UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM 8-K
CURRENT REPORT
Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported): October 4, 2008
Sucampo Pharmaceuticals, Inc.
| Delaware | 001-33609 | 13-3929237 | ||
| (State or Other Juris- | (Commission | (IRS Employer | ||
| diction of Incorporation) | File Number) | Identification No.) | ||
| 4520 East-West Highway, Suite 300 | 20814 | |
| Bethesda, Maryland | ||
| (Address of Principal Executive Offices) | (Zip Code) | |
Registrant’s telephone number, including area code: (301) 961-3400
(Former Name or Former Address, if Changed Since Last Report)
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy
the filing obligation of the registrant under any of the following provisions (see General
Instruction A.2. below):
o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17
CFR 240.14d-2(b))
o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17
CFR 240.13e-4(c))
Item 8.01. Other Events.
On October 4, 2008, Sucampo Pharmaceuticals, Inc. delivered a scientific conference
presentation at the 2nd World Conference on Magic Bullets (Ehrlich II) and American
College of Gastroenterology that included written communication comprised of a presentation and
poster. The presentation and poster at the 2nd World Conference on Magic Bullets
(Ehrlich II) and American College of Gastroenterology are being furnished as Exhibits 99.1 and 99.2
to this Current Report on Form 8-K.
The information in this Item 8.01 and Exhibits 99.1 and 99.2 to this Form 8-K shall not be
deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (the “Exchange
Act”) or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated
by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act,
except as expressly set forth by specific reference in such a filing.
Item 9.01. Financial Statements and Exhibits.
(d) Exhibits
| 99.1 | Presentation for the 2nd World Conference on Magic Bullets (Ehrlich II), dated October 4, 2008 | ||
| 99.2 | Poster for American College of Gastroenterology, dated October 4, 2008 |
SIGNATURE
Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly
caused this report to be signed on its behalf by the undersigned hereunto duly authorized.
| SUCAMPO PHARMACEUTICALS, INC. | ||||
Date: October 7, 2008
|
By: | /s/ JAN SMILEK | ||
| Name: Jan Smilek | ||||
| Title: VP, Finance and Acting Chief Financial Officer | ||||
Exhibit 99.1
| PROSTONES AS ClC-2 Cl- ClC Cl CHANNEL ACTIVATORS FOR TREATMENT OF DISEASES AND DISORDERS John Cuppoletti University of Cincinnati, Cincinnati,OH and Ryuji Ueno, Sucampo Pharmaceuticals Inc., Bethesda, MD |
| Prostones · Prostones are derivatives of metabolites of prostaglandins. · Lubiprostone is a prostone which is used to clinically to treat chronic idiopathic constipation and irritable bowel syndrome related to constipation (IBS-C). · Lubiprostone is a ClC-2 chloride channel activator which increases salt and water secretion in the intestine. |
| ClC Cl- CHANNEL IS THE TARGET FOR LUBIPROSTONE
ClC Cl- CHANNELS ARE DIMERS
MEMBRANE DOMAIN1
CYTOSOLIC C- TERMINAL
DOMAIN2
1R.Dutzler, E.B. Campbell, M. Cadene, B.T. Chait and R.MacKinnon Nature 415,
287-294(2002) 2S. Alioth, S. Meyer, R. Dutzler and K. Pervushin Journal of Molecular Biology Vol. 369, Issue 5, 22 June 2007, Pages 1163-1169 |
| LUBIPROSTONE POTENTLY ACTIVATES RECOMBINANT HUMAN ClC-2 CHLORIDE CHANNELS STUDIED BY WHOLE CELL PATCH CLAMP Cuppoletti, J. et al. Am J Physiol Cell Physiol 287: C1173-C1183 2004 ©2004 American Physiological Society |
| LUBIPROSTONE ACTIVATES RECOMBINANT HUMAN ClC-2 Cl- CHANNELS IN HEK293 CELLS AT SINGLE CHANNEL LEVEL RECORDED BY PATCH CLAMP |
| siRNA TO ClC-2 ABLATES LUBIPROSTONE ACTIVATION OF CHLORIDE TRANSPORT BY RECOMBINANT HUMAN ClC-2 IN HEK293 CELLS Cuppoletti J, Malinowska DH Tewari K, Chakrabarti J, Ueno R Gastroenterology, Vol. 134, Issue: 4, April, 2008. pp. A-582 |
| LUBIPROSTONE ACTIVATES Cl- TRANSPORT IN T84 INTESTINAL CELL CULTURES STUDIED BY SHORT
CIRCUIT CURRENT WITH USSING CHAMBERS
USSING CHAMBER Cuppoletti, J. et al. Am J Physiol Cell Physiol 287: C1173-C1183 2004 |
| LUBIPROSTONE POTENTLY STIMULATES Cl- TRANSPORT IN T84 INTESTINAL CELLS Cuppoletti, J. et al. Am J Physiol Cell Physiol 287: C1173-C1183 2004 |
| siRNA TO ClC-2 ABLATES STIMULATION OF Cl-TRANSPORT BY LUBIPROSTONE IN T84 CELLS Cuppoletti J, Malinowska DH Tewari K, Chakrabarti J, Ueno R Gastroenterology, Vol. 134, Issue: 4, April, 2008. pp. A-582 |
| ClC-2 IS EXPRESSED ON THE APICAL MEMBRANE AS SHOWN USING NYSTATIN SOLUBILIZATION OF APICAL OR BASOLATERAL MEMBRANE Cuppoletti, J. et al. Am J Physiol Cell Physiol 287: C1173-C1183 2004 |
| LUBIPROSTONE DOES NOT STIMULATE Cl- TRANSPORT BY CFTR Cuppoletti, J. et al. Am J Physiol Cell Physiol 287: C1173-C1183 2004 |
| LUBIPROSTONE DOES NOT ACT THROUGH INCREASES IN INTRACELLULAR CALCIUM Cuppoletti J, Malinowska DH Tewari K, Chakrabarti J, Ueno R Gastroenterology, Vol. 134, Issue: 4, April, 2008. pp. A581-A-582 |
| LUBIPROSTONE DOES NOT ACTIVATE Cl-TRANSPORT THROUGH EP OR FP RECEPTORS J.Cuppoletti, D.H.Malinowska, R.Ueno. ACG meeting, Orlando,Fl October 5, 2008 |
| LUBIPROSTONE PROMOTES REPAIR OF BARRIER FUNCTION AFTER DAMAGE BY INDOMETHACIN AND ISCHEMIA Moeser, A. J. et al. Am J Physiol Gastrointest Liver Physiol 292: G647-G656 2007; |
| SUMMARY OF LUBIPROSTONE MECHANISMS OF ACTION · LUBIPROSTONE TARGETS ClC-2 CHLORIDE CHANNELS IN THE INTESTINE AS SHOWN BY WHOLE CELL CURRENTS, SINGLE CHANNELS AND SHORT CIRCUIT CURRENT. · LUBIPROSTONE POTENTLY ACTIVATES ClC-2 CHLORIDE CHANNELS · LUBIPROSTONE DOES NOT AFFECT OTHER INTESTINAL CHLORIDE CHANNELS · THE SITE OF ACTION OF LUBIPROSTONE IS THE APICAL MEMBRANE · LUBIPROSTONE DOES NOT ACT THROUGH EP- OR FP-RECEPTORS, INCREASES IN cAMP, OR INCREASED CALCIUM · LUBIPROSTONE INCREASES SALT AND WATER SECRETION IN INTESTINAL CELLS AND THIS IS THE BASIS FOR CLINICAL ACTION IN CONSTIPATION · LUBIPROSTONE PROMOTES REPAIR OF EPITHELIAL BARRIERS AND THIS MAY CONTRIBUTE TO CLINICAL ACTION IN IBS-C |
| ACKNOWLEGDEMENT · THESE STUDIES WERE SUPPORTED BY A GRANT FROM SUCAMPO PHARMACEUTICALS, INC., BETHESDA MD, USA |
Exhibit 99.2
| Prostaglandin Receptor Activation Properties of Lubiprostone
J. Cuppoletti*, D.H. Malinowska*, R. Ueno**
*Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, OH;
**Sucampo Pharmaceuticals, Inc., Bethesda, MD
Introduction
Lubiprostone is used clinically to treat chronic idiopathic constipation and irritable bowel
syndrome with constipation1. It is a prostone (derived from metabolites of
prostaglandins) that activates ClC-2 Cl- of 20 nM2 and increases
channels with an EC50
intestinal 3uid secretion. In the present study, the agonist and antagonist activity of
lubiprostoneonclonedhumanEPandFPreceptorswasexaminedtomoredirectlydetermine for lubiprostone
binding to these speci3c receptors. This reduces the need to use
the EC50
either EP receptor antagonists or complex biological processes such as contraction to infer binding
of lubiprostone to prostaglandin receptors.
Purpose
The aim of the present study was to determine the activities of lubiprostone on recombinant
prostaglandin receptors.
Methods
and FP receptors was assayed by
Lubiprostone binding to recombinant EP1, EP2, EP3, EP4
Millipore Corporation, Bioscience Division (St. Charles, MO), using Chemiscreen calcium optimized
FLIPR cell lines containing high levels of the promiscuous G protein, Galpha15, to enhance coupling
of the receptor to the calcium signaling pathway. These cells were
transfected with cDNA containing either full-length human EP1, EP2,
splice variant 6 of
or FP receptors. Triplicate assays of lubiprostone effects were carried out with
EP3, EP4
as a positive control. In all cases, the readout was relative 3uorescence
PGE2 or PGF2_
units related to [Ca2+ through calcium release activated calcium ion channel (CRAC)
]i
measured by Fluo-4 relative 3uorescence. To measure antagonist effects of lubiprostone, to give
cells with cloned human receptors were 3rst stimulated with either PGE2 or
PGF2_
about 80% of the maximum response and then lubiprostone was added.
Results
Positive controls: Measured agonist activity of on and
PGE2 EP1, EP2, EP3 EP4
receptor-expressing cells generated
EC50 values of 7.46, 49.82, 3.86 and 31.18 nM
respectively. Agonist activity of on FP receptor-expressing cells gave an
PGF2_ EC50
of 3.40 nM. or FP receptors (Figure 1).
Lubiprostone exhibited no agonist effects on cloned EP2, EP4
values
There was weak agonist activity of lubiprostone on EP1 and EP3 receptors
with EC50
of 330 nM and 280 nM, respectively, which are 44 and 73 times higher than the agonist activity on
the respective EP receptors.
activity of PGE2
or FP receptors
Lubiprostone did not demonstrate any detectable antagonist effects on EP2
receptors
(Figure 2). However, there was weak antagonist effect of lubiprostone on EP4
=127 nM).
(EC50 E001820 Figure 1. Agonist Effect of Lubiprostone on Cloned EP and FP Receptors Figure 1. and FP Dose response curve for agonist activity of lubiprostone on cloned EP1, EP2, EP3, EP4 receptors expressed in cultured cells. Data represent the mean (± SE) of 3 determinations. Figure 2. Antagonist Effect of Lubiprostone on Cloned EP and FP Receptors Figure 2. and FP Dose response curve for a ntagonist activity of lubiprostone on cloned human EP2, EP4 receptors expressed in cultured cells. Data represent the mean (± SE) of 3 determinations. Summary It has been shown in the present study that lubiprostone does not act as an agonist or FP receptors. The lack of agonist activity of lubiprostone on cloned human EP2, EP4 on cloned human contradicts the 3nding that lubiprostone reduced electrically EP4 stimulated neural contractions in rat and human colon circular muscle with an EC50 at near nanomolar levels that were inhibited by an (but not other EP) receptor EP4 antagonist3 receptor occupation and implies that these reported effects are not due to EP4 by lubiprostone. Agonist activity of lubiprostone on cloned was very low with an EP1 EC50= 330 nM, a receptor. Moreover, this concentration is value 44 times higher than for PGE2 on the EP1 for lubiprostone for activation of ClC-2 chloride approximately 15 times higher than the EC50 channels2. Lubiprostone remains mostly in the lumen of the gut and does not enter the circulation1. This means that lubiprostone will not reach sufficiently high concentrations to antagonists do not affect activate EP1 receptors in the stomach muscle layer. Since EP1 effects on the vagal nerve4, lubiprostone is unlikely to act on the stomach through the PGE2 (or other EP or FP) receptors causing vagal nerve stimulation. This study con3rms EP1 the previous 3ndings of Ueno et al5 that demonstrated that lubiprostone does not have pharmacologically relevant activity on prostaglandin receptors. Conclusions At clinically relevant doses lubiprostone is unlikely to have signi3cant PG receptor activity. The results demonstrate that activation of ClC-2 chloride channels underlying the clinical receptor occupation. effects of lubiprostone is independent of EP or FP2_ References 1. Amitiza [package insert]. Bethesda, MD: Sucampo Pharmaceuticals, Inc., 2008. 2. Cuppoletti J, Malinowska DH, Tewari KP, Li QJ, Sherry AM, Patchen ML, Ueno R. SPI-0211 activates T84 cell chloride transport and recombinant human ClC-2 chloride currents. Am J Physiol Cell Physiol. 2004 287(5):C1173-83. 3. Bassil AK, Borman RA, Jarvie EM, McArthur-Wilson RJ, Thangiah R, Sung EZ, Lee K, Sanger GJ. Activation of prostaglandin EP receptors by lubiprostone in rat and human stomach and colon. Br J Pharmacol. 2008 154(1):126-35. 4. Kan KK, Jones RL, Ngan MP, Rudd JA. Excitatory action of prostanoids on the ferret isolated vagus nerve preparation. Eur J Pharmacol. 2004 Apr 26;491(1):37-41. 5. Ueno R, Engelke KJ, and Osama H. Effects of lubiprostone, a novel GI chloride channel activator, on isolated smooth muscle. Neurogastroenterol Motil. 2005 17(4): 625-626. Supported by Sucampo Pharmaceuticals, Inc. and Takeda Pharmaceutical Company, Ltd. Presented at The American College of Gastroenterology 2008 Scienti3c Meeting |