Ignite Creation Date:
2025-12-24 @ 9:40 PM
Ignite Modification Date:
2025-12-30 @ 5:42 PM
Study NCT ID:
NCT01215032
Status:
TERMINATED
Last Update Posted:
2017-05-15
First Post:
2010-10-04
Is NOT Gene Therapy:
True
Has Adverse Events:
True
Brief Title:
Metformin in Castration-Resistant Prostate Cancer
Sponsor:
Organization:
Raw JSON
{'hasResults': True, 'derivedSection': {'miscInfoModule': {'versionHolder': '2025-12-24'}, 'conditionBrowseModule': {'meshes': [{'id': 'D011471', 'term': 'Prostatic Neoplasms'}], 'ancestors': [{'id': 'D005834', 'term': 'Genital Neoplasms, Male'}, {'id': 'D014565', 'term': 'Urogenital Neoplasms'}, {'id': 'D009371', 'term': 'Neoplasms by Site'}, {'id': 'D009369', 'term': 'Neoplasms'}, {'id': 'D005832', 'term': 'Genital Diseases, Male'}, {'id': 'D000091662', 'term': 'Genital Diseases'}, {'id': 'D000091642', 'term': 'Urogenital Diseases'}, {'id': 'D011469', 'term': 'Prostatic Diseases'}, {'id': 'D052801', 'term': 'Male Urogenital Diseases'}]}, 'interventionBrowseModule': {'meshes': [{'id': 'D008687', 'term': 'Metformin'}], 'ancestors': [{'id': 'D001645', 'term': 'Biguanides'}, {'id': 'D006146', 'term': 'Guanidines'}, {'id': 'D000578', 'term': 'Amidines'}, {'id': 'D009930', 'term': 'Organic Chemicals'}]}}, 'resultsSection': {'moreInfoModule': {'pointOfContact': {'email': 'mkempner@partners.org', 'phone': '508.533.4132', 'title': 'Maria Kempner', 'organization': 'Mass General Hospital Cancer Center'}, 'certainAgreement': {'piSponsorEmployee': True}, 'limitationsAndCaveats': {'description': 'Early termination due to slow accrual led to small numbers of subjects. Therefore, meaningful assessment of the study endpoints is severely limited by the small sample size.'}}, 'adverseEventsModule': {'eventGroups': [{'id': 'EG000', 'title': 'Metformin', 'description': 'This is the only arm of this phase 2 open label study\n\nMetformin: Taken orally twice daily each 28-day cycle', 'otherNumAtRisk': 21, 'otherNumAffected': 16, 'seriousNumAtRisk': 21, 'seriousNumAffected': 0}], 'otherEvents': [{'term': 'Hypothyroidism', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Endocrine disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'cataract', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Eye disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'abdominal pain', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Gastrointestinal disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'diarrhea', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 10}], 'organSystem': 'Gastrointestinal disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'flatulence', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 2}], 'organSystem': 'Gastrointestinal disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'frequent bowel movements', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Gastrointestinal disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'nausea', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 4}], 'organSystem': 'Gastrointestinal disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'vomiting', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Gastrointestinal disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'chills', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'General disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'fatigue', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 4}], 'organSystem': 'General disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'fever', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'General disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Generalized achiness', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'General disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Non-cardiac chest pain', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'General disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'anorexia', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 3}], 'organSystem': 'Metabolism and nutrition disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'hyperglycemia', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Metabolism and nutrition disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Vitamin D deficiency', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Metabolism and nutrition disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Back pain', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Musculoskeletal and connective tissue disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Bone pain', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Musculoskeletal and connective tissue disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Buttock pain', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Musculoskeletal and connective tissue disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Chest wall pain', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Musculoskeletal and connective tissue disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Pain in extremity', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Musculoskeletal and connective tissue disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Numbness in Toes', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Musculoskeletal and connective tissue disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Numbness - buttocks', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Musculoskeletal and connective tissue disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Urinary frequency', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Renal and urinary disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Urinary incontinence', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Renal and urinary disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Sore throat', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Respiratory, thoracic and mediastinal disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Rash maculo-papular', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Skin and subcutaneous tissue disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}, {'term': 'Hypertension', 'stats': [{'groupId': 'EG000', 'numAtRisk': 21, 'numAffected': 1}], 'organSystem': 'Vascular disorders', 'assessmentType': 'NON_SYSTEMATIC_ASSESSMENT', 'sourceVocabulary': 'CTCAE (4.0)'}], 'frequencyThreshold': '5'}, 'outcomeMeasuresModule': {'outcomeMeasures': [{'type': 'PRIMARY', 'title': 'PSA (Prostate Specific Antigen) Response', 'denoms': [{'units': 'Participants', 'counts': [{'value': '21', 'groupId': 'OG000'}]}], 'groups': [{'id': 'OG000', 'title': 'Metformin', 'description': 'This is the only arm of this phase 2 open label study\n\nMetformin: Taken orally twice daily each 28-day cycle, for 12 cycles'}], 'classes': [{'categories': [{'measurements': [{'value': '161', 'groupId': 'OG000', 'lowerLimit': '96.1', 'upperLimit': '309.5'}]}]}], 'paramType': 'MEDIAN', 'timeFrame': 'Approximately 12 weeks', 'description': 'Percent change in PSA from baseline to 12 weeks.', 'unitOfMeasure': 'percentage of baseline PSA', 'dispersionType': 'Full Range', 'reportingStatus': 'POSTED'}, {'type': 'SECONDARY', 'title': 'Number of Participants With PSA Response', 'denoms': [{'units': 'Participants', 'counts': [{'value': '21', 'groupId': 'OG000'}]}], 'groups': [{'id': 'OG000', 'title': 'Metformin', 'description': 'This is the only arm of this phase 2 open label study\n\nMetformin: Taken orally twice daily each 28-day cycle, for 12 cycles'}], 'classes': [{'categories': [{'measurements': [{'value': '0', 'groupId': 'OG000'}]}]}], 'paramType': 'COUNT_OF_PARTICIPANTS', 'timeFrame': '12 weeks', 'description': 'PSA response is defined as a 50% decline from baseline confirmed by a second PSA value 4 weeks later.', 'unitOfMeasure': 'Participants', 'reportingStatus': 'POSTED'}, {'type': 'SECONDARY', 'title': 'Relationship Between Baseline Metabolomic Profile and PSA Response', 'denoms': [{'units': 'Participants', 'counts': [{'value': '0', 'groupId': 'OG000'}]}], 'groups': [{'id': 'OG000', 'title': 'Metformin', 'description': 'This is the only arm of this phase 2 open label study\n\nMetformin: Taken orally twice daily each 28-day cycle, for 12 cycles'}], 'timeFrame': '2 years', 'description': 'To determine the plasma metabolomic profiles associated with response to metformin using the Metabolon platform. The Metabolon platform is a proprietary technique of metabolic profiling using mass spectrometry coupled with liquid and/or gas chromatography and robust bioinformatics. The aim is to test the hypothesis that insulin level is a biomarker that predicts activity of metformin therapy for the treatment of castrate-resistant prostate cancer.', 'reportingStatus': 'POSTED', 'populationDescription': 'Data was not collected for this outcome measure because blood (plasma) samples were never run on the Metabolon platform, as the study was terminated early.'}, {'type': 'SECONDARY', 'title': 'Percent Maintaining Glycemic Control', 'denoms': [{'units': 'Participants', 'counts': [{'value': '15', 'groupId': 'OG000'}, {'value': '6', 'groupId': 'OG001'}]}], 'groups': [{'id': 'OG000', 'title': 'Normal Baseline Hemoglobin A1c', 'description': 'Hemoglobin A1c less than 6.0 before metformin dosing began.'}, {'id': 'OG001', 'title': 'Abnormal Baseline Hemoglobin A1c', 'description': 'Hemoglobin A1c greater than or equal to 6.0 before metformin dosing began.'}], 'classes': [{'categories': [{'measurements': [{'value': '15', 'groupId': 'OG000'}, {'value': '6', 'groupId': 'OG001'}]}]}], 'paramType': 'COUNT_OF_PARTICIPANTS', 'timeFrame': '2 years', 'description': 'To describe glycemic control as assessed by hemoglobin A1C. Glycemic control was defined as maintaining fasting plasma glucose levels less than or equal to 130 mg/dL. Plasma glucose levels were measured at baseline (prior to metformin dosing), pre-month 2, pre-month 4, pre-month 7, pre-month 10 and pre-month 13, and/or at off-study visit.', 'unitOfMeasure': 'Participants', 'reportingStatus': 'POSTED', 'populationDescription': 'Participants were stratified based on baseline hemoglobin A1c. HbA1c \\< 6.0 is considered normal; HbA1c \\>/= 6.0 is considered abnormal.'}]}, 'participantFlowModule': {'groups': [{'id': 'FG000', 'title': 'Metformin', 'description': 'This is the only arm of this phase 2 open label study\n\nMetformin: Taken orally twice daily each 28-day cycle'}], 'periods': [{'title': 'Overall Study', 'milestones': [{'type': 'STARTED', 'achievements': [{'groupId': 'FG000', 'numSubjects': '21'}]}, {'type': 'COMPLETED', 'achievements': [{'groupId': 'FG000', 'numSubjects': '1'}]}, {'type': 'NOT COMPLETED', 'achievements': [{'groupId': 'FG000', 'numSubjects': '20'}]}], 'dropWithdraws': [{'type': 'Adverse Event', 'reasons': [{'groupId': 'FG000', 'numSubjects': '3'}]}, {'type': 'Lack of Efficacy', 'reasons': [{'groupId': 'FG000', 'numSubjects': '17'}]}]}]}, 'baselineCharacteristicsModule': {'denoms': [{'units': 'Participants', 'counts': [{'value': '21', 'groupId': 'BG000'}]}], 'groups': [{'id': 'BG000', 'title': 'Metformin', 'description': 'This is the only arm of this phase 2 open label study\n\nMetformin: Taken orally twice daily each 28-day cycle'}], 'measures': [{'title': 'Age, Categorical', 'classes': [{'categories': [{'title': '<=18 years', 'measurements': [{'value': '0', 'groupId': 'BG000'}]}, {'title': 'Between 18 and 65 years', 'measurements': [{'value': '8', 'groupId': 'BG000'}]}, {'title': '>=65 years', 'measurements': [{'value': '13', 'groupId': 'BG000'}]}]}], 'paramType': 'COUNT_OF_PARTICIPANTS', 'unitOfMeasure': 'Participants'}, {'title': 'Age, Continuous', 'classes': [{'categories': [{'measurements': [{'value': '65.86', 'spread': '7.23', 'groupId': 'BG000'}]}]}], 'paramType': 'MEAN', 'unitOfMeasure': 'years', 'dispersionType': 'STANDARD_DEVIATION'}, {'title': 'Sex: Female, Male', 'classes': [{'categories': [{'title': 'Female', 'measurements': [{'value': '0', 'groupId': 'BG000'}]}, {'title': 'Male', 'measurements': [{'value': '21', 'groupId': 'BG000'}]}]}], 'paramType': 'COUNT_OF_PARTICIPANTS', 'unitOfMeasure': 'Participants'}, {'title': 'Ethnicity (NIH/OMB)', 'classes': [{'categories': [{'title': 'Hispanic or Latino', 'measurements': [{'value': '0', 'groupId': 'BG000'}]}, {'title': 'Not Hispanic or Latino', 'measurements': [{'value': '9', 'groupId': 'BG000'}]}, {'title': 'Unknown or Not Reported', 'measurements': [{'value': '12', 'groupId': 'BG000'}]}]}], 'paramType': 'COUNT_OF_PARTICIPANTS', 'unitOfMeasure': 'Participants'}, {'title': 'Race (NIH/OMB)', 'classes': [{'categories': [{'title': 'American Indian or Alaska Native', 'measurements': [{'value': '0', 'groupId': 'BG000'}]}, {'title': 'Asian', 'measurements': [{'value': '0', 'groupId': 'BG000'}]}, {'title': 'Native Hawaiian or Other Pacific Islander', 'measurements': [{'value': '0', 'groupId': 'BG000'}]}, {'title': 'Black or African American', 'measurements': [{'value': '1', 'groupId': 'BG000'}]}, {'title': 'White', 'measurements': [{'value': '18', 'groupId': 'BG000'}]}, {'title': 'More than one race', 'measurements': [{'value': '0', 'groupId': 'BG000'}]}, {'title': 'Unknown or Not Reported', 'measurements': [{'value': '2', 'groupId': 'BG000'}]}]}], 'paramType': 'COUNT_OF_PARTICIPANTS', 'unitOfMeasure': 'Participants'}, {'title': 'Region of Enrollment', 'classes': [{'title': 'United States', 'categories': [{'measurements': [{'value': '21', 'groupId': 'BG000'}]}]}], 'paramType': 'NUMBER', 'unitOfMeasure': 'participants'}]}}, 'protocolSection': {'designModule': {'phases': ['PHASE2'], 'studyType': 'INTERVENTIONAL', 'designInfo': {'allocation': 'NA', 'maskingInfo': {'masking': 'NONE'}, 'primaryPurpose': 'TREATMENT', 'interventionModel': 'SINGLE_GROUP'}, 'enrollmentInfo': {'type': 'ACTUAL', 'count': 21}}, 'statusModule': {'whyStopped': 'slow accrual, competing clinical trials', 'overallStatus': 'TERMINATED', 'startDateStruct': {'date': '2010-09'}, 'expandedAccessInfo': {'hasExpandedAccess': False}, 'statusVerifiedDate': '2017-04', 'completionDateStruct': {'date': '2015-01', 'type': 'ACTUAL'}, 'lastUpdateSubmitDate': '2017-04-03', 'studyFirstSubmitDate': '2010-10-04', 'resultsFirstSubmitDate': '2017-01-09', 'studyFirstSubmitQcDate': '2010-10-04', 'lastUpdatePostDateStruct': {'date': '2017-05-15', 'type': 'ACTUAL'}, 'resultsFirstSubmitQcDate': '2017-01-09', 'studyFirstPostDateStruct': {'date': '2010-10-05', 'type': 'ESTIMATED'}, 'resultsFirstPostDateStruct': {'date': '2017-02-27', 'type': 'ACTUAL'}, 'primaryCompletionDateStruct': {'date': '2015-01', 'type': 'ACTUAL'}}, 'outcomesModule': {'primaryOutcomes': [{'measure': 'PSA (Prostate Specific Antigen) Response', 'timeFrame': 'Approximately 12 weeks', 'description': 'Percent change in PSA from baseline to 12 weeks.'}], 'secondaryOutcomes': [{'measure': 'Number of Participants With PSA Response', 'timeFrame': '12 weeks', 'description': 'PSA response is defined as a 50% decline from baseline confirmed by a second PSA value 4 weeks later.'}, {'measure': 'Relationship Between Baseline Metabolomic Profile and PSA Response', 'timeFrame': '2 years', 'description': 'To determine the plasma metabolomic profiles associated with response to metformin using the Metabolon platform. The Metabolon platform is a proprietary technique of metabolic profiling using mass spectrometry coupled with liquid and/or gas chromatography and robust bioinformatics. The aim is to test the hypothesis that insulin level is a biomarker that predicts activity of metformin therapy for the treatment of castrate-resistant prostate cancer.'}, {'measure': 'Percent Maintaining Glycemic Control', 'timeFrame': '2 years', 'description': 'To describe glycemic control as assessed by hemoglobin A1C. Glycemic control was defined as maintaining fasting plasma glucose levels less than or equal to 130 mg/dL. Plasma glucose levels were measured at baseline (prior to metformin dosing), pre-month 2, pre-month 4, pre-month 7, pre-month 10 and pre-month 13, and/or at off-study visit.'}]}, 'oversightModule': {'oversightHasDmc': True}, 'conditionsModule': {'keywords': ['castration-resistant prostate cancer', 'insulin levels', 'metformin'], 'conditions': ['Prostate Cancer']}, 'descriptionModule': {'briefSummary': "Metformin is a medication that is prescribed for people with diabetes to help the body respond better to its own insulin and decrease sugar production by the liver. This helps control the body's blood sugar level and is approved by the Food and Drug Administration (FDA) for the treatment of diabetes. Participant's in this research study will already be receiving androgen deprivation therapy (ADT) for prostate cancer. ADT is considered standard of care for prostate cancer. Changes in the participant's metabolism, including changes in insulin and blood sugar levels, are often seen as a result of this type of hormone therapy. Some studies have shown a relationship between insulin and prostate cancer. These studies have suggested that insulin may signal tumor cells to grow. Other studies suggest that people receiving metformin treatment for diabetes may enjoy better outcomes from their prostate cancer then other similar patients who are not treated with metformin.", 'detailedDescription': "* Each treatment cycle lasts 4 weeks (28 days). Participants will take metformin twice a day for all 28 days (except for the first 7 days of the first cycle when they will take it just once daily.)\n* The following procedures will be done on Day 1 of treatment cycles 1, 2, 4, 7 and 10: medical history review, performance status, physical exam, blood tests.\n* If the participant's first computed tomography (CT) or bone scan at the time of screening showed evidence of cancer, CT and bone scans will be repeated on Day 1 of treatment cycles 4, 7 and 10.\n* Participants will be in this research study for about 12 months."}, 'eligibilityModule': {'sex': 'MALE', 'stdAges': ['CHILD', 'ADULT', 'OLDER_ADULT'], 'healthyVolunteers': False, 'eligibilityCriteria': 'Inclusion Criteria:\n\n* Histologically or cytologically confirmed adenocarcinoma of the prostate\n* History of bilateral orchiectomies or ongoing treatment with a GnRH agonist for GnRH antagonist\n* Disease progression according to PSA Working Group 2\n* Minimum starting PSA (Prostate Specific Antigen) level of 2.0 ng/mL\n* Eastern Cooperative Oncology Group (ECOG) Performance Status 0 or 1\n\nExclusion Criteria:\n\n* Symptomatic metastases\n* Receiving any other agents for the treatment of prostate cancer except gonadotropin releasing hormone (GnRH) agonist or antagonist within the last 30 days\n* Received any investigational cancer treatment agents within the last 30 days\n* Prior treatment with docetaxel\n* History of diabetes requiring drug therapy\n* Current treatment with metformin or metformin treatment within the last year\n* History of allergic reaction to metformin\n* Have uncontrolled intercurrent illness including, but not limited to ongoing or unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements\n* Serum creatinine 1.5mg/dL or greater\n* Hepatic impairment\n* Need for ongoing treatment with cimetidine\n* History of a different malignancy except for the following circumstances: Individuals with a history of other malignancies are eligible of they have been disease-free for at least 5 years and are deemed by the investigator to be at low risk for recurrence of that malignancy. Individuals with the following cancers are eligible if diagnosed and treated within the past 5 years: basal cell or squamous cell carcinoma of the skin'}, 'identificationModule': {'nctId': 'NCT01215032', 'briefTitle': 'Metformin in Castration-Resistant Prostate Cancer', 'organization': {'class': 'OTHER', 'fullName': 'Massachusetts General Hospital'}, 'officialTitle': 'Prospective Study of Metformin in Castration-Resistant Prostate Cancer', 'orgStudyIdInfo': {'id': '10-244'}}, 'armsInterventionsModule': {'armGroups': [{'type': 'EXPERIMENTAL', 'label': 'Metformin', 'description': 'This is the only arm of this phase 2 open label study', 'interventionNames': ['Drug: Metformin']}], 'interventions': [{'name': 'Metformin', 'type': 'DRUG', 'description': 'Taken orally twice daily each 28-day cycle, for 12 cycles', 'armGroupLabels': ['Metformin']}]}, 'contactsLocationsModule': {'locations': [{'zip': '02114', 'city': 'Boston', 'state': 'Massachusetts', 'country': 'United States', 'facility': 'Massachusetts General Hospital', 'geoPoint': {'lat': 42.35843, 'lon': -71.05977}}, {'zip': '02115', 'city': 'Boston', 'state': 'Massachusetts', 'country': 'United States', 'facility': 'Beth Israel Deaconess Medical Center', 'geoPoint': {'lat': 42.35843, 'lon': -71.05977}}, {'zip': '02115', 'city': 'Boston', 'state': 'Massachusetts', 'country': 'United States', 'facility': 'Dana-Farber Cancer Institute', 'geoPoint': {'lat': 42.35843, 'lon': -71.05977}}], 'overallOfficials': [{'name': 'Matthew R. Smith, MD, PhD', 'role': 'PRINCIPAL_INVESTIGATOR', 'affiliation': 'Massachusetts General Hospital'}]}, 'ipdSharingStatementModule': {'ipdSharing': 'NO'}, 'sponsorCollaboratorsModule': {'leadSponsor': {'name': 'Massachusetts General Hospital', 'class': 'OTHER'}, 'collaborators': [{'name': 'Dana-Farber Cancer Institute', 'class': 'OTHER'}, {'name': "Brigham and Women's Hospital", 'class': 'OTHER'}, {'name': 'Beth Israel Deaconess Medical Center', 'class': 'OTHER'}], 'responsibleParty': {'type': 'PRINCIPAL_INVESTIGATOR', 'investigatorTitle': 'Professor of Medicine', 'investigatorFullName': 'Matthew R. Smith, MD, PhD', 'investigatorAffiliation': 'Massachusetts General Hospital'}}}}