Neoplasms

Urinary Tract, Sexual Organs, and Pregnancy Conditions

All Conditions

Symptoms and General Pathology

Prostatic Neoplasms

Carcinoma

Hot Flashes

All Drugs and Chemicals

Urological Agents

Androgens

Hormones

Oxybutynin

Parasympatholytics

Muscarinic Antagonists

Cholinergic Antagonists

Cholinergic Agents

Neurotransmitter Agents

Patients receive low-dose oxybutynin chloride (2.5 mL twice daily) PO BID on days 8-49 (6 weeks) in the absence of unacceptable toxicity.

Patients receive high-dose oxybutynin chloride (5.0 mL twice daily) PO BID on days 8-49 (6 weeks) in the absence of unacceptable toxicity.

Patients receive a low-dose placebo (2.5 mL twice daily) PO BID on days 8-49 (6 weeks). After 6 weeks, patients may cross over to experimental arm - low-dose oxybutynin per physician discretion.

Patients receive a high-dose placebo (5.0 mL twice daily) PO BID on days 8-49 (6 weeks). After 6 weeks, patients may cross over to experimental arm - high-dose oxybutynin chloride per physician discretion.

Oxybutynin Chloride

Placebo Administration

Quality-of-Life Assessment

Questionnaire Administration

Bradley J. Stish, MD

This phase II trial compares the effect of oxybutynin versus placebo for reducing hot flashes in men receiving androgen deprivation (hormone) therapy for the treatment of prostate cancer . Androgen deprivation therapy decreases testosterone and other androgens through medications or surgical removal of the testicles. Relative to placebo, low- or high-dose oxybutynin may reduce hot flashes in men receiving androgen deprivation therapy.

The primary and secondary objectives of the study:

PRIMARY OBJECTIVE:

I. To assess the effects of two doses of oxybutynin chloride (oxybutynin) on hot flash scores relative to placebo.

SECONDARY OBJECTIVES:

I. To assess study accrual rates and compliance with the therapy. II. To characterize the safety and adverse event profile of two doses of oxybutynin in the study population.

III. To evaluate the consistency of the results across the various methods used to evaluate the efficacy of oxybutynin (i.e., hot flash scores versus hot flash frequencies, mean differences versus 50% or greater reduction since baseline, single day versus full week to define patients' baseline hot flash scores).

IV. To compare patient-reported quality of life and hot flash interference, as measured by the Hot Flash Related Daily Interference Scale (HFRDIS), across arms.

V. To compare other changes in patient symptoms, as measured by the Symptom Experience Questionnaire, across arms.

OUTLINE: Patients are randomized to 1 of 4 arms in a 2:2:1:1 ratio according to the dynamic allocation scheme.

Experimental Arm (low dose): Patients receive low-dose oxybutynin chloride orally (PO) twice daily (BID) on days 8-49 (6 weeks) in the absence of unacceptable toxicity.

Experimental Arm (high dose): Patients receive high-dose oxybutynin chloride PO BID on days 8-49 (6 weeks) in the absence of unacceptable toxicity.

Placebo Arm (low dose): Patients receive low-dose placebo PO BID on days 8-49 (6 weeks). After 6 weeks, patients may cross over to Experimental Arm (low dose) per physician discretion.

Placebo Arm (high dose): Patients receive high-dose placebo PO BID on days 8-49 (6 weeks). After 6 weeks, patients may cross over to Experimental Arm (high dose) per physician discretion.

There will be a 6-week follow-up for the Placebo Arm patients who participate in the optional crossover phase.

Testing the Effects of Oxybutynin for the Treatment of Hot Flashes in Men Receiving Hormone Therapy for Prostate Cancer

A Randomized, Double-Blind, Placebo-Controlled Phase II Study of Oxybutynin Versus Placebo for the Treatment of Hot Flashes in Men Receiving Androgen Deprivation Therapy

Using patients' hot flash diaries, daily hot flash scores will be determined by multiplying the frequency of each defined hot flash grade by the severity and summing the values over a 24-hour period. Weekly hot flash scores will be computed by averaging these hot flash scores across 7 days. A mixed model will be estimated that includes baseline and weekly hot flash scores across the 6-week treatment period. Estimates from the mixed model will be used to construct 90% confidence intervals for mean differences in hot flash score reduction from baseline to 6 weeks between the oxybutynin and placebo arms. Contrasts estimated via the mixed model will involve a two-sided t-test with alpha = .10. At 6 weeks, the proportion of patients who experience a 50% or greater reduction in hot flash scores since baseline will be compared across the oxybutynin and placebo arms using Fisher's exact test or logistic regression.

Weekly hot flash frequencies will be determined by patients' hot flash diaries. A mixed model will be estimated that includes baseline and weekly hot flash frequencies across the 6-week treatment period. The mixed model and subsequent contrasts will account for the observed distribution of weekly hot flash frequencies. At 6 weeks, the proportion of patients who experience a 50% or greater reduction in hot flash frequency since baseline will be compared across the oxybutynin and placebo arms using Fisher's exact test or logistic regression. Consistency of the results will be assessed across the various methods used to evaluate the efficacy of oxybutynin in this trial (i.e., hot flash scores versus hot flash frequencies, mean differences versus 50% or greater reduction since baseline, single day versus full week to define patients' baseline hot flash scores).

Grade 3 or higher adverse events will be assessed by the National Cancer Institute's Common Terminology Criteria for Adverse Events, version 5.0 and summarized by arm.

Patient-reported symptoms will be assessed by the Symptom Experience Questionnaire. A mixed model will be estimated that includes baseline and weekly patient-reported symptoms across the 6-week treatment period. Estimates from the mixed model will be used to construct 90% confidence intervals for mean differences in patient-reported symptoms between the oxybutynin and placebo arms at 6 weeks. Contrasts estimated via the mixed model will involve a two-sided t-test with alpha = .10.

The time required to accrue 87 patients will be reported.

Treatment adherence rates will be calculated by dividing the number of patients who completed treatment per protocol by the number of patients who started treatment. Treatment adherence rates will be summarized by arm.

A mixed model will be estimated that includes patients' scores on the Hot Flash Related Daily Interference Scale (HFRDIS) across the 6-week treatment period. Estimates from the mixed model will be used to construct 90% confidence intervals for mean differences in patient-reported quality of life between the oxybutynin and placebo arms at 6 weeks. Contrasts estimated via the mixed model will involve a two-sided t-test with alpha = .10.

A mixed model will be estimated that includes patients' scores on the Hot Flash Related Daily Interference Scale (HFRDIS) across the 6-week treatment period. Estimates from the mixed model will be used to construct 90% confidence intervals for mean differences in patient-reported hot flash interference between the oxybutynin and placebo arms at 6 weeks. Contrasts estimated via the mixed model will involve a two-sided t-test with alpha = .10.

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization	Link
Testing the Effects of Oxybutynin for the Treatment of Hot Flashes in Men Receiving Hormone Therapy for Prostate Cancer	NCT04600336	Prostate Carcin...	Oxybutynin Chlo... Placebo Adminis... Quality-of-Life... Questionnaire A...	18 Years -	Alliance for Clinical Trials in Oncology
Testing the Effects of Oxybutynin for the Treatment of Hot Flashes in Men Receiving Hormone Therapy for Prostate Cancer	NCT04600336	Prostate Carcin...	Oxybutynin Chlo... Placebo Adminis... Quality-of-Life... Questionnaire A...	18 Years -	Alliance for Clinical Trials in Oncology

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