- No other chemotherapeutic agents, biological response modifiers, radiation therapy, corticosteroid or hormonal concomitant therapy (other than continuing LHRH treatment) may be given during protocol treatment; bisphosphonates may not be given during protocol treatment except under the circumstances outlined; no unconventional therapy (e.g. St. John's Wort, PC-SPES, or any other herbal remedies taken for the purpose of treating prostate cancer) may be given during protocol treatment