AzTrials
AzTrials

Prostatic NeoplasmsPhase 3NCT03834506

Study of Pembrolizumab (MK-3475) Plus Docetaxel Versus Placebo Plus Docetaxel in Chemotherapy-naïve Metastatic Castration-resistant Prostate Cancer (mCRPC) (MK-3475-921/KEYNOTE-921)

A Phase 3 study testing Pembrolizumab, Docetaxel and Prednisone in people with Prostatic Neoplasms, run by Merck Sharp & Dohme LLC at 215 sites in 21 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

The purpose of this study is to assess the efficacy and safety of the combination of pembrolizumab (MK-3475) and docetaxel in the treatment of men with metastatic castration-resistant prostate cancer (mCRPC) who have not received chemotherapy for mCRPC but have progressed on or are intolerant to Next Generation… Read more about this study

Who is it for?
Ages 18 years and older, men only
Conditions the study is for
Prostatic Neoplasms
What is being tested?
Pembrolizumab, Docetaxel and Prednisone
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
1,030 participants
Where
215 sitesin 21 countries
Study dates
2 May 2019to 18 Jul 2023
Phase
Phase 3
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • Men only
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Has histologically- or cytologically-confirmed adenocarcinoma of the prostate without small cell histology
  • Has prostate cancer progression while on androgen deprivation therapy (or post bilateral orchiectomy) within 6 months prior to screening
  • Has current evidence of metastatic disease documented by either bone lesions on bone scan and/or soft tissue disease by computed tomography/magnetic resonance imaging (CT/MRI)
  • Has received prior treatment with one (but not more than one) NHA (eg, abiraterone acetate, enzalutamide, apalutamide, or darolutamide) for metastatic hormone-sensitive prostate cancer (mHSPC) or castration-resistant prostate cancer (CRPC) and either a) progressed through treatment OR b) has become intolerant of the drug
  • Has ongoing androgen deprivation with serum testosterone <50 ng/dL (<2.0 nM)
  • Participants receiving bone resorptive therapy (including, but not limited to, bisphosphonate or denosumab) must have been on stable doses prior to randomization
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  • Participants must agree to the following during the study treatment period and for at least 120 days after the last dose of pembrolizumab or for at least 180 days after the last dose of docetaxel (whichever is longer): Refrain from donating sperm PLUS Use contraception unless confirmed to be azoospermic (vasectomized or secondary to medical cause)
  • Participants must agree to use male condom when engaging in any activity that allows for passage of ejaculate to another person of any sex
  • 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
  • Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 assessed within 7 days of randomization

Who cannot join

  • 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
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  • Has a history of (non-infectious) pneumonitis that required steroids or current pneumonitis
  • Has known active human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV) infection
  • Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis
  • Has severe hypersensitivity (≥Grade 3) to pembrolizumab and/or any of its excipients
  • Has symptomatic congestive heart failure (New York Heart Association Class III or IV heart disease)
  • Has had a prior anti-cancer monoclonal antibody (mAb) prior to randomization or who has not recovered (i.e., Grade ≤1 or at baseline) from AEs due to mAbs
  • Has used herbal products that may have hormonal anti-prostate cancer activity and/or are known to decrease PSA levels (e.g. saw palmetto) prior to randomization
  • Has received prior treatment with radium or other therapeutic radiopharmaceuticals for prostate cancer
  • 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 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, CD137)
  • Has received prior treatment with docetaxel or another chemotherapy agent for mCRPC
  • Has hypersensitivity to docetaxel or polysorbate 80
  • Is currently receiving either strong or moderate inhibitors of cytochrome P450 (CYP)3A4 that cannot be discontinued for the duration of the study
  • Has received prior targeted small molecule therapy or abiraterone acetate, enzalutamide, apalutamide, or darolutamide within 4 weeks prior to the first dose of study treatment, or has not recovered (i.e., Grade ≤1 or at baseline) from AEs due to a previously administered agent
  • Has received prior radiotherapy to within 2 weeks of start of study treatment. Participants must have recovered from all radiation-related toxicities, not require corticosteroids, and not have had radiation pneumonitis
  • Has received a live vaccine within 30 days prior to randomization
  • Has received treatment with 5α reductase inhibitors (eg, finasteride or dutasteride), estrogens, and/or cyproterone within 4 weeks prior to randomization
  • Has received prior treatment with ketoconazole for prostate cancer
  • Is currently participating in or has participated in a study of an investigational agent or has used an investigational device within 4 weeks prior to the first dose of study treatment
  • Has a "superscan" bone scan
  • 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 had an allogenic tissue/solid organ transplant

Trial locations and contacts

215 sites in 21 countries.

215 sites in 21 countries

United States28 sites

  • Georgia Cancer Center at Augusta University ( Site 0026)

    Augusta, Georgia, 30912

  • University of Colorado Cancer Center ( Site 0022)

    Aurora, Colorado, 80045

  • St. Vincent Frontier Cancer Center ( Site 0016)

    Billings, Montana, 59102

  • Mount Sinai Hospital Medical Center ( Site 0042)

    Chicago, Illinois, 60608

  • University Hospitals Cleveland Medical Center ( Site 0036)

    Cleveland, Ohio, 44106

  • Karmanos Cancer Institute ( Site 0077)

    Detroit, Michigan, 48201

  • Henry Ford Health System ( Site 0039)

    Detroit, Michigan, 48202-2608

  • Duke Cancer Center ( Site 0010)

    Durham, North Carolina, 27710

  • Inova Schar Cancer Institute ( Site 0006)

    Fairfax, Virginia, 22031-4867

  • St. Joseph Heritage Healthcare ( Site 0069)

    Fullerton, California, 92835

  • Cancer & Hematology Centers of Western Michigan ( Site 0013)

    Grand Rapids, Michigan, 49503

  • John Theurer Cancer Center at Hackensack University Medical Center ( Site 0004)

    Hackensack, New Jersey, 07601

  • Comprehensive Cancer Centers of Nevada ( Site 0092)

    Las Vegas, Nevada, 89169

  • University of Southern California Norris Comprehensive Cancer Center ( Site 0061)

    Los Angeles, California, 90033

  • Methodist Hospital- Merriillville ( Site 0008)

    Merrillville, Indiana, 46410

  • University of South Alabama, Mitchell Cancer Institute ( Site 0065)

    Mobile, Alabama, 36604

  • Carolina Urologic Research Center ( Site 0070)

    Myrtle Beach, South Carolina, 29572

  • Yale Cancer Center ( Site 0038)

    New Haven, Connecticut, 06510

  • USC Norris Oncology Hematology Newport Beach ( Site 0093)

    Newport Beach, California, 92663

  • Nebraska Cancer Specialists ( Site 0034)

    Omaha, Nebraska, 68130

  • Oregon Health Sciences University ( Site 0031)

    Portland, Oregon, 97239

  • Virginia Cancer Institute ( Site 0052)

    Richmond, Virginia, 23230

  • Blue Ridge Cancer Care ( Site 0086)

    Roanoke, Virginia, 24014

  • W. G. Bill Hefner VA Medical Center ( Site 0029)

    Salisbury, North Carolina, 28144

  • University of California San Francisco ( Site 0023)

    San Francisco, California, 94158

  • Washington University School of Medicine ( Site 0057)

    St Louis, Missouri, 63110

  • Associated Medical Professionals of NY ( Site 0060)

    Syracuse, New York, 13210

  • Moffitt Cancer Center ( Site 0080)

    Tampa, Florida, 33612

Other trials in United States

Japan20 sites

  • Chiba Cancer Center ( Site 0704)

    Chiba, 260-8717

  • Kyushu University Hospital ( Site 0718)

    Fukuoka, 812-8582

  • Hamamatsu University Hospital ( Site 0720)

    Hamamatsu, Shizuoka, 431-3192

  • Saitama Medical University International Medical Center ( Site 0708)

    Hidaka, Saitama, 1932

  • Kanazawa University Hospital ( Site 0701)

    Kanazawa, Ishikawa-ken, 920-8641

  • Nara Medical University Hospital ( Site 0715)

    Kashihara, Nara, 634-8522

  • National Cancer Center Hospital East ( Site 0702)

    Kashiwa, Chiba, 277-8577

  • Dokkyo Medical University Saitama Medical Center ( Site 0707)

    Koshigaya, Saitama, 343-8555

  • National Hospital Organization Shikoku Cancer Center ( Site 0716)

    Matsuyama, Ehime, 791-0280

  • University of Miyazaki Hospital ( Site 0721)

    Miyazaki, 889-1692

  • Nagasaki University Hospital ( Site 0719)

    Nagasaki, 852-8501

  • Kitasato University Hospital ( Site 0705)

    Sagamihara, Kanagawa, 252-0375

  • Toho University Sakura Medical Center ( Site 0703)

    Sakura, Chiba, 285-8741

  • Kindai University Hospital ( Site 0714)

    Sayama, Osaka, 589-8511

  • Osaka University Hospital ( Site 0713)

    Suita, Osaka, 565-0871

  • Toranomon Hospital ( Site 0711)

    Tokyo, 105-8470

  • Nippon Medical School Hospital ( Site 0709)

    Tokyo, 113-8603

  • Keio University Hospital ( Site 0710)

    Tokyo, 160-8582

  • Yamaguchi University Hospital ( Site 0717)

    Ube, Yamaguchi, 755-8505

  • Yokohama City University Medical Center ( Site 0706)

    Yokohama, Kanagawa, 232-0024

Other trials in Japan

France18 sites

  • CHU Amiens Picardie Site Sud Amiens ( Site 0438)

    Amiens, Somme, 80000

  • Institut Sainte Catherine ( Site 0447)

    Avignon, Vaucluse, 84000

  • CHU Jean Minjoz ( Site 0423)

    Besançon, Doubs, 25000

  • Institut Bergonie ( Site 0421)

    Bordeaux, Gironde, 33076

  • CHU de Brest -Site Hopital Morvan ( Site 0441)

    Brest, Finistere, 29200

  • Centre Jean Perrin ( Site 0434)

    Clermont-Ferrand, Auvergne, 63011

  • Centre Leon Berard ( Site 0422)

    Lyon, Auvergne, 69373

  • Institut Paoli Calmettes. ( Site 0419)

    Marseille, Bouches-du-Rhone, 13009

  • Centre D Oncologie de Gentilly ( Site 0432)

    Nancy, Meurthe-et-Moselle, 54100

  • Centre Hospitalier Regional du Orleans ( Site 0430)

    Orléans, Loiret, 45100

  • Institut Mutualiste Montsouris ( Site 0446)

    Paris, 75014

  • C.H.U. Lyon Sud ( Site 0436)

    Pierre-Bénite, Rhone, 69310

  • Institut De Cancerologie De L Ouest ( Site 0448)

    Saint-Herblain, Loire-Atlantique, 44805

  • C.H. de Saint Quentin ( Site 0481)

    Saint-Quentin, Aisne, 02321

  • Clinique Sainte Anne ( Site 0431)

    Strasbourg, Alsace, 67000

  • Hopital Foch ( Site 0428)

    Suresnes, Hauts-de-Seine, 92151

  • Institut Claudius Regaud IUCT Oncopole ( Site 0418)

    Toulouse, Haute-Garonne, 31059

  • Institut Gustave Roussy ( Site 0416)

    Villejuif, Val-de-Marne, 94800

Other trials in France

China15 sites

  • Peking University First Hospital ( Site 1303)

    Beijing, Beijing Municipality, 100034

  • The Fifth Medical Center of PLA General Hospital ( Site 1307)

    Beijing, Beijing Municipality, 100071

  • Beijing Cancer Hospital ( Site 1305)

    Beijing, Beijing Municipality, 100142

  • Hunan Cancer Hospital ( Site 1320)

    Changsha, Hunan, 410013

  • Sun Yat Sen Memorial Hospital ( Site 1323)

    Guangzhou, Guangdong, 510220

  • The First Affiliated Hospital of Guangzhou Medical University ( Site 1330)

    Guangzhou, Guangdong, 510230

  • The Second Affiliated Hospital of Zhejiang University School of Medicine ( Site 1309)

    Hangzhou, Zhejiang, 310009

  • Zhejiang Provincial People's Hospital ( Site 1310)

    Hangzhou, Zhejiang, 310014

  • Harbin Medical University Cancer Hospital ( Site 1326)

    Harbin, Heilongjiang, 150081

  • Nanjing Drum Tower Hospital ( Site 1312)

    Nanjing, Jiangsu, 210008

  • Fudan University Shanghai Cancer Center ( Site 1300)

    Shanghai, Shanghai Municipality, 200032

  • Zhongshan Hospital Fudan University ( Site 1301)

    Shanghai, Shanghai Municipality, 200032

  • Hubei Cancer Hospital ( Site 1329)

    Wuhan, Hubei, 430079

  • The First Affiliated Hospital of Xiamen University ( Site 1319)

    Xiamen, Fujian, 361003

  • Henan Cancer Hospital ( Site 1321)

    Zhengzhou, Henan, 450008

Other trials in China

Russia14 sites

  • Chelyabinsk Regional Clinical Oncological Dispensary ( Site 0565)

    Chelyabinsk, Chelyabinsk Oblast, 454087

  • Krasnoyarsk Regional Clinical Oncological Dispensary ( Site 0585)

    Krasnoyarsk, Krasnoyarsk Krai, 660133

  • SBIH City clinical hospital named after D.D. Pletniov ( Site 0575)

    Moscow, Moscow, 105077

  • Russian Scientific Center of Radiology ( Site 0559)

    Moscow, Moscow, 117485

  • Central Clinical Hospital with Polyclinic ( Site 0562)

    Moscow, Moscow, 121359

  • National Medical Research Radiological Center ( Site 0556)

    Moscow, Moscow, 125284

  • Volga District Medical Center Federal Medical and Biological Agency ( Site 0572)

    Nizhny Novgorod, Nizhny Novgorod Oblast, 603074

  • Omsk Clinical Oncology Dispensary ( Site 0568)

    Omsk, Omsk Oblast, 644013

  • Leningrad Regional Oncology Center ( Site 0588)

    Saint Petersburg, Sankt-Peterburg, 188663

  • Clinical Research Center of specialized types medical care-Oncology ( Site 0570)

    Saint Petersburg, Sankt-Peterburg, 197758

  • Russian Scientific Center of Radiology and Surgical Technologies ( Site 0567)

    Saint Petersburg, Sankt-Peterburg, 197758

  • SPb SBHI City Clinical Oncological Dispensary ( Site 0571)

    Saint Petersburg, Sankt-Peterburg, 198255

  • SBHI Samara Regional Clinical Oncology Dispensary ( Site 0576)

    Samara, Samara Oblast, 443031

  • Tomsk National Research Medical Center of Russian Academy of Sciences ( Site 0579)

    Tomsk, Tomsk Oblast, 634050

Other trials in Russia

Germany12 sites

  • Uniklinik RWTH Aachen ( Site 0308)

    Aachen, North Rhine-Westphalia, 52074

  • Charite Universitaetsmedizin Berlin ( Site 0301)

    Berlin, 10117

  • Universitaetsklinikum Freiburg - Medizinische Klinik ( Site 0304)

    Freiburg im Breisgau, Baden-Wurttemberg, 79106

  • Universitaetsklinikum Goettingen ( Site 0345)

    Göttingen, Lower Saxony, 37075

  • Universitaetsklinikum des Saarlandes ( Site 0348)

    Homburg, Saarland, 66421

  • Universitaetsklinikum Jena ( Site 0305)

    Jena, Thuringia, 07747

  • Universitaetsklinikum in Mannheim ( Site 0314)

    Mannheim, Baden-Wurttemberg, 68167

  • Klinikum Rechts der Isar ( Site 0300)

    Munich, Bavaria, 81675

  • Universitaetsklinik der Paracelsus Medizinischen Privatuniversitaet ( Site 0318)

    Nuremberg, Bavaria, 90419

  • Studienpraxis Urologie ( Site 0309)

    Nürtingen, Baden-Wurttemberg, 72622

  • Universitaetsklinik fuer Urologie ( Site 0307)

    Tübingen, Baden-Wurttemberg, 72076

  • Universitaetsklinikum Wuerzburg ( Site 0302)

    Würzburg, Bavaria, 97080

Other trials in Germany

Netherlands11 sites

  • Jeroen Bosch Ziekenhuis ( Site 1200)

    's-Hertogenbosch, North Brabant, 5223 GZ

  • Antoni van Leeuwenhoek Ziekenhuis ( Site 0480)

    Amsterdam, North Holland, 1066 CX

  • Reinier de Graaf Groep ( Site 0484)

    Delft, South Holland, 2625 AD

  • Ziekenhuis Gelderse Vallei ( Site 0485)

    Ede, Gelderland, 6746 RP

  • Catharina Ziekenhuis ( Site 0472)

    Eindhoven, North Brabant, 5623 EJ

  • Ziekenhuisgroep Twente ( Site 0469)

    Hengelo, Overijssel, 7555 DL

  • Ziekenhuis Hilversum ( Site 0466)

    Hilversum, North Holland, 1213 XZ

  • Medisch Centrum Leeuwarden ( Site 0477)

    Leeuwarden, Provincie Friesland, 8934 AD

  • Radboud University Medical Center ( Site 0470)

    Nijmegen, Gelderland, 6525 GA

  • Hagaziekenhuis ( Site 1201)

    The Hague, South Holland, 2545 AA

  • VieCuri Medisch Centrum ( Site 0487)

    Venlo, Limburg, 5912 BL

Other trials in Netherlands

Spain11 sites

  • Hospital del Mar ( Site 0333)

    Barcelona, 08003

  • Hospital Clinic ( Site 0323)

    Barcelona, 08036

  • Hospital Josep Trueta ( Site 0321)

    Girona, Gerona, 17007

  • Instituto Catalan de Oncologia - ICO ( Site 0330)

    L'Hospitalet de Llobregat, Barcelona, 08908

  • Hospital Universitario Ramon y Cajal ( Site 0328)

    Madrid, 28034

  • Hospital Clinico San Carlos ( Site 0324)

    Madrid, 28040

  • Hospital Universitario HM Sanchinarro ( Site 0322)

    Madrid, 28050

  • Hospital Universitario Virgen de la Victoria ( Site 0337)

    Málaga, 29016

  • Hospital Consorci Sanitari Parc Tauli ( Site 0335)

    Sabadell, Barcelona, 08208

  • Hospital Universitario Marques de Valdecilla ( Site 0336)

    Santander, Cantabria, 39008

  • Hospital Virgen del Rocio ( Site 0329)

    Seville, 41013

Other trials in Spain

Colombia10 sites

  • Biomelab S A S ( Site 1067)

    Barranquilla, Atlántico, 080002

  • Clinica de la Costa Ltda. ( Site 1073)

    Barranquilla, Atlántico, 080020

  • Instituto Nacional de Cancerologia E.S.E ( Site 1061)

    Bogotá, Bogota D.C., 110321

  • Clinica Colsanitas S.A. Sede Clinica Universitaria Colombia ( Site 1062)

    Bogotá, Bogota D.C., 111321

  • Centro Medico Imbanaco de Cali S.A ( Site 1064)

    Cali, Valle del Cauca Department, 760042

  • Hemato Oncologos S.A. ( Site 1065)

    Cali, Valle del Cauca Department, 760042

  • Hospital Pablo Tobon Uribe ( Site 1066)

    Medellín, Antioquia, 050034

  • Oncomedica S.A. ( Site 1057)

    Montería, Departamento de Córdoba, 230002

  • Oncologos del Occidente S.A. ( Site 1072)

    Pereira, Risaralda Department, 660001

  • Sociedad de Oncología Y Hematología del Cesar S.A.S. ( Site 1068)

    Valledupar, Cesar Department, 200001

Other trials in Colombia

Argentina9 sites

  • Centro de Oncologia e Investigacion Buenos Aires COIBA ( Site 1013)

    Berazategui, Buenos Aires, B1884BBF

  • Centro de Diagnostico Urologico ( Site 1008)

    Buenos Aires, Buenos Aires F.D., C1120AAT

  • Hospital Britanico de Buenos Aires ( Site 1006)

    Buenos Aires, Buenos Aires F.D., C1280AEB

  • Instituto de Investigaciones Metabolicas [Buenos Aires, Argentina] ( Site 1011)

    Buenos Aires, C1012AAR

  • Hospital Aleman ( Site 1004)

    Buenos Aires, C1118AAT

  • Instituto Medico Alexander Fleming ( Site 1010)

    Buenos Aires, C1426ANZ

  • CEMAIC ( Site 1014)

    Córdoba, X5008HHW

  • Instituto de Investigaciones Clinicas ( Site 1000)

    Mar del Plata, Buenos Aires, B7600FZN

  • Sanatorio Parque ( Site 1002)

    Rosario, Santa Fe Province, S2000DSV

Other trials in Argentina

Canada9 sites

  • Nova Scotia Health Authority QEII-HSC ( Site 0114)

    Halifax, Nova Scotia, B3H 2Y9

  • Hamilton Health Sciences-Juravinski Cancer Centre ( Site 0116)

    Hamilton, Ontario, L8V5C2

  • Grand River Hospital ( Site 0120)

    Kitchener, Ontario, N2G 1G3

  • Lakeridge Health ( Site 0117)

    Oshawa, Ontario, L1G 2B9

  • CHU de Quebec-Universite Laval-Hotel Dieu de Quebec ( Site 0103)

    Québec, Quebec, G1R 2J6

  • CIUSSS du Bas Saint Laurent - Hopital Regional de Rimouski ( Site 0102)

    Rimouski, Quebec, G5L 5T1

  • CIUSSS de l Estrie - CHUS - Centre Hosp. Univ. Sherbrooke ( Site 0105)

    Sherbrooke, Quebec, J1H 5N4

  • Sunnybrook Research Institute ( Site 0108)

    Toronto, Ontario, M4N 3M5

  • Princess Margaret Cancer Centre ( Site 0107)

    Toronto, Ontario, M5G 2M9

Other trials in Canada

Israel8 sites

  • Assaf Harofeh MC ( Site 0547)

    Beer Yaakov-Zerifin, 7030001

  • Soroka Medical Center ( Site 0548)

    Beersheba, 8410101

  • Rambam Medical Center ( Site 0543)

    Haifa, 3109601

  • Hadassah Ein Kerem Medical Center ( Site 0546)

    Jerusalem, 9112001

  • Meir Medical Center ( Site 0544)

    Kfar Saba, 4428164

  • Rabin Medical Center ( Site 0545)

    Petah Tikva, 4941492

  • Chaim Sheba Medical Center ( Site 0541)

    Ramat Gan, 5262000

  • Sourasky Medical Center ( Site 0542)

    Tel Aviv, 6423906

Other trials in Israel

United Kingdom8 sites

  • University Hospitals Bristol NHS Foundation Trust ( Site 0530)

    Bristol, Bristol, City of, BS2 8ED

  • Cambridge University Hospitals NHS Trust ( Site 0540)

    Cambridge, Cambridgeshire, CB2 0QQ

  • Barts Cancer Institute ( Site 0483)

    London, London, City of, EC1A 7BE

  • Mount Vernon Cancer Centre ( Site 0536)

    Northwood, Hertfordshire, HA6 2RN

  • Weston Park Hospital ( Site 0539)

    Sheffield, England, S10 2SJ

  • University of North Midlands NHS Foundation Trust ( Site 0527)

    Stoke-on-Trent, Staffordshire, ST4 6QG

  • Royal Marsden Hospital ( Site 0526)

    Sutton, England, SM2 5PT

  • Torbay Hospital ( Site 0532)

    Torquay, Devon, TQ2 7AA

Other trials in United Kingdom

Australia7 sites

  • St George Hospital ( Site 0157)

    Kogarah, New South Wales, 2217

  • Macquarie University ( Site 0151)

    Macquarie University, New South Wales, 2109

  • Hollywood Private Hospital ( Site 0163)

    Nedlands, Western Australia, 6009

  • Port Macquarie Base Hospital ( Site 0153)

    Port Macquarie, New South Wales, 2444

  • Redcliffe Hospital ( Site 0161)

    Redcliffe, Queensland, 4020

  • John Flynn Hospital & Medical Centre ( Site 0164)

    Tugun, Queensland, 4224

  • Calvary Mater Newcastle ( Site 0148)

    Waratah, New South Wales, 2298

Other trials in Australia

Italy7 sites

  • Azienda Ospedaliera Cannizzaro ( Site 0458)

    Catania, 95126

  • A.O. Universitaria di Modena ( Site 0454)

    Modena, 41100

  • Istituto Nazionale Tumori IRCCS Fondazione Pascale ( Site 0457)

    Naples, 80131

  • Azienda Ospedaliera San Camillo Forlanini ( Site 0455)

    Roma, 00152

  • Istituto Clinico Humanitas Research Hospital ( Site 0452)

    Rozzano, Milano, 20089

  • Azienda Ospedaliera Santa Maria Terni ( Site 0456)

    Terni, 05100

  • Presidio Ospedaliero Santa Chiara ( Site 0451)

    Trento, 38122

Other trials in Italy

Chile6 sites

  • Fundacion Arturo Lopez Perez ( Site 1049)

    Santiago, Region M. de Santiago, 7500921

  • Pontificia Universidad Catolica de Chile ( Site 1047)

    Santiago, Region M. de Santiago, 8330032

  • Bradford Hill Centro de Investigaciones Clinicas ( Site 1044)

    Santiago, Region M. de Santiago, 8420383

  • Centro Investigación del Cáncer James Lind ( Site 1041)

    Temuco, Araucania, 4780000

  • Rey y Oreilly Limitada ( Site 1048)

    Temuco, Araucania, 4810148

  • Centro de Investigaciones Clinicas Vina del Mar ( Site 1042)

    Viña del Mar, Valparaiso, 2540488

Other trials in Chile

Brazil5 sites

  • Hospital de Caridade de Ijui ( Site 1038)

    Ijuí, Rio Grande do Sul, 98700-000

  • Centro de Novos Tratamentos Itajai - Clinica de Neoplasias Litoral ( Site 1035)

    Itajaí, Santa Catarina, 88301-215

  • Uniao Brasileira de Educacao e Assistencia Hospital Sao Lucas da Pucrs ( Site 1021)

    Porto Alegre, Rio Grande do Sul, 90610-000

  • Hospital de Base de Sao Jose de Rio Preto ( Site 1022)

    São José do Rio Preto, São Paulo, 15090-000

  • A.C. Camargo Cancer Center ( Site 1026)

    São Paulo, 01509-900

Other trials in Brazil

South Korea5 sites

  • National Cancer Center ( Site 0174)

    Goyang-si, Kyonggi-do, 10408

  • Seoul National University Bundang Hospital ( Site 0175)

    Seongnam-si, Kyonggi-do, 13620

  • Seoul National University Hospital ( Site 0171)

    Seoul, 03080

  • Asan Medical Center ( Site 0176)

    Seoul, 05505

  • Samsung Medical Center ( Site 0172)

    Seoul, 06351

Other trials in South Korea

Taiwan5 sites

  • China Medical University Hospital ( Site 0132)

    Taichung, 40447

  • Taichung Veterans General Hospital ( Site 0133)

    Taichung, 40705

  • National Cheng Kung University Hospital ( Site 0134)

    Tainen, Tainan, 704

  • National Taiwan University Hospital ( Site 0131)

    Taipei, 10048

  • Taipei Veterans General Hospital ( Site 0135)

    Taipei, 11217

Other trials in Taiwan

Austria4 sites

  • Medizinische Universitat Graz ( Site 0374)

    Graz, Styria, 8036

  • Ordensklinikum Linz GmbH Elisabethinen ( Site 0373)

    Linz, Upper Austria, 4020

  • SCRI-CCCIT GesmbH ( Site 0371)

    Salzburg, 5020

  • Medizinische Universitaet Wien ( Site 0375)

    Vienna, 1090

Other trials in Austria

Ireland3 sites

  • Cork University Hospital ( Site 0727)

    Cork, T12 YE02

  • Tallaght University Hospital ( Site 0730)

    Dublin, D24 NROA

  • Mid Western Cancer Centre ( Site 0728)

    Limerick

Other trials in Ireland

About this study

Official title: A Phase 3, Randomized, Double-blind Study of Pembrolizumab (MK-3475) Plus Docetaxel Plus Prednisone Versus Placebo Plus Docetaxel Plus Prednisone in Participants With Chemotherapy-naïve Metastatic Castration-Resistant Prostate Cancer (mCRPC) Who Have Progressed on a Next Generation Hormonal Agent (NHA) (KEYNOTE-921)

The purpose of this study is to assess the efficacy and safety of the combination of pembrolizumab (MK-3475) and docetaxel in the treatment of men with metastatic castration-resistant prostate cancer (mCRPC) who have not received chemotherapy for mCRPC but have progressed on or are intolerant to Next Generation Hormonal Agent (NHA).

There are two primary study hypotheses.

Read more

Hypothesis 1: The combination of pembrolizumab plus docetaxel plus prednisone is superior to placebo plus docetaxel plus prednisone with respect to Overall Survival (OS).

Hypothesis 2: The combination of pembrolizumab plus docetaxel plus prednisone is superior to placebo plus docetaxel plus prednisone with respect to Radiographic Progression-free Survival (rPFS) per Prostate Cancer Working Group (PCWG)-modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) as assessed by blinded independent central review.

Read the detailed description

With Amendment 6 (effective date: 29-Sep-2022), all participants will be unblinded and placebo treatment will be stopping. Participants who are deemed to be deriving clinical benefit from treatment may continue at the discretion of the investigator.

The global study for MK-3475-921 enrolled 1030 participants. Of the 1030 total participants enrolled in the global study, 21 were also enrolled in the China extension study for MK-3475-921 (NCT04907227).

Keywords
Programmed Cell Death 1 (PD 1, PD-1), Programmed Cell Death 1 Ligand 1 (PDL 1, PD-L1), Programmed Cell Death 1 Ligand 2 (PDL 2, PD-L2)
Medical subject headings
Prostatic Neoplasms, Parkinson Disease 4, Autosomal Dominant Lewy Body

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PembrolizumabBiological

    Also called MK-3475, KEYTRUDA®

    IV infusion

  • DocetaxelDrug

    Also called TAXOTERE®

    IV infusion

  • PrednisoneDrug

    Oral tablets

  • PlaceboDrug

    Also called Normal saline or dextrose infusion

    IV infusion

  • DexamethasoneDrug

    Also called DECADRON®

    Oral tablets

Study groups in NCT03834506
Study groupRoleWhat they receive
Pembrolizumab+DocetaxelExperimentalParticipants receive pembrolizumab 200 mg by intravenous (IV) infusion on Day 1 of each 21-day cycle (Q3W) for up to a maximum of 35 cycles (approximately 2 years) PLUS docetaxel 75 mg/m^2 by IV infusion on Day 1 of each 21-day cycle (Q3W) for a maximum of 10 cycles (approximately 7 months). Participants also concomitantly receive dexamethasone 8 mg by oral tablets at 12 hours, 3 hours, and 1 hour prior to docetaxel administration and prednisone 5 mg by oral tablets twice daily during each 21-day docetaxel cycle.
Receives: Biological: Pembrolizumab; Drug: Docetaxel; Drug: Prednisone; Drug: Dexamethasone
Placebo+DocetaxelPlacebo comparatorParticipants receive placebo by IV infusion on Day 1 of each 21-day cycle (Q3W) for up to a maximum of 35 cycles (approximately 2 years) PLUS docetaxel 75 mg/m^2 by IV infusion on Day 1 of each 21-day cycle (Q3W) for a maximum of 10 cycles (approximately 7 months). Participants also concomitantly receive dexamethasone 8 mg by oral tablets at 12 hours, 3 hours, and 1 hour prior to docetaxel administration and prednisone 5 mg by oral tablets twice daily during each 21-day docetaxel cycle.
Receives: Drug: Docetaxel; Drug: Prednisone; Drug: Placebo; Drug: Dexamethasone

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Overall Survival (OS)

    OS was defined as the time from randomization to death due to any cause. The OS was calculated using the product-limit Kaplan-Meier (K-M) method for censored data. Participants without documented death at the time of the analysis were censored at the date of the last follow-up.

    Measured: Up to 36.5 months

  2. Radiographic Progression-free Survival (rPFS) Per Prostate Cancer Working Group (PCWG)-Modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) as Assessed by Blinded Independent Central Review (BICR)

    rPFS was defined as the time from randomization to occurrence of: radiological tumor progression using RECIST 1.1 as assessed by BICR; progression of bone lesions using PCWG criteria; or death due to any cause. Radiological progression as per RECIST 1.1 was ≥20% increase in sum of diameters of target lesions and progression of existing non-target lesions. Progression of bone lesions by PCWG criteria was the appearance of ≥2 new bone lesions on bone scan, that have been confirmed to not represent tumor flare, and was persistent for ≥6 weeks. The rPFS was calculated using the product-limit K-M method for censored data. Participants without a rPFS event were censored at the date of last disease assessment.

    Measured: Up to approximately 28 months

Secondary outcomes (10)

  1. Time to Initiation of the First Subsequent Anti-cancer Therapy (TFST)

    TFST was defined as the time from randomization to initiation of the first subsequent anti-cancer therapy or death; whichever occurred first. The TFST was calculated using the product-limit K-M method for censored data. Any participant not known to have further subsequent therapy or death was censored at the last known time that no subsequent new anti-cancer therapy was received.

    Measured: Up to approximately 28 months

  2. Prostate-specific Antigen (PSA) Response Rate

    The Prostate-specific Antigen (PSA) response rate was the percentage of participants who had PSA response defined as a reduction in the PSA level from baseline by ≥50%. The reduction in PSA level was confirmed by an additional PSA evaluation performed ≥3 weeks from the original response. The analysis was performed on participants who had baseline PSA measurements.

    Measured: Up to 36.5 months

  3. Objective Response Rate (ORR) Per Prostate Cancer Working Group (PCWG)-Modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) as Assessed by Blinded Independent Central Review (BICR)

    ORR was defined as the percentage of participants with complete response (CR: disappearance of all target lesions per RECIST 1.1; and no evidence of disease (NED) on bone scan per PCWG) or partial response (PR: at least a 30% decrease in the sum of diameters of target lesions per RECIST 1.1; and non-progressive disease, non-evaluable [NE], or NED on bone scan or CR with non-progressive disease or NE bone scan per PCWG).

    Measured: Up to 36.5 months

  4. Duration of Response (DOR) Per Prostate Cancer Working Group (PCWG)-Modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) as Assessed by Blinded Independent Central Review (BICR)

    DOR was the time from first documented evidence of complete response (CR: disappearance of all target lesions per RECIST 1.1; and no evidence of disease [NED] on bone scan per PCWG) or partial response (PR: ≥30% decrease in the sum of diameters of target lesions per RECIST 1.1; and non-progressive disease, non-evaluable [NE], or NED on bone scan or CR with non-progressive disease or NE bone scan per PCWG) until progressive disease (PD) or death. PD per RECIST 1.1 was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also have demonstrated an absolute increase of at least 5 mm. PD per PCWG was the appearance of ≥2 new bone lesions on bone scan, that have been confirmed to not represent tumor flare and were persistent for ≥6 weeks. The DOR was calculated using the product-limit K-M method for censored data. If a participant had not progressed, the participant was censored at the date of last disease assessment.

    Measured: Up to 36.5 months

  5. Time to Pain Progression (TTPP) as Assessed by Brief Pain Inventory-Short Form (BPI-SF) Item 3 ("Worst Pain in 24 Hours") and Opiate Analgesic Use Assessed by the Analgesic Quantification Algorithm (AQA) Score

    TTPP was the time from randomization to pain progression (PP) based on BPI-SF Item 3 and AQA score. BPI-SF assesses pain intensity; for item 3, participant responses to "Please rate your pain at its worst in the last 24 hours" are scored from 0 (no pain) to 10 (worst pain). A higher score indicates greater pain. AQA captures the intensity of analgesic use in pain management, scored from 0 (no analgesic) to 7 (strong opioid use). A higher score indicates higher intensity of analgesic use.

    For participants asymptomatic at baseline, PP was ≥2-point change from baseline in BPI-SF item 3 score OR initiation of opioid use. For participants symptomatic at baseline, PP was ≥2-point change from baseline in the BPI-SF Item 3 score, a score of ≥4 and no decrease in average opioid use OR any increase in opioid use (e.g., 1 point change in AQA score). TTPP was assessed by product-limit K-M method. Participants with >2 consecutive unevaluable visits were censored at the last evaluable assessment.

    Measured: Up to 36.5 months

  6. Time to First Symptomatic Skeletal-related Event (SSRE)

    SSRE was the time from randomization to the first symptomatic skeletal-related event defined as:

    1. Use of external-beam radiation therapy (EBRT) to prevent or relieve skeletal symptoms
    2. Occurrence of new symptomatic pathologic bone fracture (vertebral or non-vertebral)
    3. Occurrence of spinal cord compression
    4. Tumor-related orthopedic surgical intervention, whichever occurs first.

    The SSRE was calculated using the product-limit K-M method for censored data. Participants without symptomatic skeletal-related events were censored at the last evaluable assessment.

    Measured: Up to 36.5 months

  7. Time to Prostate-specific Antigen (PSA) Progression

    The time to PSA progression was the time from randomization to PSA progression. The PSA progression date was defined as the date of:

    1. ≥25% increase and ≥2 ng/mL above the nadir, confirmed by a second value ≥3 weeks later if there was PSA decline from baseline; OR
    2. ≥25% increase and ≥2 ng/mL increase from baseline beyond 12 weeks if there was no PSA decline from baseline

    Time to PSA progression was calculated using the product-limit K-M method for censored data. Participants without PSA progression were censored at the last evaluable assessment.

    Measured: Up to 36.5 months

  8. Time to Radiographic Soft Tissue Progression Per Soft Tissue Rules of Prostate Cancer Working Group (PCWG)-Modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) as Assessed by Blinded Independent Central Review (BICR)

    The time to radiographic soft tissue progression was defined as the time from randomization to radiographic soft tissue progression per soft tissue rules of PCWG-modified RECIST 1.1 as assessed by BICR. Progression was defined as ≥20% increase in the sum of diameters of target lesions. In addition to the relative increase of 20%, the sum must also have demonstrated an absolute increase of ≥5 mm. The appearance of one or more new lesions was also considered progression. Time to radiographic soft tissue progression was calculated using the product-limit K-M method for censored data. Participants without radiographic soft tissue progression were censored at the last evaluable assessment.

    Measured: Up to 36.5 months

  9. Number of Participants Who Experienced an Adverse Event (AE)

    An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE could therefore have been any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The number of participants who experienced an AE is presented.

    Measured: Up to approximately 30 months

  10. Number of Participants Who Discontinued Study Treatment Due To an Adverse Event (AE)

    An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An AE could therefore have been any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a study intervention. The number of participants who discontinued study treatment due to an AE is presented.

    Measured: Up to approximately 27 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Feb 2019
  2. Study start2 May 2019
  3. Primary completion20 Jun 2022
  4. Study completion18 Jul 2023

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
1,030 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03834506
Sponsor's protocol ID
3475-921
Other IDs
MK-3475-921, KEYNOTE-921, JAPAC-CTI, 2018-004116-22, 2018
Status last verified
Jul 2025
First submitted
6 Feb 2019
Last updated
18 Jul 2025
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: http://engagezone.msd.com/doc/ProcedureAccessClinicalTrialData.pdf

Publications

  • Petrylak DP, Ratta R, Matsubara N, Korbenfeld E, Gafanov R, Mourey L, Todenhofer T, Gurney H, Kramer G, Bergman AM, Zalewski P, De Santis M, Armstrong AJ, Gerritsen W, Pachynski R, Byun SS, Retz M, Levesque E, McDermott R, Bracarda S, Manneh R, Levartovsky M, Li XT, Schloss C, Poehlein CH, Fizazi K. Pembrolizumab Plus Docetaxel Versus Docetaxel for Previously Treated Metastatic Castration-Resistant Prostate Cancer: The Randomized, Double-Blind, Phase III KEYNOTE-921 Trial. J Clin Oncol. 2025 May 10;43(14):1638-1649. doi: 10.1200/JCO-24-01283. Epub 2025 Mar 5.

    PubMed 40043230

  • Petrylak DP, Ratta R, Gafanov R, Facchini G, Piulats JM, Kramer G, Flaig TW, Chandana SR, Li B, Burgents J, Fizazi K. KEYNOTE-921: Phase III study of pembrolizumab plus docetaxel for metastatic castration-resistant prostate cancer. Future Oncol. 2021 Sep;17(25):3291-3299. doi: 10.2217/fon-2020-1133. Epub 2021 Jun 8.

    PubMed 34098744

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Pembrolizumab, Docetaxel and Prednisone in people with Prostatic Neoplasms, run by Merck Sharp & Dohme LLC at 215 sites in 21 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 10 inclusion and 27 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 18 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 215 sites in United States, Japan, France, China, Russia and 16 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 18 Jun 2023). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Overall Survival (OS) (time frame: Up to 36.5 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03834506, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Jul 2025.

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