798PImpact of the addition of metformin (Met) to abiraterone (Abi) in metastatic castration-resistant prostate cancer (mCRPC) patients (pts) progressing on Abi treatment: A phase II pilot study. (18th September 2017) - Mark, M.; Klingbiel, D.; Mey, U.; Winterhalder, R.; Rothermundt, C.; Gillessen, S.; von Moos, R.; Manetsch, G.; Cathomas, R.