New Drug Approvals

Home » 0rphan drug status » IPI 504, Retaspamycin, Retaspimycin

IPI 504, Retaspamycin, Retaspimycin



Read all about Organic Spectroscopy on ORGANIC SPECTROSCOPY INTERNATIONAL 


Recent Posts

Blog Stats

  • 3,672,524 hits

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 2,655 other followers

add to any


IPI 504, Retaspamycin, Retaspimycin

CAS 857402-63-2

Cas 857402-23-4 ( Retaspimycin); 857402-63-2 ( Retaspimycin  HCl).


MW: 587.32067 BASE

Infinity Pharmaceuticals Inc,  INNOVATOR

[(3R,5S,6R,7S,8E,10S,11S,12Z,14E)-6,20,22-trihydroxy-5,11-dimethoxy-3,7,9,15-tetramethyl-16-oxo-21-(prop-2-enylamino)-17-azabicyclo[16.3.1]docosa-1(22),8,12,14,18,20-hexaen-10-yl] carbamate;hydrochloride

17-Allylamino-17-demethoxygeldanamycin Hydroquinone Hydrochloride

  1. UNII-928Q33Q049
  2. SEE………
Retaspimycin hydrochloride; 8,21-didehydro-17-demethoxy-18,21-dideoxo-18,21-dihydroxy-17-(2-propenylamino)-geldanamycin monohydrochloride
Application: A novel, water-soluble, potent inhibitor of heat-shock protein 90 (Hsp90)
Molecular Weight: 624.17 ……….HCl salt
Molecular Formula: C31H46ClN3O8……….HCl salt


IPI-504 is a novel, water-soluble, potent inhibitor of heat-shock protein 90 (Hsp90).

Orphan drug designation was assigned to the compound by the FDA for the treatment of gastrointestinal stromal cancer (GIST).

Retaspimycin Hydrochloride is the hydrochloride salt of a small-molecule inhibitor of heat shock protein 90 (HSP90) with antiproliferative and antineoplastic activities. Retaspimycinbinds to and inhibits the cytosolic chaperone functions of HSP90, which maintains the stability and functional shape of many oncogenic signaling proteins and may be overexpressed or overactive in tumor cells. Retaspimycin-mediated inhibition of HSP90 promotes the proteasomal degradation of oncogenic signaling proteins in susceptible tumor cell populations, which may result in the induction of apoptosis.

Phase I study of Retaspimycin: A phase 1 study of IPI-504 (retaspimycin hydrochloride) administered intravenously twice weekly for 2 weeks at 22.5, 45, 90, 150, 225, 300 or 400 mg/m(2) followed by 10 days off-treatment was conducted to determine the safety and maximum tolerated dose (MTD) of IPI-504 in patients with relapsed or relapsed/refractory multiple myeloma (MM). Anti-tumor activity and pharmacokinetics were also evaluated. Eighteen patients (mean age 60.5 years; median 9 prior therapies) were enrolled. No dose-limiting toxicities (DLTs) were reported for IPI-504 doses up to 400 mg/m(2).

The most common treatment-related adverse event was grade 1 infusion site pain (four patients). All other treatment-related events were assessed as grade 1 or 2 in severity. The area under the curve (AUC) increased with increasing dose, and the mean half-life was approximately 2-4 h for IPI-504 and its metabolites. Four patients had stable disease, demonstrating modest single-agent activity in relapsed or relapsed/refractory MM.  (source: Leuk Lymphoma. 2011 Dec;52(12):2308-15.)


Figure Hsp90 protein partners and clients destabilized by Hsp90 inhibition (Jackson et al., 2004).

In a different approach, Infinity Pharmaceuticals has developed IPI504 (retaspimycin or 17-AAG hydroquinone, Figure 4) (Adams et al., 2005; Sydor et al., 2006), a new GA analogue, in which the quinone moiety was replaced by a dihydroquinone one. Indeed, the preclinical data suggested that the hepatotoxicity of 17-AAG was attributable to the ansamycin benzoquinone moiety, prone to nucleophilic attack.

Furthermore, it was recently reported that the hydroquinone form binds Hsp90 with more efficiency than the corresponding quinone form (Maroney et al., 2006). In biological conditions, the hydroquinone form can interconvert with GA, depending on redox equilibrium existing in cell. It has been recently proposed, that NQ01 (NAD(P)H: quinone oxidoreductase) can produce the active hydroquinone from the quinone form of IPI504 (Chiosis, 2006).

However, Infinity Pharmaceuticals showed that if the overexpression of NQ01 increased the level of hydroquinone and cell sensitivity to IPI504, it has no significant effect on its growth inhibitory activity. These results suggest that NQ01 is not a determinant of IPI504 activity in vivo (Douglas et al., 2009).

Figure 4: GA, 17-AAG, 17-DMAG and IPI504.



Geldanamycin (IUPAC name ([18S-(4E,5Z,8R*.9R*.10E,12R*.13S*,14R*,l6S*)]- 9- [(aminocarbonyl)oxy]- 13- hydroxy- 8,14,19- trimetoxy- 4,10,12,16- tetramethyl- 2- azabicyclo[16.3.1.]docosa- 4,6.10,18,21- pentan- 3.20,22trion) is a benzoquinone ansamycin antibiotic which may be produced by the bacterium Streptorayces hygroscopicus. Geldanamycin binds specifically to HSP90 (Heat Shock Protein 90) and alters its function.

While Hsp90 generally stabilizes folding of proteins and, in particular in tumor cells, folding of overexpressed/mutant proteins such as v-Src. Bcr-Abl and p53. the Hsp90 inhibitor Geldanamycin induces degradation of such proteins.

The respectiv e formula of geldanamycin is given herein below:

Figure imgf000022_0001

E\en though geldanamycin is a potent antitumor agent, the use of geldanamycin also shows some negathe side-effects (e.g. hepatotoxicity) which led to the dev elopment of geldanamycin analogues/derivatives, in particular analogues/deriv atives containing a derivatisation at the 17 position. Without being bound by theory , modification at the 17 position of geldanamycin may lead to decreases hepatotoxicity.

Accordingly geldanamycin analogues/derivatives which are modified at the 17 position, such as 17-AAG (17-N-Allylamino-17-demethoxygeldanamycin), are preferred in context of the present invention. Also preferred herein are geldanamycin derivatives to be used in accordance with the present invention which are water-soluble or which can be dissoh ed in water completely (at least 90 %. more preferably 95 %. 96 %. 97 %, 98 % and most preferably 99 %). 17-AAG ([QS.5S,6RJS$EΛ0R,l \SΛ2E,14E)-2\- (allylamino)-6-hydroxy-5.11-diraethoxy-

3.7.9,15-tetramethyl-16.20.22-trioxo-17-azabicyclo[16.3.1]docosa-8,12.14,18,21-pentaen-10- yl] carbamate) is. as mentioned above a preferred derivative of geldanamycin. 17- AAG is commercially available under the trade name “Tanespimycin (also known as KOS-953) for example from Kosan Biosciences Incorporated (Acquired by Bristol-Myers Squibb Company). Tanespimycin is presently studied in phase II clinical trials for multiple myeloma and breast cancer and is usually administered intravenously.

The respective formula of 17- AAG is given herein below:

Figure imgf000023_0001

Preferred geldanamycin-derh ative (HSP90 inhibitor) to be used in context of the present invention are IPI-504 (also known as retaspiimcin or Mcdi-561 : lnfinin Pharmaceuticals (Medlmmunc/ Astra Zeneca)). Clinical trials on the use of IPI-504 (which is usually administered intravenously) in the treatment of non-small cell lung cancer (NSCLC) and breast cancer are performed. Also alvespimycin hy drochloride (Kosan Biosciences Incorporated Acquired By : Bristol-Myers Squibb Company) is a highly potent, water-soluble and orally acti\e derivative of geldanamycin preferably used in context of the present invention.

Figure imgf000024_0001





WO 2005063714

Example 24

Preparation of Air-stable Hydroquinone Derivatives of the Geldanamycin Family of Molecules


Figure imgf000118_0001

17-Allylamino-17-Demethoxygeldanamycin (10.0 g, 17.1 mmol) in ethyl acetate

(200 mL) was stirred vigorously with a freshly prepared solution of 10% aqueous sodium hydrosulfite (200 mL) for 2 h at ambient temperature. The color changed from dark purple to bright yellow, indicating a complete reaction. The layers were separated and the organic phase was dried with magnesium sulfate (15 g). The drying agent was rinsed with ethyl acetate (50 mL). The combined filtrate was acidified with 1.5 M hydrogen chloride in ethyl acetate (12 mL) to pH 2 over 20 min. The resulting slurry was stirred for 1.5 h at ambient temperature. The solids were isolated by filtration, rinsed with ethyl acetate (50 mL) and dried at 40 °C, 1 mm Hg, for 16 h to afford 9.9 g (91%) of off-white solid. Crude hydroquinone hydrochloride (2.5 g) was added to a stirred solution of 5% 0.01 N aq. hydrochloric acid in methanol (5 mL). The resulting solution was clarified by filtration then diluted with acetone (70 mL). Solids appeared after 2-3 min. The resulting slurry was stirred for 3 h at ambient temperature, then for 1 h at 0-5 °C. The solids were isolated by filtration, rinsed with acetone (15 mL) and dried



J. Med. Chem., 2006, 49 (15), pp 4606–4615
DOI: 10.1021/jm0603116
Abstract Image

17-Allylamino-17-demethoxygeldanamycin (17-AAG)1 is a semisynthetic inhibitor of the 90 kDa heat shock protein (Hsp90) currently in clinical trials for the treatment of cancer. However, 17-AAG faces challenging formulation issues due to its poor solubility. Here we report the synthesis and evaluation of a highly soluble hydroquinone hydrochloride derivative of 17-AAG, 1a (IPI-504), and several of the physiological metabolites. These compounds show comparable binding affinity to human Hsp90 and its endoplasmic reticulum (ER) homologue, the 94 kDa glucose regulated protein (Grp94). Furthermore, the compounds inhibit the growth of the human cancer cell lines SKBR3 and SKOV3, which overexpress Hsp90 client protein Her2, and cause down-regulation of Her2 as well as induction of Hsp70 consistent with Hsp90 inhibition. There is a clear correlation between the measured binding affinity of the compounds and their cellular activities. Upon the basis of its potent activity against Hsp90 and a significant improvement in solubility, 1a is currently under evaluation in Phase I clinical trials for cancer.

17-Allylamino-17-demethoxygeldanamycin Hydroquinone Hydrochloride Ia

17-AAG hydroquinone hydrochloride (1a) as an off-white solid (11 g, 18 mmol, 80% yield). HPLC purity:  99.6%;

IR (neat):  3175, 2972, 1728, 1651, 1581, 1546, 1456, 1392, 1316, 1224, 1099, 1036 cm-1;

1H NMR (CDCl3:d6-DMSO, 6:1, 400 MHz): 

δ 10.20 (1H, br), 9.62 (2H, br), 8.53 (1H, s), 8.47 (1H, s), 7.74 (1H, s), 6.72 (1H, d, J= 11.6 Hz), 6.28 (1H, dd, J = 11.6, 11.2 Hz), 5.73 (1H, dddd, J = 17.2, 10.0, 3.2, 2.4 Hz), 5.53 (1H, d, J = 10.4 Hz), 5.49 (1H, dd, J = 10.8, 10.0 Hz), 5.32 (2H, s), 5.04 (1H, d, J = 4.8 Hz), 5.02 (1H, d, J = 16.0 Hz), 4.81 (1H, s), 4.07 (1H, d, J = 9.6 Hz), 3.67 (2H, d, J = 6.4 Hz), 3.31 (1H, d,J = 8.8 Hz), 3.07 (3H, s), 3.07−3.04 (1H, m), 2.99 (3H, s), 2.64 (1H, m), 2.52−2.49 (1H, m), 1.76 (3H, s), 1.61−1.39 (3H, m), 0.78 (3H, d, J = 6.4 Hz), 0.64 (3H, d, J = 7.2 Hz);

13C NMR (CDCl3:d6-DMSO, 6:1, 100 MHz):  δ 167.3, 155.8, 143.3, 136.3, 135.0, 134.2, 132.9, 132.1, 128.8, 127.6, 125.9, 125.3, 123.7, 123.0, 115.1, 104.5, 80.9, 80.7, 80.1, 72.5, 56.2, 56.2, 52.4, 34.6, 33.2, 31.1, 27.2, 21.6, 12.1, 12.1, 11.7;

HRMS calculated for C31H45N3O8 (M+ + H):  588.3285, Found 588.3273.


Synthesis and biological evaluation of IPI-504, an aqueous soluble analog of 17-AAG and potent inhibitor of Hsp90

MEDI 210

James R. Porter,, Jie Ge, Emmanuel Normant, Janid Ali, Marlene S. Dembski, Yun Gao, Asimina T. Georges, Louis Grenier, Roger Pak, Jon Patterson, Jens R. Sydor, Jim Wright, Julian Adams, and Jeffrey K. Tong.
Infinity Pharmaceuticals, Inc, 780 Memorial Drive, Cambridge, MA 02139
IPI-504 is the hydroquinone hydrochloride salt of 17-allylamino-17-demethoxy-geldanamycin (17-AAG), an Hsp90 inhibitor that is currently in clinical trials for the treatment of cancer.

IPI-504 demonstrates high aqueous solubility (>200 mg/mL). Interestingly, in vitro and in vivo IPI-504 interconverts with 17-AAG and exists in a pH and enzyme-mediated redox equilibrium. This occurs due to oxidation of the hydroquinone (IPI-504) to the quinone (17-AAG) at physiological pH and the reduction of 17-AAG by quinone reductases such as NQO1 to IPI-504.

Here we report the design and synthesis of the stabilized hydroquinone IPI-504 and its inhibitory effect against Hsp90 and Grp94. Although IPI-504 was originally designed to be a soluble prodrug of 17-AAG, the hydroquinone is more potent than the quinone in the biochemical Hsp90 binding assay.

Various hydroquinone analogs have been prepared to investigate the structure activity relationship of hydroquinone binding to Hsp90. Hydroquinone and quinone forms of 17-AAG metabolites show comparable binding affinities for Hsp90 and in cancer cell lines, hydroquinone analogs elicit specific responses consistent with Hsp90 inhibition.

The desirable pharmacological properties as well as in vitro and in vivo activity of our lead compound, IPI-504, has led to the initiation of Phase I clinical trials in multiple myeloma.




Synthesis and biological evaluation of IPI-504, an aqueous soluble analog of 17-AAG and potent inhibitor of Hsp90
231st Am Chem Soc (ACS) Natl Meet (March 26-30, Atlanta) 2006, Abst MEDI 210

Design, synthesis, and biological evaluation of hydroquinone derivatives of 17-amino-17-demethoxygeldanamycin as potent, water-soluble inhibitors of Hsp90
J Med Chem 2006, 49(15): 4606

///////////////////Hsp90, IPI-504, infinity pharma, Retaspamycin, Retaspimycin

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.


Follow New Drug Approvals on

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 2,655 other followers



DR ANTHONY MELVIN CRASTO, Born in Mumbai in 1964 and graduated from Mumbai University, Completed his Ph.D from ICT, 1991,Matunga, Mumbai, India, in Organic Chemistry, The thesis topic was Synthesis of Novel Pyrethroid Analogues, Currently he is working with GLENMARK LIFE SCIENCES LTD, Research Centre as Principal Scientist, Process Research (bulk actives) at Mahape, Navi Mumbai, India. Total Industry exp 30 plus yrs, Prior to joining Glenmark, he has worked with major multinationals like Hoechst Marion Roussel, now Sanofi, Searle India Ltd, now RPG lifesciences, etc. He has worked with notable scientists like Dr K Nagarajan, Dr Ralph Stapel, Prof S Seshadri, Dr T.V. Radhakrishnan and Dr B. K. Kulkarni, etc, He did custom synthesis for major multinationals in his career like BASF, Novartis, Sanofi, etc., He has worked in Discovery, Natural products, Bulk drugs, Generics, Intermediates, Fine chemicals, Neutraceuticals, GMP, Scaleups, etc, he is now helping millions, has 9 million plus hits on Google on all Organic chemistry websites. His friends call him Open superstar worlddrugtracker. His New Drug Approvals, Green Chemistry International, All about drugs, Eurekamoments, Organic spectroscopy international, etc in organic chemistry are some most read blogs He has hands on experience in initiation and developing novel routes for drug molecules and implementation them on commercial scale over a 30 PLUS year tenure till date June 2021, Around 35 plus products in his career. He has good knowledge of IPM, GMP, Regulatory aspects, he has several International patents published worldwide . He has good proficiency in Technology transfer, Spectroscopy, Stereochemistry, Synthesis, Polymorphism etc., He suffered a paralytic stroke/ Acute Transverse mylitis in Dec 2007 and is 90 %Paralysed, He is bound to a wheelchair, this seems to have injected feul in him to help chemists all around the world, he is more active than before and is pushing boundaries, He has 9 million plus hits on Google, 2.5 lakh plus connections on all networking sites, 90 Lakh plus views on dozen plus blogs, 233 countries, 7 continents, He makes himself available to all, contact him on +91 9323115463, email, Twitter, @amcrasto , He lives and will die for his family, 90% paralysis cannot kill his soul., Notably he has 33 lakh plus views on New Drug Approvals Blog in 233 countries...... , He appreciates the help he gets from one and all, Friends, Family, Glenmark, Readers, Wellwishers, Doctors, Drug authorities, His Contacts, Physiotherapist, etc

Personal Links

View Full Profile →



Follow my blog with Bloglovin The title of your home page You could put your verification ID in a comment Or, in its own meta tag Or, as one of your keywords Your content is here. The verification ID will NOT be detected if you put it here.
%d bloggers like this: