Safety and Efficacy Study of Enzalutamide Versus Bicalutamide in Men With Prostate Cancer (STRIVE)

• ClinicalTrials.gov Identifier: NCT01664923
• Recruitment Status: Completed
• First Posted: August 14, 2012
• Results First Posted: May 23, 2016
• Last Update Posted: January 30, 2019
• Sponsor: Pfizer
• Collaborators: Astellas Pharma Inc; Medivation LLC, a wholly owned subsidiary of Pfizer Inc.
• Information provided by (Responsible Party): Pfizer

Tracking Information

• First Submitted Date: August 10, 2012
• First Posted Date: August 14, 2012
• Results First Submitted Date: February 22, 2016
• Results First Posted Date: May 23, 2016
• Last Update Posted Date: January 30, 2019
• Actual Study Start Date: August 2012
• Actual Primary Completion Date: February 2015 (Final data collection date for primary outcome measure)

Current Primary Outcome Measures (submitted: May 9, 2016)

Progression Free Survival (PFS) [ Time Frame: From randomization until the data cut-off date of 09 February 2015, median duration of treatment was 14.7 months in the enzalutamide arm and 8.4 months in the bicalutamide arm. ]

PFS was defined as time from randomization to earliest objective evidence of prostate specific-antigen (PSA) progression, radiographic progression, or death on study. PSA progression was defined as ≥ 25% increase in PSA with an absolute increase ≥ 2 ng/mL above the nadir and was to be confirmed by a second consecutive assessment. Radiographic progression in bone was based on The Prostate Cancer Clinical Trials Working Group (PCWG2) guidelines defined as at least 2 new lesions on bone scan. Radiographic progression in soft tissue on Computerized Tomography/Magnetic Resonance Imaging (CT/MRI) was based on Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1). CT/MRI and bone scans were read locally by the same radiologist (or nuclear medicine physician for interpretation of bone scans) whenever possible. Participants not known to have had a PFS event at the time of the analysis data cutoff were censored at the date of last assessment.

• Original Primary Outcome Measures (submitted: August 13, 2012): Progression Free Survival (PFS) [ Time Frame: 24 months ]

Current Secondary Outcome Measures (submitted: January 7, 2019)

• Time to PSA Progression [ Time Frame: From randomization until the data cut-off date of 09 February 2015, median duration of treatment was 14.7 months in the enzalutamide arm and 8.4 months in the bicalutamide arm. ]
  PSA progression was defined as ≥ 25% increase in PSA with an absolute increase ≥ 2 ng/mL above the nadir and was to be confirmed by a second consecutive assessment at least 3 weeks later. Participants not known to have had PSA progression were censored at the date of last PSA assessment.
• Percentage of Participants With a PSA Response ≥ 50% [ Time Frame: From randomization until the data cut-off date of 09 February 2015, median duration of treatment was 14.7 months in the enzalutamide arm and 8.4 months in the bicalutamide arm. ]
  PSA response was defined as a reduction in PSA of at least 50% from baseline at any post baseline assessment confirmed by a second PSA assessment at least 3 weeks later.
• Duration of Radiographic PFS [ Time Frame: From randomization until the data cut-off date of 09 February 2015, median duration of treatment was 14.7 months in the enzalutamide arm and 8.4 months in the bicalutamide arm. ]
  Duration of radiographic PFS was defined as the time from randomization to the earliest objective evidence of radiographic disease progression or death on study and was to be evaluated for participants with metastatic disease at study entry. Radiographic disease progression in bone was based on PCWG2 guidelines defined as at least 2 new lesions on bone scan. Radiographic disease progression in soft tissue on CT/MRI was based on RECIST 1.1. CT/MRI and bone scans were read locally by the same radiologist (or nuclear medicine physician for interpretation of bone scans) whenever possible. Participants not known to have had radiographic progression at the time of analysis data cutoff were censored at the date of last radiographic assessment.
• Quality of Life: Time to Degradation of Functional Assessment of Cancer Therapy - Prostate (FACT-P) [ Time Frame: From randomization until the data cut-off date of 09 February 2015, median duration of treatment was 14.7 months in the enzalutamide arm and 8.4 months in the bicalutamide arm. ]
  The FACT-P is a multidimensional, self-reported quality of life instrument consisting of 27 core items that assess patient function in 4 domains: physical, social/family, emotional, and functional well-being, and supplemented by 12 site-specific items to assess for prostate-related symptoms. Each item is rated on a 0 to 4 Likert-type scale, and then combined to produce subscale scores for each domain, as well as a global quality of life score (0 to 156) with higher scores representing better quality of life. Time to degradation of FACT-P was defined as the time from randomization to first assessment with at least a 10-point decrease from baseline in the global FACT-P score for each participant. Participants with no score degradation at the time of analysis data cutoff were censored at the date of last assessment showing no degradation.
• Best Overall Soft Tissue Response [ Time Frame: From randomization until the data cut-off date of 09 February 2015, median duration of treatment was 14.7 months in the enzalutamide arm and 8.4 months in the bicalutamide arm. ]
  Best overall soft tissue response is defined as partial response (PR) or complete response (CR) while on study treatment based on investigator assessment of target, nontarget, and new lesions using RECIST 1.1. Only participants in the metastatic population with measurable soft tissue disease (at least 1 target lesion identified per RECIST 1.1) at screening were included in the analysis. All percentages are based on number of participants with metastatic and measurable soft tissue disease at screening in each treatment group.
• Percentage of Participants With Treatment Emergent Adverse Events (AEs) and Serious Adverse Events (SAEs) [ Time Frame: From first dose of study drug until the end of open label phase (up to maximum duration of 65 months) ]
  An AE was any untoward medical occurrence in a participant who received study treatment without regard to possibility of causal relationship. An SAE was an AE resulting in any of 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 or incapacity, congenital anomaly. A treatment emergent AE defined as an event that emerged during treatment period (From first dose of study drug until end of open label phase [up to maximum duration of 65 months]) that was absent before treatment, or worsened during treatment period relative to pre-treatment state. AE included both serious and non- SAE. Treatment-related AE was any untoward medical occurrence attributed to study drug in a participant who received study drug. An AE was considered related to study drug if event was assessed by investigator as probably or possibly related.

Original Secondary Outcome Measures (submitted: August 13, 2012)

• Time to Prostate Specific Antigen (PSA) Progression [ Time Frame: 24 months ]
• PSA Response [ Time Frame: 13 weeks ]
• Time to Radiographic Progression [ Time Frame: 13 weeks ]
• Functional Assessment of Cancer Therapy - Prostate (FACT-P) [ Time Frame: 24 months ]
• Safety [ Time Frame: 24 months ]
  Safety assess by AEs, frequency of study drug discontinuation due to AEs, laboratory evaluations and vital signs

• Current Other Pre-specified Outcome Measures: Not Provided
• Original Other Pre-specified Outcome Measures: Not Provided

Descriptive Information

• Brief Title: Safety and Efficacy Study of Enzalutamide Versus Bicalutamide in Men With Prostate Cancer
• Official Title: STRIVE: A MULTICENTER PHASE 2, RANDOMIZED, DOUBLE-BLIND, EFFICACY AND SAFETY STUDY OF ENZALUTAMIDE VS. BICALUTAMIDE IN MEN WITH PROSTATE CANCER WHO HAVE FAILED PRIMARY ANDROGEN DEPRIVATION THERAPY
• Brief Summary: The purpose of this study is to determine the safety and efficacy of enzalutamide vs bicalutamide in asymptomatic or mildly symptomatic patients with prostate cancer who have disease progression despite primary androgen deprivation therapy.

Detailed Description

This study is a multicenter phase 2, randomized, double-blind, efficacy and safety study of enzalutamide (160 mg/day) vs. bicalutamide (50 mg/day) in patients with recurrent prostate cancer who have serologic and/or radiographic disease progression despite primary androgen deprivation therapy.

Throughout the study, safety and tolerability will be assessed by the recording of adverse events, monitoring of vital signs, physical examinations, and safety laboratory evaluations.

Following study unblinding, study patients receiving enzalutamide or bicalutamide at the time of unblinding and qualifying patients randomized to bicalutamide who discontinued prior to unblinding will be offered the opportunity to receive open label enzalutamide treatment.

• Study Type: Interventional
• Study Phase: Phase 2
• Study Design: Allocation: Randomized; Intervention Model: Parallel Assignment; Masking: Triple (Participant, Investigator, Outcomes Assessor); Primary Purpose: Treatment
• Condition: Prostate Cancer

Intervention

• Drug: Enzalutamide
  160 mg, daily, by mouth.
  Other Names:

  • MDV3100
  • Xtandi
• Drug: Bicalutamide
  50 mg, daily, by mouth
  Other Name: Casodex

Study Arms

• Experimental: Enzalutamide
  Enzalutamide 160 mg/day orally
  Intervention: Drug: Enzalutamide
• Active Comparator: Bicalutamide
  50 mg/day orally
  Intervention: Drug: Bicalutamide

Publications *

• Penson DF, Armstrong AJ, Concepcion RS, Agarwal N, Olsson CA, Karsh LI, Dunshee CJ, Duggan W, Shen Q, Sugg J, Haas GP, Higano CS. Enzalutamide versus bicalutamide in patients with nonmetastatic castration-resistant prostate cancer: a prespecified subgroup analysis of the STRIVE trial. Prostate Cancer Prostatic Dis. 2022 Feb;25(2):363-365. doi: 10.1038/s41391-021-00465-7. Epub 2021 Oct 7. Erratum In: Prostate Cancer Prostatic Dis. 2021 Nov 30;:
• Penson DF, Armstrong AJ, Concepcion R, Agarwal N, Olsson C, Karsh L, Dunshee C, Wang F, Wu K, Krivoshik A, Phung D, Higano CS. Enzalutamide Versus Bicalutamide in Castration-Resistant Prostate Cancer: The STRIVE Trial. J Clin Oncol. 2016 Jun 20;34(18):2098-106. doi: 10.1200/JCO.2015.64.9285. Epub 2016 Jan 25.

Recruitment Information

• Recruitment Status: Completed
• Actual Enrollment (submitted: January 7, 2019): 396
• Original Estimated Enrollment (submitted: August 13, 2012): 400
• Actual Study Completion Date: January 2018
• Actual Primary Completion Date: February 2015 (Final data collection date for primary outcome measure)

Eligibility Criteria

Inclusion Criteria:

• Males age 18 or older;
• Histologically or cytologically confirmed adenocarcinoma of the prostate;
• Ongoing androgen deprivation therapy;
• Serum testosterone level ≤ 50 ng/dL (1.73 nmol/L) at the Screening visit;
• Progressive disease at study entry defined by prostate-specific antigen (PSA) progression and/or radiographic progression that occurred while the patient was on primary androgen deprivation therapy;
• Asymptomatic or mildly symptomatic from prostate cancer;
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1;
• Estimated life expectancy of ≥ 12 months;
• Able to swallow the study drug and comply with study requirements.

Exclusion Criteria:

• Severe concurrent disease, infection, or co-morbidity;
• Known or suspected brain metastasis or active leptomeningeal disease;
• History of another invasive malignancy within the previous 5 years other than treated non-melanomatous skin cancer and American Joint Committee on Cancer (AJCC) Stage 0 or Stage 1 cancers that have a remote probability of recurrence;
• Absolute neutrophil count < 1,500/µL, or platelet count < 100,000/µL, or hemoglobin < 9 g/dL at the Screening visit;
• Total bilirubin, alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 2.5 times the upper limit of normal (ULN) at the Screening visit;
• Creatinine > 2 mg/dL at the Screening visit;
• Albumin < 3.0 g/dL at the Screening visit;
• History of seizure or any condition that may predispose to seizure;
• Clinically significant cardiovascular disease;
• Gastrointestinal disorder affecting absorption (e.g., gastrectomy, active peptic ulcer disease within last 3 months);
• Major surgery within 4 weeks of enrollment;
• Use of opiate analgesics for pain from prostate cancer within 4 weeks of enrollment;
• Radiation therapy for treatment of the primary tumor within 3 weeks of enrollment;
• Prior radiation or radionuclide therapy for treatment of distant metastases;
• Prior ketoconazole, abiraterone, or cytotoxic chemotherapy for prostate cancer;
• Treatment with hormonal therapy or biologic therapy for prostate cancer within 4 weeks of enrollment;
• Use of antiandrogens within 4 weeks prior to enrollment;
• Prior disease progression, as assessed by the Investigator, while receiving bicalutamide;
• Participation in a previous clinical trial of enzalutamide or an investigational agent that inhibits the androgen receptor or androgen synthesis (patients who received placebo are acceptable);
• Use of an investigational agent within 4 weeks of enrollment;
• Use of herbal products that may have hormonal anti-prostate cancer activity and/or are known to decrease PSA levels (e.g., saw palmetto) or systemic corticosteroids for prostate cancer within 4 weeks of enrollment;
• Any condition or reason that, in the opinion of the Investigator, interferes with the ability of the patient to participate in the trial, which places the patient at undue risk, or complicates the interpretation of safety data.

Open-Label Treatment Period:

Inclusion Criteria:

• Received randomized double blind treatment in MDV3100-09 as follows:

  • Randomized to enzalutamide and receiving enzalutamide at the time of study unblinding;
  • Randomized to bicalutamide and receiving bicalutamide at the time of study unblinding;
  • Randomized to bicalutamide and discontinued bicalutamide before study unblinding;
• Willing to maintain androgen deprivation therapy with a gonadotropin releasing hormone (GnRH) agonist/antagonist or has had a bilateral orchiectomy.

Exclusion Criteria:

• Is currently or has taken commercially available enzalutamide (Xtandi) prior to participation in this open-label extension;
• Discontinued enzalutamide during the double-blind portion of the study prior to unblinding;
• Has any clinically significant cardiovascular, dermatologic, endocrine, gastrointestinal, hematologic, hepatic, infectious, metabolic, neurologic, psychiatric, psychologic, pulmonary, or renal disorder or any other condition, including excessive alcohol or drug abuse, or secondary malignancy, that may interfere with study participation in the opinion of the investigator or medical monitor;
• Has a current or previously treated brain metastasis or leptomeningeal disease;
• Has a history of seizure or any condition that may predispose to seizure (eg, prior cortical stroke or significant brain trauma);
• Has a history of loss of consciousness or transient ischemic attack within 12 months of open label day 1;
• Has taken cytotoxic chemotherapy or investigational therapy within 4 weeks before enrollment (open label day 1).

Sex/Gender

• Sexes Eligible for Study: Male
• Gender Based Eligibility: Yes

• Ages: 18 Years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Contacts: Contact information is only displayed when the study is recruiting subjects
• Listed Location Countries: United States

Administrative Information

• NCT Number: NCT01664923
• Other Study ID Numbers: MDV3100-09; C3431014 ( Other Identifier: Alias Study Number )
• Has Data Monitoring Committee: Not Provided
• U.S. FDA-regulated Product: Not Provided

IPD Sharing Statement

• Plan to Share IPD: Yes
• Plan Description: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.
• URL: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests

• Current Responsible Party: Pfizer
• Original Responsible Party: Medivation, Inc.
• Current Study Sponsor: Pfizer
• Original Study Sponsor: Medivation, Inc.

Collaborators

• Astellas Pharma Inc
• Medivation LLC, a wholly owned subsidiary of Pfizer Inc.

Investigators

• Study Director: Pfizer Pfizer CT.gov Call Center; Pfizer

• PRS Account: Pfizer
• Verification Date: January 2019