Amy E. Gravell, MS

Flavopiridol [2-(2-chlorophenyl 5 ,7-dihydroxy-8-[cis-(3-hydroxy-1-methyl-4-piperidinyl)-4H-1-benzopyran-4-one, hydrochloride] is a semisynthetic flavone with a novel structure compared with that of polyhydroxylated flavones, such as quercetin and genistein.[1] It is derived from rohitukine, an alkaloid isolated from the stem bark of Dysoxylum binectariferum, a plant indigenous to India.[2] Originally synthesized and supplied by Hoechst India Limited, flavopiridol is provided to the Division of Cancer Treatment and Diagnosis of the National Cancer Institute (NCI) by Aventis Pharmaceuticals, Inc.

R115777 (Zarnestra) is an orally available methylquinolone derivative from Johnson & Johnson Pharmaceutical Research and Development L.L.C. that is a potent and selective nonpeptidomimetic farnesyltransferase inhibitor (FTI).[1] FTIs represent a new class of agents that were originally developed to inhibit tumors by interfering with posttranslational processing of oncogenic Ras protein. The anticancer activity of FTIs might stem from their ability to effect various proteins other than Ras that can also mediate signal transduction, apoptosis, angiogenesis, and growth.[2]

Fenretinide (N-4-hydroxyphenyl-retinamide, or 4-HPR) is a semisynthetic retinoid that was initially developed as a low-dose chemopreventative agent.[1-3] Unlike other naturally occurring retinoids such as all-trans, 13-cis, and 9-cis retinoic acids, fenretinide does not induce systemic catabolism that interferes with the maintenance of effective plasma levels during long-term use. This characteristic, combined with the agent’s low toxicity and its ability to block aspects of carcinogenesis, provided the rationale for the development of fenretinide in lower doses as a chemoprevention agent for breast, prostate, and bladder cancer.

STI571 (Gleevec) is a member of the 2-phenylaminopyrimidine family of adenosine triphosphate (ATP) binding site inhibitors of protein tyrosine kinase. It potently inhibits the tyrosine kinase activity of Abl and Bcr-Abl,[1-3] platelet-derived growth factor receptor (PDGF-R), and Kit (stem cell factor receptor).[4-6]

The 4th National Institutes of Health (NIH) Consensus Conference on Adjuvant Therapy of Breast Cancer, held November 1-3, 2000, concluded that decreasing breast cancer mortality rates in the United States were due, at least in part, to advances made in adjuvant treatment. This fact lends credence to the importance of incremental improvements that have resulted from randomized, controlled clinical trials of adjuvant therapy, and underscores the value of this approach. With 185,000 new diagnoses of breast cancer expected in the United States in 2000, over 100,000 women may be candidates for some form of adjuvant therapy each year.[1]