A Study to Evaluate Serum Testosterone Levels in Patients With Metastatic Castration-Resistant Prostate Cancer

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the serum testosterone levels in patients with Metastatic Castration-Resistant Prostate Cancer on SoluMatrix™ Abiraterone Acetate as Compared to Abiraterone Acetate

Detailed Description
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This was a 12-week, open-label study of abiraterone acetate in at least 50 patients with metastatic castration-resistant prostate cancer.

Official Title
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A Randomized, Open-Label, Active-Controlled, Multi-Center Study to Evaluate Serum Testosterone Levels in Patients With Metastatic Castration-Resistant Prostate Cancer: The STAAR STUDY

Conditions
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Prostate Cancer

Intervention / Treatment
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* Drug: Zytiga® (Abiraterone Acetate)
* Drug: SoluMatrix™ (Abiraterone Acetate)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent obtained prior to any study-related procedure being performed Male subjects at least 18 years of age or older at time of consent Pathologically confirmed adenocarcinoma of the prostate Ongoing therapy with a GnRH agonist or antagonist AND serum testosterone level <50 ng/dL at screening Metastatic disease documented by computed tomography (CT)/ magnetic resonance imaging (MRI) or bone scan. Imaging obtained within 42 days prior to the start of study medication will be accepted. Meeting disease progression according to the recommendations of the prostate cancer working group 2 by one of the following criteria: Two rises of PSA (taken a minimum of 1 week apart) from a baseline measurement of at least 2 ng/mL, Imaging progression (CT/MRI) by RECIST criteria Nuclear scan progression by new lesion. Discontinuation of flutamide or nilutamide, and other anti-androgens at least 4 weeks prior to the start of study medication; discontinuation of bicalutamide at least 6 weeks prior to start of study medication. Discontinuation of Radiotherapy > 4 weeks prior to start of study medication. ECOG performance status of 0-1 at screening Screening blood counts of the following: Absolute neutrophil count > 1500/µL Platelets > 100,000/µL Hemoglobin > 9 g/dL Screening chemistry values of the following: ALT and AST < 2.5 x ULN Total bilirubin < 1.5 x ULN Creatinine< 1.5 x ULN Albumin > 3.0 g/dL Potassium > 3.5 mmol/L Life expectancy of at least 6 months at screening Subject is willing and able to comply with all protocol requirements assessments Agrees to protocol-defined use of effective contraception. Exclusion Criteria: History of impaired pituitary or adrenal gland function Prior therapy with abiraterone acetate, orteronel, ketoconazole or any other CYP17 inhibitor Prior therapy with enzalutamide Prior use of experimental androgen receptor antagonist Previous exposure to Ra-223:Xofigo Previous chemotherapy Initiation of bisphosphonate or denosumab therapy within 30 days prior to the start of study medication. Patients who are on a stable dose of these medications for at least 30 days at the time of starting study drug are eligible. Therapy with estrogen within 30 days prior to the start of study medication Use of systemic glucocorticoids equivalent to > 10 mg of prednisone daily; patients who have discontinued or have reduced dose to < 10 mg prednisone within 14 days prior to the start of study medication will be eligible Prior use of any herbal products that may decrease PSA levels (eg., saw palmetto) within 30 days of start of study medication Known metastases to the brain or CNS involvement History of other malignancy within the previous 2 years Major surgery within 30 days prior to the start of study medication Blood transfusion within 30 days of screening Serious, persistent infection within 14 days of the start of study medication Persistent pain that requires the use of a narcotic analgesic Known gastrointestinal disease or condition that may impair absorption Treatment with any investigational drug within 4 weeks prior to Day -1 of the study. Known history of human immunodeficiency virus (HIV) or seropositive test for hepatitis C virus or hepatitis B virus Have poorly controlled diabetes. Uncontrolled hypertension History of New York Heart Association (NYHA) class III or IV heart failure Serious concurrent illness, including psychiatric illness, that would interfere with study participation Inability to swallow tablets whole Known hypersensitivity to any excipients in study medications Moderate to severe hepatic impairment (Child-Pugh Classes B and C)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Zytiga® (Abiraterone Acetate)<br>1,000 MG (4 x 250 mg qd) | Drug: Zytiga® (Abiraterone Acetate)<br>* Zytiga® 1,000 mg (4 x 250 mg qd) tablets plus one 5 mg prednisone tablet to be taken bid, spaced approximately 12 hours apart<br>* Other names: Zytiga®;|
| Experimental: SoluMatrix™ (Abiraterone Acetate)<br>500 mg (4 x 125 mg qd) | Drug: SoluMatrix™ (Abiraterone Acetate)<br>* SoluMatrix™ 500 mg (4 x 125 mg qd) tablets plus one 4 mg methylprednisolone tablet bid, spaced approximately 12 hours apart<br>* Other names: SoluMatrix™;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Testosterone Levels | Blood Sample tested for Serum Testosterone Levels | Average of Day 9 and 10 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PSA Levels | All patients randomized to one of the two treatment groups, round about level of PSA. These were assessed only at the said Outcome Measure Time Frame. No additional time points to the said endpoint | Day 28, Day 56, and Day 84 | 
| Percent of Subjects With PSA-50 Response | Proportion of patients with complete suppression of PSA-50 were reported by treatment and compared for between-group differences. These were assessed only at the said Outcome Measure Time Frame. No additional time points to the said endpoint. | Day 28, Day 56, and Day 84 | 
| Serum Testosterone Levels | These were assessed only at the said Outcome Measure Time Frame. No additional time points to the said endpoint. | Day 28, Day 56, and Day 84 | 
| Steady State Trough Concentration of Arbiraterone | These were assessed only at the said Outcome Measure Time Frame. No additional time points to the said endpoint. | Day 09, Day 28, Day 56, and Day 84 | 
| AUC (0-inf) | Steady state systemic exposure parameters | 60 to 30 minutes prior to dosing and over 24 Hours post-dose | 
| AUC (0-24 hr) | Blood samples for pre-dose PK profiling were to be collected approximately 45 minutes before dosing, i.e., within 60 to 30 minutes prior to dosing. Post-dose blood samples were to be collected throughout the day at the times (15 mins, 30 mins, 1 hr, 1.5 hr, 2.0 hr 3 hr, 4 hr, 6 hr, 8 hr, 9 hr, 24 hr). | 60 to 30 minutes prior to dosing and over 24 Hours post-dose | 
| AUC (0-t) | Blood samples for pre-dose PK profiling were to be collected approximately 45 minutes before dosing, i.e., within 60 to 30 minutes prior to dosing. Post-dose blood samples were to be collected throughout the day at the times (15 mins, 30 mins, 1 hr, 1.5 hr, 2.0 hr 3 hr, 4 hr, 6 hr, 8 hr, 9 hr, 24 hr). | 60 to 30 minutes prior to dosing and over 24 Hours post-dose | 
| Cmax | Blood samples for pre-dose PK profiling were to be collected approximately 45 minutes before dosing, i.e., within 60 to 30 minutes prior to dosing. Post-dose blood samples were to be collected throughout the day at the times (15 mins, 30 mins, 1 hr, 1.5 hr, 2.0 hr 3 hr, 4 hr, 6 hr, 8 hr, 9 hr, 24 hr). | 60 to 30 minutes prior to dosing and over 24 Hours post-dose |