Trial purpose
Cancer treatment
Tumor type
Genitourinary
Age
18+
Trial acronym
KEYNOTE - 641
Clinical summary
Summary
Eligible participants will receive either intravenous infusions of pembrolizumab or placebo on Day 1 of each 28-day cycle for up to 35 cycles, in addition to single daily orally administered doses of Enzalutamide.
Conditions
This trial is treating people with metastatic castration-resistant prostate cancer (mCRPC)
Eligibility
Inclusion
The main inclusion criteria include but are not limited to the following:
- 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 randomization
- 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 met one of the following criteria with regard to abiraterone acetate exposure: (1) is abiraterone-naïve; (2) received prior abiraterone acetate for the treatment of mHSPC or mCRPC, for a minimum of 4 weeks and not progressed while on treatment; or (3) received prior abiraterone acetate for the treatment of mHSPC or mCRPC and progressed on treatment after a minimum of 8 weeks treatment (minimum 14 weeks for those with bone progression)
- 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
- Participants must agree to the following during the study treatment period and for at least 90 days after the last dose of enzalutamide: Refrain from donating sperm, plus EITHER be abstinent OR must agree to use male condom
- 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
Exclusion
The main exclusion criteria include but are not limited to the following:
- 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
- Has a history of (noninfectious) pneumonitis/interstitial lung disease that required steroids or current pneumonitis/interstitial lung disease
- Has known active human immunodeficiency virus (HIV), concurrent active hepatitis B virus (HBV) or known active hepatitis C virus (HCV) infection
- Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis
- Has hypersensitivity to pembrolizumab and/or enzalutamide and/or any of their excipients
- Has a history of seizure or any condition that may predispose to seizure
- Has a history of loss of consciousness within 12 months of screening
- Has hypotension (systolic blood pressure <86 millimeters of mercury [mmHg]) or uncontrolled hypertension (systolic blood pressure >170 mmHg or diastolic blood pressure >105 mmHg) at the screening visit
- Has bradycardia (heart rate of <50 beats per minute) on the screening electrocardiogram (ECG)
- Has history of prostate cancer progression on ketoconazole
- Has had prior treatment with enzalutamide, apalutamide, darolutamide or cytochrome P450 (CYP) 17 inhibitor other than abiraterone acetate
- 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 coinhibitory T-cell receptor
- Has received prior treatment with radium or other therapeutic radiopharmaceuticals for prostate cancer
- Has received prior treatment with docetaxel or another chemotherapy agent for mCRPC
- Has had a prior anti-cancer monoclonal antibody (mAb) prior to randomization
- Has used herbal products that may have hormonal anti-prostate cancer activity and/or are known to decrease PSA levels (eg, saw palmetto) prior to randomization
- Has received a live or live attenuated vaccine within 30 days prior to randomization
- 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 90 days after the last dose of enzalutamide
- Has had an allogenic tissue/solid organ transplant
Inclusion
- You are able to swallow medication by mouth.
- You have had treatment but your cancer has gotten worse or has not responded to the treatment you have been given.
- Your cancer has spread to other parts of the body (metastatic) or has grown into nearby parts of the body (locally advanced).
Exclusion
- You have been diagnosed with a prior or secondary type of cancer.
- You have certain types of non-cancer medical conditions.
- You have had certain treatments, surgical procedures or drugs.
- You are currently being treated on a clinical trial.
Clinical trials have complex eligibility criteria, and other criteria may apply for this trial. Ask your doctor about whether this trial could be right for you.
More information
Trial Identifiers
Information on this page is partially produced from ClinicalTrials.gov *. View further details about this trial on the registry via the links below:
Trial sponsor
Merck
Scientific Title
Study of Pembrolizumab (MK-3475) plus Enalutamide versus placebo plus Enzalutamide in participants with metastatic castraion-resistant prostate cancer (mCRPC)
Get Support
You might find it helpful to speak to someone who has 'been there before'. Our Peer Connect program can provide one-on-one phone support from someone who understands what you're going through and has clinical trials experience.
Know more about Peer Connect
If you need cancer information and practical support for yourself, a carer, family or friend, contact Cancer Council to speak with an experienced health professional on 13 11 20.
Get support
Learn more about clinical trials through this collection of resources in languages other than English.
View information