title: Retaspimycin hydrochloride (IPI-504): a novel heat shock protein inhibitor as an anticancer agent.
abstract: Heat shock proteins are vital to cell survival under conditions of stress. They bind client proteins to assist in protein stabilization, translocation of polypeptides across cell membranes and recovery of proteins from aggregates. Heat shock protein inhibitors are a diverse group of novel agents that have been demonstrated to have pro-apoptotic effects on malignant cells through inhibition of ATP binding on the ATP/ADP-binding pocket of the heat shock protein. Initial development of heat shock protein 90 inhibitors, geldanamycin and 17-AAG, were limited by hepatotoxicity and the need for solvent carrying agents. In contrast, retaspimycin, or IPI-504, a derivative of geldanamycin and 17-AAG, is highly soluble in water and generally well tolerated. In Phase I/II trials, retaspimycin has shown activity in NSCLC and gastrointestinal stromal tumor. The most promising activity was observed in gastrointestinal stromal tumors. Phase I/II trials are currently underway to evaluate the dosing schedules and activity of IPI-504 in breast cancer. Given the in vitro activity in diffuse large B-cell lymphoma, mantle cell lymphoma, melanoma, leukemia and pancreatic cancer, current and future trials are of clinical interest. This article reviews IPI-504 and its utility in a wide variety of cancer phenotypes.
authors: Loyola University Chicago, Stritch School of Medicine, Division of Hematology/Oncology, Department of Medicine, 2160 S 1st Avenue Maywood, IL 60153, USA.
authors: Britt Erika
authors: BE
authors: Hanson
authors: David H
authors: DH
authors: Vesole
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D016227:Benzoquinones / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D018841:HSP90 Heat-Shock Proteins / Q000037:antagonists & inhibitors*; D006801:Humans; D047029:Lactams, Macrocyclic / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D015394:Molecular Structure; D009369:Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D016227:Benzoquinones; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; C112765:tanespimycin