Phase 3 Study of Pembrolizumab plus Docetaxel in mCRPC
Research type
Research Study
Full 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)
IRAS ID
262142
Contact name
Johann De Bono
Contact email
Sponsor organisation
Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.
Eudract number
2018-004116-22
Duration of Study in the UK
2 years, 2 months, 15 days
Research summary
Prostate cancer represents the second most common cancer diagnosed in men worldwide with an incidence of over 1,000,000 cases and >300,000 deaths annually.
While the currently available therapies are initially effective, patients with metastatic prostate cancer develop a lethal disease stage known as metastatic castration-resistant prostate cancer (mCRPC). A number of systemic therapies are available for mCRPC and include the next generation hormonal agents (NHA), abiraterone acetate and enzalutamide, and the taxanes, docetaxel and cabazitaxel.
Docetaxel is the first approved systemic therapy to improve survival for men with mCRPC. Cabazitaxel, although also associated with superior survival, can be a toxic therapy. Thus, an unmet need remains for participants after treatment in the mCRPC setting with targeted endocrine therapy and docetaxel .
Docetaxel works by stopping the cancer cells from separating into two new cells, thereby blocking the growth of the cancer. Docetaxel may be combined with prednisone/prednisolone, a steroid that slows the growth of prostate cancer cells by decreasing testosterone production from the adrenal glands.
Pembrolizumab is a type of immunotherapy that stimulates the body's immune system to fight cancer cells. Pembrolizumab targets and blocks a protein called PD-1 on the surface of certain immune cells called T-cells. Blocking PD-1 triggers the T-cells to find and kill cancer cells.
This clinical trial will study the combination of the study drug, pembrolizumab, with standard of care docetaxel plus prednisone/prednisolone versus placebo (dummy drug) with docetaxel plus prednisone/prednisolone in the treatment of patients with mCRPC who have not received chemotherapy but have progressed on an NHA.
Approximately 1000 male participants will be randomly assigned in 1:1 ratio to treatment with either pembrolizumab, docetaxel and prednisone/prednisolone or placebo, docetaxel and prednisone/prednisolone.
The study is funded by Merck Sharp and Dohme Limited and will take place at eight study centres in UK.
Lay summary of study results: https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Fmsd.trialsummaries.com%252FHome%252FLandingPage%2FNBTI%2FV6S-AQ%2FAQ%2F0f6a6933-506e-4fbd-bf02-2ef9eb5cb01e%2F1%2FeTYqHMzn8a&data=05%7C02%7Csurreyborders.rec%40hra.nhs.uk%7Cbb3211fb7a1349faff3008dde585ea65%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638919085506248358%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=oSwD6cSba9wUR%2FOczZuyEhHk%2Fur%2Fi8XMNKj2FL5nHvs%3D&reserved=0
Has the registry been updated to include summary results?: Yes
If yes - please enter the URL to summary results: TrialSummaries.com - 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)
If no – why not?:
Did you follow your dissemination plan submitted in the IRAS application form (Q A51)?: Yes
If yes, describe or provide URLs to disseminated materials: "1. Patient-reported outcomes (PROs) in KEYNOTE-921
- ASCO 2023 Abstract
- DOI: 10.1200/JCO.2023.41.6_suppl.129
- https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3t%2Fdx.doi.org%252F10.1200%252Fjco.2023.41.6_suppl.129%2FNBTI%2FV6S-AQ%2FAQ%2F0f6a6933-506e-4fbd-bf02-2ef9eb5cb01e%2F2%2Fi9gw7RdJAE&data=05%7C02%7Csurreyborders.rec%40hra.nhs.uk%7Cbb3211fb7a1349faff3008dde585ea65%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638919085506266581%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=zXzthwl0EkX13dqVFQnEztEoRvAn4r7cJEMcegAFA8s%3D&reserved=02. Pembrolizumab plus docetaxel for mCRPC: Randomized, double-blind, phase 3 KEYNOTE-921 study
- ASCO 2023 Abstract
- DOI: 10.1200/JCO.2023.41.6_suppl.19
- https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Fdoi.org%252F10.1200%252Fjco.2023.41.6_suppl.19%2FNBTI%2FV6S-AQ%2FAQ%2F0f6a6933-506e-4fbd-bf02-2ef9eb5cb01e%2F3%2Fs8QPPX6JSz&data=05%7C02%7Csurreyborders.rec%40hra.nhs.uk%7Cbb3211fb7a1349faff3008dde585ea65%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638919085506279862%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=xOfQY92XXrwVMMdOavkvQPkCgRIsMX51fiNv17ekwPc%3D&reserved=03. Pembrolizumab Plus Docetaxel Versus Docetaxel for Previously Treated mCRPC: The Randomized, Double-Blind, Phase III KEYNOTE-921 Trial
- Journal of Clinical Oncology, 2025
- DOI: 10.1200/JCO-24-01283
- https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3t%2Fdx.doi.org%252F10.1200%252FJCO-24-01283%2FNBTI%2FV6S-AQ%2FAQ%2F0f6a6933-506e-4fbd-bf02-2ef9eb5cb01e%2F4%2FHYcu1Qm7cB&data=05%7C02%7Csurreyborders.rec%40hra.nhs.uk%7Cbb3211fb7a1349faff3008dde585ea65%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638919085506293139%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=yCWRJdLw%2F1DmNa3SarjbQLSjlpGgp4obwFIneuA3J4A%3D&reserved=04. Patient-reported Outcomes in KEYNOTE-921: Pembrolizumab with Docetaxel and Prednisone for mCRPC
- European Urology Oncology, 2025
- DOI: 10.1016/j.euo.2025.02.015
- https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3t%2Fdx.doi.org%252FS2588-9311&data=05%7C02%7Csurreyborders.rec%40hra.nhs.uk%7Cbb3211fb7a1349faff3008dde585ea65%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638919085506305995%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=%2BDBaovgL0LeG8juPralpu1zMBpBmrkqSDT0Tat1jRbo%3D&reserved=0(25)00050-110.1016%2Fj.euo.2025.02.015/NBTI/V6S-AQ/AQ/0f6a6933-506e-4fbd-bf02-2ef9eb5cb01e/5/IeQd5PnopPhttps://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Fclinicaltrials.gov%252Fstudy%252FNCT03834506%2FNBTI%2FV6S-AQ%2FAQ%2F0f6a6933-506e-4fbd-bf02-2ef9eb5cb01e%2F6%2FqbpYlhV_a3&data=05%7C02%7Csurreyborders.rec%40hra.nhs.uk%7Cbb3211fb7a1349faff3008dde585ea65%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638919085506318695%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=tvjS0suLrGS%2FJ1rQ6ApCsOOUmkf6cScTBytorv5xGrU%3D&reserved=0"
If pending, date when dissemination is expected:
If no, explain why you didn't follow it:
Have participants been informed of the results of the study?: Yes
If yes, describe and/or provide URLs to materials shared and how they were shared: The Sponsor has shared the study results with the Investigators and the Investigators have been asked to share the results with the trial participants, as appropriate.The main Participant Information Sheet directs participants to the website: https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Fwww.ClinicalTrials.gov%2FNBTI%2FV6S-AQ%2FAQ%2F0f6a6933-506e-4fbd-bf02-2ef9eb5cb01e%2F7%2F6Qr2n1X-d1&data=05%7C02%7Csurreyborders.rec%40hra.nhs.uk%7Cbb3211fb7a1349faff3008dde585ea65%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638919085506331229%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=zUF9J%2FTZwSKDer%2FimdQmk%2FcjBIZJ5SUb11xyTzjTJDg%3D&reserved=0 where a summary of results for the study can be located.
A description of this clinical trial is also be available on: https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Fmsd.trialsummaries.com%2FNBTI%2FV6S-AQ%2FAQ%2F0f6a6933-506e-4fbd-bf02-2ef9eb5cb01e%2F8%2FPsvrYszU2V&data=05%7C02%7Csurreyborders.rec%40hra.nhs.uk%7Cbb3211fb7a1349faff3008dde585ea65%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638919085506343764%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=OfbFamuF7Zm1HgNkSfKHYdCr3D%2BoKki%2B0Gj7P0qr3HE%3D&reserved=0
This website will also include a summary of the trial results written in plain language for general audiences. By visiting the website, participants can sign up for email notifications to be alerted when the trial results summary is posted.If pending, date when feedback is expected:
If no, explain why they haven't:
Have you enabled sharing of study data with others?: Yes
If yes, describe or provide URLs to how it has been shared: MSD’s data sharing policy is publicly available at EngageZone: Data Sharing https://gbr01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrack.pstmrk.it%2F3ts%2Fengagezone.msd.com%252Fds_documentation.php%2FNBTI%2FV6S-AQ%2FAQ%2F0f6a6933-506e-4fbd-bf02-2ef9eb5cb01e%2F9%2F_4-XK1Wrnq&data=05%7C02%7Csurreyborders.rec%40hra.nhs.uk%7Cbb3211fb7a1349faff3008dde585ea65%7C8e1f0acad87d4f20939e36243d574267%7C0%7C0%7C638919085506356363%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=tEiToknulE24gRTivA4V2yxn%2BhBqlpggUKh4N1FiheY%3D&reserved=0 (also referenced on the ClinicalTrials.gov page).
If no, explain why sharing hasn't been enabled:
Have you enabled sharing of tissue samples and associated data with others?: No
If yes, describe or provide a URL:
If no, explain why: "At this time, the Sponsor has no specific plans to share the genomic data with anyone or on any public genomic databases. However, the Sponsor may share data as scientific journals are increasingly calling for transparency when publishing genomic results and this sometimes may include sharing anonymised genomic data on public genomic databases.Specimens will not be sold for commercial purposes; however, they may be used by the Sponsor or our collaborators to develop new drugs or diagnostics. While the Sponsor will not sell the samples, the Sponsor may need to share them with other parties who are working for or with the Sponsor.
Only Sponsor designated researchers will have access to the samples.
Research conducted utilising the coded future use samples will help us to understand human health and differences in response to drugs and therapies. An approved and marketed diagnostic formally derived from such studies will be of direct benefit to future recipients of drugs when used in conjunction with diagnostic information."
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REC name
London - Surrey Borders Research Ethics Committee
REC reference
19/LO/0952
Date of REC Opinion
14 Aug 2019
REC opinion
Further Information Favourable Opinion