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A Safety and Efficacy Study of Oral MDV3100 in Chemotherapy-Naive Patients With Progressive Metastatic Prostate Cancer

PREVAIL: A MULTINATIONAL PHASE 3, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED EFFICACY AND SAFETY STUDY OF ORAL MDV3100 IN CHEMOTHERAPY-NAÏVE PATIENTS WITH PROGRESSIVE METASTATIC PROSTATE CANCER WHO HAVE FAILED ANDROGEN DEPRIVATION THERAPY

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01212991
Acronym
PREVAIL
Enrollment
1717
Registered
2010-10-01
Start date
2010-09-16
Completion date
2019-02-14
Last updated
2020-03-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Prostate Cancer

Keywords

Progressive Metastatic Prostate Cancer

Brief summary

The purpose of this study is to determine the benefit of enzalutamide versus placebo as assessed by overall survival and progression-free survival in patients with progressive metastatic prostate cancer who have failed androgen deprivation therapy but not yet received chemotherapy.

Interventions

DRUGEnzalutamide

Participants received enzalutamide 160 mg, administered as four 40-mg capsules, once per day by mouth. Study drug treatment continued until disease progression (evidence of radiographic progression, a skeletal-related event, or clinical progression) and the initiation of a cytotoxic chemotherapy or an investigational agent, unacceptable toxicity, or withdrawal.

DRUGPlacebo

Participants received placebo, administered as four capsules, once per day by mouth. Study drug treatment continued until disease progression (evidence of radiographic progression, a skeletal-related event, or clinical progression) and the initiation of a cytotoxic chemotherapy or an investigational agent, unacceptable toxicity, or withdrawal.

Sponsors

Astellas Pharma Inc
CollaboratorINDUSTRY
Medivation LLC, a wholly owned subsidiary of Pfizer Inc.
CollaboratorINDUSTRY
Pfizer
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
MALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

Randomized, Double Blind Treatment Period: Inclusion Criteria: * Histologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell features * Ongoing androgen deprivation therapy with a GnRH analogue or bilateral orchiectomy * Progressive disease despite androgen deprivation therapy as defined by rising PSA levels or progressive soft tissue or bony disease * No prior treatment with cytotoxic chemotherapy * Asymptomatic or mildly symptomatic from prostate cancer

Exclusion criteria

* Severe concurrent disease, infection, or co-morbidity that, in the judgment of the Investigator, would make the patient inappropriate for enrollment * Known or suspected brain metastasis or active leptomeningeal disease * History of another malignancy within the previous 5 years other than curatively treated non-melanomatous skin cancer Open-Label Treatment Period: The following inclusion criteria apply to patients receiving enzalutamide or placebo during double-blind treatment. Eligible patients must meet all inclusion criteria. * Received randomized double-blind treatment in PREVAIL; * Open-label day 1 visit is within 6 months after this amendment is approved and becomes effective at the study site; * Is willing to maintain androgen deprivation therapy with a gonadotropin-releasing hormone (GnRH) agonist/antagonist or has had a bilateral orchiectomy; The

Design outcomes

Primary

MeasureTime frameDescription
Radiographic Progression-free Survival (rPFS)During study period (up to 20 months)Radiographic progression-free survival was defined as the time from randomization to the first objective evidence of radiographic disease progression assessed by independent central radiology review or death due to any cause within 168 days after treatment discontinuation, whichever was first. Radiographic disease progression was evaluated by CT scan or MRI and radionuclide bone scans at regularly scheduled visits. Radiographic disease progression in bone required a confirmatory scan. Radiographic disease progression in soft tissue did not require a confirmatory scan for purposes of analysis. Radiographic disease progression was evaluated by independent central radiology review using RECIST 1.1 for soft tissue disease and PCWG2 guidelines for bone disease. Patients who did not reach the endpoint were censored at their last assessment.
Overall SurvivalDuring study period (up to 3 years)Overall survival was defined as the time from randomization to death due to any cause. For patients who were alive at the time of the analysis data cutoff, overall survival was censored at the last date the patient was known to be alive or analysis data cutoff date, whichever was first. This included patients who were known to have died after the data analysis cutoff date. Patients with no post-baseline survival information were censored on the date of randomization.

Secondary

MeasureTime frameDescription
Time to Initiation of Cytotoxic ChemotherapyDuring study period (up to 3 years)The time to initiation of cytotoxic chemotherapy is defined as the time from randomization to the date of initiation of cytotoxic chemotherapy for the treatment of prostate cancer for each patient. For patients who did not start cytotoxic chemotherapy at the time of the analysis data cutoff, time to initiation of cytotoxic chemotherapy was censored at the date of last assessment where no cytotoxic chemotherapy was indicated or at the analysis data cutoff date, whichever was first. Time to initiation of cytotoxic chemotherapy for patients with no postbaseline assessments was censored on the date of randomization.
Time to Prostate-specific Antigen (PSA) ProgressionDuring study period (up to 3 years)Time to PSA progression was defined as the time from randomization to date of first confirmed observation of PSA progression for each patient. For patients with PSA declines at week 13, the PSA progression date was defined as the date that a ≥ 25% increase and an absolute increase of ≥ 2 ng/mL above the nadir was documented, and confirmed 3 or more weeks later. For patients with no PSA decline at week 13, the PSA progression date was defined as the date that a ≥ 25% increase and an absolute increase of ≥ 2 ng/mL above baseline was documented, and confirmed 3 or more weeks later. For patients who did not have confirmed PSA progression at the time of the analysis data cutoff, time to PSA progression was censored at the date of the last PSA assessment showing no evidence of confirmed PSA progression or the analysis data cutoff date, whichever was first. Time to PSA progression for patients with no postbaseline assessments was censored on the date of randomization.
Time to First Skeletal-related EventDuring study period (up to 3 years)Time to first skeletal-related event was defined as the time from randomization to the date of the first occurrence of a skeletal-related event for each patient. A skeletal-related event was defined as radiation therapy or surgery to bone for prostate cancer, pathological bone fracture, spinal cord compression, or initiation/change in antineoplastic therapy to treat bone pain from prostate cancer. Skeletal-related events were recorded at each scheduled and unscheduled study visit and during long-term follow-up if a skeletal-related event was not documented previously. Patients who did not have a skeletal-related event at the time of the analysis data cutoff were censored at the date of last assessment indicating no evidence of skeletal-related event. Patients with no postbaseline assessments were censored on the date of randomization.
Percentage of Patients With Prostate Specific Antigen (PSA) Response ≥ 50%During study period (up to 3 years)PSA response was defined as a ≥ 50% reduction in PSA from baseline to the lowest postbaseline PSA value and required confirmation by a consecutive assessment at least 3 weeks later. Patients were evaluable for PSA response rate if a patient had a PSA level measured at baseline and at least one postbaseline assessment.
Best Overall Soft Tissue ResponseDuring study period (up to 3 years)The best overall soft tissue objective response is defined as partial response \[PR\] or complete response \[CR\] while on study treatment based on investigator assessments of target, nontarget, and new lesions using RECIST 1.1. Soft tissue was assessed by CT or MRI at regularly scheduled visits. Only patients with measurable soft tissue disease (ie, at least 1 target lesion identified per RECIST 1.1) at screening are included in this analysis. All percentages are based on number of participants with measurable soft tissue disease at screening in each treatment group.

Other

MeasureTime frameDescription
Number of Participants With Treatment-Emergent Adverse Events (AEs) Greater Than or Equal to (>=) Grade 3, Based on National Cancer Institute Common Terminology Criteria for AEs (CTCAE), Version 4.0Baseline to discontinuation from the study or death, whichever occurred first (maximum duration of 6.5 years)An AE is any untoward medical occurrence in participant who received study drug without regard to possibility of causal relationship. As per NCI CTCAE, Grade 3 events =medically significant but not immediately life-threatening, unacceptable or intolerable events, significantly interrupting usual daily activity, require systemic drug therapy/other treatment, Grade 4 events =participant to be in imminent danger of death. Grade 5 events =death. A treatment-emergent AE (TEAE) was defined as an AE that occurred from the date and time of the first dose of study drug up to a maximum duration of 6.5 years. Number of participants with AEs of any of the Grade 3 or above (Grade 4, 5) were reported.
Number of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)Baseline to discontinuation from the study or death, whichever occurred first (maximum duration of 6.5 years)An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent were events between first dose of study drug and up to a maximum of 6.5 years that were absent before treatment or that worsened relative to pretreatment state. AEs included both serious and non-serious AEs.
Number of Participants With Treatment-Related Adverse Events (AEs) and Serious Adverse Events (SAEs)Baseline to discontinuation from the study or death, whichever occurred first (maximum duration of 6.5 years)Treatment-related AE was any untoward medical occurrence attributed to study drug in a participant who received study drug. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent were events between first dose of study drug and up to a maximum duration of 6.5 years that were absent before treatment or that worsened relative to pre-treatment state. Relatedness to study drug was assessed by the investigator.

Countries

Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Israel, Italy, Japan, Lithuania, Netherlands, Poland, Russia, Singapore, Slovakia, South Korea, Spain, Sweden, United Kingdom, United States

Participant flow

Pre-assignment details

Following the independent data monitoring committee's recommendation, a protocol amendment was implemented for double-blind phase to be proceeded to open-label phase, which allowed previously placebo treated participants who had not received commercial enzalutamide the opportunity, to receive open-label access to enzalutamide.

Participants by arm

ArmCount
Enzalutamide
Participants received enzalutamide 160 mg, administered as four 40-mg capsules, once per day by mouth.
872
Placebo
Participants received placebo, administered as four capsules, once per day by mouth.
845
Total1,717

Withdrawals & dropouts

PeriodReasonFG000FG001FG002
Double-blindDeath6995500
Double-blindLost to Follow-up840
Double-blindOther700
Double-blindSponsor decision142380
Double-blindWithdrawal by Subject16190
Open-labelDeath00166
Open-labelLost to Follow-up005
Open-labelOther003
Open-labelSponsor decision0053
Open-labelWithdrawal by Subject007

Baseline characteristics

CharacteristicTotalEnzalutamidePlacebo
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
1359 Participants693 Participants666 Participants
Age, Categorical
Between 18 and 65 years
358 Participants179 Participants179 Participants
Age, Continuous71.3 years
STANDARD_DEVIATION 8.47
71.3 years
STANDARD_DEVIATION 8.51
71.2 years
STANDARD_DEVIATION 8.42
Region of Enrollment
Australia
232 count of participants116 count of participants116 count of participants
Region of Enrollment
Austria
18 count of participants9 count of participants9 count of participants
Region of Enrollment
Belgium
57 count of participants28 count of participants29 count of participants
Region of Enrollment
Canada
179 count of participants91 count of participants88 count of participants
Region of Enrollment
Denmark
87 count of participants43 count of participants44 count of participants
Region of Enrollment
Finland
33 count of participants18 count of participants15 count of participants
Region of Enrollment
France
175 count of participants85 count of participants90 count of participants
Region of Enrollment
Germany
83 count of participants41 count of participants42 count of participants
Region of Enrollment
Israel
25 count of participants14 count of participants11 count of participants
Region of Enrollment
Italy
30 count of participants15 count of participants15 count of participants
Region of Enrollment
Japan
61 count of participants28 count of participants33 count of participants
Region of Enrollment
Korea, Republic of
78 count of participants40 count of participants38 count of participants
Region of Enrollment
Lithuania
14 count of participants8 count of participants6 count of participants
Region of Enrollment
Netherlands
28 count of participants15 count of participants13 count of participants
Region of Enrollment
Poland
39 count of participants21 count of participants18 count of participants
Region of Enrollment
Russian Federation
22 count of participants12 count of participants10 count of participants
Region of Enrollment
Singapore
9 count of participants5 count of participants4 count of participants
Region of Enrollment
Slovakia
27 count of participants13 count of participants14 count of participants
Region of Enrollment
Spain
81 count of participants44 count of participants37 count of participants
Region of Enrollment
Sweden
39 count of participants21 count of participants18 count of participants
Region of Enrollment
United Kingdom
153 count of participants78 count of participants75 count of participants
Region of Enrollment
United States
247 count of participants127 count of participants120 count of participants
Sex: Female, Male
Female
0 Participants0 Participants0 Participants
Sex: Female, Male
Male
1717 Participants872 Participants845 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
deaths
Total, all-cause mortality
699 / 871550 / 844166 / 234
other
Total, other adverse events
814 / 871723 / 844180 / 234
serious
Total, serious adverse events
384 / 871229 / 844104 / 234

Outcome results

Primary

Overall Survival

Overall survival was defined as the time from randomization to death due to any cause. For patients who were alive at the time of the analysis data cutoff, overall survival was censored at the last date the patient was known to be alive or analysis data cutoff date, whichever was first. This included patients who were known to have died after the data analysis cutoff date. Patients with no post-baseline survival information were censored on the date of randomization.

Time frame: During study period (up to 3 years)

Population: Intent to Treat (ITT) - All patients randomly assigned to treatment.

ArmMeasureValue (MEDIAN)
EnzalutamideOverall Survival32.4 months
PlaceboOverall Survival30.2 months
p-value: <0.000195% CI: [0.596, 0.837]Log Rank
Primary

Radiographic Progression-free Survival (rPFS)

Radiographic progression-free survival was defined as the time from randomization to the first objective evidence of radiographic disease progression assessed by independent central radiology review or death due to any cause within 168 days after treatment discontinuation, whichever was first. Radiographic disease progression was evaluated by CT scan or MRI and radionuclide bone scans at regularly scheduled visits. Radiographic disease progression in bone required a confirmatory scan. Radiographic disease progression in soft tissue did not require a confirmatory scan for purposes of analysis. Radiographic disease progression was evaluated by independent central radiology review using RECIST 1.1 for soft tissue disease and PCWG2 guidelines for bone disease. Patients who did not reach the endpoint were censored at their last assessment.

Time frame: During study period (up to 20 months)

Population: Intent to Treat (ITT) - All patients randomly assigned to treatment excluding 84 patients who were not randomized before the radiographic Progression-free Survival data cutoff date of 06 May 2012.

ArmMeasureValue (MEDIAN)
EnzalutamideRadiographic Progression-free Survival (rPFS)NA months
PlaceboRadiographic Progression-free Survival (rPFS)3.9 months
p-value: <0.000195% CI: [0.149, 0.231]Log Rank
Secondary

Best Overall Soft Tissue Response

The best overall soft tissue objective response is defined as partial response \[PR\] or complete response \[CR\] while on study treatment based on investigator assessments of target, nontarget, and new lesions using RECIST 1.1. Soft tissue was assessed by CT or MRI at regularly scheduled visits. Only patients with measurable soft tissue disease (ie, at least 1 target lesion identified per RECIST 1.1) at screening are included in this analysis. All percentages are based on number of participants with measurable soft tissue disease at screening in each treatment group.

Time frame: During study period (up to 3 years)

Population: Intent to treat (ITT) population With Measurable Disease - All participants who were randomly assigned to treatment and had at least one target lesion at screening.

ArmMeasureValue (NUMBER)
EnzalutamideBest Overall Soft Tissue Response58.8 Percentage of participants
PlaceboBest Overall Soft Tissue Response5.0 Percentage of participants
p-value: <0.000195% CI: [48.53, 59.17]Cochran-Mantel-Haenszel
Secondary

Percentage of Patients With Prostate Specific Antigen (PSA) Response ≥ 50%

PSA response was defined as a ≥ 50% reduction in PSA from baseline to the lowest postbaseline PSA value and required confirmation by a consecutive assessment at least 3 weeks later. Patients were evaluable for PSA response rate if a patient had a PSA level measured at baseline and at least one postbaseline assessment.

Time frame: During study period (up to 3 years)

Population: Evaluable intent to treat (ITT) population - All patients randomly assigned to treatment with PSA values at baseline and at least one postbaseline assessment.

ArmMeasureValue (NUMBER)
EnzalutamidePercentage of Patients With Prostate Specific Antigen (PSA) Response ≥ 50%78 Percentage of Participants
PlaceboPercentage of Patients With Prostate Specific Antigen (PSA) Response ≥ 50%3.5 Percentage of Participants
p-value: <0.000195% CI: [71.45, 77.57]Cochran-Mantel-Haenszel
Secondary

Time to First Skeletal-related Event

Time to first skeletal-related event was defined as the time from randomization to the date of the first occurrence of a skeletal-related event for each patient. A skeletal-related event was defined as radiation therapy or surgery to bone for prostate cancer, pathological bone fracture, spinal cord compression, or initiation/change in antineoplastic therapy to treat bone pain from prostate cancer. Skeletal-related events were recorded at each scheduled and unscheduled study visit and during long-term follow-up if a skeletal-related event was not documented previously. Patients who did not have a skeletal-related event at the time of the analysis data cutoff were censored at the date of last assessment indicating no evidence of skeletal-related event. Patients with no postbaseline assessments were censored on the date of randomization.

Time frame: During study period (up to 3 years)

Population: Intent to Treat (ITT) - All patients randomly assigned to treatment.

ArmMeasureValue (MEDIAN)
EnzalutamideTime to First Skeletal-related Event31.1 months
PlaceboTime to First Skeletal-related Event31.3 months
p-value: <0.000195% CI: [0.61, 0.844]Log Rank
Secondary

Time to Initiation of Cytotoxic Chemotherapy

The time to initiation of cytotoxic chemotherapy is defined as the time from randomization to the date of initiation of cytotoxic chemotherapy for the treatment of prostate cancer for each patient. For patients who did not start cytotoxic chemotherapy at the time of the analysis data cutoff, time to initiation of cytotoxic chemotherapy was censored at the date of last assessment where no cytotoxic chemotherapy was indicated or at the analysis data cutoff date, whichever was first. Time to initiation of cytotoxic chemotherapy for patients with no postbaseline assessments was censored on the date of randomization.

Time frame: During study period (up to 3 years)

Population: Intent to Treat (ITT) - All patients randomly assigned to treatment.

ArmMeasureValue (MEDIAN)
EnzalutamideTime to Initiation of Cytotoxic Chemotherapy28.0 months
PlaceboTime to Initiation of Cytotoxic Chemotherapy10.8 months
p-value: <0.000195% CI: [0.303, 0.403]Log Rank
Secondary

Time to Prostate-specific Antigen (PSA) Progression

Time to PSA progression was defined as the time from randomization to date of first confirmed observation of PSA progression for each patient. For patients with PSA declines at week 13, the PSA progression date was defined as the date that a ≥ 25% increase and an absolute increase of ≥ 2 ng/mL above the nadir was documented, and confirmed 3 or more weeks later. For patients with no PSA decline at week 13, the PSA progression date was defined as the date that a ≥ 25% increase and an absolute increase of ≥ 2 ng/mL above baseline was documented, and confirmed 3 or more weeks later. For patients who did not have confirmed PSA progression at the time of the analysis data cutoff, time to PSA progression was censored at the date of the last PSA assessment showing no evidence of confirmed PSA progression or the analysis data cutoff date, whichever was first. Time to PSA progression for patients with no postbaseline assessments was censored on the date of randomization.

Time frame: During study period (up to 3 years)

Population: Intent to Treat (ITT) - All patients randomized.

ArmMeasureValue (MEDIAN)
EnzalutamideTime to Prostate-specific Antigen (PSA) Progression11.2 months
PlaceboTime to Prostate-specific Antigen (PSA) Progression2.8 months
p-value: <0.000195% CI: [0.147, 0.195]Log Rank
Other Pre-specified

Number of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)

An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent were events between first dose of study drug and up to a maximum of 6.5 years that were absent before treatment or that worsened relative to pretreatment state. AEs included both serious and non-serious AEs.

Time frame: Baseline to discontinuation from the study or death, whichever occurred first (maximum duration of 6.5 years)

Population: The safety analysis set included all randomized participants who received at least 1 dose or partial dose of study drug.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
EnzalutamideNumber of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)AEs857 Participants
EnzalutamideNumber of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)SAEs384 Participants
PlaceboNumber of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)AEs791 Participants
PlaceboNumber of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)SAEs229 Participants
Placebo Participants Crossover to EnzalutamideNumber of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)AEs212 Participants
Placebo Participants Crossover to EnzalutamideNumber of Participants With Treatment-Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs)SAEs104 Participants
Other Pre-specified

Number of Participants With Treatment-Emergent Adverse Events (AEs) Greater Than or Equal to (>=) Grade 3, Based on National Cancer Institute Common Terminology Criteria for AEs (CTCAE), Version 4.0

An AE is any untoward medical occurrence in participant who received study drug without regard to possibility of causal relationship. As per NCI CTCAE, Grade 3 events =medically significant but not immediately life-threatening, unacceptable or intolerable events, significantly interrupting usual daily activity, require systemic drug therapy/other treatment, Grade 4 events =participant to be in imminent danger of death. Grade 5 events =death. A treatment-emergent AE (TEAE) was defined as an AE that occurred from the date and time of the first dose of study drug up to a maximum duration of 6.5 years. Number of participants with AEs of any of the Grade 3 or above (Grade 4, 5) were reported.

Time frame: Baseline to discontinuation from the study or death, whichever occurred first (maximum duration of 6.5 years)

Population: The safety analysis set included all randomized participants who received at least 1 dose or partial dose of study drug.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
EnzalutamideNumber of Participants With Treatment-Emergent Adverse Events (AEs) Greater Than or Equal to (>=) Grade 3, Based on National Cancer Institute Common Terminology Criteria for AEs (CTCAE), Version 4.0465 Participants
PlaceboNumber of Participants With Treatment-Emergent Adverse Events (AEs) Greater Than or Equal to (>=) Grade 3, Based on National Cancer Institute Common Terminology Criteria for AEs (CTCAE), Version 4.0318 Participants
Placebo Participants Crossover to EnzalutamideNumber of Participants With Treatment-Emergent Adverse Events (AEs) Greater Than or Equal to (>=) Grade 3, Based on National Cancer Institute Common Terminology Criteria for AEs (CTCAE), Version 4.0129 Participants
Other Pre-specified

Number of Participants With Treatment-Related Adverse Events (AEs) and Serious Adverse Events (SAEs)

Treatment-related AE was any untoward medical occurrence attributed to study drug in a participant who received study drug. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent were events between first dose of study drug and up to a maximum duration of 6.5 years that were absent before treatment or that worsened relative to pre-treatment state. Relatedness to study drug was assessed by the investigator.

Time frame: Baseline to discontinuation from the study or death, whichever occurred first (maximum duration of 6.5 years)

Population: The safety analysis set included all randomized participants who received at least 1 dose or partial dose of study drug.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
EnzalutamideNumber of Participants With Treatment-Related Adverse Events (AEs) and Serious Adverse Events (SAEs)AEs579 Participants
EnzalutamideNumber of Participants With Treatment-Related Adverse Events (AEs) and Serious Adverse Events (SAEs)SAEs38 Participants
PlaceboNumber of Participants With Treatment-Related Adverse Events (AEs) and Serious Adverse Events (SAEs)AEs423 Participants
PlaceboNumber of Participants With Treatment-Related Adverse Events (AEs) and Serious Adverse Events (SAEs)SAEs22 Participants
Placebo Participants Crossover to EnzalutamideNumber of Participants With Treatment-Related Adverse Events (AEs) and Serious Adverse Events (SAEs)AEs119 Participants
Placebo Participants Crossover to EnzalutamideNumber of Participants With Treatment-Related Adverse Events (AEs) and Serious Adverse Events (SAEs)SAEs14 Participants

Source: ClinicalTrials.gov · Data processed: Mar 17, 2026