-
`
`Inflammatory bowel diseases.
`v. 5, no. 2 (May 1999)
`General Collection
`\N1 II\141KX
`A
`44 Received, 05-10-1999
`
`ITATOIZI TAT
`LIBRARY OF
`MEDICINE
`
`OFFICIAL JOURNAL OF THE
`
`CCO
`
`Crohn's & Colitis Foundation
`of America, Inc.
`
`LIPPINCOTT WILLIAMS & WILKINS
`
`Volumeh5,,,,,-_0_:Niumber 2 o May 1999
`
`att- (cid:9)
`
`3 rrIE,..T
`t Ls,
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`Ex. 1005 - Page 1
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`Ex. 1005 - Page 1
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`

`

`Inflammatory Bowel Diseases®
`
`Robert Burakoff, M.D., FACG, FACP
`Professor of Medicine
`State University of New York at Stony Brook
`Chief, Division of GI, Flepatology & Nutrition
`Winthrop-University Hospital
`Mineola, New York
`
`Editors
`
`Richard P. MacDermott, M.D.
`Chief, Gastroenterology Section
`Lahey Clinic
`Burlington, Massachusetts
`
`Clinical Articles
`Brian G. Feagan
`London, Ontario, Canada
`William J. Tremainc
`Rochester, Minnesota
`
`Pediatric
`Richard J. Grand
`Boston, Massachusetts
`
`Basic Science Articles
`Stephen P. James
`Baltimore, Maryland
`William F. Stenson
`St. Louis, Missouri
`Joel V. Weinstock
`Iowa City, lowa
`
`Section Editors
`
`Clinical Trials and Therapeutics
`Stephen B. Hanauer
`Chicago, Illinois
`Lloyd R. Sutherland
`Calgary, Alberta, Canada
`
`Clinical Reviews
`David B. Sachar
`New York, New York
`William J. Sandborn
`Rochester, Minnesota
`Harland S. Winter
`Boston, Massachusetts
`
`Crohn's & Colitis Foundation of America, Inc.
`Marjorie Merrick
`New York, New York
`
`Basic Science Reviews
`Claudio Fiocchi
`Cleveland, Ohio
`Lloyd F. Mayer
`New York, New York
`R. Balfour Sartor
`Chapel Hill, North Carolina
`
`Controversies in IBD
`Peter A. Banks
`Boston, Massachusetts
`Daniel H. Present
`New York, New York
`
`Selected Summaries
`Mark A. Peppercorn
`Boston, Massachusetts
`
`Shelley Johnson
`Publisher
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`Rebecca Morelli
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`Official Journal of the Crohn's & Colitis Foundation of America, Inc.
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`Lisa H. Richardson, Chairperson of the Board (cid:9)
`
`James V. Romano, Ph.D., President and CEO
`
`Published by Lippincott Williams & Wilkins, Inc./227 East Washington Square/Philadelphia, PA 19106-3780
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`t
`
`at
`
`Ex. 1005 - Page 2
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`Ex. 1005 - Page 2
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`

`Inflammatory Bowel Diseases®
`
`Official Journal of the Crohn's & Colitis Foundation of America, Inc.
`
`Volume 5, Number 2, May 1999
`
`CONTENTS
`
`73 (cid:9)
`
`79 (cid:9)
`
`85 (cid:9)
`
`92 (cid:9)
`
`98 (cid:9)
`
`ORIGINAL CONTRIBUTIONS
`The Influence of Cigarette Smoking on Cytokine Levels in Patients with Inflammatory
`Bowel Disease
`Marc E. Sher, Simmy Bank, Ronald Greenberg, T. Cristina Sardinha, Sam Weissman,
`Beverly Bailey, Robert Gilliland, and Steven D. Wexner
`
`Time Trends in the Incidence and Disease Location of Crohn's Disease 1980-1995:
`A Prospective Analysis in an Urban Population in Germany
`Antje Timmer, Bettina Breuer-Katschinski, and Harald Goebell
`
`Intestinal Permeability and Postheparin Plasma Diamine Oxidase Activity in the
`Prediction of Crohn's Disease Relapse
`Robert J. Hilsden, Jon B. Meddings, James Hardin, D. Grant Gall, and Lloyd R. Sutherland
`
`The Importance of Ileocaecal Integrity in the Arthritic Complications Of Crohn's Disease
`Timothy R. Orchard and Derek P. Jewell
`
`Concurrent Inflammatory Bowel Disease and Myelodysplastic Syndromes
`Gavin C. Harewood, Edward V. Loftus, Jr., Ayalew Tefferi, William J. Tremaine, and
`William J. Sandborn
`
`104 (cid:9)
`
`Perinatal Exposure to Measles Virus Is Not Associated with the Development of
`Inflammatory Bowel Disease
`Darrell S. Pardi, William J. Tremaine, William J. Sandborn, Edward V. Loftus, Jr.,
`Gregory A. Poland, and L. Joseph Melton Ill
`
`107 (cid:9)
`
`BASIC SCIENCE REVIEW
`Adapter Molecules in T Cell Receptor Signaling
`Nancy J. Boerth and Gary A. Koretzky
`
`(Continued)
`
`Listed in Index Medicus/MEDUVE, Current Contents/Clinical Medicine, Research Alert, and SCISLARCII
`
`Inflammatory Bowel Diseases (ISSN 1078-0998) is published quarterly in February, May, August, and November by Lippincott
`Williams & Wilkins, Inc., at 12107 Insurance Way, Hagerstown, MD 21740. Business offices are located at 227 E. Washington Square.
`Philadelphia, PA 19106-3780. Copyright © 1999 Crohn's & Colitis Foundation of America, Inc. All rights reserved. Printed in the
`U.S.A. Perodicals postage rates pending at Hagerstown, MD, and at additional mailing offices.
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`Postmaster: Send changes of address to Inflammatory Bowel Diseases", Box 1550,11agerstown, MD 21740.
`
`:: isd
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`Ex. 1005 - Page 3
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`

`

`CONTENTS
`
`CLINICAL REVIEW
`Antitumor Necrosis Factor Therapy for Inflammatory Bowel Disease: A Review of Agents,
`Pharmacology, Clinical Results, and Safety
`William J. Sandborn and Stephen B. Hanauer
`
`CLINICAL TRIALS AND THERAPEUTICS
`Patient Compliance and Outcomes
`Sunanda Kane
`
`CONTROVERSIES IN IBD
`The Crohn's Disease Activity Index Is a Useful Tool in Clinical Practice
`of Gastroenterology
`John W. Singleton
`
`Is the Crohn's Disease Activity Index Outdated? Yes. Is It the Gold Standard that
`Clinicians Should Use? No.
`Burton I. Korelitz
`
`Section Editors' Commentary. Usefulness of Crohn's Disease Activity Index in Medicine
`Peter A. Banks and Daniel H. Present
`
`PROFESSIONAL AFFAIRS AND PUBLIC POLICY
`Clinical Pearls from the 1998 FMAC/CMAC Meeting
`Douglas C. Wolf
`
`SELECTED SUMMARIES
`Aberrant Mucosal Cytokines: The Key to the Pathogenesis of IBD?
`Samir A. Shah
`
`Mephitic Muchness in Colitis: A "Future Therapy" Target?
`William E. W. Roediger
`
`Will the Real 5-Aminosalicylic Acid Please Stand Up?
`Miguel D. Reguciro
`
`Mesalamine: Sale at First Look
`Lawrence J. Saube•mann and Jacqueline L. Wolf
`
`LETTER To THE Eourok
`Underlying Cholangiocarcinoma in a Patient with High-Grade Dysplasia in the
`Pelvic Pouch
`Dagny Stiihlberg and Robert LOtberg
`
`119 (cid:9)
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`134 (cid:9)
`
`138 (cid:9)
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`139 (cid:9)
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`141 (cid:9)
`
`144 (cid:9)
`
`146
`
`147
`
`147
`
`148
`
`150 (cid:9)
`
`Manuscripts should be submitted to Caroline Manganicilo, Editorial Coordinator, Inflammatory Bowel Diseases'-', Lippincott
`Williams & Wilkins, Inc., 1803 Research Blvd., Suite 300, Rockville, MD 20850.
`Lippincott Williams & Wilkins, Inc., and the Crohn's & Colitis Foundation of America, Inc., cannot be held responsible for errors
`or for any consequences arising from the use of the information contained in this journal. The appearance of advertising in this journal
`does not constitute an endorsement or approval by Lippincott Williams & Wilkins, Inc., or the Foundation for the quality of the product
`advertised or of the claims made for it by its manufacturer.
`
`PERMISSION TO PHOTOCOPY ARTICLES: This publication is protected by copyright. Permission to photocopy must be
`secured in writing from: Permissions Dept., Lippincott Williams & Wilkins, Inc., 227 East Washington Square, Philadelphia, PA
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`750-4470; or UNII, Box 49, 300 North Zeeb Road, Ann Arbor, MI 48106-1346; FAX: 313-761-1203.
`
`Th (cid:9)
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`-nate ri i • - • (cid:9)
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`i
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`Sub (cid:9)
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`- (cid:9)
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`i = t LE.ws
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`Ex. 1005 - Page 4
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`Ex. 1005 - Page 4
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`

`Inflammatory Bowel Diseases"
`5(2):I19-133 (0 1999 Crohn's & Colitis Foundation of America, Inc.
`
`Clinical Review
`
`Antitumor Necrosis Factor Therapy for Inflammatory Bowel
`Disease: A Review of Agents, Pharmacology, Clinical Results,
`and Safety
`
`William J. Sandborn and *Stephen B. Hanauer
`
`htflaminator), Bowel Disease Clinic, Division of Gastroenterology and Hepatology, Mayo Clinic and Mayo Foundation,
`Rochester, Minnesota: and *Inflammatory Bowel Disease Center, Section of Gastroenterology, University of Chicago,
`Chicago, Illinois, U.S.A.
`
`Summary: Tumor necrosis factor-et (TNFa), a proinflamma-
`tory cytokine, plays an important role in the pathogenesis of
`inflammatory bowel disease (IBD). Biotechnology agents in-
`cluding a chimeric monoclonal anti-TNF antibody (infliximab),
`a humanized monoclonal anti-TNF antibody (CDP571), and a
`recombinant TNF receptor fusion protein (etanercept) have
`been used to inhibit TNFa activity. Controlled trials have dem-
`onstrated efficacy for infliximab in moderately to severely ac-
`tive Crohn's disease (CD) and fistulizing CD sufficient to jus-
`tify recent U.S. Food and Drug Administration (FDA) ap-
`proval. Additional trials have been completed in rheumatoid
`arthritis (RA). Similarly, preliminary controlled trials have sug-
`gested efficacy for CDP571 in active CD and RA. Larger con-
`trolled trials have demonstrated efficacy for etanercept in RA
`
`patients who have failed disease modifying antirheumatic drug
`(DMARD) therapy leading to FDA approval for RA. Toxicities
`observed with anti-TNF therapies have included formation of
`human antichimeric antibodies (HACA) with associated acute
`and delayed hypersensitivity infusion reactions, human antihu-
`man antibodies (HAHAs), and formation of autoantibodies
`with rare instances of drug-induced lupus. Several cases of
`non-Hodgkin's lymphoma also has been described. Future
`studies should evaluate optimal timing and duration of anti-
`TNF therapy, the utility of adjuvant medical treatments during
`anti-TNF therapy, and evaluate long-term safety and efficacy of
`the various anti-TNF agents. Key Words: Antitumor necrosis
`factor-41ntibody—Crohn's disease—Rheumatoid arthritis—
`Infliximab—CDP571—Etanercept.
`
`INTRODUCTION
`
`Current therapies for inflammatory bowel disease
`(IBD) are limited by low-to-moderate efficacy, delayed
`onset of action, frequent dosing regimens, and side ef-
`fects. Medications that inhibit tumor necrosis factor-a
`(TNFa) have been proposed as a new therapeutic class
`with high efficacy, rapid onset of action, prolonged ef-
`fect, and improved tolerance. This article reviews the use
`of anti-TNFa agents including infliximab (a chimeric
`monoclonal anti-TNF antibody), CDP57I (a humanized
`monoclonal anti-TNF antibody), and etanercept (a hut-
`
`Address correspondence and reprint requests to Dr. W. J. Sandborn,
`Mayo Clinic, 200 First St., Rochester, MN 55905, U.S.A.
`Manuscript received January 24, 1999; accepted February 4, 1999.
`
`man recombinant TNF receptor fusion protein), for pa-
`tients with IBD and rheumatoid arthritis (RA).
`
`TNF LIGAND, RECEPTORS, AND
`BIOLOGIC EFFECTS
`
`The gene encoding TNFa is located on the short arm
`of chromosome 6, between the HLA class I and class II
`loci (1). Transcription of this gene in monocytes, mac-
`rophages, and T cells results in the secretion of inactive
`soluble 17 kD monomer proteins that subsequently com-
`bine to form 51 kD trimers, the active form of TNFa
`ligand (2,3). There are two different transmembrane re-
`ceptors for TNFa identified on most cell types: a 55 kD
`protein (p55) and a 75 kD protein (p75) (4,5). Circulating
`TNFa trimers bind to two or three TNFa receptors re-
`
`119
`
`This matE.:ial..EZ
`
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`120 (cid:9)
`
`W. J. SANDBORN AND S. B. HANAUER
`
`suiting in cross-linking and signal transduction (6,7).
`Both the p55 and p75 TNF receptors undergo enzymatic
`cleavage by protein kinase C at the membrane surface
`releasing soluble binding proteins that increase the ac-
`tivity of TNFa at low concentrations (due to an increased
`half-life of TNFa from slow release of TNFa) and in-
`hibit TNFa activity at higher concentrations (Fig. 1) (8-
`10). After binding to its membrane bound receptors, the
`proinflammatory cytokine TNFa mediates multiple bio-
`logic effects including recruitment of neutrophils to local
`sites of inflammation, induction of edema, activation of
`coagulation, and induction of granuloma formation (Fig.
`2) (11,12).
`
`ROLE OF TNFot IN IBD
`
`TNFa has been found in the serum (13-15), stool
`(16,17), and intestinal tissue (18-21) of patients with
`IBD. The specificity remains unclear and may be com-
`parable to other forms of inflammation (14,15,20,21).
`Cells that express TNF can be found in the gut mucosa
`and lamina propria of Crohn's disease (CD) patients (22-
`24). One study suggested enhanced secretion of TNFa
`and failure to release enhanced amounts of soluble TNF
`receptors by lamina propria mononuclear cells (25).
`TNFot may be a cofactor for mucosal T helper cell type
`1 (Thl) response, and in a clinical study treatment with
`the chimeric monoclonal anti-TNFa antibody infliximab
`resulted in the down-regulation of mucosal Th 1 cyto-
`kines (26). The clinical response of patients with CD to
`chimeric or humanized monoclonal antibody therapy
`with infliximab or CDP571 reinforces the potential piv-
`otal role of TNFec in the pathogenesis of CD (27,28).
`
`MONOCLONAL ANTIBODIES AND
`FUSION PROTEINS
`
`The development of monoclonal antibody therapies
`has been reviewed elsewhere (29). Antibodies serve as
`adapters connecting antigens to effector molecules. An-
`tibody binding alone may provide sufficient neutraliza-
`tion although cell lysis via complement fixation or anti-
`body-dependent cellular toxicity is another potential
`mechanism to reduce cytokine production. Attempts to
`therapeutically administer murine monoclonal antibodies
`(100% murine antibody) created using hybridoma tech-
`nology resulted in significant human immune responses
`due to the formation of human antimouse antibodies
`(HAMAs) directed against the constant region of the
`mouse antibody (30,31). With repeat treatment, forma-
`tion of HAMAs caused both a shortening of the half-life
`for the murine monoclonal antibody (due to increased
`clearance of the antibody from the serum) and hypersen-
`sitivity reactions (29-31).
`Protein engineering techniques that transplant antigen
`binding sites from murine to human antibodies have been
`used to decrease amounts of murine protein in therapeu-
`tic monoclonal antibodies, thus reducing immunogenic-
`ity. The first generation of engineered monoclonal anti-
`bodies were simple chimeric monoclonal antibodies in
`which the variable domains of a mouse monoclonal an-
`tibody were transplanted to the constant domains of hu-
`man antibodies (Fig. 3). The resulting chimeric mono-
`clonal antibody is approximately 75% human and 25%
`murine (Fig. 4). While chimeric monoclonal antibodies
`are less immunogenic than murine monoclonal antibod-
`ies, they still result in the formation of human antichi-
`meric antibodies (HACAs) (32) directed against the
`
`r.
`
`TNF trimer
`
`TNF/TNF-BP complex
`
`TNF
`receptor-
`trimer
`
`TNF
`receptor-
`dimer
`
`TNF
`receptor
`
`TNF-BP
`
`Proteolytic
`cleavage n
`
`' G-C7
`
`FIG. 1. Production of soluble forms
`of TNF receptors (TNF-BP). TNF-BP
`is produced by proteolytic cleavage of
`transmembrane TNF receptors (p55
`and p75), e.g., as an effect of activa-
`tion of protein kinase C (PKC). Re-
`leased TNF-BP can bind to trimeric
`TNF with high affinity. [Reproduced
`with permission from: Olsson I, Ga-
`tanaga T, Gullberg U, Lantz M,
`Granger GA. Tumor necrosis factor
`(TNF) binding proteins (soluble TNF
`receptor forms) with possible roles in
`inflammation and malignancy. Eur
`Cytokine Netw 1993;4:169-80.]
`
`Signal
`
`Signal
`
`PKC
`
`Inflammatory lionel Diseasesb, Vol. 5, No. 2, May /999
`
`Thiz r (cid:9)
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`'al (cid:9)
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`z
`
`Ex. 1005 - Page 6
`
`Ex. 1005 - Page 6
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`

`ANTI-TNF FOR IBD (cid:9)
`
`121
`
`Cytokines,
`adhesion molecules,
`coagulation factors, iNOS
`
`TNF,
`IL-1,
`IL-6 v\
`
`Endothelium
`
`Antibodies
`
`B cell
`
`IL-2
`IFN-y,
`other cytokines
`
`T cell
`
`Monocyte
`
`Stimulus
`Monocyte/macrophage
`
`► TNF
`
`Bone (cid:9)
`•
`Bone ,A0steoclast
`resorption (cid:9)
`
`Myocyte z
`
`Proteolysis
`
`Fever,
`sleep
`
`Liver
`
`Adipocyte (cid:9)
`
`Acute phase
`proteins
`
`Fibroblast
`
`Inhibition of
`lipoprotein lipase
`
`IFN-13, collagenase
`FIG. 2. Biological activities of tumor necrosis factor (TNF). Although several types of cells produce TNF, the main source of the cytokine
`is monocyte/macrophages. TNF induces a number of proinflammatory changes in endothelial cells, including cytokine production,
`expression of adhesion molecules, release of procoagulatory substances, and induction of iNOS. These alterations may lead to septic
`shock. Furthermore, TNF stimulates B and T cells, induces fever in the brain, suppresses the lipoprotein lipase in adipocytes (contributing
`to cachexia), and stimulates hepatocytes to produce acute phase proteins. In rheumatoid arthritis, fibroblasts and osteoclasts are target
`cells for TNF. INF, interferon; IL, interleukin; iNOS, inducible nitric oxide synthase. [Reproduced with permission from: Bigler A, Sinha B,
`Hartman G, Endres S. Taming TNF: strategies to restrain this proinflammatory cytokine. Immunol Today 1997;18:487-92.]
`
`VH
`
`VL
`
`5
`3'
`Ig mRNA template
`
`H—H , (cid:9)
`VH (cid:9)
`
`3'
`5'
`Ig mRNA template
`PCR amplification
`of V-genes
`
`Cloning V-genes
`
`, H (cid:9) H
`VL
`
`%CH1
`Expression
`vector for n Hinge
`heavy
`chains
`
`H2
`
`CH3
`
`IgG expression in
`mammalian cells
`
`CL
`
`Expression
`vector for
`light
`chains
`
`FIG. 3. Cloning of heavy and light chain V genes from the mRNA
`of a mouse B-cell hybridoma into vectors comprising (human)
`genes encoding constant domains, for expression of mouse-
`human chimaeric antibodies in mammalian cells. [Reproduced
`with permission from: Winter G, Harris WJ. Humanized antibod-
`ies. Immunol Today 1993;14:243-6.)
`
`Thiz
`
`transplanted variable domain from the mouse. However,
`these chimeric monoclonal antibodies appear to have
`better pharmacokinetics than murine monoclonal anti-
`bodies, with half-lives significantly extended in humans
`(29,33).
`The second generation of engineered monoclonal an-
`tibodies were "humanized" by transplanting the antigen
`binding region (complimentarity determining regions or
`CDR) of murine variable domains to human antibodies.
`The resulting humanized monoclonal antibody is ap-
`proximately 95% human and 5% murine (Fig. 4). While
`expected to be less immunogenic than chimeric mono-
`clonal antibodies, humanized monoclonal antibodies do
`result in formation of human antihuman antibodies
`(HAl-lAs) directed against both the variable regions
`(mouse and human) and the allotype (human) antibody
`structures (29,34,35). Similar to chimeric monoclonal
`antibodies, these humanized monoclonal antibodies ap-
`pear to have better pharmacokinetics than murine mono-
`clonal antibodies, with significantly prolonged half-lives
`in humans (29,33).
`The third generation of engineered antibodies are
`more properly termed "fusion proteins." Fusion proteins
`are created by linking DNA encoding a human protein
`receptor to DNA encoding the Fc portion of a human
`
`Infianimatory Bowel Disease?', Vol. 5, No. 2, May 1999
`
`Ex. 1005 - Page 7
`
`Ex. 1005 - Page 7
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`

`

`122
`
`VV. J. SANDBORN AND S. 13. HANAUER
`
`Chimeric
`Monoclanal
`Antibody
`
`Humanized
`Monoclanal
`Antibody
`
`Human
`Recombinant
`Receptor/Fc
`Fusion Protein
`
`Schematic Diagram
`of an Antibody
`
`Light-
`chain
`gene
`
`Heavy-
`chain
`gene
`
`ES
`
`( 75% human
`
`Es Mouse
`Human
`
`Receptor
`
`Constant 2
`
`Constant 3
`
`100% human
`
`CI Human
`
`95% human
`
`Mouse
`CI Human
`CDR = Complementarity
`determining
`regions
`
`EZI Variable
`Constant
`EJ Constant 1
`EJ Constant 2
`Constant 3
`[7] Fab
`Hinge
`Fc
`FIG. 4. Schematic diagrams demonst ating the structural components of antibodies and the protein engineering required to create
`chimeric monoclonal antibodies such as infliximab, humanized monoclonal antibodies such as CDP571, and human recombinant re-
`ceptor/Fc fusion proteins such as the p75 TNRx receptor/Fc fusion protein etanercept. CDR indicates complementarity determining
`regions.
`
`antibody, followed by expression of the DNA in a mam-
`malian cell line. The resulting recombinant protein is a
`100% human, immunoglobulin-like dimer (Fig. 4). Even
`these completely human recombinant proteins have some
`immunogenicity and can result in the formation of
`I-IAHAs. The fusion of the Fc portion of an antibody to
`soluble protein receptors significantly prolongs the half-
`lives of soluble receptors.
`Selection of different constant domains has implica-
`tions for the effector function of chimeric and humanized
`monoclonal antibodies and fusion proteins. For example,
`the IgG I isotype results in complement fixation and an-
`tibody-dependent cytotoxicity whereas the IgG4 isotype
`has more favorable blocking characteristics.
`
`ANTI-TNFet AGENTS AND MECHANISMS
`OF ACTION
`
`Infliximab
`
`Infliximab (previously cA2) is a chimeric monoclonal
`antibody to human TNFa constructed by linking the
`variable regions of a mouse antihuman TNF monoclonal
`
`antibody (A2) to human IgG1 with k light chains (36). It
`is produced commercially by Centocor (Malvern, PA,
`U.S.A.) and marketed as Remicade. Infliximab has a
`strong binding affinity to soluble tritners of INLAY. (k(l
`100 pM) (34,37). Similarly, infliximab has a strong bind-
`ing affinity to the transmembrane form of INIkx (Kd 46
`pM) (38). In vitro, infliximab binding to transmembrane
`INFot results in complement fixation and antibody-
`dependent cytotoxicity in a tumor cell line, whereas an
`investigational IgG4 form of infliximab showed no cell-
`killing activity (38). Some or all of these effects may
`play a role in the in vivo activity of infliximab (Fig. 5)
`(39). Infliximab does not promote the rapid removal of
`INF, instead it paradoxically prolongs the half-life of
`INFu (40). Thus infliximab acts both as a cytokine "car-
`rier" and as a TNF antagonist, with the net effect of
`rendering TNF biologically inactive (40). In vivo studies
`with infliximab have demonstrated down regulation of
`mucosal Thl cytokines, (26), decreased activation of co-
`agulation (41), decreased circulating secretory phospho-
`lipase A, (42), decreased concentrations of IL-1, IL-6,
`soluble E-selectin, and ICAM-1 (43,44), and a decrease
`in serum matrix metalloproteinase 1 and matrix metallo-
`proteinase 3 (45).
`
`ItYlammatory Bowel Diseases*, Vul. 5, No. 2, May 1999
`
`Thismatwialw- z
`atv
`
`Ex. 1005 - Page 8
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`Ex. 1005 - Page 8
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`(cid:9)
`

`

`ANTI-TNF FOR 113D
`
`123
`
`Chimeric anti-TNF-a (infliximab)
`Humanized anti-TNF-a (CDP571)
`Human recombinant TNF-a p75 receptor
`Fe fusion protein (Etanercept)
`
`•
`
`I '
`
`fill
`
`TNF-a producing marophages
`or activated T cells
`
`eze
`
`‘1111116, 001110
`
`Neutralization of
`transmembrane
`TNF-a
`-infliximab
`
`Neutralization of
`soluble TNF-a
`-infliximab
`-CDP571
`-Etanercept
`
`Lysis of TF-a producing
`cells via complement
`fixation or ADCC
`-infliximab
`
`FIG. 5. Mechanisms for antibody neutralization of TNF-a. Infliximab (chimeric anti-TNF-a antibody) works by binding to and neutralizing
`transmembrane TNF-tx on macrophage or activated T-cell surfaces, binding to and neutralizing free TNF-ei in the serum, and lysis of
`TNF-a producing cells via complement fixation or antibody-dependent cellular cytotoxicity (ADCC). CDP571 (humanized anti-TNF-a
`antibody) works by binding to and neutralizing free TNF-cx in the serum. Etanercept (human recombinant fusion protein with two soluble
`p75 TNF receptors per Fc molecule) works by binding to and neutralizing free TNF-cx in the serum. [Modified and reproduced with
`permission from: Kam L, Targan S. Infliximab and Crohn's disease. Clin Persp Gastroenterol 1998;1:67-72.]
`
`CDP571
`
`A humanized monoclonal antibody to human TNFx
`initially named CDP571 (Cclltech, Slough, England,
`U.K.) was constructed by transplanting the complimen-
`tarily determining regions or CDR of a mouse antihuman
`TNF monoclonal antibody to human IgG4 with k light
`chains (46). CDP571 has a strong binding affinity to
`soluble trimers of INFot (kd 100 pM) (29) and is be-
`lieved to bind to the transmembrane form of TNFx.
`CDP571 and other investigational versions of humanized
`1gG4 anti-TNRa antibodies neither fix complement nor
`mediate antibody-dependent cytotoxicity (47). Thus, the
`in vivo effect of CDP571 is believed to result from the
`binding of soluble trimers of TNFot and membrane-
`bound TNFa. (Fig. 5) (47). The only in vivo mechanistic
`study, to date, demonstrated a decrease in the concentra-
`tion of IL-1 after treatment with CDP571 (48).
`
`Etanercept
`
`Etanercept (Enbrel, Immunex, Seattle, WA, U.S.A.), a
`human fusion protein initially named TNFR:Fc, was con-
`
`structed by linking the extracellular ligand-binding por-
`tion of the human p75 TNF receptor to the Fc portion of
`IgG1 (49). The Fe component contains the C112 domain,
`the CH3 domain, and the hinge region but not the C01
`domain of IgG I. The fusion protein is produced by re-
`combinant DNA technology in a Chinese hamster ovary
`system. The resulting fusion protein is an immunoglob-
`ulin-like dimer consisting of two soluble p75 TNF re-
`ceptors per Fc molecule.
`Etanercept binds soluble trimers of TNFct with the
`same high affinity as membrane-bound p75 TNF recep-
`tors but with a higher affinity than binding of soluble
`TNF trimers by soluble p75 TNF receptor monomers
`(49). The serum half-life of etanercept is significantly
`longer than the soluble p75 TNF receptor monomer (50).
`In vivo, etanercept competitively inhibits binding of
`soluble TNFot trimers to membrane bound TNFot recep-
`tors (Fig. 5) (49,51). Similar to infliximab, etanercept
`does not promote the rapid removal of TNF but para-
`doxically prolongs the half-life of TNFa by acting as a
`cytokine "carrier" and as a TNF antagonist, with the net
`effect of rendering TNF biologically inactive (51). In
`
`Ilanonafory Bowel Diseases 4, Vol. 5, No. 2, May 1999
`
`This mats'ial az _ sied
`
`Sit.cije
`
`Ex. 1005 - Page 9
`
`Ex. 1005 - Page 9
`
`

`

`124 (cid:9)
`
`W. J. SANDBORN AND S. B. HANA UER
`
`vitro, etanercept binding to transmembrane TNRx does
`not result in complement fixation or antibody-dependent
`cytotoxicity (51). Mechanistic studies have demonstrated
`decreased concentrations of IL-1, IL-6, soluble E-
`selectin, ICAM-1, and matrix metalloproteinase 3
`(51,53) after treatment with etanercept.
`
`PHARMACOKINETICS
`
`Infliximab
`
`Data from a study of single intravenous infusions of 1,
`5, 10, or 20 mg/kg of infliximab showed a direct and
`linear relationship between the dose administered and the
`maximum serum concentration (C„,„x) and the area under
`the concentration-time curve (Table 1) (40,54). The me-
`dian serum concentrations versus time profiles for a
`single i.v. infusion of 5, 10, or 20 mg/kg of infliximab
`are shown in Fig. 6A (40). The volume of distribution at
`steady state (Vd), clearance, and mean residence time are
`independent of the administered dose (Table 1) (40,54).
`Infliximab is predominantly distributed in the vascular
`compartment and has a prolonged half-life (Table 1)
`(40,54). Following a single dose, the serum levels de-
`clined in an exponential fashion through 8-12 weeks
`(Fig. 6A). The median serum concentration of the 5 mg/
`kg treatment group was undetectable by 12 weeks fol-
`lowing the infusion. No evidence of accumulation was
`observed after repeated dosing with infliximab 5 mg/kg
`at weeks 0, 2, and 6, or in after repeated dosing with 4
`infusions of infliximab 10 mg/kg at 8-week intervals
`(54).
`
`CDP571
`
`Data from a study of single intravenous infusions of
`0.1, 0.3, 1, 2, 5, and 10 mg/kg of CDP571 showed a
`direct and linear relationship between administered dose,
`maximum serum concentration (C,„,x) and the area under
`the concentration-time curve (Table I) (46). The mean
`serum concentrations versus time profiles for single is.
`infusions of 0.1, 0.3, 1, 2, 5, or 10 mg/kg of CDP571 are
`shown in Fig. 6B (46). CDP571 has a prolonged half-life
`and is predominantly distributed in the vascular compart-
`ment (Table 1) (46). Following a single dose, the serum
`levels declined in an exponential fashion through 3-12
`weeks (Fig. 1). CDP571 was detectable in the serum 12
`weeks after a single infusion in 7 of 12 of the subjects
`who received doses of 2, 5, or 10 mg/kg (46).
`
`Etanercept
`
`Data from single subcutaneous injections of 25 mg of
`etanercept in 3 patients with RA showed a median half-
`life of 115 hours (range 98-300 hours) with a clearance
`of 89 mL/hour (52 mL/hr/m2) (51). A maximum serum
`concentration (C111a0 of 1.2 mcg/mL (range 0.6- 1.5 mcg/
`mL) and a time to C„,a, of 72 hours (range 48-96 hours)
`was observed in these patients (51). After continued dos-
`ing in RA patients, (11 = 25) for 6 months with 25 mg
`twice weekly, the median observed level was 3.0 mcg/
`mL (range 1.7-5.6 mcg/mL) (51). Based on the available
`data, individual patients may undergo two- to fivefold
`increase in serum levels with repeated dosing.
`
`TABLE 1. Pharmacokinetics of anti-TAIrcx agents fur Crohn's disease
`
`Parameter
`
`0.1 mg/kg
`
`0.3 mg./kg
`
`I mg/kg (cid:9)
`
`5 mg,/kg
`
`10 mg/kg
`
`20 mg/kg
`
`Dose
`
`Infliximab (Refs. 40, 54)
`C,,,,,, (ug/mL)
`AUC (ug/niLxhr)
`Vd (mL/hr)
`CI (L)
`MRT (days)
`T12 (days)
`CDP571 (Ref. 46)
`C„,„ (ug/mL)
`AUC (ug/mLxhr)
`T12 (days)
`
`2.5
`236
`5
`
`—
`
`—
`
`118
`30,900
`9.8
`3.0
`13
`10
`
`292
`69,500
`10.2
`3.0
`12
`12
`
`471
`122,300
`10.8
`4.0
`15
`14
`
`9.1
`1,058
`6
`
`25.5
`3,968
`6.9
`
`52.7
`11,184
`14.3
`
`166.8
`26,539
`11.1
`
`272.3
`49,729
`13.0
`
`Cm.,„: Indicates maximum serum concentration.
`AUC: Indicates area under the concentration-time curve.
`Vd: Indicates volume of distribution at steady state.
`CI: Indicates clearance.
`MRT: Indicates mean residence time.
`T,,,: Indicates half life.
`
`Inflammatory Bowel Diseases', Vol. 5, No. 2, May /999
`
`Lri
`
`Ex. 1005 - Page 10
`
`Ex. 1005 - Page 10
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`

`

`ANTI-TNF FOR IBD (cid:9)
`
`125
`
`-0- 5 mg/kg
`-A- 10 mg/kg
`20 mg/kg
`
`FIG. 6. A: The median serum concentrations ver-
`sus time profiles are shown for active, moderate to
`severe Crohn's disease patients (n = 25 patients
`per group) in reference 27 receiving a single i.v.
`infusion of 5, 10, or 20 mg/kg of infliximab. The
`median serum concentration was dose propor-
`tional, and remained stable through at least 4 hours
`following the infusion. The serum levels declined in
`an exponential fashion through 8-12 weeks follow-
`ing treatment. The median serum concentration of
`the 5 mg/kg treatment group was undetectable (<
`0.1 pg/mL) by 12 weeks following the infusion. [Re-
`produced with permission from: Wagner C, Mace K,
`DeWoody K, Zelinger D, Leone A, Schaible T, She-
`aly D. Infliximab treatment benefits correlate with
`pharmacodynamic parameters in Crohn's disease
`patients. Digestion 1998;59(suppl 3):124-5.] B:
`The pharmacokinetics of CDP571 in human volun-
`teers. Elimination profiles after CDP571 was admin-
`istered as a single i.v. infusion at the following
`doses (n = 4 per group): 0.1 mg/kg; 0.3 mg/kg; 1
`mg/kg; 2 mg/kg; 5 mg/kg; or 10 mg/kg. Results are
`expressed as geometric means (± 95% CI). [Repro-
`duced with permission from: Stephens S, Emtage
`S, Vetterlein 0, Chaplin L, Bebbington C, Nesbitt A,
`Sopwith M, Athwal D, Novak C, Bodmer M. Com-
`prehensive pharmacokinetics of a humanized anti-
`body and analysis of residual anti-idiotypic re-
`sponses. Immunology 1995;85:668-74.]
`
`1,000
`
`100
`
`10
`
`Infliximab concentration (pg/mL)
`
`A
`
`0.1
`
`
`ii/i (cid:9)
`0 1 2 (cid:9)
`4 2
`8
`4-- Hours --.
`(cid:9)
`Weeks (cid:9)
`
`Time following end of infusion
`
`12
`
`2.0 mg/kg
`-II- 0.1 mg/kg (cid:9)
`0.3 mg/kg -4- 5.0 mg/kg
`-
`-4- 1.0 mg/kg -0- 10.0 mg/kg
`
`1,000 F
`
`CDP571 (µg/mL)
`
`0.01
`
`0
`
`B
`
`7
`
`14 (cid:9)
`
`21
`
`28
`
`35
`
`Days
`
`RESULTS IN CROHN'S DISEASE
`
`Infliximab
`
`The clinical studies of in