Muscadine Grape Skin Extract (MPX) in Men with Biochemically Recurrent Prostate Cancer: A Randomized, Multicenter, Placebo-Controlled Clinical Trial

Clin Cancer Res. 2018 Jan 15;24(2):306-315. doi: 10.1158/1078-0432.CCR-17-1100. Epub 2017 Nov 7.


Purpose: MuscadinePlus (MPX), a commercial preparation of pulverized muscadine grape skin, was evaluated as a therapeutic option for men with biochemically recurrent (BCR) prostate cancer wishing to defer androgen deprivation therapy.Experimental Design: This was a 12-month, multicenter, placebo-controlled, two-dose, double-blinded trial of MPX in 125 men with BCR prostate cancer, powered to detect a PSA doubling time (PSADT) difference of 6 months (low dose) and 12 months (high dose) relative to placebo. Participants were stratified (baseline PSADT, Gleason score) and randomly assigned 1:2:2 to receive placebo, 500 mg MPX (low), or 4,000 mg MPX (high) daily. Correlates included superoxide dismutase-2 (SOD2) genotype, lipid peroxidation, and polyphenol pharmacokinetics.Results: The evaluable population included 112 patients, all treated for at least 6 months and 62% treated for 12 months. No significant difference was found in PSADT change between control and treatment arms (P = 0.81): control 0.9 months (n = 20; range, 6.7-83.1), low dose 1.5 months (n = 52; range, 10.3-87.2), high dose 0.9 months (n = 40; range, 27.3-88.1). One high-dose patient experienced objective response. No drug-related CTCAE grade 3-4 adverse events were seen. In a preplanned exploratory analysis, PSADT pre-to-post increase was significant in the 27 (26%) genotyped patients with SOD2 Alanine/Alanine genotype (rs4880 T>C polymorphism) on MPX (pooled treatment arms; 6.4 months, P = 0.02), but not in control (1.8 months, P = 0.25).Conclusions: Compared with placebo, MPX did not significantly prolong PSADT in BCR patients over two different doses. Exploratory analysis revealed a patient population with potential benefit that would require further study. Clin Cancer Res; 24(2); 306-15. ©2017 AACR.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers
  • Case-Control Studies
  • Genotype
  • Humans
  • Lipid Peroxidation / drug effects
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Plant Extracts / chemistry
  • Plant Extracts / therapeutic use*
  • Prostatic Neoplasms / drug therapy*
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / metabolism
  • Prostatic Neoplasms / pathology
  • Recurrence
  • Superoxide Dismutase / genetics
  • Vitis / chemistry*


  • Biomarkers
  • Plant Extracts
  • Superoxide Dismutase
  • superoxide dismutase 2