Study of Abiraterone Acetate in Participants With Metastatic Castration-Resistant Prostate Cancer (mCRPC), Chemo-Naive, Who Received a Prior Diethylstilbestrol Therapy

Phase 2

Completed

Conditions: Prostatic Neoplasms

Interventions: Drug: Abiraterone acetate
Drug: Prednisone
Drug: Androgen deprivation therapy (ADT)

Registration Number: NCT02217566

Lead Sponsor: Janssen Research & Development, LLC

Brief Summary: The purpose of this study is to evaluate the efficacy, based on prostate-specific antigen (PSA) progression, of abiraterone acetate in participants with metastatic (spread of cancer cells from one part of the body to another) castration (any action, surgical, chemical, or otherwise, by which a male loses the functions of the testes) resistant prostate cancer (cancer in prostrate; a gland that makes fluid that aids movement of sperm) (mCRPC), chemo-naive (treatment of cancer is not done using drugs), who received a prior diethylstilbestrol therapy (DES).

Detailed Description: This is a Phase 2, multinational (when medical research study takes place in more than one country), multicenter (when more than one hospital or medical school team work on a medical research study), open-label (all people know the identity of the intervention), and single arm study to determine benefits of abiraterone acetate and low-dose prednisone to androgen deprivation therapy (ADT) in mCRPC participants who failed to prior DES therapy. The study will consist of a Screening Phase of up to 28 days before enrollment; a PSA Evaluation Phase; and a Follow-up Phase of up to 24 months. Each cycle of abiraterone therapy will be of 28 days. Participants will receive 1000 milligram (mg) abiraterone acetate orally once daily plus prednisone 5 mg orally once daily plus stable regimen of ADT (luteinizing hormone-releasing hormone \[LHRH\] agonists) as per Investigator's discretion. Treatment will continue until PSA progression, clinical progression, consent withdrawal, or the occurrence of unacceptable toxicity. Efficacy will primarily be assessed by time to PSA progression. Participants' safety will be monitored throughout the study.

Recruitment & Eligibility

Status: COMPLETED

Sex: Male

Target Recruitment: 46

Inclusion Criteria

Histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small cell histology
Prior therapy with diethylstilbestrol (DES) for castration resistant prostate cancer. Participants should demonstrate evidence of progression on DES or evidence of grades 3/4 toxicities on DES
Metastatic disease documented by positive bone scan or metastatic lesions on computerized tomography (CT) or magnetic resonance imaging (MRI)
May have received prior androgen blockage (bicalutamide or flutamide) but must have been discontinued for least 28 days
Ongoing androgen deprivation therapy (ADT) (luteinizing hormone-releasing hormone [LHRH] agonist or orchiectomy), with serum testosterone level of less than 50 nanogram per deciliter (1.7 nanomole per liter) and eligible participants must maintain ADT

Exclusion Criteria

Active infection or other medical condition that would make prednisone use contraindicated
Any chronic medical condition requiring a higher systemic dose of corticosteroid than 5 milligram (mg) prednisone per day
Pathological finding consistent with small cell carcinoma of the prostate
Known brain metastasis
Has had prior cytotoxic chemotherapy or biologic therapy for the treatment of metastatic castration-resistant prostate cancer (mCRPC)

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Abiraterone Acetate	Androgen deprivation therapy (ADT)	Participants will receive abiraterone acetate 1000 milligram (mg) orally once daily along with prednisone 5 mg orally once daily and androgen deprivation therapy (ADT) as per Investigator's discretion until prostate-specific Antigen (PSA) progression, clinical progression, consent withdrawal, or the occurrence of unacceptable toxicity.
Abiraterone Acetate	Abiraterone acetate	Participants will receive abiraterone acetate 1000 milligram (mg) orally once daily along with prednisone 5 mg orally once daily and androgen deprivation therapy (ADT) as per Investigator's discretion until prostate-specific Antigen (PSA) progression, clinical progression, consent withdrawal, or the occurrence of unacceptable toxicity.
Abiraterone Acetate	Prednisone	Participants will receive abiraterone acetate 1000 milligram (mg) orally once daily along with prednisone 5 mg orally once daily and androgen deprivation therapy (ADT) as per Investigator's discretion until prostate-specific Antigen (PSA) progression, clinical progression, consent withdrawal, or the occurrence of unacceptable toxicity.

Primary Outcome Measures

Name	Time	Method
Time to Prostate-specific Antigen (PSA) Progression	Up to 2 years	Time to PSA progression was calculated from date of enrollment to the date of first documentation of PSA progression. As per Prostate Cancer Clinical Trials Working Group (PCWG2) criteria, PSA progression was defined as greater than or equal to (\>=) 25 percent (%) and \>=2 nanogram/milliliter (ng/mL) after 12 weeks (in case of no decline in PSA from Baseline), or first PSA increase that is \>=25% and \>=2 ng/mL above the nadir, and which was confirmed by a second value 3 or more weeks later (in case of decline of PSA from Baseline).

Secondary Outcome Measures

Name	Time	Method
Percentage of Participants With Pain Progression as Assessed by Brief Pain Inventory - Short Form (BPI-SF) - Pain Severity Score	Up to 2 years	The BPI-SF is a publicly available instrument to assess the pain and includes severity and interference scores. BPI-SF is an 11-item self-report questionnaire that is designed to assess the severity and impact of pain on daily functions of a participant. Pain severity score is a mean value for BPI-SF questions 3, 4, 5 and 6 (questions inquiring about the extent of pain, where the extent is ranked from 0 \[no pain\] to 10 \[pain as bad as you can imagine\]). Pain severity progression was defined as an increase in score of 30% or greater from baseline without decrease in analgesic use.
Percentage of Participants Who Achieved Prostate-Specific Antigen (PSA) Response	Week 12 to any time up to 2 years	The PSA response according to Prostate Specific Antigen Working Group 3 criteria was defined as at least 50% decrease in PSA level from Baseline.
Overall Survival	Up to 4 years	Overall survival was defined as the time from date of the first dose of abiraterone acetate to the date of death due to any cause. For participants who did not die until the time of analysis, survival time was censored at the time of last contact alive.
Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs)	Up to 4 years	An AE is any untoward medical occurrence in a participant who will receive study drug without regard to possibility of causal relationship. An SAE is 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; or congenital anomaly.
Percentage of Participants With Pain Progression as Assessed by Brief Pain Inventory - Short Form (BPI-SF) - Pain Interference Score	Up to 2 years	The BPI-SF is a publicly available instrument to assess the pain and includes severity and interference scores. BPI-SF is an 11-item self-report questionnaire that is designed to assess the severity and impact of pain on daily functions of a participant. Pain interference score is mean value for the 7 BPI-SF questions (questions inquiring about the extent of interference with activities by pain) where the extent is ranked from 0 (does not interfere) to 10 (completely interferes). Pain interference progression was defined as an increase in score of 50% or greater from baseline without decrease in analgesic use.