Prospective, multicenter, randomized phase II trial of the herbal supplement, PC-SPES, and diethylstilbestrol in patients with androgen-independent prostate cancer

William K. Oh, Philip W. Kantoff, Vivian Weinberg, Graham Jones, Brian I. Rini, Mika K. Derynck, Robert Bok, Matthew R. Smith, Glenn J. Bubley, Robert T. Rosen, Robert S. DiPaola, Eric J. Small

Research output: Contribution to journalArticlepeer-review

110 Scopus citations

Abstract

Purpose: To evaluate the herbal combination, PC-SPES, and diethylstilbestrol (DES) in patients with androgen independent prostate cancer (AIPC). Patients and Methods: A randomized phase II study was conducted with cross-over design. Patients were randomly assigned to receive either three PC-SPES capsules orally three times a day or DES 3 mg orally once a day. Prophylactic warfarin was administered. At clinical or prostate-specific antigen progression, patients received the other therapy. The study closed prematurely after PC-SPES was withdrawn from the market. Chemical analyses were performed on multiple lots of PC-SPES. Results: Ninety patients were enrolled, of whom 85 were assessable for response. Prostate-specific antigen declines ≥ 50% were noted in 40% (95% CI, 25% to 56%) with PC-SPES, and 24% (95% CI, 12% to 39%) with DES. Median response duration was not reached with PC-SPES, and was 3.8 months with DES. Median time to progression for randomly assigned patients was 5.5 months for PC-SPES and 2.9 months for DES. Common toxicities included mild fatigue, gynecomastia, and mastodynia. Five thromboembolic events occurred (one PC-SPES, four DES). Responses in the cross-over phase were inconclusive. Four lots of PC-SPES had measurable quantities of DES, ranging from 0.01% to 3.1% of the dose used in the DES arm. Ethinyl estradiol was also detected in PC-SPES lots. Conclusion: PC-SPES and DES demonstrate activity in AIPC and are well tolerated. However, the synthetic estrogens, DES and ethinyl estradiol, were detected in various lots of PC-SPES, including those used in this trial. Clinical trials that utilize herbal therapies must account for issues of purity and consistency.

Original languageEnglish
Pages (from-to)3705-3712
Number of pages8
JournalJournal of Clinical Oncology
Volume22
Issue number18
DOIs
StatePublished - 2004
Externally publishedYes

Fingerprint

Dive into the research topics of 'Prospective, multicenter, randomized phase II trial of the herbal supplement, PC-SPES, and diethylstilbestrol in patients with androgen-independent prostate cancer'. Together they form a unique fingerprint.

Cite this