Efficacy and Safety of Pembrolizumab (MK-3475) Plus Enzalutamide Plus Androgen Deprivation Therapy (ADT) Versus Placebo Plus Enzalutamide Plus ADT in Participants With Metastatic Hormone-Sensitive Prostate Cancer (mHSPC) (MK-3475-991/KEYNOTE-991)

NCT ID: NCT04191096

Last Updated: 2025-08-29

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: PHASE3
• Total Enrollment: 1251 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2020-02-12
• Study Completion Date: 2026-02-02

Brief Summary

This study will assess the efficacy and safety of pembrolizumab plus enzalutamide plus Androgen Deprivation Therapy (ADT) versus placebo plus enzalutamide plus ADT in participants with mHSPC. The primary hypothesis is that in participants with mHSPC, the combination of pembrolizumab plus enzalutamide plus ADT is superior to placebo plus enzalutamide plus ADT with respect to 1) radiographic progression-free survival (rPFS) per Prostate Cancer Working Group (PCWG)-modified Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 as assessed by blinded independent central review (BICR) and 2) overall survival (OS). As of 19-JAN-2023, the study was unblinded and all study participants stopped ongoing treatment with pembrolizumab/placebo and will continue to receive Standard of Care treatment until meeting protocol-specified discontinuation criteria if deriving clinical benefit. Safety analysis will be performed at the end of the study; there will be no further analyses for efficacy and electronic patient-reported outcome (ePRO) endpoints collected from participants beyond the IA1 cutoff date. All study participants will stop ongoing treatment with pembrolizumab/placebo. Exceptions may be requested for study participants who, in the assessment of their study physician, are benefitting from the combination of enzalutamide and pembrolizumab, after consulting with the Sponsor. All other study participants should be discontinued from study and be offered standard of care (SOC) treatment as deemed necessary by the Investigator. If enzalutamide as SOC is not accessible off study to the participant, central sourcing may continue. As of Amendment 04, disease progression will no longer be centrally verified, participants will only be assessed locally. As of Amendment 4, Second Course treatment is not an option for participants. There are currently no participants in the Second Course Phase.

Conditions

Metastatic Hormone-Sensitive Prostate Cancer

Study Design

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

Study Groups

Pembrolizumab + Enzalutamide + ADT

Starting on Day 1 of each 21-day cycle, participants receive 200 mg pembrolizumab IV every 3 weeks (Q3W) for up to 35 cycles (approximately 2 years), plus 160 mg enzalutamide taken orally once daily, while maintaining continuous ADT with a luteinizing-hormone releasing hormone (LHRH) agonist or antagonist during study treatment. Participants will continue to receive enzalutamide and ADT until criteria for discontinuation are met.

Group Type: EXPERIMENTAL

Pembrolizumab

Intervention Type: BIOLOGICAL

Pembrolizumab is administered as an IV infusion at 200 mg on Day 1 of each 21-day cycle for up to 35 cycles.

Enzalutamide

Intervention Type: DRUG

Enzalutamide is administered orally as capsules/tablets at a dosage of 160 mg daily. Enzalutamide is administered continuously until criteria for discontinuation are met.

Androgen Deprivation Therapy (ADT)

Intervention Type: DRUG

Stable regimen of ADT (LHRH agonist or antagonist) at a dose and frequency of administration that is consistent with the local product label.

Placebo + Enzalutamide + ADT

Starting on Day 1 of each 21-day cycle, participants receive placebo IV Q3W for up to 35 cycles (approximately 2 years), plus 160 mg enzalutamide taken orally once daily, while maintaining continuous ADT with a LHRH agonist or antagonist during study treatment. Participants will continue to receive enzalutamide and ADT until criteria for discontinuation are met.

Group Type: PLACEBO_COMPARATOR

Enzalutamide

Intervention Type: DRUG

Enzalutamide is administered orally as capsules/tablets at a dosage of 160 mg daily. Enzalutamide is administered continuously until criteria for discontinuation are met.

Androgen Deprivation Therapy (ADT)

Intervention Type: DRUG

Stable regimen of ADT (LHRH agonist or antagonist) at a dose and frequency of administration that is consistent with the local product label.

Placebo

Intervention Type: OTHER

Placebo infusion solution is administered as an IV infusion on Day 1 of each 21-day cycle for up to 35 cycles.

Interventions

Pembrolizumab

Pembrolizumab is administered as an IV infusion at 200 mg on Day 1 of each 21-day cycle for up to 35 cycles.

Intervention Type: BIOLOGICAL

Enzalutamide

Enzalutamide is administered orally as capsules/tablets at a dosage of 160 mg daily. Enzalutamide is administered continuously until criteria for discontinuation are met.

Intervention Type: DRUG

Androgen Deprivation Therapy (ADT)

Stable regimen of ADT (LHRH agonist or antagonist) at a dose and frequency of administration that is consistent with the local product label.

Intervention Type: DRUG

Placebo

Placebo infusion solution is administered as an IV infusion on Day 1 of each 21-day cycle for up to 35 cycles.

Intervention Type: OTHER

Other Intervention Names

KEYTRUDA®; MK-3475; XTANDI®

Eligibility Criteria

Inclusion Criteria

• Male participants with histologically- or cytologically-confirmed adenocarcinoma of the prostate without small cell histology
• Has metastatic disease assessed by investigator and verified by BICR by either ≥2 bone lesions on bone scan and/or visceral disease by computed tomography/magnetic resonance imaging (CT/MRI)
• Willing to maintain continuous Androgen Deprivation Therapy (ADT) with a luteinizing-hormone releasing hormone (LHRH) agonists or antagonists during study treatment or have a history of bilateral orchiectomy
• Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 assessed within 10 days of randomization
• Participants receiving bone resorptive therapy (including, but not limited to, bisphosphonate or denosumab) must have been on stable doses prior to randomization
• Has adequate organ function
• Has provided newly obtained core or excisional biopsy (obtained within 12 months of screening) from soft tissue not previously irradiated (samples from tumors progressing in a prior site of radiation are allowed). Participants with bone only or bone predominant disease may provide a bone biopsy sample
• Male participants must agree to the following during the intervention period and for at least 120 days after the last dose of study intervention: Refrain from donating sperm PLUS either be abstinent from heterosexual intercourse and agree to remain abstinent OR agree to use contraception, unless confirmed to be azoospermic
• Male participants must agree to use male condom when engaging in any activity that allows for passage of ejaculate to another person of any sex

Exclusion Criteria

• Has a known additional malignancy that is progressing or has required active treatment in the last 3 years
• 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 undergone major surgery including local prostate intervention (excluding prostate biopsy) within 28 days prior to randomization and not recovered adequately from the toxicities and/or complications
• Has a gastrointestinal disorder affecting absorption or is unable to swallow tablets/capsules
• Has an active infection (including tuberculosis) requiring systemic therapy
• Has a history of (non-infectious) pneumonitis that required steroids or has current pneumonitis
• Has known active human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV) infection
• Has known or suspected central nervous system (CNS) metastases and/or carcinomatous meningitis
• Has a history of seizure or any condition that may predispose to seizure
• Has a history of loss of consciousness within 12 months of screening
• Has had myocardial infarction or uncontrolled angina within 6 months prior to randomization, or has New York Heart Association class III or IV congestive heart failure or a history of New York Heart Association class III or IV congestive heart failure
• Has hypotension (systolic blood pressure <86 millimeters of mercury [mmHg]) or uncontrolled hypertension (systolic blood pressure >170 mmHg or diastolic blood pressure >105 mmHg) at the screening visit
• Has a history of clinically significant ventricular arrhythmias
• Has hypersensitivity to pembrolizumab and/or enzalutamide and/or any of their excipients
• Has received prior ADT as neoadjuvant/adjuvant therapy for non-metastatic prostate cancer for >39 months in duration or within 9 months prior to randomization or with evidence of disease progression while receiving ADT
• Has had prior treatment with a next generation hormonal agent (eg, abiraterone, enzalutamide, apalutamide, darolutamide)
• 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
• Has received a live vaccine within 30 days prior to randomization
• Has a "superscan" bone scan
• Has had an allogenic tissue/solid organ transplant
• Is 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 any prior pharmacotherapy, radiation therapy or surgery for metastatic prostate cancer with the following exceptions:

1. Up to 3 months of ADT or orchiectomy with or without concurrent first-generation antiandrogens, if patient was not treated with docetaxel

2. May have 1 course of palliative radiation or surgical therapy to treat symptoms resulting from metastatic disease if it was administered at least 4 weeks prior to randomization

3. For participants with low volume metastatic disease, may have 1 course of definitive radiotherapy if it was administered at least 4 weeks prior to randomization

4. Up to 6 cycles of docetaxel therapy with final treatment administration completed within 2 months of randomization and no evidence of disease progression. In these participants up to 6 months of ADT permitted

• Minimum Eligible Age: 18 Years
• Eligible Sex: MALE
• 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

Alaska Clinical Research Center ( Site 0274)

Anchorage, Alaska, United States

Providence Alaska Medical Center ( Site 0276)

Anchorage, Alaska, United States

City of Hope Medical Center ( Site 0217)

Duarte, California, United States

UCLA Hematology/Oncology - Santa Monica ( Site 0241)

Los Angeles, California, United States

University of Colorado, Anschutz Cancer Pavilion ( Site 0236)

Aurora, Colorado, United States

Hartford HealthCare Medical Group ( Site 0212)

Manchester, Connecticut, United States

Smilow Cancer Center at Yale-New Haven ( Site 0250)

New Haven, Connecticut, United States

Sibley Memorial Hospital ( Site 0275)

Washington D.C., District of Columbia, United States

Winship Cancer Institute of Emory University ( Site 0209)

Atlanta, Georgia, United States

The University of Chicago ( Site 0264)

Chicago, Illinois, United States

Springfield Clinic [Springfield, IL] ( Site 0240)

Springfield, Illinois, United States

Cotton-O'Neil Cancer Center ( Site 0228)

Topeka, Kansas, United States

The Sidney Kimmel Comprehensive Cancer Center ( Site 0204)

Baltimore, Maryland, United States

St. Vincent Frontier Cancer Center-Research ( Site 0213)

Billings, Montana, United States

Comprehensive Cancer Centers of Nevada ( Site 0269)

Las Vegas, Nevada, United States

Laura and Isaac Perlmutter Cancer Center at NYU Langone Health ( Site 0270)

New York, New York, United States

Weill Cornell Medical College ( Site 0263)

New York, New York, United States

Associated Medical Professionals of NY ( Site 0251)

Syracuse, New York, United States

Duke University ( Site 0206)

Durham, North Carolina, United States

TriState Urologic Services PSC Inc. dba The Urology Group ( Site 0253)

Cincinnati, Ohio, United States

MidLantic Urology ( Site 0273)

Bala-Cynwyd, Pennsylvania, United States

Ralph H. Johnson VA Center ( Site 0256)

Charleston, South Carolina, United States

Carolina Urologic Research Center ( Site 0259)

Myrtle Beach, South Carolina, United States

Urology Associates [Nashville, TN] ( Site 0233)

Nashville, Tennessee, United States

Inova Health System ( Site 0205)

Fairfax, Virginia, United States

Urology of Virginia ( Site 0224)

Virginia Beach, Virginia, United States

Fred Hutchinson Cancer Center ( Site 0258)

Seattle, Washington, United States

Chris OBrien Lifehouse ( Site 0300)

Camperdown, New South Wales, Australia

Port Macquarie Base Hospital ( Site 0301)

Port Macquarie, New South Wales, Australia

Riverina Cancer Care Center ( Site 0302)

Wagga Wagga, New South Wales, Australia

Gallipoli Medical Research Ltd ( Site 0309)

Greenslopes, Queensland, Australia

John Flynn Hospital & Medical Centre ( Site 0308)

Tugun, Queensland, Australia

Box Hill Hospital ( Site 0304)

Box Hill, Victoria, Australia

Monash Health ( Site 0305)

Clayton, Victoria, Australia

Peter MacCallum Cancer Centre-Parkville Cancer Clinical Trials Unit (PCCTU) ( Site 0306)

Melbourne, Victoria, Australia

Fiona Stanley Hospital ( Site 0311)

Perth, Western Australia, Australia

Ordensklinikum Linz GmbH Elisabethinen ( Site 0901)

Linz, Upper Austria, Austria

Landeskrankenhaus Salzburg - Universitatklinikum der PMU ( Site 0900)

Salzburg, , Austria

Krankenhaus der Barmherzigen Brüder Wien ( Site 0904)

Vienna, , Austria

Medizinische Universität Wien ( Site 0903)

Vienna, , Austria

Oncocentro Ceara ( Site 2309)

Fortaleza, Ceará, Brazil

Instituto de Cancer e Transplante de Curitiba ICTR ( Site 2306)

Curitiba, Paraná, Brazil

Hospital Sao Vicente de Paulo ( Site 2303)

Passo Fundo, Rio Grande do Sul, Brazil

Hospital de Clinicas de Porto Alegre ( Site 2304)

Porto Alegre, Rio Grande do Sul, Brazil

Clinica de Oncologia Reichow ( Site 2308)

Blumenau, Santa Catarina, Brazil

Fundacao Dr Amaral Carvalho ( Site 2302)

Jaú, São Paulo, Brazil

Instituto do Cancer do Estado de Sao Paulo - ICESP ( Site 2305)

São Paulo, , Brazil

The Ottawa Hospital ( Site 0100)

Ottawa, Ontario, Canada

Niagara Health System - St. Catharines ( Site 0107)

St. Catharines, Ontario, Canada

CISSS de la Monteregie-Centre ( Site 0105)

Greenfield Park, Quebec, Canada

Centre Hospitalier de l Universite de Montreal - CHUM ( Site 0109)

Montreal, Quebec, Canada

CIUSSS Ouest de l Ile - St-Mary s Hospital ( Site 0106)

Montreal, Quebec, Canada

Centre intégré de cancérologie du CHU de Québec Université Laval, Hôpital de l'Enfant-Jésus ( Site 0101)

Québec, Quebec, Canada

IC La Serena Research ( Site 2406)

La Serena, Coquimbo Region, Chile

Clinica Universidad Catolica del Maule ( Site 2407)

Talca, Maule Region, Chile

Clinica Alemana ( Site 2408)

Santiago, Region M. de Santiago, Chile

Pontificia Universidad Catolica de Chile ( Site 2402)

Santiago, Region M. de Santiago, Chile

Bradfordhill ( Site 2403)

Santiago, Region M. de Santiago, Chile

Centro Investigación del Cáncer James Lind ( Site 2401)

Temuco, Región de la Araucanía, Chile

Oncocentro ( Site 2400)

Viña del Mar, Región de Valparaíso, Chile

Peking University First Hospital ( Site 0800)

Beijing, Beijing Municipality, China

Beijing Cancer Hospital ( Site 0802)

Beijing, Beijing Municipality, China

Chongqing Cancer Hospital ( Site 0815)

Chongqing, Chongqing Municipality, China

The First Affiliated Hospital of Xiamen University ( Site 0816)

Xiamen, Fujian, China

The First Affiliated Hospital of Guangzhou Medical University-Urology ( Site 0837)

Guangdong, Guangdong, China

Sun Yat-Sen University Cancer Center ( Site 0825)

Guangzhou, Guangdong, China

Sun Yat Sen Memorial Hospital ( Site 0819)

Guangzhou, Guangdong, China

Southern Medical University Nanfang Hospital ( Site 0838)

Guangzhou, Guangdong, China

Harbin Medical University Cancer Hospital ( Site 0822)

Harbin, Heilongjiang, China

Henan Cancer Hospital ( Site 0818)

Zhengzhou, Henan, China

Union Hospital Tongji Medical College Huazhong University of Science and Technology ( Site 0829)

Wuhan, Hubei, China

Hubei Cancer Hospital ( Site 0833)

Wuhan, Hubei, China

Hunan Cancer Hospital ( Site 0817)

Changsha, Hunan, China

Nanjing Drum Tower Hospital ( Site 0811)

Nanjing, Jiangsu, China

The First Affiliated Hospital of Nanchang University ( Site 0821)

Nanchang, Jiangxi, China

The Second Affiliated Hosp of Xi'an Jiaotong Univ College of Medicine ( Site 0831)

Xi'an, Shaanxi, China

Renji Hospital Shanghai Jiaotong University School of Medicine ( Site 0807)

Shanghai, Shanghai Municipality, China

The first affiliated Hospital of Xi an Jiaotong University ( Site 0812)

Xi’an, Shanxi, China

Tianjin Medical University Cancer Institute & Hospital ( Site 0804)

Tianjin, Tianjin Municipality, China

2nd Affil Hosp of Zhejiang University College of Medicine ( Site 0808)

Hangzhou, Zhejiang, China

The 1st Affil Hosp of College of Medicine, Zhejiang Univ ( Site 0830)

Hangzhou, Zhejiang, China

Zhejiang Provincial People's Hospital ( Site 0809)

Hangzhou, Zhejiang, China

Ningbo First Hospital-Urology ( Site 0835)

Ningbo, Zhejiang, China

The First Affiliated Hospital of Wenzhou Medical University ( Site 0834)

Wenzhou, Zhejiang, China

Clinica de la Costa S.A.S. ( Site 2504)

Barranquilla, Atlántico, Colombia

Administradora Country SA - Clinica del Country ( Site 2507)

Bogotá, Bogota D.C., Colombia

Instituto Nacional de Cancerologia E.S.E ( Site 2506)

Bogotá, Bogota D.C., Colombia

Sociedad de Oncología Y Hematología del Cesar S.A.S. ( Site 2509)

Valledupar, Cesar Department, Colombia

Hemato Oncologos ( Site 2503)

Cali, Valle del Cauca Department, Colombia

Rigshospitalet ( Site 1005)

Copenhagen, Capital Region, Denmark

Herlev og Gentofte Hospital. ( Site 1004)

Herlev, Capital Region, Denmark

Aalborg Universitetshospital ( Site 1000)

Aalborg, North Denmark, Denmark

Odense Universitetshospital ( Site 1003)

Odense, Region Syddanmark, Denmark

Vejle Sygehus ( Site 1002)

Vejle, Region Syddanmark, Denmark

Keski-Suomen keskussairaala ( Site 1017)

Jyväskylä, Central Finland, Finland

Tampereen yliopistollinen sairaala ( Site 1022)

Tampere, Pirkanmaa, Finland

HYKS ( Site 1020)

Helsinki, Southwest Finland, Finland

TYKS T-sairaala Syopatautien pkl ( Site 1019)

Turku, Southwest Finland, Finland

Institut de cancérologie Strasbourg Europe (ICANS) ( Site 1114)

Strasbourg, Alsace, France

Centre Georges Francois Leclerc ( Site 1112)

Dijon, Cote-d Or, France

CHU-Jean Minjoz ( Site 1101)

Besançon, Doubs, France

CHU de Brest -Site Hopital Morvan ( Site 1103)

Brest, Finistere, France

Institut Bergonie ( Site 1104)

Bordeaux, Gironde, France

Centre Bourgogne ( Site 1119)

Lille, Hauts-de-France, France

Hopital Foch ( Site 1105)

Suresnes, Hauts-de-Seine, France

C.H.R.U. de Rennes. Hopital de Pontchaillou ( Site 1117)

Rennes, Ille-et-Vilaine, France

Institut Jean Godinot-Clinical Research Unit ( Site 1118)

Reims, Marne, France

Centre D Oncologie de Gentilly ( Site 1107)

Nancy, Meurthe-et-Moselle, France

Centre Leon-Berard ( Site 1110)

Lyon, Rhone, France

Hospices Civils de Lyon Centre Hospitalier Lyon Sud ( Site 1102)

Pierre-Bénite, Rhone, France

Hopital Henri Mondor ( Site 1116)

Créteil, Val-de-Marne, France

Universitaetsklinikum Freiburg ( Site 1200)

Freiburg im Breisgau, Baden-Wurttemberg, Germany

Klinikum der Universitaet Muenchen - Grosshadern ( Site 1210)

Munich, Bavaria, Germany

Klinikum Rechts der Isar ( Site 1206)

München, Bavaria, Germany

Klinikum Nuernberg Nord ( Site 1213)

Nuremberg, Bavaria, Germany

Staedtisches Klinikum Braunschweig gGmbH ( Site 1217)

Braunschweig, Lower Saxony, Germany

Universitaetsklinikum der Technischen Universitaet Dresden ( Site 1204)

Dresden, Saxony, Germany

Universitaetsklinikum Magdeburg A.o.R. ( Site 1211)

Magdeburg, Saxony-Anhalt, Germany

Charite Universitaetsmedizin Berlin ( Site 1201)

Berlin, , Germany

Universitaetsklinikum Hamburg-Eppendorf ( Site 1212)

Hamburg, , Germany

St Vincents University Hospital ( Site 1300)

Dublin, Dublin, Ireland

Cork University Hospital ( Site 1304)

Cork, , Ireland

Tallaght University Hospital ( Site 1301)

Dublin, , Ireland

Beaumont Hospital ( Site 1302)

Dublin, , Ireland

University Hospital Limerick ( Site 1305)

Limerick, , Ireland

University Hospital Waterford ( Site 1303)

Waterford, , Ireland

Rambam Health Care Campus-Oncology Division ( Site 1400)

Haifa, , Israel

Hadassah Ein Kerem Medical Center ( Site 1404)

Jerusalem, , Israel

Meir Medical Center ( Site 1401)

Kfar Saba, , Israel

Rabin Medical Center ( Site 1402)

Petah Tikva, , Israel

Sourasky Medical Center ( Site 1403)

Tel Aviv, , Israel

Yitzhak Shamir Medical Center. ( Site 1405)

Ẕerifin, , Israel

Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori ( Site 1503)

Meldola, Forli-Cesena, Italy

Fondazione Policlinico Universitario A. Gemelli ( Site 1512)

Rome, Lazio, Italy

Istituto Clinico Humanitas Research Hospital ( Site 1500)

Rozzano, Lombardy, Italy

Centro Di Riferimento Oncologico ( Site 1511)

Aviano, Pordenone, Italy

IRCCS Giovanni Paolo II. Ospedale Oncologico ( Site 1509)

Bari, , Italy

Azienda Ospedaliera Cannizzaro ( Site 1501)

Catania, , Italy

Istituto Nazionale dei Tumori ( Site 1510)

Milan, , Italy

Istituto Nazionale Tumori IRCCS Fondazione Pascale ( Site 1508)

Napoli, , Italy

Azienda Ospedaliera Santa Maria ( Site 1502)

Terni, , Italy

A.O. Verona-Ospedale Civile Maggiore Borgo-Trento ( Site 1504)

Verona, , Italy

Toho University Sakura Medical Center ( Site 0732)

Sakura, Chiba, Japan

Ehime University Hospital ( Site 0745)

Tōon, Ehime, Japan

Sapporo Medical University Hospital ( Site 0730)

Sapporo, Hokkaido, Japan

Kitasato University Hospital ( Site 0734)

Sagamihara, Kanagawa, Japan

Yokohama City University Medical Center ( Site 0735)

Yokohama, Kanagawa, Japan

Nara Medical University Hospital ( Site 0744)

Kashihara, Nara, Japan

Kindai University Hospital ( Site 0743)

Sayama, Osaka, Japan

The University of Osaka Hospital ( Site 0742)

Suita, Osaka, Japan

Saitama Medical University International Medical Center ( Site 0737)

Hidaka, Saitama, Japan

Dokkyo Medical University Saitama Medical Center ( Site 0736)

Koshigaya, Saitama, Japan

Hamamatsu University Hospital ( Site 0748)

Hamamatsu, Shizuoka, Japan

Yamaguchi University Hospital ( Site 0746)

Ube, Yamaguchi, Japan

Chiba Cancer Center ( Site 0733)

Chiba, , Japan

Harasanshin Hospital ( Site 0747)

Fukuoka, , Japan

Nagano Municipal Hospital ( Site 0731)

Nagano, , Japan

Osaka Metropolitan University Hospital ( Site 0741)

Osaka, , Japan

Toranomon Hospital ( Site 0740)

Tokyo, , Japan

Nippon Medical School Hospital ( Site 0738)

Tokyo, , Japan

Tokyo Women's Medical University ( Site 0739)

Tokyo, , Japan

Hospital San Lucas Cardiologica del Sureste ( Site 2606)

Tuxtla Gutiérrez, Chiapas, Mexico

Hospital Civil de Guadalajara Fray Antonio Alcalde ( Site 2607)

Guadalajara, Jalisco, Mexico

Centro Estatal de Cancerologia de Chihuahua ( Site 2608)

Chihuahua City, , Mexico

Grupo Medico Camino SC ( Site 2613)

Mexico City, , Mexico

Centro Oncologico Internacional. SEDNA ( Site 2609)

Mexico City, , Mexico

Boca Raton Clinical Research QTO ( Site 2611)

Querétaro, , Mexico

Radboud University Medical Center ( Site 1606)

Nijmegen, Gelderland, Netherlands

Antoni van Leeuwenhoek Ziekenhuis ( Site 1603)

Amsterdam, North Holland, Netherlands

Vrije Universiteit Medisch Centrum ( Site 1601)

Amsterdam, North Holland, Netherlands

Isala Klinieken, Locatie Sophia ( Site 1604)

Zwolle, Overijssel, Netherlands

Franciscus Gasthuis en Vlietland ( Site 1605)

Schiedam, South Holland, Netherlands

Meander Medisch Centrum ( Site 1602)

Amersfoort, Utrecht, Netherlands

St. Antonius Ziekenhuis ( Site 1600)

Utrecht, , Netherlands

Auckland City Hospital ( Site 0321)

Auckland, , New Zealand

Hospital Nacional Carlos Alberto Seguin Escobedo ESSALUD ( Site 2700)

Arequipa, Ariqipa, Peru

Clinica Peruano Americana S.A. ( Site 2702)

Trujillo, La Libertad, Peru

Hospital Nacional Guillermo Almenara Irigoyen ( Site 2708)

Lima, , Peru

IPOR Instituto Peruano de Oncología & Radioterapia-Centro de Investigación ( Site 2706)

Lima, , Peru

Hospital Militar Central [Lima, Peru] ( Site 2704)

Lima, , Peru

Uniwersytecki Szpital Kliniczny w Poznaniu ( Site 1710)

Poznan, Greater Poland Voivodeship, Poland

Szpital Uniwersytecki nr 1 im. Dr. Antoniego Jurasza w Bydgoszczy ( Site 1720)

Bydgoszcz, Kuyavian-Pomeranian Voivodeship, Poland

Centrum Onkologii im. Prof. Franciszka Lukaszczyka ( Site 1716)

Bydgoszcz, Kuyavian-Pomeranian Voivodeship, Poland

MICS Centrum Medyczne Torun ( Site 1718)

Torun, Kuyavian-Pomeranian Voivodeship, Poland

Szpital Uniwersytecki w Krakowie ( Site 1707)

Krakow, Lesser Poland Voivodeship, Poland

Radomskie Centrum Onkologii ( Site 1701)

Radom, Masovian Voivodeship, Poland

Wojewodzki Szpital im. Sw. Ojca Pio w Przemyslu ( Site 1700)

Przemyśl, Podkarpackie Voivodeship, Poland

Wojewodzki Szpital Specjalistyczny nr 4 w Bytomiu ( Site 1717)

Bytom, Silesian Voivodeship, Poland

Szpital Wojewodzki im. Mikolaja Kopernika ( Site 1709)

Koszalin, West Pomeranian Voivodeship, Poland

Twoja Przychodnia - Szczeciskie Centrum Medyczne ( Site 1721)

Szczecin, West Pomeranian Voivodeship, Poland

Krasnoyarsk Regional Clinical Oncological Dispensary ( Site 1810)

Krasnoyarsk, Krasnoyarsk Krai, Russia

SBIH City clinical hospital named after D.D. Pletniov ( Site 1813)

Moscow, Moscow, Russia

Russian Scientific Center of Roentgenoradiology ( Site 1800)

Moscow, Moscow, Russia

Volga District Medical Center Federal Medical and Biological Agency ( Site 1805)

Nizhny Novgorod, Nizhny Novgorod Oblast, Russia

Omsk Clinical Oncology Dispensary ( Site 1809)

Omsk, Omsk Oblast, Russia

Chonnam National University Hwasun Hospital ( Site 0406)

Jeollanam-do, Jeonranamdo, South Korea

National Cancer Center ( Site 0400)

Gyeonggi-do, Kyonggi-do, South Korea

Seoul National University Bundang Hospital ( Site 0401)

Seongnam-si, Kyonggi-do, South Korea

Kyungpook National University Chilgok Hospital ( Site 0404)

Daegu, Kyongsangbuk-do, South Korea

Seoul National University Hospital ( Site 0405)

Seoul, , South Korea

Severance Hospital Yonsei University Health System ( Site 0402)

Seoul, , South Korea

Asan Medical Center ( Site 0403)

Seoul, , South Korea

Instituto Catalan de Oncologia - ICO ( Site 1901)

L'Hospitalet de Llobregat, Barcelona, Spain

Institut Català d'Oncologia (ICO) - Girona ( Site 1900)

Girona, Gerona, Spain

Hospital Universitario Lucus Augusti ( Site 1905)

Lugo, , Spain

Hospital Universitario Ramon y Cajal ( Site 1902)

Madrid, , Spain

Hospital Clinico San Carlos ( Site 1906)

Madrid, , Spain

Hospital 12 de Octubre de Madrid ( Site 1903)

Madrid, , Spain

Hospital Virgen de la Macarena ( Site 1904)

Seville, , Spain

Kantonsspital St. Gallen ( Site 2000)

Sankt Gallen, Canton of St. Gallen, Switzerland

CHUV (centre hospitalier universitaire vaudois) ( Site 2002)

Lausanne, Canton of Vaud, Switzerland

Universitaetsspital Zuerich ( Site 2001)

Zurich, Canton of Zurich, Switzerland

Kantonsspital Graubuenden ( Site 2003)

Chur, Kanton Graubünden, Switzerland

Kaohsiung Chang Gung Memorial Hospital ( Site 0504)

Kaohsiung City, , Taiwan

National Cheng Kung University Hospital ( Site 0503)

Tainan City, , Taiwan

National Taiwan University Hospital ( Site 0500)

Taipei, , Taiwan

Taipei Veterans General Hospital ( Site 0501)

Taipei, , Taiwan

Chang Gung Medical Foundation. Linkou ( Site 0502)

Taoyuan District, , Taiwan

Chulalongkorn Hospital, Medical Oncology Unit ( Site 0600)

Bangkok, Bangkok, Thailand

Ramathibodi Hospital. ( Site 0601)

Bangkok, Bangkok, Thailand

Faculty of Medicine Siriraj Hospital ( Site 0602)

Bangkok, Bangkok, Thailand

Srinagarind Hospital ( Site 0604)

Khon Kaen, , Thailand

Ankara Bilkent Sehir Hastanesi ( Site 2103)

Ankara, Adana, Turkey (Türkiye)

Acibadem Adana Hastanesi ( Site 2106)

Adana, , Turkey (Türkiye)

Ankara Universitesi Tip Fakultesi. ( Site 2101)

Ankara, , Turkey (Türkiye)

Hacettepe Universitesi Tıp Fakultesi ( Site 2105)

Ankara, , Turkey (Türkiye)

Istanbul Uni. Cerrahpasa Tip Fakultesi ( Site 2100)

Istanbul, , Turkey (Türkiye)

Ege University Medical Faculty Tulay Aktas Oncology Hospital ( Site 2102)

Izmir, , Turkey (Türkiye)

Konya Necmettin Erbakan University Medical Faculty ( Site 2104)

Konya, , Turkey (Türkiye)

Aberdeen Royal Infirmary ( Site 1315)

Aberdeen, Aberdeen City, United Kingdom

Royal Cornwall Hospitals NHS Trust ( Site 1317)

Truro, Cornwall, United Kingdom

University College London Hospitals NHS Foundation Trust ( Site 1320)

London, London, City of, United Kingdom

ROYAL MARSDEN HOSPITAL (CHELSEA) ( Site 1318)

London, London, City of, United Kingdom

Velindre Cancer Centre Hospital ( Site 1322)

Cardiff, Wales, United Kingdom

Countries

United States; Australia; Austria; Brazil; Canada; Chile; China; Colombia; Denmark; Finland; France; Germany; Ireland; Israel; Italy; Japan; Mexico; Netherlands; New Zealand; Peru; Poland; Russia; South Korea; Spain; Switzerland; Taiwan; Thailand; Turkey (Türkiye); United Kingdom

References

Gratzke C, Kwiatkowski M, De Giorgi U, Martins da Trindade K, De Santis M, Armstrong AJ, Niu C, Liu Y, Poehlein CH. KEYNOTE-991: pembrolizumab plus enzalutamide and androgen deprivation for metastatic hormone-sensitive prostate cancer. Future Oncol. 2023 Jan 27. doi: 10.2217/fon-2022-0776. Online ahead of print.

Reference Type: DERIVED

PMID: 36705526 (View on PubMed)

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Related Links

http://merckoncologyclinicaltrials.com

Merck Oncology Clinical Trial Information

https://msd.trialsummaries.com/Study/StudyDetails?id=26244&tenant=MT_MSD_9011

Plain Language Summary

Other Identifiers

MK-3475-991

Identifier Type: OTHER

Identifier Source: secondary_id

KEYNOTE-991

Identifier Type: OTHER

Identifier Source: secondary_id

jRCT2080225171

Identifier Type: REGISTRY

Identifier Source: secondary_id

2023-507024-24-00

Identifier Type: REGISTRY

Identifier Source: secondary_id

U1111-1294-9592

Identifier Type: REGISTRY

Identifier Source: secondary_id

2019-003633-41

Identifier Type: EUDRACT_NUMBER

Identifier Source: secondary_id

3475-991

Identifier Type: -

Identifier Source: org_study_id