The purpose of this study is to evaluate the safety, pharmacokinetics, pharmacodynamics, and anti-tumor activities of abiraterone acetate (also referred to as CB7630) in patients with hormone refractory prostate cancer (HRPC).
This is an open-label (identity of assigned study drug will be known) study to evaluate the safety, pharmacokinetics (study of what the body does to a drug), pharmacodynamics (study of what a drug does to the body), and anti-tumor activities of abiraterone acetate (also known as CB7630) in patients with HRPC. The study will be conducted in 2 phases (Phase 1 and Phase 2). In the first part of the study (Phase 1), the maximum tolerated dose (MTD) of abiraterone acetate will be determined for use in the second part of the study (Phase 2) where the number of patients who achieve at least a 50% decrease in prostate specific antigen (PSA) during treatment with abiraterone acetate will be assessed (MTD from Phase 1). Abiraterone acetate will be taken orally (by mouth) in fed and fasted patients once daily. Doses of abiraterone acetate (starting at 250 mg up to a maximum of 2000 mg) will be taken for 28-day treatment periods to determine the MTD. Patients will take MTD of abiraterone acetate for up to twelve 28 day cycles (12 months; patients will be given the option of staying on abiraterone acetate treatment if they are deriving benefit). In Phase 2, prednisone or dexamethasone will be administered concurrently with abiraterone acetate. Serial pharmacokinetic and pharmacodynamic samples will be collected and safety will be monitored throughout the study.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
66
The first cohort was a abiraterone acetate 250 mg/day orally (by mouth), once daily for 28-day treatment periods , if no dose limiting toxicity (DLT) was documented at this dose, the dose will be escalated to next dose levels 500, 750, and 1000 mg/day. The dose escalation will continue to a maximum of 1000mg/day until Maximum Tolerated Dose (MTD) and a recommended Phase II dose was established.
Abiraterone acetate 1000 mg daily under fasted conditions upto 10 cycles of therapy.
prednisone/prednisolone (5 mg twice daily) or dexamethasone (0.5 mg once daily) concurrent with abiraterone acetate
Unnamed facility
San Francisco, California, United States
Unnamed facility
Boston, Massachusetts, United States
Unnamed facility
Houston, Texas, United States
Phase 1: Maximum Tolerated Dose (MTD) of Abiraterone Acetate
The MTD is the highest dose of a drug or treatment that does not cause unacceptable side effects.
Time frame: Up to Cycle 12
Phase 2: Participants With Greater Than or Equal to 50 Percent Decline in Prostate Specific Antigen (PSA)
Number of participants with greater than or equal to 50 percent decrease in PSA levels were assessed. PSA decline was evaluated according to (Prostate Specific Antigen Working Group) PSAWG criteria. Decrease in PSA levels represented improvement.
Time frame: Up to 12 weeks from start of treatment
Phase 1: Maximum Plasma Concentration (Cmax) of Abiraterone Acetate
Blood samples for pharmacokinetic (PK) measurements was taken on Day -7 at hour 0 (predose), at hours 1, 2, 4, 6, 8, and 12 (postdose). On Day -6 at 24 hour (postdose) and Day -5 at 48 hour (postdose). On Days 1, 8, 15, 22 of Cycle 1 and Day 1 of Cycles 2 and 3 (Predose).
Time frame: At hours 1, 2, 4, 6, 8, 12, 24 and 48 post dose and pre-dose on day 1, day 8, day 15 and day 22 cycle 1, day 1 cycle 2 and day 1 cycle 3.
Phase 1: Time to Reach the Maximum Plasma Concentration (Tmax) of Abiraterone Acetate
Blood samples for pharmacokinetic (PK) measurements was taken on Day -7 at hour 0 (predose), at hours 1, 2, 4, 6, 8, and 12 (postdose). On Day -6 at 24 hour (postdose) and Day -5 at 48 hour (postdose). On Days 1, 8, 15, 22 of Cycle 1 and Day 1 of Cycles 2 and 3 (Predose)
Time frame: At hours 1, 2, 4, 6, 8, 12, 24 and 48 post dose and pre-dose on day 1, day 8, day 15 and day 22 cycle 1, day 1 cycle 2 and day 1 cycle 3
Phase 1: Area Under the Plasma-Concentration-Time Curve From Time 0 to the Last Quantifiable Concentration (AUClast) of Abiraterone Acetate
Blood samples for pharmacokinetic (PK) measurements was taken on Day -7 at hour 0 (predose), at hours 1, 2, 4, 6, 8, and 12 (postdose). On Day -6 at 24 hour (postdose) and Day -5 at 48 hour (postdose). On Days 1, 8, 15, 22 of Cycle 1 and Day 1 of Cycles 2 and 3 (Predose).
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Time frame: At hours 1, 2, 4, 6, 8, 12, 24 and 48 post dose and pre-dose on day 1, day 8, day 15 and day 22 cycle 1, day 1 cycle 2 and day 1 cycle 3
Phase 1: Area Under the Plasma-Concentration-time Curve From Time 0 to Infinite Time (AUCINF_obs) of Abiraterone Acetate
Blood samples for pharmacokinetic (PK) measurements was taken on Day -7 at hour 0 (predose), at hours 1, 2, 4, 6, 8, and 12 (postdose). On Day -6 at 24 hour (postdose) and Day -5 at 48 hour (postdose). On Days 1, 8, 15, 22 of Cycle 1 and Day 1 of Cycles 2 and 3 (Predose).
Time frame: At hours 1, 2, 4, 6, 8, 12, 24 and 48 post dose and pre-dose on day 1, day 8, day 15 and day 22 cycle 1, day 1 cycle 2 and day 1 cycle 3
Phase 1: Terminal Half-life (HL_Lambda_z) of Abiraterone Acetate
Blood samples for pharmacokinetic (PK) measurements was taken on Day -7 at hour 0 (predose), at hours 1, 2, 4, 6, 8, and 12 (postdose). On Day -6 at 24 hour (postdose) and Day -5 at 48 hour (postdose). On Days 1, 8, 15, 22 of Cycle 1 and Day 1 of Cycles 2 and 3 (Predose).
Time frame: At hours 1, 2, 4, 6, 8, 12, 24 and 48 post dose and pre-dose on day 1, day 8, day 15 and day 22 cycle 1, day 1 cycle 2 and day 1 cycle 3
Phase 1: Total Body Clearance (Cl_F_obs) of Abiraterone Acetate
Blood samples for pharmacokinetic (PK) measurements was taken on Day -7 at hour 0 (predose), at hours 1, 2, 4, 6, 8, and 12 (postdose). On Day -6 at 24 hour (postdose) and Day -5 at 48 hour (postdose). On Days 1, 8, 15, 22 of Cycle 1 and Day 1 of Cycles 2 and 3 (Predose).
Time frame: At hours 1, 2, 4, 6, 8, 12, 24 and 48 post dose and pre-dose on day 1, day 8, day 15 and day 22 cycle 1, day 1 cycle 2 and day 1 cycle 3
Phase 1: Volume of Distribution (Vz_F_obs) of Abiraterone Acetate
Volume of distribution is defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired blood concentration of a drug. Volume of distribution is normally calculated by using equation volume of distribution =dose/initial concentration. Blood samples for pharmacokinetic (PK) measurements was taken on Day -7 at hour 0 (predose), at hours 1, 2, 4, 6, 8, and 12 (postdose). On Day -6 at 24 hour (postdose) and Day -5 at 48 hour (postdose). On Days 1, 8, 15, 22 of Cycle 1 and Day 1 of Cycles 2 and 3 (Predose).
Time frame: At hours 1, 2, 4, 6, 8, 12, 24 and 48 post dose and pre-dose on day 1, day 8, day 15 and day 22 cycle 1, day 1 cycle 2 and day 1 cycle 3
Phase 2: Radiographic Progression Free Survival (RAD-PFS)
RAD-PFS is the time interval from the date of first dose of abiraterone acetate therapy to the date of death or radiographic disease progression according to the RECIST (Response Evaluation Criteria In Solid Tumors) criteria. Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.0) for target lesions and assessed by MRI: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Overall Response (OR) = CR + PR.
Time frame: Up to 12 weeks from start of treatment
Phase 2: PSA Progression Free Survival (PSA-PFS)
PSA-PFS is the time interval from the date of first dose of abiraterone acetate therapy to the date of death or the PSA progression as defined by the Prostate Specific Antigen Working Group (PSAWG) criteria.
Time frame: Up to 12 weeks from start of treatment
Phase 2: Radiographic Objective Response Rate (RAD-ORR)
The objective response rate is defined as the proportion of participants with measurable lesions achieving a Complete Response (CR) or Partial Response (PR) based on Response Evaluation Criteria In Solid Tumors (RECIST) criteria. Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.0) for target lesions and assessed by MRI: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Overall Response (OR) = CR + PR.
Time frame: Up to 12 weeks from start of treatment
Phase 2: Time to PSA Progression
The time interval from the date of first dose of abiraterone acetate therapy to the date of the PSA progression as defined by the PSAWG criteria.
Time frame: Up to 12 weeks from start of treatment
Phase 2: Duration of PSA Response
Duration of PSA response was defined as the duration between the date of confirmed PSA response and subsequent PSA progression date as defined by the PSAWG criteria.
Time frame: Up to 12 weeks from start of treatment
Phase 2: Participants With Change in Eastern Cooperative Oncology Group (ECOG) Performance Status Score
ECOG performance status score ranges from 0 to 5 where 0=fully active, perform all pre-disease activities without restriction. 1=restricted in physically strenuous activity but ambulatory, carry out work of a light or sedentary nature. 2=ambulatory, capable of self-care, unable to carry out any work activities, up and about more than (\>) 50% of waking hours. 3=capable of limited self-care, confined to bed or chair \>50% of waking hours. 4=completely disabled, not capable of any self-care, totally confined to bed or chair. 5=dead.
Time frame: Up to 12 weeks from start of treatment
Phase 2: Overall Survival
Overall survival is the time interval from the date of first dose (cycle 1 day 1) of abiraterone acetate therapy to the date of death from any cause.
Time frame: Up to Month 60
Phase 2: Duration of Objective Response
Duration of objective response was assessed only in participants who achieved a CR or PR, and measured from the first documented date of response to the first documented date of disease progression according to the RECIST criteria. Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.0) for target lesions and assessed by MRI: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Overall Response (OR) = CR + PR.
Time frame: Up to 12 weeks from start of treatment