This phase I/II trial studies the side effects and best dose of cabazitaxel when given together with enzalutamide in treating patients with prostate cancer that has spread to other places in the body (metastatic) and has not responded to treatment with hormones or no longer responds to treatment with hormones (hormone-resistant). Drugs used in chemotherapy, such as cabazitaxel, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Androgen can cause the growth of prostate cancer cells. Hormone therapy using enzalutamide may fight prostate cancer by blocking the use of androgen by the tumor cells. Giving cabazitaxel together with enzalutamide may work better in treating metastatic, hormone-resistant prostate cancer.
PRIMARY OBJECTIVES: I. To determine the safety and tolerability of combination treatment with enzalutamide and cabazitaxel (as determined by percent dose limiting toxicities \[DLT\], where DLT \< 17% is consistent with it being a tolerable combination). II. To determine the efficacy of treatment with the hormonal agent enzalutamide and the chemotherapy cabazitaxel in combination in men with metastatic castration-resistant prostate cancer (CRPC) (as determined by percent of patients achieving \>= 90% prostate specific antigen \[PSA\] declines following initiation of treatment). SECONDARY OBJECTIVES: I. To further define the anticancer effect and safety profile of the combination of enzalutamide and cabazitaxel. Ia. Collect toxicity data (description of adverse events). Ib. Determine PSA response (percent of patients who achieve \>= 50% PSA decline and \>= 30% PSA decline). Ic. Examine pharmacokinetic (PK) data of cabazitaxel to characterize enzalutamide and cabazitaxel pharmacokinetic blood levels. Id. Determine tumor response by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 for measurable disease and Prostate Cancer Working Group 2 criteria for non-measurable (bone) disease. Ie. Determine overall survival. EXPLORATORY OBJECTIVES: I. To determine baseline (and at progression) biological tumor characteristics to evaluate for possible biomarkers indicative or predictive of response: apoptosis by cleaved caspase 3; androgen signaling axis (including but not limited to: androgen receptor expression, androgen receptor splice variants, and intratumoral androgen levels), and glucocorticoid receptor. II. To collect circulating tumor cells (CTCs) and determine the degree to which tumor characteristics (delineated above) are shared by the CTCs. III. To collect plasma and serum pre-treatment and at progression for assessment of circulating micro-ribonucleic acid (RNA)s and other circulating markers. IV. To collect buffy coat to evaluate for steroid transporters. OUTLINE: This is a dose de-escalation study of cabazitaxel. Patients receive cabazitaxel intravenously (IV) over 1 hour on day 1 and enzalutamide orally (PO) once daily (QD) on days 1-21 (days 2-21 of cycle 1). Patients also receive prednisone PO twice daily (BID) as standard of care with cabazitaxel. Cycles repeat every 21 days for 6-10 cycles in the absence of disease progression or unacceptable toxicity. Patients may continue enzalutamide PO QD on days 1-28 in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 28 days and then every 6 months for up to 5 years.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
37
Given IV
Given PO
Correlative studies
Correlative studies
Given PO
OHSU Knight Cancer Institute
Portland, Oregon, United States
Portland VA Medical Center
Portland, Oregon, United States
Seattle Cancer Care Alliance
Seattle, Washington, United States
Percentage of Participants With Dose Limiting ToxicitiesGgraded by National Cancer Institute Common Terminology Criteria for Adverse Events, Version 4.0 (Phase I)
The percentage of participants will be reported with 95% confidence interval using exact method.
Time frame: Up to 42 days
PSA Response 1, Defined as >= 90% PSA Decline From Baseline
The percentage of participants with a \>= 90% PSA decline from baseline will be reported with 95% confidence interval using exact method. 'PSA response' is based on Prostate Cancer Working Group 2's (PCWG2) recommendations, which do not offer a specific definition as no single degree of decline has been established.
Time frame: Baseline to time of >= 90% PSA decline, assessed up to 68 weeks
Incidence of Adverse Events Graded by National Cancer Institute Common Terminology Criteria for Adverse Events, Version 4.0
Descriptive statistical analysis will be conducted. The proportion estimate will be reported with 95% confidence interval using exact method.
Time frame: Up to 28 days after the last dose of study medication
Overall Survival
Descriptive statistical analysis will be conducted. The median overall survival will be estimated with 95% confidence interval (if available). Kaplan-Meier plot will be used to graphically illustrate the overall survival distribution.
Time frame: Up to 5 years
Pharmacokinetic Parameters of Cabazitaxel: Max Plasma Concentration (Cmax)
Mean plasma concentration (Cmax) will be plotted over time for cabazitaxel (day 1, cycle 1) and cabazitaxel co-administered with enzalutamide (day 1, cycle 2). Noncompartmental pharmacokinetic analysis will be performed on individual concentration-time data to calculate maximum concentration from 0 hours to last measurable concentration and to infinity, and half-life, for cabazitaxel administered alone or coadministered with enzalutamide.
Time frame: Day 1 at 0.5, 1, 1.5, 2, 4, 8, and 24 hours after the start of cabazitaxel infusion of cycles 1 and 2 (each cycle is 21 days)
Pharmacokinetic Parameters of Cabazitaxel: Mean Area Under the Curve (AUC)
Mean area under the curve (AUC) will be plotted over time for cabazitaxel (day 1, cycle 1) and cabazitaxel co-administered with enzalutamide (day1, cycle 2). Noncompartmental pharmacokinetic analysis will be performed on individual concentration-time data to calculate AUC from 0 hours to last measurable concentration for cabazitaxel administered alone or coadministered with enzalutamide.
Time frame: Day 1 at 0.5, 1, 1.5, 2, 4, 8, and 24 hours after the start of cabazitaxel infusion of cycles 1 and 2 (each cycle is 21 days)
Pharmacokinetic Parameters of Cabazitaxel: Mean Cabazitaxel Half-Life
Mean cabazitaxel half-life will be plotted over time for cabazitaxel (day 1, cycle 1) and cabazitaxel co-administered with enzalutamide (day1, cycle 2). Noncompartmental pharmacokinetic analysis will be performed on individual concentration-time data to calculate half-life from 0 hours to last measurable concentration for cabazitaxel administered alone or coadministered with enzalutamide.
Time frame: Day 1 at 0.5, 1, 1.5, 2, 4, 8, and 24 hours after the start of cabazitaxel infusion of cycles 1 and 2 (each cycle is 21 days)
PSA Response 2, Defined as >= 50% PSA Decline From Baseline
The percentage of participants with a \>= 50% PSA decline from baseline will be reported with 95% confidence interval using exact method. 'PSA response' is based on Prostate Cancer Working Group 2's (PCWG2) recommendations, which do not offer a specific definition as no single degree of decline has been established.
Time frame: Baseline to time of >= 50% PSA decline, assessed up to 68 weeks
PSA Response 3, Defined as >= 30% PSA Decline From Baseline
The percentage of participants with a \>= 30% PSA decline from baseline will be reported with 95% confidence interval using exact method. 'PSA response' is based on Prostate Cancer Working Group 2's (PCWG2) recommendations, which do not offer a specific definition as no single degree of decline has been established.
Time frame: Baseline to time of >= 30% PSA decline, assessed up to 68 weeks
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