A Positron Emission Tomography/Computed Tomography (PET/CT) Bone Imaging Study in Patients Receiving Enzalutamide for Castration-Resistant Prostate Cancer (CRPC)

Phase 2

Completed

Conditions: Prostate Carcinoma Metastatic to the Bone
Castration Resistant Prostate Cancer

Brief Summary: The purpose of this study is to evaluate 18F-sodium fluoride positron-emission tomography / computed tomography (18F-NaF PET/CT) imaging as a method for determining treatment response in metastatic bone lesions in patients who are receiving enzalutamide for castration-resistant prostate cancer.

Recruitment & Eligibility

Inclusion Criteria

Histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation, or signet cell or small cell features;
Presence of bone metastatic disease as assessed by at least two lesions on whole body metastable technetium-methylene diphosphonate (99mTc-MDP) bone scintigraphy;
Throughout the study, ongoing androgen deprivation therapy with a luteinizing hormone-releasing hormone (LHRH) analogue or prior bilateral orchiectomy (medical or surgical castration);
Testosterone ≤ 1.73 nmol/L (≤ 50 ng/dL) at screening;
Progressive disease on androgen deprivation therapy at screening defined as a minimum of two sequentially rising prostate-specific antigen (PSA) values (PSA1 < PSA2 < PSA3);
The screening PSA (PSA3) must be ≥ 2 μg/L (≥ 2 ng/mL).

Exclusion Criteria

Prior enzalutamide, abiraterone acetate, aminoglutethimide, ketoconazole, radium Ra 223 dichloride or other bone-targeting radionuclides, or cytotoxic chemotherapy in the CRPC setting for the treatment of prostate cancer or participation in a clinical trial of an investigational agent that inhibits the androgen receptor or androgen synthesis (unless treatment was placebo);
Treatment with hormonal therapy (eg, androgen receptor inhibitors, 5-alpha reductase inhibitors) or biologic therapy for prostate cancer (other than LHRH analogue therapy) within 4 weeks before enrollment;
Initiation of new treatment with denosumab, bisphosphonates, or systemic corticosteroids for treatment of prostate cancer within 4 weeks before enrollment;
Use of an investigational agent within 4 weeks before the screening visit;
Radiation therapy to bone within 4 weeks before enrollment;
Use of opiate analgesics for prostate cancer pain within 4 weeks before enrollment;
Screening 99mTc-MDP bone scintigraphy showing a superscan;
Visceral (eg, lung, liver) metastatic disease. Adenopathy is allowed;
Current or previously treated brain metastasis or active leptomeningeal disease;
History of seizure any time in the past for any reason or any condition that may predispose to seizures.

Arm && Interventions

Group	Intervention	Description
Enzalutamide monotherapy	Enzalutamide	Enzalutamide (160 mg) administered as four 40-mg capsules by mouth once daily

Primary Outcome Measures

Name	Time	Method
Percentage of Participants With at Least (>=) 1 Responding Bone Lesion Assessed by Total Sodium Fluoride (NaF) Standardized Uptake Value [SUVtotal] at Third 18F-NaF PET/CT Imaging (NaF-3) Schedule	At NaF-3 schedule: at time of PSA, or radiographic(bone or soft tissue), or clinically relevant progression, or at 2years without progression after treatment initiation, whichever occurred first(From first dose of study drug up to maximum of 34.1 months)	Bone lesion responded: if its change from baseline in SUVtotal is below limit of agreement (LOA, no specific value, based upon test/retest analysis using software). SUVtotal: total NaF uptake,indicated tumor burden across all bone lesions/in individual lesions reflecting bone-metastatic prostate cancer.NaF-3 performed on any of these: 1) prostate-specific antigen (PSA) progression(increase of \>=25% and absolute increase of \>=2.0 ng/mL above nadir); 2) bone progressive disease(PD)(appearance of \>=2 new lesions after screening assessed by technetium Tc 99m medronate \[99mTc-MDP\] bone scintigraphy); 3) soft tissue PD; 4) clinically relevant progression by investigator; 5) at 2 years without progression after treatment initiation. PD, RECIST1.1:\>=20% increase in sum of diameters of target lesions,(reference smallest sum on study, included baseline sum if that is smallest on study),relative increase of 20%,sum of diameters indicated absolute increase of \>=5mm, appearance of \>=1 new lesions.

Secondary Outcome Measures

Name	Time	Method
Mean Heterogeneity of Response Across All Bone Lesions as Measured by Global Heterogeneity of NaF Standardized Uptake (SUVhetero) Score at Third 18F-NaF PET/CT Imaging (NaF-3) Schedule	At NaF-3 schedule: at time of PSA, or radiographic(bone or soft tissue), or clinically relevant progression, or at 2years without progression after treatment initiation, whichever occurred first(From first dose of study drug up to maximum of 34.1 months)	Global SUVhetero score:Sum of(SUVmean of each lesion minus global SUVmean of all lesion)\^2/number of lesions,measure of heterogeneity of tumor activity across all bone lesions.SUVmean(mean NaF uptake)indicated average activity of each lesions.Real limits for SUVhetero score ranged:0(minimum) to infinite(maximum).Higher global SUVhetero score:more heterogeneity in bone lesion activity.NaF-3 performed on any of these 1)PSA progression(increase of\>=25% and absolute increase of\>=2.0ng/mL above nadir);2)bone PD(appearance of\>=2 new lesions after screening assessed by 99mTc-MDP bone scintigraphy);3)soft tissue PD(RECIST1.1);4)clinically relevant progression by investigator;5)at 2years without progression after treatment initiation.PD perRECIST1.1:\>=20%increase in sum of diameters of target lesions,(reference smallest sum on study,this included baseline sum if that is smallest on study),relative increase of20%,sum of diameters indicated absolute increase of\>=5mm,appearance of\>=1 new lesions.

Locations (5): Karmanos Cancer Institute Weisberg Cancer Treatment Center
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Farmington Hills, Michigan, United States
Karmanos Cancer Institute
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Detroit, Michigan, United States
Wimr Pet/Ct
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Madison, Wisconsin, United States
UW Clinical Sciences Center
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Madison, Wisconsin, United States
Rutgers Cancer Institute of New Jersey
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New Brunswick, New Jersey, United States