SAKK 08/15 - PROMET - Salvage Radiotherapy +/- Metformin for Patients With Prostate Cancer After Prostatectomy

Although the use of salvage radiotherapy (SRT) is the only potentially curative treatment after prostatectomy failure, it has provided suboptimal results over the years. Metformin may represent an effective and inexpensive means to improve SRT outcomes with a favorable therapeutic ratio. Taken pre-clinical and retrospective clinical data together, there is a compelling rationale for conducting a RCT with SRT and metformin. Herein we propose a multicenter, randomized, open-label, proof-of-concept phase II trial with the hypothesis that the addition of metformin to SRT can delay time to progression compared to the standard-of-care SRT. The study has 1:1 randomization and stratification variables include Gleason score, PSA at SRT, surgical margin status and ADT use.