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)-China Extension
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 Chinese 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. 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.
Timeline
- Start
- 2020-09-23
- Primary completion
- 2022-08-03
- Completion
- 2023-07-18
Outcome
Missed primary endpoint
Stopped: “The data did not support study endpoints”
registry analysis (other test); Pembrolizumab + Docetaxel vs Placebo + Docetaxel; Hazard Ratio (HR) 0.88 (95% CI 0.32 to 2.46) NCT04907227 ↗
registry analysis (other test); Pembrolizumab + Docetaxel vs Placebo + Docetaxel; Hazard Ratio (HR) 1.59 (95% CI 0.68 to 3.67) NCT04907227 ↗
Drugs
| Evaluation | Drug | Modality | Dose | Route |
|---|---|---|---|---|
| Subject | Pembrolizumab | Monoclonal antibody | 200 mg | Intravenous |
| Background | Dexamethasone | Small molecule | 8 mg | Oral |
| Background | Docetaxel | Small molecule | 75 mg/m2 | Intravenous |
| Background | Prednisone | Other / unclassified | 5 mg | Oral |