Tadalafil in Preventing Erectile Dysfunction in Patients With Prostate Cancer Treated With Radiation Therapy
Condition: Prostate Cancer; Sexual Dysfunction
MeSH terms: Prostatic Neoplasms; Erectile Dysfunction
Study type: Interventional
Phase: Phase 3

Summary: 
      RATIONALE: Tadalafil may help prevent erectile dysfunction (ED) in patients with prostate
      cancer that has been treated with radiation therapy. It is not yet known whether tadalafil is
      more effective than a placebo in preventing erectile dysfunction.

      PURPOSE: This randomized phase III trial is studying tadalafil to see how well it works
      compared with a placebo in preventing erectile dysfunction in patients with prostate cancer
      treated with radiation therapy.
    

Detailed description: 
      OBJECTIVES:

      Primary

        -  To determine whether tadalafil maintains spontaneous (off-drug) erectile function, as
           measured by the International Index of Erectile Function (IIEF) as compared to placebo
           at weeks 28-30 after initiation of radiotherapy in patients with prostate cancer.

      Secondary

        -  Determine the difference in spontaneous (off-drug) erectile function between tadalafil
           and placebo at 1 and 2 years.

        -  Determine the difference in overall sexual function as measured by the IIEF between
           tadalafil and placebo at weeks 28-30 and at 1 and 2 years.

        -  Determine differences in patient and partner overall sexual satisfaction as measured by
           the Sexual Adjustment Questionnaire (SAQ) between tadalafil and placebo at weeks 28-30
           and at 1 and 2 years.

        -  Determine differences in patient and partner marital adjustment as measured by Locke's
           Marital Adjustment Test (LMAT) between tadalafil and placebo at weeks 28-30 and at 1 and
           2 years.

        -  Determine associations between patient and partner overall sexual satisfaction as
           measured by SAQ and patient and partner marital adjustment as measured by LMAT at weeks
           28-30 and at 1 and 2 years.

        -  Determine patient-related factors (i.e., age, pretreatment sexual response, tobacco use,
           and comorbidities) that may predict response to tadalafil therapy at weeks 28-30 and at
           1 and 2 years.

        -  Determine the difference in adverse events between tadalafil and placebo as assessed by
           Common Toxicity Criteria for Adverse Effects (CTCAE) v3.0 criteria.

      Tertiary

        -  Characterization of preference and erectile function among patients who choose to stay
           on (or if on placebo, to start) tadalafil, a phosphodiesterase type 5 (PDE5) inhibitor
           other than tadalafil, a non-PDE5-inhibitor erectile aide, or no PDE5 inhibitor or
           erectile aide at 28-30 weeks and at 1 and 2 years.

        -  Identification of radiotherapy factors (i.e., modality, prescribed total dose, planning
           target volume margin, penile bulb dose-volume parameters) associated with erectile
           function.

        -  Evaluation of the number of patients screened for eligibility, the number eligible that
           are presented the study, the number who refuse, and the number who are accrued.

      OUTLINE: This is a multicenter study. Patients are stratified according to age (≤ 65 years vs
      > 65 years) and radiotherapy treatment (external beam radiation therapy vs brachytherapy*).
      Patients are randomized to 1 of 2 treatment arms.

      Note: * Radiotherapy start date for brachytherapy patients is the date of the procedure.

      All patients undergo either external beam radiotherapy alone to the prostate ± seminal
      vesicles only or low-dose rate permanent brachytherapy alone.

        -  Arm I: Beginning ≤ 7 days after the start of radiotherapy, patients receive oral
           tadalafil once daily for 24 weeks in the absence of disease progression or unacceptable
           toxicity.

        -  Arm II: Beginning ≤ 7 days after the start of radiotherapy, patients receive oral
           placebo once daily for 24 weeks in the absence of disease progression or unacceptable
           toxicity.

      Patients complete the International Index of Erectile Function (IIEF), the Sexual Adjustment
      Questionnaire (SAQ), the Locke's Marital Adjustment Test (LMAT) (if applicable), and the
      Expanded Prostate Cancer Index Composite Sexual Medications and Devices Evaluations
      Supplement questionnaires periodically. Partners or spouses complete the SAQ-Partner, LMAT
      (if applicable), and IIEF questionnaires periodically.

      After completion of study treatment, patients are followed at 28-30 weeks, and annually for
      up to 2 years.
    

Intervention name(s): Tadalafil; Placebo
Intervention type(s): Drug; Other
Intervention description(s): Beginning ≤ 7 days after the start of radiotherapy, patients receive oral tadalafil 5mg once daily for 24 weeks.; Beginning ≤ 7 days after the start of radiotherapy, patients receive oral placebo once daily for 24 weeks.
Intervention MeSH terms: Tadalafil
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Supportive Care
Keywords: sexual dysfunction; stage IIB prostate cancer; stage IIA prostate cancer; adenocarcinoma of the prostate