Metformin in Prostate Cancer


Why metformin in prostate cancer?

  • Approximately 20-30% of men treated with surgery or radiation will develop recurrence of their prostate cancer, which most commonly manifests as a rising PSA level in the blood, commonly referred to as a “biochemical recurrence”.
    • This can occur many years before any evidence of cancer spread can be detected on imaging tests such as CT scans or bone scans.
  • Standard therapy for prostate cancer that has spread is treatment to lower the testosterone level in the body (aka, androgen deprivation therapy or ‘hormonal therapy’). This treatment has unfavorable side effects. Whether such treatment should be started for patients with a rising PSA, without any evidence of detectable spread on cancer on scans, is controversial.
  • Metformin is an oral drug used to treat diabetes. Several lines of evidence point to a potential for metformin to be effective in the treatment of prostate cancer.
  • Epidemiologic studies of patients with prostate cancer and diabetes have shown that patients taking metformin may have a lower likelihood of recurrence of the prostate cancer after surgery or radiation, and they may have a lower likelihood of dying of prostate cancer, when compared to patients not taking the drug.
  • Metformin can be tested for efficacy in patients with prostate cancer who experience a recurrence, as manifested by a rising PSA blood level after surgery or radiation. If clinical studies confirm its utility, it may provide an alternative for patients with prostate cancer, delaying or preventing the need for androgen deprivation therapy.

Please take part in designing an innovative clinical study of metformin in patients with recurrent prostate cancer, as manifested by a rising PSA blood test (biochemical recurrence), after surgery or radiation. 

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An Opportunity for Publication

All participants will be able to review and comment on drafts of the protocol as they are produced, and they will be mailed a TLS Development Team membership certificate to show their support for open innovation.

Participating in the Protocol Builder also enters you into a friendly competition among the research community. When we identify the researchers who have provided the best input for a certain section of the Protocol Builder, we will name up to three winners of the section.

By winning a section, researchers will enter into a discussion with the TLS study team on how to draft the best protocol. When this protocol is published, the top researchers will have co-authorship rights and an ongoing say into the design and implementation of the trial.

Protocol Builder Results


Here are excerpts of users' reasoning for the rationale:

  • I know IGF are on breast cancer cells, seems reasonable they may be on prostate as well
  • Good scientific evidence that metformin activates AMPK, but whether this is truly a direct effect is questionable.
  • The epidemiology remains the strongest data. The preclinical lab rationale is important but by itself would not be as compelling.
We have not yet reached a broad consensus on our rationale. Do you have anything to add?

Patients are being asked to answer demographic questions, as well as questions that relate to their experience in clinical trials, instead of being asked to respond to the rationale.

Please comment on the proposed rationale in the Protocol Builder itself or in the forum.




Researcher Population Results

Agree with Chosen Population 37
Disagree with Chosen Population 13
Total 50
Which segment of patients do you believe we should include in our study?

Patients are being asked in this section to provide details on their experiences with previous clinical trials. We will use this data to tailor our trial design and study population to the community's characteristics and needs.

Researchers are being asked to respond to specific population criteria. Please begin the Protocol Builder to view this information.



What's the correct dose for our study?

Patients are being asked to rate their familiarity with metformin.

Researchers are being asked to agree or disagree with a proposed dosage.


Primary Endpoint

What is an appropriate primary endpoint for a clinical trial in patients with prostate cancer and a rising PSA after surgery or radiation?

Patients are being asked to evaluate which PSA outcomes would make a clinical trial most worthwhile.

Researchers are being asked to evaluate specific possible endpoints.


Secondary Endpoints

Here are excerpts from patients' responses:

  • Maintaining a good quality of life along with improving survival or time to progression
  • How effective was it in patients in watchful waiting, how effective in psa < .2 ; 1.0 : 2.0 ; 3.0 and in patients with medical conditions

  • Other impacts on health, ie blood sugar.

What other endpoints should we monitor?

Patients are being asked to provide additional aspects of prostate cancer that could be meaningful secondary endpoints.

Researchers are being asked to respond to specific possible secondary endpoints.



Here are excerpts from users' responses:

  • Yes because it is generic. I assume the extended release is also generic.
  • Doesn't seem like it. Perhaps it could just be submitted for "compendia listing"?

Is a 505(b)2 path feasible?

Let us know your thoughts on drug regulation in the forum by cicking the comments button below.

Please begin the Protocol Builder to help develop our study's regulatory path.



Do you have any safety concerns?

Patients are being asked to express any safety concerns with metformin or any other part of the trial.

Researchers are being asked to express any safety concerns.



Here are excerpts from users' responses:

  • Blood glucose testing via a cell phone attachment. Toxicity surveys could be collected online. PSA data could be obtained in the community and uploaded by patients.
  • There a pill bottle cap which will electronically monitor compliance (or at least opening the bottle to access the medications).
  • Depends on the end point. If it is just a regular check-up, skype video or telephone call is fine as long it is done using a system that is compatible with HIPAA rules.

In what ways can this study be executed remotely?

Patients are being asked to provide any ideas of how this study can be executed remotely. They are also being asked about any previous experiences with home monitoring devices.

Researchers are being asked to provide ideas about how the study can be executed remotely.


Data Visualization

Here are excerpts from users' responses:

  • Show PSA slopes and waterfalls in real time.
  • Ultimately depends on primary endpoint selected. Visual rather than tabular.
  • Web-centered viewer could access a database with patient data that could be aggregated into multiple visualizations on demand: average PSA of cohort per time on study in a large line graph, volume of patients with certain characteristics in comparative circles. Could also have integrated into the data as an optional background the results from other historic trials for comparison.
Please help us create a data visualization plan.

Please continue the discussion on data transparency by clicking the comments button below.

We aim at making real life data available for all to see and understand. The only exceptions will be individual identification of patients and data which may lead to un­blinding of the study, if applicable.


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