Using Metformin to Help Prostate Cancer Patients with Glucose Intolerance or High BMI

A Randomized, Pragmatic, Adaptive Trial of Metformin for Glucose Intolerance or Increased Body Mass Index in Prostate Cancer Patients

Early Phase 1 Interventional University of Colorado, Denver · NCT05515978

This study is testing if giving metformin to prostate cancer patients who have trouble with blood sugar or are overweight, along with lifestyle changes, can help improve their health compared to just lifestyle changes alone.

Quick facts

PhaseEarly Phase 1
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years and up
SexMale
SponsorUniversity of Colorado, Denver Academic / other
Locations4 sites (Aurora, Colorado and 3 other locations)
Trial IDNCT05515978 on ClinicalTrials.gov

What this trial studies

This study investigates the use of metformin, a medication commonly prescribed for type 2 diabetes, in prostate cancer patients who have glucose intolerance or increased body mass index (BMI). Participants will be randomly assigned to receive either metformin along with lifestyle modification education or lifestyle modification education alone. The study aims to assess the feasibility of this approach and its potential benefits over a follow-up period of up to 10 years. Previous research has suggested that metformin may improve outcomes in prostate cancer patients, making this a promising area of exploration.

Who should consider this trial

Good fit: Ideal candidates are male prostate cancer patients aged 18 and older with glucose intolerance or a BMI of 25 kg/m² or higher.

Not a fit: Patients currently on diabetes therapy or those without prostate cancer may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a new therapeutic option for improving health outcomes in prostate cancer patients with metabolic issues.

How similar studies have performed: Previous studies have shown promising results regarding the use of metformin in prostate cancer patients, indicating potential for success in this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

In order to be eligible to participate in this study, an individual must meet all of the following criteria. The patients will be screening for eligibility and offered an electronic consent via the Epic medical record and the patient portal (My Health Connection - MHC) or otherwise through Epic:

1. Provision to sign and date the consent form in MHC or otherwise via Epic.
2. Subjects must have an MHC Account to participate in the study
3. Be a male aged ≥18 years of age on day of signing the informed consent.
4. Impaired glucose tolerance and/or overweight, and appropriate to receive metformin, meeting at least one of the following in the last year (timing relative to the consent presentation not start of therapy):

   * HbA1c of 5.7 - 6.4 %
   * BMI≥25 kg/m\^2
5. Have a prostate cancer diagnosis
6. Have a clinical relationship with a participating provider at a UCHealth facility.

Exclusion Criteria:

1. On therapy for diabetes including any of the following alone or in combination medications (diet controlled or managed diabetes is allowed - e.g.

   diagnosis of Diabetes, but without an active prescription for anti-glycemic medication):
   1. Metformin
   2. Insulin
   3. Glipizide
   4. Glyburide
   5. Glimepiride
   6. Pioglitazone
   7. Rosiglitazone
   8. Sitagliptin
   9. Saxagliptin
   10. Linagliptin
   11. Alogliptin
   12. Canagliflozin
   13. Dapagliflozin
   14. Empagliflozin
   15. Ertugliflozin
   16. Liraglutide
   17. Dulaglutide
   18. Semaglutide
   19. Exenatide
   20. Lixisenatide
   21. Nateglinide
   22. Repaglinide
   23. Tirzepatide
2. Contraindication for metformin use which include any of the following which are exclusionary (in Epic will use most recent lab values):

   1. Estimated glomerular filtration rate (eGFR) of \< 50 ml/minute (calculated according to the formula utilized within Epic).
   2. Known Total Bilirubin ≥3 mg/dL)
   3. Diagnosis of fibrosis or cirrhosis of the liver (ICD10: K74)
   4. Diagnosis of alcohol related disorders (ICD10: F10)
   5. Metformin allergy in Epic (ICD10: T50.995A)
3. Non-English-speaking patient until Spanish language consent form and relevant materials can be made available. Due to the novel aspect of this trial, we plan to get some experience in treating approximately the first 50 patients, make any changes needed in the study operations and then implement a Spanish consent, as feasible.
4. Taking any medication with a known class D or higher drug interaction with metformin, including:

   1. Cimetidine
   2. Dolutegravir
   3. Patiromer
   4. Ranolazine
   5. Tafenoquine
5. The use of any carbonic anhydrase inhibitors since they are a risk factor for lactic acidosis, including:

   1. Topiramate
   2. Dichlorphenamide
   3. Acetazolamide
   4. Methazolamide
   5. Dorzolamide
   6. Brinzolamide
   7. Dichlorphenamide
   8. Sultiame
   9. Zonisamide
   10. Indisulam
6. Any treating investigator concern, related to tolerance, safety, adherence or for any other reason

Where this trial is running

Aurora, Colorado and 3 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Prostate CancerPragmaticProstateCancerMetforminLifestyleLifestyle changesLifestyle Modifications
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.