Phase II Trial of Acai Juice Product in Biochemically Recurrent Prostate Cancer.

BACKGROUND: Plant derivatives have been studied as therapies for prostate cancer based on their purported anti-inflammatory and antioxidant properties and low toxicities. The acai berry is an example of a plant rich in phytochemicals, which may slow the growth of prostate cancer. METHODS: This was a phase II, Simon 2-stage clinical trial in patients with biochemically recurrent prostate cancer with a primary endpoint of prostate-specific antigen (PSA) response. Patients were asymptomatic, with a rising PSA of at least 0.2 ng/mL, and were treated with twice daily intake of Acai Juice Product until PSA progression, with a primary endpoint of PSA response. RESULTS: Twenty-one patients were enrolled in the first stage of the trial. One of those patients had a PSA response within the study time period. The PSA doubling time was lengthened in 71% of patients (95% confidence interval = 48% to 89%) on the trial, and in a small number of responders, this was sustained over an extended time. CONCLUSIONS: This study did not meet its primary endpoint of 50% PSA response. Nevertheless, the overall tolerability and effects on PSA stabilization warrant further exploration in a biochemically recurrent population.

A phase I and pharmacokinetic study of silybin-phytosome in prostate cancer patients.

Silibinin is a polyphenolic flavonoid isolated from milk thistle with anti-neoplastic activity in several in vitro and in vivo models of cancer, including prostate cancer. Silybin-phytosome is a commercially available formulation containing silibinin. This trial was designed to assess the toxicity of high-dose silybin-phytosome and recommend a phase II dose. Silybin-phytosome was administered orally to prostate cancer patients, giving 2.5-20 g daily, in three divided doses. Each course was 4 weeks in duration. Thirteen patients received a total of 91 courses of silybin-phytosome. Baseline patient characteristics included: median age of 70 years, median baseline prostate specific antigen (PSA) of 4.3 ng/ml, and a median ECOG performance status of 0. The most prominent adverse event was hyperbilirubinemia, with grade 1-2 bilirubin elevations in 9 of the 13 patients. The only grade 3 toxicity observed was elevation of alanine aminotransferase (ALT) in one patient; no grade 4 toxicity was noted. No objective PSA responses were observed. We conclude that 13 g of oral silybin-phytosome daily, in 3 divided doses, appears to be well tolerated in patients with advanced prostate cancer and is the recommended phase II dose. Asymptomatic liver toxicity is the most commonly seen adverse event.