Effect of Enzalutamide Dose Reduction on Fatigue, Cognition, and Drug Trough Levels in Patients With Prostate Cancer

Study Overview
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Brief Summary
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The primary purpose of this trial is to determine whether dose reduction of enzalutamide in patients with grade 3 fatigue and/or cognition change will lead to an improvement in symptoms while maintaining active drug levels. Patients within 3 months of starting enzalutamide will be assessed by their oncologist as being potentially eligible for dose reduction due to the onset of moderate to severe fatigue and/or cognition change, which is assessed as being due to enzalutamide

Official Title
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Effect of Enzalutamide Dose Reduction on Fatigue, Cognition, and Drug Trough Levels in Patients With Prostate Cancer

Conditions
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Prostate Cancer

Intervention / Treatment
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* Drug: Enzalutamide


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with prostate cancer who have commenced enzalutamide within 3 months Patient must have concomitant LHRH agonist or antagonist (no single agent enzalutamide) Receiving enzalutamide before or after docetaxel Patients may have hormone-sensitive or castrate resistant disease Patients may have metastatic (M1) or non-metastatic (M0) disease Onset of grade 3 or more cognition change and/or fatigue after commencement of enzalutamide considered to be due to enzalutamide Exclusion Criteria: Clinical dementia Concomitant use of drugs known to impair cognition such as benzodiazepines or antihistamines. Concomitant use of strong CYP3A4 and/ or CYP2C8 inducers or inhibitors. Patient expected to have a change in opioid dose during the study period or have had a change 4 weeks before study entry. Diagnosed with sleep apnoea Brain metastases, prior seizures, drugs that significantly reduce seizure threshold. Active infection or other intercurrent illness that may contribute to fatigue or cognition change within 4 weeks of study entry.

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
Intervention Model: Single Group Assignment
Interventional Model Description: Patients will have commenced standard dose enzalutamide (160mg) daily and dose will be reduced if Grade 3 fatigue or cognition change has occurred and if toxicity is attributed to enzalutamide
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Enzalutamide<br>Patients will have commenced standard dose enzalutamide (160mg) daily and dose will be reduced if Grade 3 fatigue or cognition change has occurred and if toxicity is attributed to enzalutamide | Drug: Enzalutamide<br>* Enzalutamide is a FDA and Therapeutic Goods Administration (TGA, Regulatory Authority of therapeutic goods in Australia) approved treatment for castration resistant prostate cancer<br>* Other names: Xtandi;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The proportion of patients who have an improvement in cognition/ fatigue symptoms | The primary endpoint is an improvement in the fatigue and cognition symptoms. Improvement will be de ned as the patient answering 'Better' in the cognition/ fatigue question at the lowest dose of enzalutamide. | 1 year post enrolment |