Soy Protein/Effexor Hormone Therapy for Prostate Cancer

OBJECTIVES:

Primary

- Assess the effect of soy protein/isoflavones and venlafaxine on the hot flash symptom
severity score in patients undergoing hormonal manipulation for treatment of prostate
cancer.

Secondary

- Assess the effect of soy protein/isoflavones and venlafaxine on quality of life of these
patients.

- Monitor and assess the participant drop out rate.

OUTLINE: This is a randomized, double-blind, multicenter study. Patients are stratified
according to severity of disease (metastatic vs nonmetastatic) and baseline severity of hot
flashes. Patients are randomized to 1 of 4 treatment arms.

- Arm I: Patients receive oral placebo pill and oral soy protein/isoflavones powder once
daily.

- Arm II: Patients receive oral venlafaxine and oral placebo powder once daily.

- Arm III: Patients receive oral venlafaxine and oral soy protein/isoflavones powder once
daily.

- Arm IV: Patients receive oral placebo pill and oral placebo powder once daily. Treatment
in all arms continues for 12 weeks in the absence of disease progression or unacceptable
toxicity. After 12 weeks of treatment, patients in arms I and III receive a tapered dose
of oral venlafaxine once daily for 1 week.

Patients complete a vasomotor symptom diary once daily beginning 7 days before the initiation
of study treatment and continuing until the completion of study treatment. Quality of life is
assessed at baseline and at week 12.

PROJECTED ACCRUAL: A total of 176 patients will be accrued for this study.

Inclusion Criteria:

- Histologic documentation of prostate cancer, any stage Life expectancy of > nine
months

- Prior or current androgen deprivation for treatment or control of prostate cancer to
include:

- Bilateral Orchiectomy

- LHRH agonist (with or without antiandrogen therapy) ie: leuprolide (Lupron), goserelin
(Zoladex), bicalutamide (Casodex), flutamide (Eulexin), or similar agents

- Chemotherapy

- Radiation (Patients may undergo concurrent radiation therapy to the prostate, prostate
+ seminal vesicles, and/or pelvis). Seed implants are allowed

- Participant report of hot flash frequency of an average of four or more per day, as
defined by sweating, flushing, sensation of warmth, night sweats (Average of 28 per
week)

- Hot flashes must be moderate or severe (See appendix A for hot flash definitions)

- Grade 2 (Moderate flashes) are warmer, produce obvious perspiration, and last 2 to 3
minutes

- Grade 3 (Severe flashes) causes profuse perspiration, generate intense heat, last
longer and interfere with ongoing activity

- Age >21

- No allergies to soy or dairy products

- No current use of SSRIs, SNRI's, MAOIs, or Linezolide

- No uncontrolled hypertension (160/90) or greater than Class I American Heart
Association functional capacity

- No history of mania, hypomania, bipolar disorder, or anorexia nervosa

- No history of seizures

- No history of hepatic dysfunction)

- Must have a telephone

- Signed protocol-specific Informed Consent

- Participants consuming soy foods or soy based supplements must continue on a stable
regimen during study participation

- Patients should maintain same treatment and medications for prostate cancer throughout
entire study.

- No change in treatment for 2 weeks prior to registration.

- Current use of medications and herbal supplements for hot flashes are allowed if on a
stable regimen throughout the entire study. (Does not include anti-depressants)

Exclusion Criteria:

- Anticipated changes in prostate cancer treatment plan (i.e., hormonal manipulation,
changes in chemotherapy)

- Concurrent antidepressant therapy

- History of intolerance to venlafaxine

- Recent (within 14 days) use of venlafaxine (Effexor XRTM), monoamine oxidase
inhibitor, SSRI (selective serotonin reuptake inhibitor), or SNRI (selective
norepinephrine reuptake inhibitor)

- History of seizure disorder