In a study conducted by Christian Rothermundt, MD, Kantonsspital St. Gallen in St. Gallen, Switzerland, and colleagues, 44 men with metastatic CRPC received metformin 1,000 mg twice daily until disease progression. The primary endpoint was the absence of disease progression at 12 weeks.
Results showed that 36% of patients were progression-free at 12 weeks and 9.1% were progression-free at 24 weeks. The researchers confirmed a 50% or greater PSA decline in two patients. In 23 patients (52.3%), the researchers observed a prolongation of PSA doubling time after starting metformin.