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Study of Enzalutamide in Patients With Castration-resistant Prostate Cancer

Phase II Trial of Enzalutamide for Castrate-resistant Prostate Cancer (CRPC) With Correlative Assessment of Androgen Receptor (AR) Signaling and Whole-exome and Transcriptome Sequencing

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01942837
Enrollment
67
Registered
2013-09-16
Start date
2013-09-13
Completion date
2022-09-30
Last updated
2022-10-24

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

Conditions

Metastatic Castration-resistant Prostate Cancer

Keywords

Enzalutamide, Metastatic Castration-resistant Prostate Cancer

Brief summary

This research study is evaluating a drug called enzalutamide in metastatic castration resistant prostate cancer. Enzalutamide is already FDA approved for metastatic castration resistant prostate cancer after treatment with chemotherapy. The purpose of this study is to analyze features of tumor specimens sampled prior to therapy and at disease progression to determine why patients respond or stop responding to treatment with Enzalutamide. Prior chemotherapy is not a requirement of this trial.

Detailed description

After the screening procedures confirm that the patient is able to participate in the study, * The patient will have the first of two required prostate biopsies prior to starting study treatment. * The patient will be given a prescription for study drug and a study drug-dosing diary for each treatment cycle. Each treatment cycle lasts 28 days (4 weeks), during which time the patient will be taking the study drug once daily. The diary will also include special instructions for taking the study drug. The study drug (enzalutamide) should be taken orally (by mouth) at home. On Day 1 of each cycle (+/- 4 days), the following procedures will be performed in clinic: * A medical history. * A Physical examination * Performance status * Blood tests (2-3 tablespoons). * The patient will be asked about medications they are currently taking, including over-the counter medications, herbal remedies, vitamins, and supplements. * The patient will be asked about any disease-related symptoms they are experiencing. * The patient will receive a new supply and the medication diary will be reviewed. Every 12 weeks (+/-1 week) the following procedures will be performed in clinic: * Blood tests. A small sample of the patient's blood (about 1-2 tablespoons) will be collected. This blood will be collected for specialized laboratory tests. * A (CT) scan of the patient's chest and a CT or MRI scan of abdomen, and pelvis and a bone scan will be performed every 12 weeks (+/- 1 week) while the patient is on active treatment. If your baseline CT of the patient's chest does not show disease, the investigator may not asked for this to be repeated. End of Study Visit in clinic: * A medical history. * A physical examination * Performance status * Blood tests (2-3 tablespoons) * The patient will be asked about any disease-related symptoms If the patient completed at least 4 cycles of enzalutamide, the patient will undergo a second of two required biopsies.

Interventions

DRUGEnzalutamide

Enzalutamide, formerly known as MDV3100, is a rationally-designed second generation AR inhibitor which functions by blocking several steps in the AR signaling cascade. Enzalutamide competitively binds the AR with great potency. Additionally, enzalutamide inhibits nuclear translocation of activated AR and inhibits the association of activated AR with DNA.

Sponsors

Medivation, Inc.
CollaboratorINDUSTRY
Dana-Farber Cancer Institute
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

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

Inclusion criteria

* Participants must meet the following criteria on screening examination to be eligible to participate in the study: * Be a male ≥ 18 years of age. * Participants must have histologically or cytologically confirmed adenocarcinoma of the prostate without ≥50% neuroendocrine differentiation or small cell histology. * Participants must have progressive disease as defined by either: * Castrate resistant disease as defined by PCWG. Participants must have a rise in PSA on two successive determinations at least one week apart and PSA levels ≥ 2 ng/ml (only the screening PSA needs to be ≥ 2 ng/ml) and testosterone levels \< 50 ng/dL, OR * Soft tissue progression defined by RECIST 1.1, OR * Bone disease progression defined by PCWG2 with two or more new lesions on bone scan. * CRPC with metastatic disease with at least one site of metastatic disease must be amenable to needle biopsy. Soft tissue biopsy sites include: lymph node or visceral metastases. Bone sites include lumbar vertebrae, pelvic bones and long bones. Excluded sites are thoracic, cervical vertebrae, skull and rib lesions. Biopsy site will be selected with guidance of interventional radiologist determining best site to optimize balance of obtaining useful tissue for analysis and minimizing risk. * Participants without orchiectomy must be maintained on LHRH agonist/antagonist therapy. * Participants may have had any number of previous hormonal therapies (antiandrogens, steroids, estrogens, finasteride, dutasteride, ketoconazole, abiraterone) provided these were discontinued ≥ 4 weeks before enrollment. * Participants may have had up to two previous cytotoxic therapeutic regimens provided these were discontinued ≥ 4 weeks before enrollment. * At least a 4 week interval from previous prostate cancer treatment other than LHRH agonist/antagonist therapy or bisphosphonates to enrollment. * Participants receiving bisphosphonates therapy can be maintained on this therapy. If participants have not started bisphosphonates, it is recommended that they start treatment after the first biopsy. * ECOG performance status \< 2 (Karnofsky \>60%, see Appendix A). * Participants must have normal organ and marrow function as defined below: * WBC ≥ 3,000/mcL * ANC ≥ 1,500/mcL * Platelets ≥ 100,000/mcL * Hemoglobin ≥ 9 g/dL * Serum albumin ≥ 3.0 g/dL * AST, ALT, and total bilirubin ≤ 1.5 x Institutional ULN * Creatinine ≤ 1.5 Institutional ULN or a calculated creatinine clearance ≥ 50 mL/min using the Cockcroft Gault equation * PTT ≤ 60, INR ≤ 1.5 Institutional ULN unless on warfarin therapy (investigator would need to determine if safe for participant to stop warfarin prior to biopsy) * Have signed an informed consent document indicating that the subjects understands the purpose of and procedures required for the study and are willing to participate in the study. * Be willing/able to adhere to the prohibitions and restrictions specified in this protocol. * Written Authorization for Use and Release of Health and Research Study Information (US sites only) has been obtained. * Able to swallow the study drug whole as a tablet. * Participants who have partners of childbearing potential must be willing to use a method of birth control with adequate barrier protection as determined to be acceptable by the principal investigator during the treatment period and for 1 week after last dose of enzalutamide.

Exclusion criteria

* Participants who exhibit any of the following conditions at screening will not be eligible for admission into the study. * Uncontrolled illness including, but not limited to ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements within 6 months of enrollment. Clinically significant heart disease as evidenced by: * Myocardial infarction within 6 months of enrollment. * Uncontrolled angina within 6 months of enrollment. * Congestive heart failure NYHA Class III or IV, or a history of congestive heart failure NYHA Class III or IV in the past, unless a screening ECHO or MUGA within 3 months results in a left ventricular ejection fraction ≥ 45%. * Clinically significant ventricular arrhythmias. * History of Mobitz II second degree or third degree heart block without a permanent pacemaker in place. * Bradycardia as indicated by a heart rate \< 50 beats per minute at screening visit. * Hypotension as indicated by SBP ≤ 85 on 2 consecutive measurements. * Uncontrolled hypertension as indicated by SBP \> 170 mmHg or DBP \> 105 mmHg on 2 consecutive measurements at screening visit. * Thromboembolism within 6 months of enrollment. * History of gastrointestinal disorders (medical disorders or extensive surgery) which may interfere with the absorption of the study drug. * History of seizure or any condition or concurrent medication that may predispose to seizure. * Individuals with a history of a different malignancy are ineligible except for the following circumstances: 1) individuals with a history of other malignancies are eligible if they have been disease-free for at least 5 years and are deemed by the investigator to be at low risk for recurrence of that malignancy, or 2) individuals with the following cancers are eligible if diagnosed and treated within the past 5 years: superficial bladder cancer, basal cell or squamous cell carcinoma of the skin. * Known brain metastasis. Participants with brain metastasis can only be included if they were treated \> 4 week prior to enrollment with radiation and the effects of treatment have resolved. Subjects with treated brain metastases must have a post-treatment brain MRI showing no further progression of prior lesions and no new metastatic lesions. Subjects will be ineligible if they have any ongoing symptoms from brain metastases or if there continues to be radiographic evidence of cerebral edema. * Have known allergies, hypersensitivity, or intolerance to enzalutamide or their excipients. * Surgery or local prostatic intervention within 30 days of the first dose. In addition, any clinically relevant issues from the surgery must have resolved prior to enrollment. * Major surgery or radiation therapy within 4 weeks of enrollment. Radium-223, strontium-89, or samarium-153 therapy within 4 weeks of enrollment. Radiotherapy, chemotherapy or immunotherapy within 4 weeks, or single fraction of palliative radiotherapy within 14 days of administration of enrollment. * Prior treatment with enzalutamide. * Current enrollment in an investigational drug or device study or participation in such a study within 30 days of enrollment. * Concomitant use of medications that may alter pharmacokinetics of enzalutamide. See section 5.3. * Any acute toxicities due to prior chemotherapy and/or radiotherapy that have not resolved to a NCI CTCAE (version 4) grade of ≤ 1. Chemotherapy induced alopecia and grade 2 peripheral neuropathy are allowed. * Condition or situation which, in the investigator's opinion, may put the participant at significant risk, may confound the study results, or may interfere significantly with participant's participation in the study. * Individuals not willing to comply with the procedural requirements of this protocol. * HIV-positive individuals on combination antiretroviral therapy are ineligible because of the potential for pharmacokinetic interactions with enzalutamide. Appropriate studies will be undertaken in participants receiving combination antiretroviral therapy when indicated.

Design outcomes

Primary

MeasureTime frameDescription
Number of Patients With Gene AlterationsTumor biopsies were performed at pre-study and progression. Progression occurred up to 41 months after initiation of enzalutamide.Serial biopsies was performed at pre-study and progression to analyze mechanisms of resistance to enzalutamide, such as alterations in AR (mutations, amplifications), tumor suppression genes, DNA repair genes, and SPOP. Whole exome sequencing was performed on tumor tissue biopsies.

Secondary

MeasureTime frameDescription
Number of Participants With a PSA ResponsePSA was measured at pre-treatment, each C1D1 (1 cycle=28 days), end of treatment, and follow-up visits (every 6 months). PSA were measured up to 52 months.PSA response is defined per PCWG2 criteria (PSA decline \>=50% relative to cycle 1 PSA) and is summarized as frequency and percent.
Duration of PSA ResponsePSA was measured at pre-treatment, each C1D1 (1 cycle=28 days), end of treatment, and follow-up visits (every 6 months). PSA were measured up to 52 months.Duration of PSA response is defined as time from the first achievement of PSA response (PSA decline \>=50% from cycle 1) to the date of PSA progression or death, whichever occurs first.
Response of Measurable Disease at BaselineImaging was performed at pre-study and every 12 weeks on treatment. Treatment cycles is 28 days. Patients were assessed up to 41 months.Objective responses for measurable disease was evaluated using RECIST 1.1 criteria. Complete Response (CR): Disappearance of all target lesions. Any pathological lymph nodes must have reduction in short axis to \<10 mm. Partial Response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. Response was tabulated with frequency.
Changes in Serum Androgen Concentrations Between Baseline and Subsequent Assessment VisitsNot collected.Serum testosterone were be collected at pre-study (C1D1) and every cycle and changes over time from baseline were planned to be summarized descriptively.
Toxicity MeasurementsToxicity was reported at pre-study, every cycle, and end of treatment visit. Patients reported toxicities up to 39 months.For safety and tolerability, treatment-related grade 3 or higher toxicities was assessed using CTCAE v. 4.0 and was provided using frequency.
Number of Participants With PSA Response Stratified by Gene Alterations in Serial Tumor BiopsiesTumor biopsies will be performed at pre-treatment and end of treatment visit. Treatment cycle is 28 days. PSA was collected up to 52 months.Serial biopsies was performed at pre-study and progression to analyze mechanisms of resistance to enzalutamide, such as alterations in AR (mutations, amplifications), DNA repair genes, and SPOP. Whole exome sequencing was performed on tumor tissue biopsies. Gene alterations were tabulated with PSA response.
Subsequent Lines of TherapySubsequent treatments were followed up to 31 months after discontinuation of study drug.Subsequent lines of therapy following study drug discontinuation was summarized descriptively.
Duration of Response of Measurable DiseaseImaging was performed at pre-study and every 12 weeks on treatment. Treatment cycles is 28 days. Patients were assessed up to 41 months.Duration of response of measurable disease is defined as time from the date of first objective response (PR/CR) to date of progression or death, whichever comes first. Objective response is per RECIST 1.1 criteria: Complete Response (CR): Disappearance of all target lesions. Any pathological lymph nodes must have reduction in short axis to \<10 mm. Partial Response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters.

Countries

United States

Participant flow

Participants by arm

ArmCount
Enzalutamide
Participants will be treated with four 40 mg capsules (160 mg) once daily of enzalutamide taken orally. All participants without orchiectomy will be maintained on LHRH agonist/antagonist therapy. Participants will be evaluated clinically and with laboratory studies on day 1 of every 28 day cycle. Participants will maintain a drug diary from time of initiation of study treatment to time of discontinuation from the study (Appendix C). Enzalutamide: Administration: 160 mg orally once daily. Treatment will be continued until evidence of symptomatic or radiographic progression or the participant is taken off the study for another reason. Dosing: 160 mg orally taken once daily as four 40 mg capsules.
65
Total65

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyAdverse Event6
Overall StudyDeath1
Overall StudyIntercurrent Illness1
Overall StudyNever initiate the treatment2
Overall StudyOn treatment3
Overall StudyPhysician Decision3
Overall StudySymptomatic or radiographic progression49
Overall StudyWithdrawal by Subject2

Baseline characteristics

CharacteristicEnzalutamide
Age, Continuous70 years
Institution
Beth Israel Deaconess Medical Center
6 Participants
Institution
Dana-Farber Cancer Institute
39 Participants
Institution
South Shore Hospital
1 Participants
Institution
University of Washington
19 Participants
Prior abiraterone
No
43 Participants
Prior abiraterone
Yes
22 Participants
Prior chemotherapy
No
49 Participants
Prior chemotherapy
Yes
16 Participants
Prior docetaxel
No
50 Participants
Prior docetaxel
Yes
15 Participants
Prior ketoconazole
No
56 Participants
Prior ketoconazole
Yes
9 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Asian
1 Participants
Race (NIH/OMB)
Black or African American
4 Participants
Race (NIH/OMB)
More than one race
1 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
8 Participants
Race (NIH/OMB)
White
51 Participants
Sex/Gender, Customized
Male
65 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
41 / 65
other
Total, other adverse events
65 / 65
serious
Total, serious adverse events
8 / 65

Outcome results

Primary

Number of Patients With Gene Alterations

Serial biopsies was performed at pre-study and progression to analyze mechanisms of resistance to enzalutamide, such as alterations in AR (mutations, amplifications), tumor suppression genes, DNA repair genes, and SPOP. Whole exome sequencing was performed on tumor tissue biopsies.

Time frame: Tumor biopsies were performed at pre-study and progression. Progression occurred up to 41 months after initiation of enzalutamide.

Population: Patients who had paired biopsies of pre-study and progression.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
EnzalutamideNumber of Patients With Gene AlterationsSPOP alteration at pre-study4 Participants
EnzalutamideNumber of Patients With Gene AlterationsAR amplifications at pre-study7 Participants
EnzalutamideNumber of Patients With Gene AlterationsAR mutations at pre-study4 Participants
EnzalutamideNumber of Patients With Gene AlterationsTP53 alteration at pre-study7 Participants
EnzalutamideNumber of Patients With Gene AlterationsRB1 alteration at pre-study7 Participants
EnzalutamideNumber of Patients With Gene AlterationsPTEN alteration at pre-study6 Participants
EnzalutamideNumber of Patients With Gene AlterationsBRCA2 alteration at pre-study4 Participants
EnzalutamideNumber of Patients With Gene AlterationsCDK12 alteration at pre-study1 Participants
EnzalutamideNumber of Patients With Gene AlterationsATM alteration at pre-study1 Participants
Secondary

Changes in Serum Androgen Concentrations Between Baseline and Subsequent Assessment Visits

Serum testosterone were be collected at pre-study (C1D1) and every cycle and changes over time from baseline were planned to be summarized descriptively.

Time frame: Not collected.

Population: Serum data on the trial was collected but hormone assays were not run due to insufficient funding.

Secondary

Duration of PSA Response

Duration of PSA response is defined as time from the first achievement of PSA response (PSA decline \>=50% from cycle 1) to the date of PSA progression or death, whichever occurs first.

Time frame: PSA was measured at pre-treatment, each C1D1 (1 cycle=28 days), end of treatment, and follow-up visits (every 6 months). PSA were measured up to 52 months.

Population: Patients who experienced PSA response defined as more than equal to 50% decline from baseline.

ArmMeasureValue (MEDIAN)
EnzalutamideDuration of PSA Response3.2 months
Secondary

Duration of Response of Measurable Disease

Duration of response of measurable disease is defined as time from the date of first objective response (PR/CR) to date of progression or death, whichever comes first. Objective response is per RECIST 1.1 criteria: Complete Response (CR): Disappearance of all target lesions. Any pathological lymph nodes must have reduction in short axis to \<10 mm. Partial Response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters.

Time frame: Imaging was performed at pre-study and every 12 weeks on treatment. Treatment cycles is 28 days. Patients were assessed up to 41 months.

Population: Patients with CR or PR to enzalutamide. There was no CR achieved and 11 PRs.

ArmMeasureValue (MEDIAN)
EnzalutamideDuration of Response of Measurable Disease2.8 months
Secondary

Number of Participants With a PSA Response

PSA response is defined per PCWG2 criteria (PSA decline \>=50% relative to cycle 1 PSA) and is summarized as frequency and percent.

Time frame: PSA was measured at pre-treatment, each C1D1 (1 cycle=28 days), end of treatment, and follow-up visits (every 6 months). PSA were measured up to 52 months.

Population: Patients who received ≥1 dose of enzalutamide

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
EnzalutamideNumber of Participants With a PSA Response≥50% PSA reduction38 Participants
EnzalutamideNumber of Participants With a PSA Response≥90% PSA reduction20 Participants
Secondary

Number of Participants With PSA Response Stratified by Gene Alterations in Serial Tumor Biopsies

Serial biopsies was performed at pre-study and progression to analyze mechanisms of resistance to enzalutamide, such as alterations in AR (mutations, amplifications), DNA repair genes, and SPOP. Whole exome sequencing was performed on tumor tissue biopsies. Gene alterations were tabulated with PSA response.

Time frame: Tumor biopsies will be performed at pre-treatment and end of treatment visit. Treatment cycle is 28 days. PSA was collected up to 52 months.

Population: Patients who had paired biopsies of pre-study and progression.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
EnzalutamideNumber of Participants With PSA Response Stratified by Gene Alterations in Serial Tumor BiopsiesPSA response among patients in Patients with AR amplification3 Participants
EnzalutamideNumber of Participants With PSA Response Stratified by Gene Alterations in Serial Tumor BiopsiesPSA response among patients with AR mutation1 Participants
EnzalutamideNumber of Participants With PSA Response Stratified by Gene Alterations in Serial Tumor BiopsiesPSA response among patients with SPOP alteration2 Participants
Secondary

Response of Measurable Disease at Baseline

Objective responses for measurable disease was evaluated using RECIST 1.1 criteria. Complete Response (CR): Disappearance of all target lesions. Any pathological lymph nodes must have reduction in short axis to \<10 mm. Partial Response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. Response was tabulated with frequency.

Time frame: Imaging was performed at pre-study and every 12 weeks on treatment. Treatment cycles is 28 days. Patients were assessed up to 41 months.

Population: Patients with measurable disease at baseline.

ArmMeasureCategoryValue (COUNT_OF_PARTICIPANTS)
EnzalutamideResponse of Measurable Disease at BaselineComplete response0 Participants
EnzalutamideResponse of Measurable Disease at BaselinePartial response11 Participants
EnzalutamideResponse of Measurable Disease at BaselineStable disease11 Participants
EnzalutamideResponse of Measurable Disease at BaselineProgressive disease7 Participants
EnzalutamideResponse of Measurable Disease at BaselineInevaluable/missing3 Participants
Secondary

Subsequent Lines of Therapy

Subsequent lines of therapy following study drug discontinuation was summarized descriptively.

Time frame: Subsequent treatments were followed up to 31 months after discontinuation of study drug.

Population: Patients who received at least one dose of enzalutamide.

ArmMeasureValue (MEDIAN)
EnzalutamideSubsequent Lines of Therapy2 Lines of treatment
Secondary

Toxicity Measurements

For safety and tolerability, treatment-related grade 3 or higher toxicities was assessed using CTCAE v. 4.0 and was provided using frequency.

Time frame: Toxicity was reported at pre-study, every cycle, and end of treatment visit. Patients reported toxicities up to 39 months.

Population: Patients who received at least one dose of enzalutamide.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
EnzalutamideToxicity MeasurementsGrade 3 hypertension4 Participants
EnzalutamideToxicity MeasurementsGrade 3 colitis1 Participants
EnzalutamideToxicity MeasurementsGrade 3 fatigue1 Participants

Source: ClinicalTrials.gov · Data processed: Feb 15, 2026