CClinicalTrials.gg
Sign In
CompletedNCT00584532GCPUpdated Nov 24, 2023

Effects of a Genistein Concentrated Polysaccharide (GCP) for Prostate Cancer on Active Surveillance.

A Phase 2/3 interventional study of Placebo and GCP - Genistein Combined Polysaccharide in Prostate Cancer, sponsored by University of California, Davis. Completed. Open to male participants. Per ClinicalTrials.gov, last updated 2023-11-24.

Sponsored by University of California, Davis · Phase 2/3, Interventional, and Treatment

Phase
Phase 2/3
Study type
Interventional
Enrollment
66
Allocation
Randomized
Sex
Male
01

Study summary

Genistein Combined Polysaccharide (GCP) may play a role as a secondary chemopreventive agent in the treatment of localized prostate cancer.

02

Conditions studied

  • Prostate Cancer

Browse trials for

Keywords

  • Localized
  • Prostate
  • Cancer
03

In context

Prostatic Neoplasms

6,370 studies on the registry are indexed under Prostatic Neoplasms; 1,400 are open to participants now.

This study's enrollment of 66 is above the median of 58 across 4,822 interventional studies indexed under Prostatic Neoplasms.

Browse Prostatic Neoplasms studies →

Lead sponsor

University of California, Davis is the lead sponsor of 798 studies on the registry; 146 are open to participants now.

Of its 65 completed or terminated interventional studies of FDA-regulated products, 43 (66%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
Child (0–17), Adult (18–64), Older adult (65+)
Sexes eligible
Male
Accepts healthy volunteers
No

Inclusion criteria

  • Participants must be male and have a pathological diagnosis of prostate cancer
  • Pathological diagnosis of prostate cancer must be confirmed and on file with CRA prior to study entry.
  • No treatment (surgery, radiation, or hormones) prior to study entry.
  • PSA between 2.0 and 10.0 ng/ml.
  • If PSA is >10.0, patient must have been on Active Surveillance for 12 months prior to study initiation.
  • No known allergy to soy or soy products.
  • The patient is not currently taking more than 2 grams of genistein a day in nutritional or diet enhancing supplements (OTC supplements).
  • Participant has not been on any previous GCP clinical trial.
  • Normal Chemistry values prior to study entry.

Exclusion criteria

Exclusion Criteria:

  • No pathological documentation of prostate cancer.
  • Prior treatment for prostate cancer.
  • PSA >10.0 ng/ml but not on Active Surveillance for 12 months.
  • Allergy to soy or soy products.
  • Abnormal chemistry values.
05

Study design

Phase
Phase 2 / Phase 3
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Double (Participant, Investigator)
Enrollment
66 participants (actual)

Study arms

  • Placebo comparator
    A

    A=Placebo ARM of Study

    Drug: Placebo

  • Active comparator
    B

    B=GCP Capsules. Ten 500 mg capsules per day for a total of 5 grams a day.

    Drug: GCP - Genistein Combined Polysaccharide

Interventions

  • DrugPlacebo

    10 Placebo Capsules taken orally every day.

    Also known as: Placebo capsules (contain cellulose only)

  • DrugGCP - Genistein Combined Polysaccharide

    Ten 500 mg capsules given orally per day. Total of 5 grams per day per patient.

06

What researchers measure

Primary outcomes

  1. Decrease in PSA levels in men on GCP

    Time frame: 6 Months

Secondary outcomes

  1. Increased PSA Doubling Time (PSADT)in men on GCP.

    Time frame: 6 Months

07

Study locations

No study locations are listed for this record.

08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Nov 24, 2023, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT00584532
Lead sponsor
University of California, Davis
First posted
Jan 2, 2008
Start date
Nov 2003
Primary completion
Dec 2005
Completion
Dec 2007
Last update
Nov 24, 2023

Study contacts

Robert Hackman, MD
principal investigator · University of California, Davis - Dept. of Nutrition

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Dec 2007. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Other studies in this condition

Prostatic Neoplasms→

Other studies from this sponsor

University of California, Davis

Start the discussion