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)-China Extension

Metastatic Hormone-Sensitive Prostate Cancer Clinical Trial

Official title:
A Phase 3, Randomized, Double-blind Trial of Pembrolizumab (MK-3475) Plus Enzalutamide Plus ADT Versus Placebo Plus Enzalutamide Plus ADT in Participants With Metastatic Hormone-Sensitive Prostate Cancer (mHSPC) (KEYNOTE-991)

Status Active, not recruiting

Clinical Trial Summary

This study will assess the efficacy and safety of pembrolizumab plus enzalutamide plus ADT versus placebo plus enzalutamide plus ADT in Chinese 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 Amendment 4, the study is being stopped for futility. All the prespecified interim analysis after interim analysis (IA1) and final analysis of the study described the statistical analysis plan (SAP) will not be performed. 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.

Clinical Trial Description

The China extension study will include participants previously enrolled in China in the global study for MK-3475-991 (NCT04191096) plus those enrolled during the China extension enrollment period. A total of approximately 186 Chinese participants will be enrolled. ;

Study Design

Related Conditions & MeSH terms

Hypersensitivity
Metastatic Hormone-Sensitive Prostate Cancer
Prostatic Neoplasms

Clinical Trial Details

NCT number	NCT04934722
Study type	Interventional
Source	Merck Sharp & Dohme LLC
Contact
Status	Active, not recruiting
Phase	Phase 3
Start date	May 25, 2021
Completion date	June 15, 2026

View Details

See also
Status	Clinical Trial	Phase
Not yet recruiting	`NCT06334120` - An Observational Study to Learn More About the Safety of Darolutamide in Men With Prostate Cancer in Korea
Completed	`NCT05381311` - Survey Based Discrete Choice Experiment Study in Prostate Cancer (DECIDER) Study
Active, not recruiting	`NCT00309985` - Androgen Ablation Therapy With or Without Chemotherapy in Treating Patients With Metastatic Prostate Cancer	Phase 3
Completed	`NCT03532217` - Neoantigen DNA Vaccine in Combination With Nivolumab/Ipilimumab and PROSTVAC in Metastatic Hormone-Sensitive Prostate Cancer	Phase 1
Active, not recruiting	`NCT05059236` - A Study to Learn How Well Darolutamide Administered Together With Androgen Deprivation Therapy (ADT) Works in Men With Metastatic Hormone-sensitive Prostate Cancer. Results Will be Compared With ADT Alone From a Previously Conducted Study.	Phase 2
Completed	`NCT02799602` - Darolutamide in Addition to Standard Androgen Deprivation Therapy and Docetaxel in Metastatic Hormone-Sensitive Prostate Cancer	Phase 3
Not yet recruiting	`NCT06134271` - Rezvilutamide Plus Abiraterone for Metastatic Hormone-sensitive Prostate Cancer	Phase 2
Recruiting	`NCT05901649` - A Study for the Participants With Metastatic Hormone Sensitive Prostate Cancer (mHSPC) Treated With Androgen Deprivation Therapy (ADT) Plus Apalutamide or Enzalutamide
Not yet recruiting	`NCT06452212` - Non-Interventional Study to Establish Consensus on Management of Metastatic Hormone-Sensitive Prostate Cancer Patients
Withdrawn	`NCT03343977` - Toxicity & Pharmacokinetics of 2 & 3-weekly Docetaxel in Metastatic Hormone-Sensitive Prostate Cancer (mHSPC)	Phase 1/Phase 2
Active, not recruiting	`NCT04191096` - 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)	Phase 3
Active, not recruiting	`NCT03879122` - A Trial of Immunotherapy Strategies in Metastatic Hormone-sensitive Prostate Cancer	Phase 2/Phase 3

Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.

Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.