Title

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

    Phase 2
  • Study Type

    Interventional
  • Intervention/Treatment

    abiraterone ...
  • Study Participants

    53
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
This was a 12-week, open-label study of abiraterone acetate in at least 50 patients with metastatic castration-resistant prostate cancer.
Study Started
Mar 21
2016
Primary Completion
Feb 27
2017
Study Completion
Feb 27
2017
Results Posted
Aug 12
2020
Last Update
Nov 22
2021

Drug Zytiga® (Abiraterone Acetate)

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

  • Other names: Zytiga®

Drug SoluMatrix™ (Abiraterone Acetate)

SoluMatrix™ 500 mg (4 x 125 mg qd) tablets plus one 4 mg methylprednisolone tablet bid, spaced approximately 12 hours apart

  • Other names: SoluMatrix™

Zytiga® (Abiraterone Acetate) Active Comparator

1,000 MG (4 x 250 mg qd)

SoluMatrix™ (Abiraterone Acetate) Experimental

500 mg (4 x 125 mg qd)

Criteria

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)

Summary

Zytiga® (Abiraterone Acetate)

SoluMatrix™ (Abiraterone Acetate)

All Events

Event Type Organ System Event Term Zytiga® (Abiraterone Acetate) SoluMatrix™ (Abiraterone Acetate)

Testosterone Levels

Blood Sample tested for Serum Testosterone Levels

Zytiga® (Abiraterone Acetate)

1.02
ng/dL (Mean)
Standard Error: 0.03

SoluMatrix™ (Abiraterone Acetate)

1.05
ng/dL (Mean)
Standard Error: 0.04

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

Zytiga® (Abiraterone Acetate)

Day 28

37.5
ng/mL (Least Squares Mean)
Standard Error: 11.33

Day 56

40.84
ng/mL (Least Squares Mean)
Standard Error: 12.58

Day 84

33.88
ng/mL (Least Squares Mean)
Standard Error: 13.43

SoluMatrix™ (Abiraterone Acetate)

Day 28

22.37
ng/mL (Least Squares Mean)
Standard Error: 12.02

Day 56

25.29
ng/mL (Least Squares Mean)
Standard Error: 13.68

Day 84

26.46
ng/mL (Least Squares Mean)
Standard Error: 15.41

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.

Zytiga® (Abiraterone Acetate)

Day 28

70.4
percentage of Participants

Day 56

65.4
percentage of Participants

Day 84

72.0
percentage of Participants

SoluMatrix™ (Abiraterone Acetate)

Day 28

66.7
percentage of Participants

Day 56

63.6
percentage of Participants

Day 84

68.4
percentage of Participants

Serum Testosterone Levels

These were assessed only at the said Outcome Measure Time Frame. No additional time points to the said endpoint.

Zytiga® (Abiraterone Acetate)

Day 28

1.01
ng/dL (Mean)
Standard Error: 0.01

Day 56

1.01
ng/dL (Mean)
Standard Error: 1.03

Day 84

1.0
ng/dL (Mean)
Standard Error: 0

SoluMatrix™ (Abiraterone Acetate)

Day 28

1.01
ng/dL (Mean)
Standard Error: 0.01

Day 56

2.56
ng/dL (Mean)
Standard Error: 1.07

Day 84

1.0
ng/dL (Mean)
Standard Error: 0

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.

Zytiga® (Abiraterone Acetate)

Day 09

20.938
ng/dL (Least Squares Mean)
Standard Error: 7.044

Day 28

56.721
ng/dL (Least Squares Mean)
Standard Error: 23.104

Day 56

29.978
ng/dL (Least Squares Mean)
Standard Error: 8.117

Day 84

18.263
ng/dL (Least Squares Mean)
Standard Error: 3.087

SoluMatrix™ (Abiraterone Acetate)

Day 09

27.259
ng/dL (Least Squares Mean)
Standard Error: 7.772

Day 28

18.662
ng/dL (Least Squares Mean)
Standard Error: 24.18

Day 56

18.707
ng/dL (Least Squares Mean)
Standard Error: 9.175

Day 84

13.819
ng/dL (Least Squares Mean)
Standard Error: 3.381

AUC (0-inf)

Steady state systemic exposure parameters

Zytiga® (Abiraterone Acetate)

1020.218
ng*hr/mL (Least Squares Mean)
Standard Error: 154.549

SoluMatrix™ (Abiraterone Acetate)

326.458
ng*hr/mL (Least Squares Mean)
Standard Error: 218.565

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).

Zytiga® (Abiraterone Acetate)

870.859
ng*hr/mL (Least Squares Mean)
Standard Error: 221.709

SoluMatrix™ (Abiraterone Acetate)

626.066
ng*hr/mL (Least Squares Mean)
Standard Error: 280.443

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).

Zytiga® (Abiraterone Acetate)

870.859
ng*hr/mL (Least Squares Mean)
Standard Error: 221.709

SoluMatrix™ (Abiraterone Acetate)

626.066
ng*hr/mL (Least Squares Mean)
Standard Error: 280.443

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).

Zytiga® (Abiraterone Acetate)

268.261
ng/mL (Least Squares Mean)
Standard Error: 69.967

SoluMatrix™ (Abiraterone Acetate)

111.316
ng/mL (Least Squares Mean)
Standard Error: 88.503

Total

53
Participants

Age, Continuous

75.1
years (Mean)
Standard Deviation: 9.3

Ethnicity (NIH/OMB)

Race (NIH/OMB)

Region of Enrollment

Sex: Female, Male

Overall Study

Zytiga® (Abiraterone Acetate)

SoluMatrix™ (Abiraterone Acetate)