SAKK 08/15 - PROMET - Salvage Radiotherapy +/- Metformin for Patients With Prostate Cancer After Prostatectomy
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ClinicalTrials.gov Identifier: NCT02945813 |
Recruitment Status :
Terminated
(Trial was prematurely closed for accrual by the SAKK Board and the follow-up period shortened to one year after last RT fraction of the last patient)
First Posted : October 26, 2016
Last Update Posted : April 14, 2022
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Condition or disease | Intervention/treatment | Phase |
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Prostate Cancer | Drug: Metformin Radiation: Salvage Radiotherapy SRT | Phase 2 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 112 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Treatment |
Official Title: | SAKK 08/15 - PROMET - Multicenter, Randomized Phase II Trial of Salvage Radiotherapy +/- Metformin for Patients With Prostate Cancer After Prostatectomy |
Actual Study Start Date : | October 24, 2017 |
Actual Primary Completion Date : | February 28, 2022 |
Actual Study Completion Date : | February 28, 2022 |

Arm | Intervention/treatment |
---|---|
Experimental: Arm A: Metformin
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Drug: Metformin
850mg PO BID; 48 weeks Radiation: Salvage Radiotherapy SRT SRT 35 x 2Gy; 7 weeks |
Active Comparator: Arm B: Salvage Radiotherapy
- Salvage radiotherapy SRT - 35 x 2Gy; 7 weeks
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Radiation: Salvage Radiotherapy SRT
SRT 35 x 2Gy; 7 weeks |
- Time to progression (TTP) [ Time Frame: within 18 months after randomization ]
The primary endpoint of the trial is time to progression (TTP), defined as time from randomization until one of the following events, whichever comes first:
- Biochemical progression
- Clinical progression
- Death due to clinical progression
- Progression free survival (PFS) [ Time Frame: within 18 months after randomization ]
PFS is defined as time from randomization until one of the following events, whichever comes first:
- Biochemical progression
- Clinical progression
- Death from any cause
- Undetectable Prostate Specific Antigen (PSA) under normal testosterone levels [ Time Frame: up to 18 months after last radiotherapy fraction ]Undetectable PSA is defined as a serum PSA value of ≤0.05 ng/mL for at least two consecutive measurements after the last radiotherapy fraction and up to 18 months thereafter. To count as undetectable PSA under normal testosterone levels, the testosterone level has to be ≥50 ng/dL (i.e. a non-castrate testosterone level).
- 50% PSA response [ Time Frame: at randomization up to 18 months after last radiotherapy fraction. ]50% PSA response is defined as a ≥50% PSA decline after radiotherapy compared to the serum PSA level at randomization up to 18 months after last radiotherapy fraction.
- Clinical progression-free survival [ Time Frame: week 64 then every 6 months for the first year and every 12 months thereafter up to 10 years from last RT fraction. ]Clinical progression-free survival will be calculated as the time from randomization until clinical progression or death due to any cause.
- Time to further anti-cancer systemic therapy [ Time Frame: week 64 then every 6 months for the first year and every 12 months thereafter up to 10 years from last RT fraction. ]Time to further anti-cancer systemic therapy (e.g. hormonal treatment) is defined as the time from randomization to the start of any type of salvage systemic treatment.
- Prostate cancer-specific survival (PCSS) [ Time Frame: at week 64 then every 6 months for the first year and every 12 months thereafter up to 10 years from last RT fraction. ]Prostate cancer-specific survival will be calculated as the time from randomization to the date of death due to prostate cancer.
- Overall survival (OS) [ Time Frame: at week 64 then every 6 months for the first year and every 12 months thereafter up to 10 years from last RT fraction. ]Overall survival will be calculated as the time from randomization to the date of death from any cause.
- Adverse Events (AE) [ Time Frame: until 56 weeks (specific RT-related AEs : until 10 years) ]AEs will be assessed according to NCI CTCAE v4.03.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years to 75 Years (Adult, Older Adult) |
Sexes Eligible for Study: | Male |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Written informed consent according to ICH/GCP regulations before registration and prior to any trial specific procedures
- Histologically confirmed adenocarcinoma of the prostate without small cell features
- Tumor stage pT2a-3b, pN0 or cN0, M0, R0-1 resection margins, according to UICC TNM 2009, Gleason score available
- Radical prostatectomy (RP) at least 12 weeks before registration
- PSA progression after RP defined as two consecutive rises with the final PSA > 0.1 ng/mL or three consecutive rises. The first value must be measured earliest 4 weeks after RP
- PSA ≤ 2 ng/mL within 14 days prior to registration
- Age ≥ 18 years at time of registration
- WHO performance status 0-1
- Adequate hepatic function within 14 days prior to registration: bilirubin ≤ 1.5 x ULN (exception if Gilbert's syndrome ≤ 3 x ULN), AST and ALT ≤ 2.5 x ULN
- Adequate renal function within 14 days prior to registration: calculated corrected creatinine clearance ≥ 60 mL/min, according to the formula of corrected Cockcroft-Gault Patient agrees not to father a child and to use effective contraceptive methods during salvage radiotherapy and until 6 months after the last fraction of radiotherapy
Exclusion Criteria:
- Persistent PSA (> 0.4 ng/mL) 4 to 20 weeks after RP
- Pelvic lymph node enlargement > 0.8 cm in short axis diameter (cN positive) assessed by mpMRI within 12 weeks prior to registration, unless the enlarged lymph node is sampled and negative
- Evidence of macroscopic local recurrence assessed by mpMRI within 12 weeks prior to registration
- Palpable prostatic fossa mass suggestive of recurrence, unless an ultrasound guided biopsy is negative for malignancy
- Presence or history of prostate cancer metastases. In case of clinical suspicion (e.g. bone pain), imaging (e.g. bone scan, Choline-PET, PSMA-PET, whole body MRI) must be performed. The imaging method is at the discretion of the investigator.
- If PET/CT scan was performed, any metabolic uptake considered clinically suspicious for malignancy, unless biopsy proves to be negative.
- History of hematologic or primary solid tumor malignancy, unless in remission for at least 3 years from registration with the exception of curatively treated localized non-melanoma skin cancer
- Patients diagnosed with diabetes mellitus
- Treatment with metformin within the last 3 months prior to registration
- Prior pelvic radiotherapy
- Hormonal treatment as bilateral orchiectomy prior or following RP
- Usage of products known to affect PSA levels within 4 weeks prior to start of trial treatment
- Bilateral hip prosthesis
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Severe or active co-morbidity likely to impact on the advisability of salvage RT, e.g.:
- History of inflammatory bowel disease or any malabsorption syndrome or conditions that would interfere with enteral absorption
- Acute bacterial or fungal infection requiring intravenous antibiotics at the time of registration
- Unstable angina and/or congestive heart failure requiring hospitalization within the last 6 months
- Transmural myocardial infarction within the last 6 months
- Chronic Obstructive Pulmonary Disease (COPD) exacerbation or other respiratory illness requiring hospitalization or precluding study therapy at the time of registration
- Any condition associated with increased risk of lactic acidosis (e.g. alcohol abuse, congestive heart failure NYHA III or IV
- Clinically significant history of liver disease consistent with Child-Pugh Class B or C, including viral or other hepatitis, current alcohol abuse, or cirrhosis
- Severe or uncontrolled kidney disease resulted in impaired kidney function (GFR <60ml/min)
- Any acute or chronic condition that could cause tissue hypoxia (e.g. cardiac or respiratory insufficiency, recent myocardial infarction, shock)
- Treatment with any experimental drug or participation within a clinical trial within 30 days prior to registration (exception: concurrent participation in the biobank project SAKK 63/12 is allowed)
- Any concomitant drug contraindicated for use with metformin according to the approved product information
- Known hypersensitivity to metformin/placebo or to any of its components
- Hereditary intolerance to fructose; known galactose-1-phosphate uridyl transferase deficiency, UDP galactose 4 epimerase deficiency, galactokinase deficiency, Fanconi-Bickel syndrome, congenital lactase deficiency, or glucose-galactose malabsorption (due to the lactose-containing placebo)
- Inability or unwillingness to swallow oral medication
- Any other serious underlying medical, psychiatric, psychological, familial or geographical condition, which in the judgment of the investigator may interfere with the planned staging, treatment and follow-up, affect patient compliance or place the patient at high risk from treatment-related complications

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02945813

Study Chair: | Daniel M. Aebersold, Prof | Bern University Hospital - Radiation Oncology | |
Study Chair: | Alan Dal Pra, MD | Miller School of Medicine, University of Miami |
Responsible Party: | Swiss Group for Clinical Cancer Research |
ClinicalTrials.gov Identifier: | NCT02945813 |
Other Study ID Numbers: |
SAKK 08/15 - PROMET 2016-003599-39 ( EudraCT Number ) |
First Posted: | October 26, 2016 Key Record Dates |
Last Update Posted: | April 14, 2022 |
Last Verified: | April 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Prostate Cancer Prostate Cancer after Prostatectomy Phase II Trial Salvage Radiotherapy Metformin |
Prostatic Neoplasms Genital Neoplasms, Male Urogenital Neoplasms Neoplasms by Site Neoplasms Genital Diseases, Male Genital Diseases |
Urogenital Diseases Prostatic Diseases Male Urogenital Diseases Metformin Hypoglycemic Agents Physiological Effects of Drugs |