`
`vrerner ancnrve [HPS
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`BOING. captures
`
`ures
`24 Jul 2008 - 6 Nov 2008
`
`About
`
`
`
`
`or: [E10)
`
`Clinical Trials
`
`Investor Relations
`
`Callisto
`
`Pharmaceuticals
`
`PIPELINE
`
`
`
`SP-304 Science
`
`SP-304 - A Platform to Treat Gastrointestinal Disease
`SP-304 is an analog of a natural hormone peptide called uroguanylin - a key regulator of intestinal function.
`Details of the biology of the guanylate cyclase C receptor and the therapeutic potential of SP-304 in GI diseases
`are discussed below.
`
`
` Uroguanylin and the Guany Cyclase C Recep
`
`Uroguanylin was discovered in the early 1990's by Drs. Leonard Forte and Mark Currie and their research
`teams (1, 2). It is secreted among other places in the intestinal tract and there functions by binding to a unique
`receptor found on epithelial cells of the intestine. This receptor, the guanylate cyclase C receptor or GC-C,
`the
`is
`of i
`cyclic GMP (cGMP), a key
`of cellular
`L
`works as an “agonist” of this receptor — binding of uroguanylin activates the receptor and promotes the
`intracellular synthesis of cGMP. cGMP in turn regulates a number of
`ical
`and pi
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`that have i as well as colon cancer. implications in the of several intestinal di
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`Certain bacteria, including E. coli, produce an enterotoxin called ST-peptide that is structurally related to
`uroguanylin. This peptide over-activates the GC-C receptor and p
`an
`unreg
`fluid
`intestine, producing what is commonly called travelers diarrhea.
`
`
`
`into the
`
`
`
`The Development of SP-304
`Uroguanylin is a linear peptide comprised of 16 amino acids that is folded into a three-dimensional structure (or
`ion)
`ing
`two inti
`ular
`disulfide linkages. This spatial structure and rigidity gives the
`hormone considerable stability in the intestinal tract. In addition, ur
`is quite
`and
`prot
`resistant, but not sufficient enough to permit is its use as a direct pharmacological agent. The native uroguanylin
`peptide also assumes active and inactive conformers in aqueous solution, reducing the overall potency of the
`natural hormone.
`
`
`
`« SP-304 Science
`
`* SP-304 Markets
`
`ll
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`In 2000, Callisto scientists headed by Dr. Kunwar Shailubhai used structure-function studies to develop a series
`of analogs of uroguanylin that were tested for biological activity and stability. This research effort led to the
`creation of SP-304. By changing just one key amino acid in uroguanylin the Callisto team created a compound
`that has superior pf
`i
`ies
`¢
`to uroguanylin (3). Unlike uroguanylin, SP-304 primarily
`ion.
`exists in a single bioacti
`The
`is stable,
`resistant and more potent than
`uroguanylin. It can be given orally, and is not systemically absorbed (i.e. taken up in the blood and distributed
`throughout the body) which means that the compound is likely to be very safe in clinical use. Since the GC-C
`receptors are found on the inside of the gastrointestinal
`lining,
`i
`ion
`is not needed for SP-304 to
`function as intended. The compound exerts its action locally in the intestines.
`
`
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`
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`for and IBS-C of chroni ipation
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`
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`GC-C ag
`Water plays a vital physiological role in the intestine. Proper water content of the intestinal lumen ensures
`normal transport of the content through the bowel. Water also facilitates maintenance of the intestinal mucus
`layer, which protects the GI mucosa from mechanical damage and the harmful effects of stomach acid and
`bacterial or viral pathogens. Too low water content can cause constipation, whereas too high water content, as
`occurs in diseases like cholera and toxic £. coli infections, typically leads to diarrhea. One of the major functions
`of uroguanylin is to regulate fluid and ion transport into the lumen of the intestine.
`
`In the Gl tract uroguanylin is produced by goblet cells and excreted into the lumen of the intestine. Uroguanylin
`then diffuses within the intestine to GC-C receptors on epithelial cells.
`
`=
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`Uroguanylin Function as Fluid Regulator in Intestine
`
`
`
`
`
`
`of cGMP, which in turn eventually
`the il
`Upon activation, the GC-C receptor
`activates the cystic fibrosis transmembrane receptor (CFTR) on these cells (CFTR is not related to cystic
`fibrosis in this location). The CFTR next secretes chloride and bicarbonate ions to regulate the salt content of
`the intestinal lumen. Water is also carried with the salt ions. The end effect is a secretion of salts and water into
`the intestine, resulting in a looser intestine content that is more easily transported through the bowel.
`
`Agonists of GC-C receptor provide a novel
`
`to the
`
`of chronic idi
`
`i
`
`ipation
`
`and
`
`
`
`
`
`(IBS-C). By using a GC-C receptor agonist to promote fluid
`sy
`irritable bowel
`i
`pi
`ion
`and ion transport into the intestine, it is possible to counteract the reduced motility and intestinal blockage
`common in constipation and IBS-C. GC-C receptor agonists have been clinically validated. Recent clinical data
`
`reported by Microbia Inc. on its compound Linaclotide demonstrated good efficacy and safety in the treatment of
`chronic idiopathic constipation and IBS- C (4, 5). Lil
`ide
`is a
`of ST-peptide
`and acts in
`the Gl tract by bonding to the GC-C receptor in the same way as SP-304.
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`0001
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`MYLAN - EXHIBIT 1017
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`SP-304 tor treatment of Ulcerative Lolitis
`such as nitric oxide and
`medi
`y effects of
`The GC-C pathway also
`regi
`the
`anti-i
`efficacy in
`4 inhibi
`i
`hemeoxygenase-1. Therapies that induce cGMP
`murine models of inflammatory bowel disease (IBD). SP-304 was recently shown to produce anti-inflammatory
`effects in animal models of ulcerative colitis, including TNBS- and DSS-induced colitis in mice (6). Importantly,
`the reduced i
`ion
`was
`iated
`with d
`ion
`of key pro-i
`y
`ing
`IL-4,
`IL-5, IL-23, and TNF (7). SP-304 treatment also down-regulates production of cyclooxygenase-2 (COX-2)
`i
`ion
`of
`in
`E2 (PGE), which is an i
`i
`y second
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`SP-304
`
`ism
`
`as Anti.
`
`y Agent
`
`
`
`lez
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`
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`SP-304 for prevention and control of colon cancer
`Recent studies demonstrate that uroguanylin as well as a similar human intestinal hormone guanylin are key
`
` regulators of growth and is in the epithelial layer of the i inal mucosa (8). Disruption
`
`
`
`
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`and/or
`irregularities in the turnover of cells, as is the case with individuals displaying reduced levels of endogenous
`
`uroguanylin, can lead to the development of polyps, colon cancer and i T y bowel di
`
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`of colon carcinoma cells with uroguanylin or with ST peptide was shown to inhibit cell proliferation and to induce
`apoptosis in a dose-dependent manner (9, 10).
`
`
`
`of Cell is Though U
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`A deficiency of uroguanylin is thought to be one of the primary reasons for the development of polyps in the
`colon, considerably increasing the risk of colon cancer. Oral treatment with uroguanylin in an animal model of
`colon cancer, the Apc +/min mouse, showed that
`lin
`inhibits polyp
`ion
`and also retards the
`of polyps to
`i
`(10). These mice are genetically engineered such that they mimic the
`etiology of colon carcinogenesis in humans. Thus, SP-304 has potential as an agent both to treat and prevent
`colon and other GI cancers.
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`
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`References
`
`
`
`mediated
`
`by cyclic GMP and
`
`. Hamra FK, Fan X, Krause WJ, Freeman RH, Chin DT, Smith CE, Currie MG, Forte LR. Prouroguanylin
`and
`ification
`from colon,
`, and
`of
`bi
`ity
`by
`Endocrinology. 1996 Jan;137(1):257-65.
`2. Forte, LR.,
`li
`y peptides:
`pathobiology. Reg. Pept., 81:25-39, 1999.
`. Shailubhai, K., G. Nikiforavich and Jacob, G.S. Guanylate Cyclase receptor agonists for the treatment of
`tissue inflammation and carcinogenesis. U.S. Patent 7,041,786, Issue may 9, 2006.
`Viola Andresen, Michael Camilleri, et al., Effect of 5 Days Linaclotide on Transit and Bowel Function in
`Females With Constipati
`i
`Irritable Bowel
`Sy
`»
`2007;133:761-
`768
`. Currie MG, Kurz CB, Mahajan-Miklos S, et al. Effects of a single dose administration of MD-1100 on
`safety, tolerability, exposure, and stool consistency in healthy subjects. Am J Gastoenterol.
`2005;100:5328.
`. Refaat AF. Hegazi, Fengling Li, Gabriel Calilao, Antonia Sepulveda, Kunwar Shailubhai, Scott E. Plevy
`SP304, an analog of
`i
`i
`il
`ion
`in a model of experimental colitis. Abstract,
`presented at Digestive Disease Week, 2005
`. Kunwar Shailubhai, Gary S. Jacob and Scott Plevy. SP-304, an agonist of Guanylate Cyclase C, is a
`new class of oral drug
`idate
`that
`i
`i
`ion
`in models of
`i
`colitis. To be
`presented at the 2007 Crohn's and Colitis Foundation National Research and Clinical Conference — 6th
`Annual Advances in the Inflammatory Bowel Diseases conference. December 6-9, 2007. Florida, USA.
`il
`i. KTH
`i
`ications
`of
`cyclase receptor agonists. Curr. Opin. Drug Disc.
`Dev. 5(2): 2002.
`. Pitari GM, Di Guglielmo MD, Park J, Schulz S, Waldman SA. Guanylyl cyclase C agonists regulate
`
`
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`biological
`
`activities
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`w
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`~
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`o
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`o
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`~
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`8.
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`©
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`progression through the cell cycle of human colon carcinoma cells. Proc. Natl. Acad. Sci. U.S.A. 98:
`7846-7851, 2001.
`Shailihhai K
`Vii
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`Wana V dan N
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`&
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`Kim H
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`H Kaninanandaa K Wana 1 V Fher @
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`Miedema, B. W., Abbas, Z., Boddupalli, S. B., Mark G. Currie, and Forte, L. R. (2000) UG treatment
`
`suppresses polyps formation in APC™"/+ mouse and induces apoptosis in human colon
`adenocarcinoma cells by a cGMP dependent mechanism. Cancer Research 60, 5151-5157.
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