{"preliminary_commentary":{"by_channel":{"x_thread":14,"youtube":1,"podcast":1},"note":"Preliminary. Indexed podcasts, YouTube videos and X posts that name this trial so far. This is where a report starts, not where it ends: the build searches for more, so finished reports usually cover more than this."},"free_build":{"available":true,"how":"POST https://www.erudio.com/api/trial-requests with {\"nct_id\": \"NCT03834506\", \"email\": \"<work email>\"}. The person who owns that inbox must confirm by the emailed link; agents cannot confirm. The result is the report's free public preview; the full report is still bought."},"commentary_summary":null,"name":"KEYNOTE-921","nct_id":"NCT03834506","offer":{"currency":"USD","how":"Order at https://www.erudio.com/contact?report=keynote-921-nct03834506. The price is an estimate of verified statements from the commentary indexed so far, fixed at order. Final coverage is set when the report is built. We build the report within 24 hours of confirming the order and deliver it when it passes our checks; if it cannot be built to our standard, nothing is charged.","price_usd":1250,"size":"standard","size_rule":"Standard: 151–300 verified statements, estimated at 14 per indexed commentary source"},"registry":{"acronym":null,"arms":[{"description":"Participants 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.","label":"Pembrolizumab+Docetaxel","type":"EXPERIMENTAL"},{"description":"Participants 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.","label":"Placebo+Docetaxel","type":"PLACEBO_COMPARATOR"}],"collaborators":[],"completion_date":{"date":"2023-07-18","type":"ACTUAL"},"conditions":["Prostatic Neoplasms"],"enrollment":{"count":1030,"type":"ACTUAL"},"has_results":true,"interventions":[{"name":"Pembrolizumab","otherNames":["MK-3475","KEYTRUDA®"],"type":"BIOLOGICAL"},{"name":"Docetaxel","otherNames":["TAXOTERE®"],"type":"DRUG"},{"name":"Prednisone","otherNames":[],"type":"DRUG"},{"name":"Placebo","otherNames":["Normal saline or dextrose infusion"],"type":"DRUG"},{"name":"Dexamethasone","otherNames":["DECADRON®"],"type":"DRUG"}],"last_update":"2025-07-18","lead_sponsor":"Merck Sharp & Dohme LLC","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)","overall_status":"COMPLETED","phases":["PHASE3"],"primary_completion_date":{"date":"2022-06-20","type":"ACTUAL"},"primary_outcomes":[{"measure":"Overall Survival (OS)","timeFrame":"Up to 36.5 months"},{"measure":"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)","timeFrame":"Up to approximately 28 months"}],"references":[{"citation":"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.","pmid":"40043230","type":"RESULT"},{"citation":"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.","pmid":"34098744","type":"DERIVED"}],"start_date":{"date":"2019-05-02","type":"ACTUAL"},"study_type":"INTERVENTIONAL","title":"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)","url":"https://clinicaltrials.gov/study/NCT03834506"},"report":null,"schema_id":"erudio.trial_listing","schema_version":"3.0","state":"listed","state_text":"No report yet. It can be ordered.","url":"https://www.erudio.com/trials/keynote-921-nct03834506"}