated to Fudan University ( Site 2401)

Shanghai, Shanghai Municipality, China

Cancer Hospital Affiliated to Xinjiang Medical University ( Site 2430)

Ürümqi, Xinjiang, China

The First Affiliated Hospital.Zhejiang University ( Site 2408)

Hangzhou, Zhejiang, China

Sir Run Run Shaw Hospital ( Site 2412)

Hangzhou, Zhejiang, China

Zhejiang Cancer Hospital ( Site 2409)

Hangzhou, Zhejiang, China

CHU de Rouen ( Site 0912)

Rouen, Ain, France

HUS Hopital Hautepierre ( Site 0910)

Strasbourg, Bas-Rhin, France

Hopital Jean Minjoz Besancon ( Site 0901)

Besançon, Doubs, France

C.H.R.U. de Brest - Hopital Morvan ( Site 0913)

Brest, Finistere, France

Centre Oscar Lambret ( Site 0911)

Lille, Nord, France

Centre Leon Berard ( Site 0904)

Lyon, Rhone, France

Institut de Cancerologie de l Ouest Centre Rene Gauducheau ( Site 0902)

Saint-Herblain, Val-de-Marne, France

Institut Gustave Roussy ( Site 0900)

Villejuif, Val-de-Marne, France

CHU Hopital Saint Antoine ( Site 0905)

Paris, , France

SLK-Kliniken Heilbronn ( Site 1015)

Heilbronn, Baden-Wurttemberg, Germany

Klinikum Ludwigsburg ( Site 1014)

Ludwigsburg, Baden-Wurttemberg, Germany

Innere Medizin I, Universitaetsklinikum Tuebingen ( Site 1020)

Tübingen, Baden-Wurttemberg, Germany

Klinikum rechts der Isar der Technischen Universitaet ( Site 1027)

Munich, Bavaria, Germany

Medizinische Hochschule Hannover ( Site 1019)

Hanover, Lower Saxony, Germany

Universitaetsklinikum Carl Gustav Carus der Technischen Univ ( Site 1001)

Dresden, Saxony, Germany

Universitaetsklinikum Leipzig AOeR ( Site 1007)

Leipzig, Saxony, Germany

Charite-Universitaetsmedizin Berlin Campus Virchow-Klinikum ( Site 1026)

Berlin, , Germany

Klinikum Bremen Nord ( Site 1017)

Bremen, , Germany

Facharztzentrum Eppendorf ( Site 1025)

Hamburg, , Germany

Asklepios Klinik Altona ( Site 1000)

Hamburg, , Germany

Celan SA ( Site 0504)

Guatemala City, , Guatemala

Oncomedica ( Site 0500)

Guatemala City, , Guatemala

Grupo Angeles SA ( Site 0501)

Guatemala City, , Guatemala

Nucare Center ( Site 0506)

Guatemala City, , Guatemala

Medi-K Cayala ( Site 0505)

Guatemala City, , Guatemala

Centro Regional de Sub Especialidades Medicas SA ( Site 0502)

Quetzaltenango, , Guatemala

Saint James's Hospital ( Site 1505)

Dublin, , Ireland

Beaumont Hospital ( Site 1506)

Dublin, , Ireland

Tallaght University Hospital ( Site 1513)

Dublin, , Ireland

Soroka University Medical Center ( Site 1603)

Beersheba, , Israel

Rambam Health Care Campus ( Site 1606)

Haifa, , Israel

Edith Wolfson Medical Center ( Site 1605)

Holon, , Israel

Hadassah Ein Kerem Medical Center ( Site 1604)

Jerusalem, , Israel

Meir Medical Center ( Site 1609)

Kfar Saba, , Israel

Rabin Medical Center ( Site 1602)

Petah Tikva, , Israel

Chaim Sheba Medical Center. ( Site 1607)

Ramat Gan, , Israel

Sourasky Medical Center ( Site 1601)

Tel Aviv, , Israel

AUOP Ospedale Santa Chiara ( Site 1100)

Pisa, Tuscany, Italy

Humanitas Gavazzeni ( Site 1106)

Bergamo, , Italy

Universita Magna Graecia di Catanzaro ( Site 1107)

Catanzaro, , Italy

IEO Istituto Europeo di Oncologia ( Site 1105)

Milan, , Italy

Azienda Ospedaliero - Universitaria Policlinico di Modena ( Site 1102)

Modena, , Italy

A.O.U. Universita degli Studi della Campania-Luigi Vanvitelli ( Site 1103)

Napoli, , Italy

Istituto Oncologico Veneto ( Site 1101)

Padua, , Italy

Ospedale Civile Spirito Santo ( Site 1104)

Pescara, , Italy

Aichi Cancer Center Hospital ( Site 2617)

Nagoya, Aichi-ken, Japan

National Cancer Center Hospital East ( Site 2605)

Kashiwa, Chiba, Japan

National Hospital Organization Shikoku Cancer Center ( Site 2615)

Matsuyama, Ehime, Japan

Gunma Prefectural Cancer Center ( Site 2602)

Ohta, Gunma, Japan

Hyogo Cancer Center ( Site 2619)

Akashi, Hyōgo, Japan

Kobe City Medical Center General Hospital ( Site 2614)

Kobe, Hyōgo, Japan

Ibaraki Prefectural Central Hospital ( Site 2611)

Kasama, Ibaraki, Japan

Kagawa University Hospital ( Site 2604)

Kita-gun, Kagawa-ken, Japan

Kanagawa Cancer Center ( Site 2603)

Yokohama, Kanagawa, Japan

Osaki Citizen Hospital ( Site 2626)

Ōsaki, Miyagi, Japan

Kansai Medical University Hospital ( Site 2618)

Hirakata, Osaka, Japan

Kindai University Hospital ( Site 2616)

Sayama, Osaka, Japan

Osaka University Hospital ( Site 2600)

Suita, Osaka, Japan

Saitama Cancer Center ( Site 2620)

Kitaadachi-gun, Saitama, Japan

Shizuoka Cancer Center Hospital and Research Institute ( Site 2607)

Sunto-gun, Shizuoka, Japan

Tochigi Cancer Center ( Site 2627)

Utsunomiya, Tochigi, Japan

Kyorin University Hospital ( Site 2608)

Mitaka, Tokyo, Japan

Chiba Cancer Center ( Site 2623)

Chiba, , Japan

National Hospital Organization Kyushu Cancer Center ( Site 2609)

Fukuoka, , Japan

Gifu University Hospital ( Site 2621)

Gifu, , Japan

Hiroshima City Hiroshima Citizens Hospital ( Site 2625)

Hiroshima, , Japan

Kumamoto University Hospital ( Site 2601)

Kumamoto, , Japan

Niigata Cancer Center Hospital ( Site 2622)

Niigata, , Japan

National Hospital Organization - Osaka National Hospital - Institute For Clinical Research ( Site 26

Osaka, , Japan

Osaka International Cancer Institute ( Site 2613)

Osaka, , Japan

Osaka General Medical Center ( Site 2624)

Osaka, , Japan

National Cancer Center Hospital ( Site 2612)

Tokyo, , Japan

Toranomon Hospital ( Site 2628)

Tokyo, , Japan

Tokyo Metropolitan Komagome Hospital ( Site 2606)

Tokyo, , Japan

The Cancer Institute Hospital of JFCR ( Site 2610)

Tokyo, , Japan

Auckland City Hospital ( Site 2300)

Auckland, , New Zealand

Przychodnia Lekarska Komed ( Site 1716)

Konin, Greater Poland Voivodeship, Poland

Uniwersytecki Szpital Kliniczny im. J. M. Radeckiego we Wroclawiu ( Site 1705)

Wroclaw, Lower Silesian Voivodeship, Poland

Dolnoslaskie Centrum Onkologii. ( Site 1712)

Wroclaw, Lower Silesian Voivodeship, Poland

Samodzielny Publiczny Szpital Kliniczny Nr 1 w Lublinie ( Site 1709)

Lublin, Lublin Voivodeship, Poland

Narodowy Instytut Onkologii im. Marii Sklodowskiej-Curie - Panstwowy Instytut Badawczy w Warszawie (

Warsaw, Masovian Voivodeship, Poland

Szpital Morski im. PCK. Szpitale Pomorskie Sp. Z o.o ( Site 1715)

Gdynia, Pomeranian Voivodeship, Poland

Szpital Specjalistyczny w Koscierzynie Sp. z o.o. ( Site 1708)

Kościerzyna, Pomeranian Voivodeship, Poland

Beskidzkie Centrum Onkologii im. Jana Pawla II ( Site 1710)

Bielsko-Biala, Silesian Voivodeship, Poland

Republican Clinical Oncology Dispensary of Republic of Bashkortostan ( Site 1807)

Ufa, Baskortostan, Respublika, Russia

Chelyabinsk Regional Clinical Oncological Dispensary ( Site 1815)

Chelyabinsk, Chelyabinsk Oblast, Russia

Blokhin National Medical Oncology ( Site 1805)

Moscow, Moscow, Russia

Podolsky City Clinical Hospital ( Site 1817)

Podolsk, Moscow Oblast, Russia

Medical University REAVIZ ( Site 1816)

Samara, Samara Oblast, Russia

Leningrad Regional Oncology Center ( Site 1800)

Saint Petersburg, Sankt-Peterburg, Russia

Scientific Research Oncology Institute n.a. N.N.Petrov ( Site 1801)

Saint Petersburg, Sankt-Peterburg, Russia

St Petersburg City Clinical Oncology Dispensary ( Site 1812)

Saint Petersburg, Sankt-Peterburg, Russia

Seoul National University Hospital ( Site 2703)

Seoul, , South Korea

Severance Hospital Yonsei University Health System ( Site 2700)

Seoul, , South Korea

Asan Medical Center ( Site 2702)

Seoul, , South Korea

Samsung Medical Center ( Site 2701)

Seoul, , South Korea

Hospital General Universitario de Elche ( Site 1404)

Elche, Alicante, Spain

Hospital Germans Trias i Pujol. ICO de Badalona ( Site 1410)

Badalona, Barcelona, Spain

Hospital Universitario Marques de Valdecilla ( Site 1405)

Santander, Cantabria, Spain

Hospital Universitario Quiron Madrid ( Site 1407)

Pozuelo de Alarcón, Madrid, Spain

Hospital Universitario Central de Asturias ( Site 1402)

Oviedo, Principality of Asturias, Spain

Hospital General Universitari Vall d Hebron ( Site 1401)

Barcelona, , Spain

Hospital Universitario Ramon y Cajal ( Site 1400)

Madrid, , Spain

Adana Sehir Hastanesi ( Site 2002)

Adana, , Turkey (Türkiye)

Hacettepe Universitesi Tip Fakultesi Hastanesi ( Site 2017)

Ankara, , Turkey (Türkiye)

Abdurrahman Yurtaslan Onkoloji Egitim ve Arastirma Hastanesi ( Site 2006)

Ankara, , Turkey (Türkiye)

Trakya Universitesi Tip Fakultesi ( Site 2015)

Edirne, , Turkey (Türkiye)

Ataturk Universitesi Tip Fakultesi Hastanesi ( Site 2000)

Erzurum, , Turkey (Türkiye)

Istanbul Universitesi Cerrahpasa Tip Fakultesi ( Site 2001)

Istanbul, , Turkey (Türkiye)

Dokuz Eylul Universitesi Tip Fakultesi Hastanesi ( Site 2011)

Izmir, , Turkey (Türkiye)

Malatya Inonu Universitesi Tip Fakultesi Hastanesi ( Site 2009)

Malatya, , Turkey (Türkiye)

Sakarya Universitesi Egitim ve Arastirma Hastanesi ( Site 2012)

Sakarya, , Turkey (Türkiye)

City Clinical Hosp.4 of DCC ( Site 2102)

Dnipro, Dnipropetrovsk Oblast, Ukraine

MI Kryviy Rih Center of Dnipropetrovsk Regional Council ( Site 2101)

Kryviy Rih, Dnipropetrovsk Oblast, Ukraine

MI Precarpathian Clinical Oncology Center ( Site 2105)

Ivano-Frankivsk, Ivano-Frankivsk Oblast, Ukraine

Communal non profit enterprise Regional Clinical Oncology Center ( Site 2112)

Kharkiv, Kharkivs’ka Oblast’, Ukraine

Medical Center Asklepion LLC ( Site 2115)

Khodosovka, Kyivska Oblast, Ukraine

Clinic of National Cancer Institute ( Site 2104)

Kyiv, Kyivska Oblast, Ukraine

Medical and Diagnostic Centre LLC Dobryi Prognoz ( Site 2114)

Kyiv, Kyivska Oblast, Ukraine

Lviv State Oncology Regional Treatment and Diagnostic Center ( Site 2106)

Lviv, Lviv Oblast, Ukraine

MI Odessa Regional Oncological Centre ( Site 2108)

Odesa, Odesa Oblast, Ukraine

Medical Centre LLC Oncolife ( Site 2103)

Zaporizhzhya, Zaporizhzhia Oblast, Ukraine

Kyiv City Clinical Oncology Centre ( Site 2110)

Kyiv, , Ukraine

Royal Hospital in Derby ( Site 1514)

Derby, Derbyshire, United Kingdom

Ninewells Hospital and Medical School ( Site 1504)

Dundee, Dundee City, United Kingdom

Castle Hill Hospital ( Site 1501)

Cottingham, East Riding Of Yorkshire, United Kingdom

University College London Hospital NHS Foundation Trust ( Site 1508)

London, London, City of, United Kingdom

St Georges University Hospitals NHS Foundation Trust. ( Site 1500)

London, London, City of, United Kingdom

Royal Marsden Hospital ( Site 1510)

Sutton, Surrey, United Kingdom

Royal Marsden NHS Foundation Trust ( Site 1512)

London, , United Kingdom

The Christie Hospital NHS Foundation Trust ( Site 1503)

Manchester, , United Kingdom

Mount Vernon Cancer Centre ( Site 1507)

Northwood, , United Kingdom

Manor Hospital Walsall England ( Site 1515)

Walsall, , United Kingdom

Countries

United States; Australia; Brazil; Chile; China; France; Germany; Guatemala; Ireland; Israel; Italy; Japan; New Zealand; Poland; Russia; South Korea; Spain; Turkey (Türkiye); Ukraine; United Kingdom

References

Janjigian YY, Kawazoe A, Bai Y, Xu J, Lonardi S, Metges JP, Yanez P, Wyrwicz LS, Shen L, Ostapenko Y, Bilici M, Chung HC, Shitara K, Qin SK, Van Cutsem E, Tabernero J, Li K, Shih CS, Bhagia P, Rha SY; KEYNOTE-811 Investigators. Pembrolizumab plus trastuzumab and chemotherapy for HER2-positive gastric or gastro-oesophageal junction adenocarcinoma: interim analyses from the phase 3 KEYNOTE-811 randomised placebo-controlled trial. Lancet. 2023 Dec 9;402(10418):2197-2208. doi: 10.1016/S0140-6736(23)02033-0. Epub 2023 Oct 20.

Reference Type: RESULT

PMID: 37871604 (View on PubMed)

Janjigian YY, Kawazoe A, Bai Y, Xu J, Lonardi S, Metges JP, Yanez P, Wyrwicz LS, Shen L, Ostapenko Y, Bilici M, Chung HC, Shitara K, Qin S, Van Cutsem E, Tabernero J, Luo S, Mahave M, Tang Y, Lowery M, Monteiro MMF, Xu L, Shih CS, Sharan KP, Bhagia P, Rha SY. Pembrolizumab in HER2-Positive Gastric Cancer. N Engl J Med. 2024 Oct 10;391(14):1360-1362. doi: 10.1056/NEJMc2408121. Epub 2024 Sep 14. No abstract available.

Reference Type: RESULT

PMID: 39282917 (View on PubMed)

Janjigian YY, Kawazoe A, Yanez P, Li N, Lonardi S, Kolesnik O, Barajas O, Bai Y, Shen L, Tang Y, Wyrwicz LS, Xu J, Shitara K, Qin S, Van Cutsem E, Tabernero J, Li L, Shah S, Bhagia P, Chung HC. The KEYNOTE-811 trial of dual PD-1 and HER2 blockade in HER2-positive gastric cancer. Nature. 2021 Dec;600(7890):727-730. doi: 10.1038/s41586-021-04161-3. Epub 2021 Dec 15.

Reference Type: DERIVED

PMID: 34912120 (View on PubMed)

Chung HC, Bang YJ, S Fuchs C, Qin SK, Satoh T, Shitara K, Tabernero J, Van Cutsem E, Alsina M, Cao ZA, Lu J, Bhagia P, Shih CS, Janjigian YY. First-line pembrolizumab/placebo plus trastuzumab and chemotherapy in HER2-positive advanced gastric cancer: KEYNOTE-811. Future Oncol. 2021 Feb;17(5):491-501. doi: 10.2217/fon-2020-0737. Epub 2020 Nov 10.

Reference Type: DERIVED

PMID: 33167735 (View on PubMed)

Provided Documents

Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Related Links

https://www.merckclinicaltrials.com/

Merck Clinical Trials Information

https://msd.trialsummaries.com/Study/StudyDetails?id=26254&tenant=MT_MSD_9011

Plain Language Summary

Other Identifiers

MK-3475-811

Identifier Type: OTHER

Identifier Source: secondary_id

184142

Identifier Type: REGISTRY

Identifier Source: secondary_id

2023-508253-98-00

Identifier Type: REGISTRY

Identifier Source: secondary_id

U1111-1297-9360

Identifier Type: REGISTRY

Identifier Source: secondary_id

2018-000224-34

Identifier Type: EUDRACT_NUMBER

Identifier Source: secondary_id

3475-811

Identifier Type: -

Identifier Source: org_study_id