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IPI-504 (retaspimycin)

IPI-504 (generic name retaspimycin) was previously under development by manufacturer Infinity Pharmaceuticals in conjunction with MedImmune, a part of AstraZeneca.  You may sometimes see it without the hyphen as IPI504.  This drug targets Heat-shock protein 90 (Hsp90). Hsp90 is one of a class of chaperone proteins, whose normal job is to help other proteins acquire and maintain the shape required for those proteins to do their jobs. Chaperone proteins work by being in physical contact with other proteins. Hsp90 can also enable cancer cells to survive and even thrive despite genetic defects which would normally cause such cells to die. Thus, blocking the function of Hsp90 and related chaperone proteins may cause cancer cells to die, especially if blocking chaperone function is combined with other strategies to block cancer cell survival.

2009 poster about IPI-504 in GIST

Click here to open an Adobe pdf of a poster presented about the IPI-504 RING trial described below.


RING Trial  (suspended 4/15/2009)


The RING trial described below was suspended April 15, 2009 due to safety concerns that require further analysis.  For further information please link to details at the Infinity website.

Message to GIST Patients from Infinity Pharmaceuticals:

"On  April 15, 2009, Infinity Pharmaceuticals announced that it has ended its Ph 3 study of IPI-504 (retaspimycin hydrochloride)—also known as the RING trial-- in patients with refractory GIST.  This decision was made after an early safety analysis showed a higher than anticipated mortality rate among patients who were treated with  IPI-504 vs. those who were receiving placebo.  Once the data are more comprehensively analyzed, Infinity will make additional  information available. 

Infinity and all of its employees would like to extend its deepest gratitude to all the patients and caregivers who participated in this global trial and thank them for their support. "


Additional Information

There are no open trial of retaspimycin listed on for any condition.

Data about IPI-504 trial performance were presented at the June 2008 ASCO meeting: you can link to this abstract by clicking the title below:
Inhibition of heat shock protein 90 (Hsp90) with the novel agent IPI-504 in metastatic GIST following failure of tyrosine kinase inhibitors (TKIs) or other sarcomas: Clinical results from phase I trial. Abstract - No. 10503

To download a pdf of a poster presented at EORTC 2006 about early results with IPI-504, click the preceding word "poster" and then use the magnification feature of Adobe reader to enlarge the poster for easy reading (try viewing at 200% manification).  This poster was graciously provided by Infinity Pharmaceuticals.

A January 2007 presentation about IPI-504 at the ASCO Gastrointestinal Cancers Symposium is available at this link.  You can choose to view the slides only or the webcast (voice of speaker plus slides) by selecting either the "slides" or "video" icon under #2 below the abstract.

A scientific paper about IPI-504 published electronically in November 2006 is available free-access through the journal Proceedings of the National Academy of Sciences at this link.  The paper, by Sydor et al, is entitled "Development of 17-allylamino-17-demethoxygeldanamycin hydroquinone hydrochloride (IPI-504), an anti-cancer agent directed against Hsp90."

Here is a link to a very detailed scientific article in Medscape about HSP 90, the target of this drug.  Medscape content is free-access, but you must complete a free registration.

Here is a link to information about Hsp90 in Wikipedia.

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