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The relatively large molecular size, diastereoisomeric nature, and complex impurity profiles of therapeutic phosphorothioate oligonucleotides create significant analytical challenges for the quality control laboratory. To overcome the lack of selectivity inherent to traditional chromatographic approaches, an ion pair liquid chromatography-mass spectrometry (LCMS) method combining ultraviolet and mass spectrometry quantification was developed and validated for >35 different oligonucleotide drug substances and products, including several commercialized drugs. The selection of chromatographic and spectrometric conditions, data acquisition and processing, critical aspects of sample and buffer preparation and instrument maintenance, and results from method validation experiments are discussed.

Protein kinase C α (PKCα) is a ubiquitously expressed member of the PKC family of serine/threonine kinases with diverse functions in normal and neoplastic cells. Early studies identified anti-proliferative and differentiation-inducing functions for PKCα in some normal tissues (e.g., regenerating epithelia) and pro-proliferative effects in others (e.g., cells of the hematopoietic system, smooth muscle cells). Additional well documented roles of PKCα signaling in normal cells include regulation of the cytoskeleton, cell adhesion, and cell migration, and PKCα can function as a survival factor in many contexts. While a majority of tumors lose expression of PKCα, others display aberrant overexpression of the enzyme. Cancer-related mutations in PKCα are uncommon, but rare examples of driver mutations have been detected in certain cancer types (e. g., choroid gliomas). Here we review the role of PKCα in various cancers, describe mechanisms by which PKCα affects cancer-related cell functions, and discuss how the diverse functions of PKCα contribute to tumor suppressive and tumor promoting activities of the enzyme. We end the discussion by addressing mutations and expression of PKCα in tumors and the clinical relevance of these findings., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Delivery to the target site and adversities related to off-target exposure have made the road to clinical success and approval of antisense oligonucleotide (AON) therapies challenging. Various classes of AONs have distinct chemical features and pharmacological properties. Understanding the similarities and differences in pharmacokinetics (PKs) among AON classes is important to make future development more efficient and may facilitate regulatory guidance of AON development programs. For the class of 2'- O -methyl phosphorothioate (2OMe PS) RNA AONs, most nonclinical and clinical PK data available today are derived from development of exon skipping therapies for Duchenne muscular dystrophy (DMD). While some publications have featured PK aspects of these AONs, no comprehensive overview is available to date. This article presents a detailed review of absorption, distribution, metabolism, and excretion of 2OMe PS AONs, compiled from publicly available data and previously unpublished internal data on drisapersen and related exon skipping candidates in preclinical species and DMD patients. Considerations regarding drug-drug interactions, toxicokinetics, and pharmacodynamics are also discussed. From the data presented, the picture emerges of consistent PK properties within the 2OMe PS class, predictable behavior across species, and a considerable overlap with other single-stranded PS AONs. A level of detail on muscle as a target tissue is provided, which was not previously available. Furthermore, muscle biopsy samples taken in DMD clinical trials allowed confirmation of the applicability of interspecies scaling approaches commonly applied in the absence of clinical target tissue data.

Intestinal immune cell trafficking has been identified as a central event in the pathogenesis of inflammatory bowel diseases (IBD). Intensive research on different aspects of the immune mechanisms controlling and controlled by T cell trafficking and retention has led to the approval of the anti-α4β7 antibody vedolizumab, the ongoing development of a number of further anti-trafficking agents (ATAs) such as the anti-β7 antibody etrolizumab or the anti-MAdCAM-1 antibody ontamalimab and the identification of potential future targets like G-protein coupled receptor 15. However, several aspects of the biology of immune cell trafficking and regarding the mechanism of action of ATAs are still unclear, for example, which impact these compounds have on the trafficking of non-lymphocyte populations like monocytes and how precisely these therapies differ with regard to their effect on immune cell subpopulations. This review will summarise recent advances of basic science in the field of intestinal immune cell trafficking and discuss these findings with regard to different pharmacological approaches from a translational perspective., Competing Interests: Competing interests: MFN has served as an advisor for Pentax, Giuliani, MSD, Abbvie, Janssen, Takeda and Boehringer. SZ, MFN received research support from Takeda, Hoffmann-La Roche and Shire., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

The molecular mechanisms of toxicity of chemically modified phosphorothioate antisense oligonucleotides (PS-ASOs) are not fully understood. Here, we report that toxic gapmer PS-ASOs containing modifications such as constrained ethyl (cEt), locked nucleic acid (LNA) and 2'-O-methoxyethyl (2'-MOE) bind many cellular proteins with high avidity, altering their function, localization and stability. We show that RNase H1-dependent delocalization of paraspeckle proteins to nucleoli is an early event in PS-ASO toxicity, followed by nucleolar stress, p53 activation and apoptotic cell death. Introduction of a single 2'-O-methyl (2'-OMe) modification at gap position 2 reduced protein-binding, substantially decreasing hepatotoxicity and improving the therapeutic index with minimal impairment of antisense activity. We validated the ability of this modification to generally mitigate PS-ASO toxicity with more than 300 sequences. Our findings will guide the design of PS-ASOs with optimal therapeutic profiles.

Phosphorothioate nucleotides have emerged as powerful pharmacological substitutes of their native phosphodiester analogs with important translational applications in antisense oligonucleotide (ASO) therapeutics and cyclic dinucleotide (CDN) synthesis. Stereocontrolled installation of this chiral motif has long been hampered by the systemic use of phosphorus(III) [P(III)]-based reagent systems as the sole practical means of oligonucleotide assembly. A fundamentally different approach is described herein: the invention of a P(V)-based reagent platform for programmable, traceless, diastereoselective phosphorus-sulfur incorporation. The power of this reagent system is demonstrated through the robust and stereocontrolled synthesis of various nucleotidic architectures, including ASOs and CDNs, via an efficient, inexpensive, and operationally simple protocol., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

The objective of cancer immunotherapy is to prime the host's immune system to recognize and attack malignant tumor cells. IMO‑2125, a Toll‑like receptor 9 (TLR9) agonist, exhibited potent antitumor effects in the murine syngeneic A20 lymphoma and the CT26 colon carcinoma models. IMO‑2125 exhibited superior A20 antitumor activity when injected intratumorally (i.t.) compared with equivalent subcutaneous doses. In mice bearing dual CT26 grafts, the i.t. injection of right flank tumors elicited infiltration of cluster of differentiation (CD)3+ T lymphocytes into tumors, resulting in the regression of injected and uninjected left flank tumors. Depletion of CD8+, but not CD4+, T‑cells abrogated the IMO‑2125‑mediated antitumor response, suggesting that CD8+ lymphocytes are required for the antitumor activity. In mice harboring right flank CT26 and left flank β‑galactosidase (β‑gal)‑expressing CT26.CL25 grafts, the i.t. administration of IMO‑2125 to the CT26 graft resulted in potent and dose‑dependent antitumor activity against the two grafts. Splenic T‑cells isolated from these mice responded to AH1 antigen (present in the two tumors) and β‑gal antigen (present only in CT26.CL25) in an interferon γ enzyme‑linked immunospot assay, suggesting the clonal expansion of T‑cells directed against antigens from the two tumors. Mice with ablated CT26 tumors by previous IMO‑2125 treatment rejected re‑implanted CT26 tumor cells, but not A20 tumor cells, demonstrating that the initial IMO‑2125 treatment created a long‑lived tumor‑specific immune memory of CT26 antigens. A quantitative increase in CD3+ T lymphocytes in injected A20 tumors and an upregulation of selected checkpoint genes, including indoleamine 2,3‑dioxygenase (IDO)‑1, IDO‑2, programmed cell death protein-1 (PD-1); programmed cell death protein ligand 1 (PD-L1), carcinoembryonic antigen‑related cell adhesion molecule 1, tumor necrosis factor receptor superfamily member 4 (OX40), OX40 ligand, T‑cell immunoglobulin and mucin‑domain‑containing 3 protein, lymphocyte‑activation gene 3, cytotoxic T‑lymphocyte‑associated protein 4, were observed following IMO‑2125 treatment. IMO‑2125 also increased immune checkpoint gene expression in injected and uninjected contralateral CT26 tumors, suggesting that the co‑administration of anti‑CTLA‑4, anti‑PD‑1 or anti‑PD‑L1 therapies with IMO‑2125 may provide additional therapeutic efficacy.

Specific blockade of the endothelial ligands intercellular adhesion molecule-1 [ICAM-1] and mucosal addressin cell adhesion molecule [MAdCAM] involved in leukocyte recruitment to the site of inflammation as therapeutic targets in inflammatory bowel disease [IBD] has been recognized from their overexpression in the inflamed mucosa and successful intervention based on these ligands in preclinical animal models. Interventions to target ICAM-1 in human IBD are confined to the ICAM-1 anti-sense oligonucleotide alicaforsen. While results with parenteral formulations of alicaforsen in Crohn's disease have largely been negative, efficacy signals derived from studies with an enema formulation in ulcerative colitis and pouchitis are promising and have led to a Food and Drug Administration Fast-Track designation for the latter. A large phase III programme in pouchitis is underway. Phase II studies with the anti-MAdCAM-1 antibody [SHP647] delivered positive results in ulcerative colitis and anti-inflammatory signals in Crohn's disease. Furthermore, it was shown that SHP647 does not affect the number and composition of cells in cerebrospinal fluid, suggesting that the compound is not affecting immune surveillance in the central nervous system. In addition, both alicaforsen and SHP647 are promising compounds based on the clear safety profile observed so far.

Studies in the 1990s using animal models of intestinal inflammation delineated the crucial molecules involved in leukocyte attraction and retention to the inflamed gut and associated lymphoid tissues. The first drug targeting leukocyte trafficking tested in inflammatory bowel diseases was the anti-ICAM-1 antisense oligonucleotide alicaforsen, showing only modest efficacy. Subsequently, the anti-α4 monoclonal antibody natalizumab proved efficacious for induction and maintenance of remission in Crohn's disease, but was associated with progressive multifocal leukoencephalopathy due to its ability to interfere with both α4β1 and α4β7 function. Later developments in this area took advantage of the fairly selective expression of MAdCAM-1 in the digestive organs, showing that vedolizumab, a more specific monoclonal antibody selectively blocking MAdCAM-1 binding to integrin α4β7, was efficacious for induction and maintenance of remission in ulcerative colitis and Crohn's disease, and it was not associated with neurological complications. Currently, other drugs targeting the β7 subunit, immunoglobulin superfamily molecules expressed on the endothelium, as well as blockade of lymphocyte recirculation in lymph nodes through modulation of sphingosine 1-phosphate receptors are under development. The potential use and risks of combined anti-trafficking therapy will be examined in this review.

Background: Data on the efficacy of intercellular adhesion molecule-1 antisense oligonucleotide alicaforsen in ulcerative colitis (UC) is inconsistent., Methods: All patients, who had received at least one dose of alicaforsen, were analyzed retrospectively. Alicaforsen's efficacy was assessed in patients treated for left-sided UC and proctitis by comparing clinical and (if applicable) endoscopic disease activity before/after treatment., Results: Twelve patients were treated for left-sided UC or proctitis. Eleven patients received a 6-week course of a once-daily 240 mg alicaforsen enema formulation. In 1 patient, treatment was discontinued, because it was found to be inefficient. Disease activity measured by the partial Mayo score and 6-point symptom score was significantly reduced after treatment (6.0 vs. 2.4, p = 0.011 and 3.7 vs. 1.4, p = 0.008). Faecal calprotectin showed a trend towards reduction (484.4 vs. 179.5 μg/g, p = 0.063). Clinical improvement was achieved in 10 patients (83.3%). In 7 patients, a relapse occurred (70%). Median duration of clinical improvement was 18.0 weeks (range 1-112). Three patients showed an ongoing improvement of >9 months. No adverse events were reported., Conclusions: A 6-week course of alicaforsen seemed to be safe and efficacious in inducing clinical improvement in patients with left-sided UC and proctitis. Prolonged clinical improvement was observed in many but not all patients., (© 2017 S. Karger AG, Basel.)

Alicaforsen is a 20-base antisense oligonucleotide inhibiting ICAM-1 production, which is an important adhesion molecule involved in leukocyte migration and trafficking to the site of inflammation. Hitherto, alicaforsen has been granted orphan drug designation and is prescribed as an unlicensed medicine in accordance with international regulation for the treatment of pouchitis and left-sided ulcerative colitis. Given the positive results evolving from one open-label trial and one case series in patients with chronic refractory pouchitis, US FDA has agreed to a rolling submission for a license application for the treatment of pouchitis, which has been recently initiated. Whether alicaforsen leads to higher endoscopic and clinical remission rates as placebo and whether the response can be maintained in the long-term in larger studies is yet unknown. An ongoing multicenter international Phase III trial will definitely address these unanswered questions.

Introduction: Intracellular adhesion molecule-1 (ICAM-1), is a transmembrane glycoprotein of the immunoglobulin family, constitutively expressed on vascular endothelial cells and upregulated in inflamed colonic tissue. Alicaforsen, a 20 base ICAM-1 anti-sense oligonucleotide and highly selective ICAM-1 inhibitor, down-regulates ICAM-1 mRNA. Areas covered: We review mechanism of action, pharmacokinetics, pre-clinical, clinical and safety data of alicaforsen for the treatment of ulcerative colitis (UC), pouchitis and Crohn's disease (CD). Expert opinion: After 6 weeks of treatment, topical alicaforsen was significantly more effective than placebo in inducing remission in patients with moderate-severe distal UC, with treatment effects lasting up to 30 weeks. No difference was observed in head-head comparison with mesalamine topical enema, although alicaforsen appeared to have more durable treatment effect. Clinical trials of an intravenous formulation in Crohn's disease showed no significant treatment effect compared to placebo. An open-label trial in alicaforsen for pouchitis demonstrated encouraging results, now being assessed in a multi-national phase 3 trial. No major safety signals have been observed in UC patients treated with alicaforsen enemas. The potential as a novel therapy for pouchitis has led to orphan designation for this indication by the FDA and European Medicines Agency.

This article provides an overview of the discussions held by the Immunomodulatory Subcommittee of the Oligonucleotide Safety Working Group on complement activation induced by oligonucleotides, most notably the phosphorothioate-containing oligonucleotides. Alternative complement pathway activation in monkeys is a common effect of single-stranded phosphorothioate backbone oligonucleotides in toxicology studies. This article discusses the mechanism for activation, general investigational strategy, and the impact of various chemical modifications. The goal is to provide the best practice approach to characterizing this effect, understanding the implication of the species specificity, and the interpretation of clinical relevance.

Despite the great success of anti-tumour necrosis factor-based therapies, the treatment of Crohn's disease (CD) and ulcerative colitis (UC) still remains a challenge for clinicians, as these drugs are not effective in all patients, their efficacy may wane with time, and their use can increase the risk of adverse events and be associated with the development of new immune-mediated diseases. Therefore, new therapeutic targets are currently being investigated both in pre-clinical studies and in clinical trials. Among the technologies used to build new therapeutic compounds, the antisense oligonucleotide (ASO) approach is slowly gaining space in the field of inflammatory bowel diseases (IBDs), and three ASOs have been investigated in clinical trials. Systemic administration of alicaforsen targeting intercellular adhesion molecule-1, a protein involved in the recruitment of leukocytes to inflamed intestine, was not effective in CD, even though the same compound was of benefit when given as an enema to UC patients. DIMS0150, targeting nuclear factor (NF) κB-p65, a transcription factor that promotes pro-inflammatory responses, was very promising in pre-clinical studies and is currently being tested in clinical trials. Oral mongersen, targeting Smad7, an intracellular protein that inhibits transforming growth factor (TGF)-β1 activity, was safe and well tolerated by CD patients, and the results of a phase II clinical trial showed the efficacy of the drug in inducing clinical remission in patients with active disease. In this leading article, we review the rationale and the clinical data available regarding these three agents, and we discuss the challenge of using ASOs in IBD.

Phosphorothioates have found their usefulness in the general area of oligonucleotide therapeutic applications. Initially this modification was introduced into the antisense methodology because of the nuclease resistance of the phosphorothioate linkage in comparison with that of the phosphate linkage. However, as experimental data accumulated, it was detected that this chemical modification also facilitates cellular uptake and bioavailibity in vivo. Thus, today the majority of therapeutic oligonucleotides contain this modification. This review will discuss the historical development of this modification and present some of its chemical properties where they differ from those of the phosphate group. The antisense application will be discussed in the original context with cleavage of the target mRNA, but other target RNAs such as microRNAs and long noncoding RNAs will also be covered. It continues with applications where the target RNA should not be cleaved. A brief presentation of decoy oligonucleotides will be included, as well as some miscellaneous applications. Cellular uptake is a crucial step for oligonucleotides to reach their target and will be briefly reviewed. Lastly, a most surprising recent observation is the presence of phosphorothioate groups in bacterial DNA where functions still remain to be fully determined.

Enterovirus 71 (EV71) is a highly infectious virus that is a major cause of hand, foot, and mouth disease (HFMD), which can lead to severe neurological complications. Currently, there is no effective therapy against EV71. Five antisense oligodeoxynucleotides targeting the 5'-terminal conserved domain of the viral genome were designed using a method based on multiple predicted target mRNA structures. They were then screened for anti-EV71 activity in vitro based on their ability to inhibit an EV71-induced cytopathic effect (CPE). A novel antisense oligonucleotide (EV5) was tested both in rhabdomyosarcoma (RD) cells and in vivo using a mouse model, with a random oligonucleotide (EV5R) of EV5 as a control. EV5 was identified as having significant anti-EV71 activity in vitro and in vivo without significant cytotoxicity. Treatment of RD and Vero cells with antisense oligodeoxynucleotide EV5 significantly and specifically alleviated the cytopathic effect of EV71 in vitro. The inhibitory effect was dose dependent and specific, with a corresponding decrease in viral RNA and viral protein levels. In vivo, EV5 was specifically effective against EV71 virus in preventing death, decreasing weight reduction and reducing the viral RNA copy number and the level of viral proteins in the lungs, intestines and muscles. These results demonstrate the potential and feasibility of using antisense oligodeoxynucleotides specific for the 5'-terminal conserved domain of the viral genome as an antiviral therapy for EV71 disease.

Lymphocyte homing antagonists represent promising therapeutic agents for the treatment of idiopathic inflammatory bowel disease (IBD). Several critical molecules involved in the recruitment of inflammatory cells in the intestine, including integrins and chemokine receptors, have been successfully targeted for the treatment of IBD. These agents have shown great promise for the induction and maintenance of remission for both Crohn disease and ulcerative colitis. This article discusses currently approved prototypic agents for the treatment of IBD (natalizumab, anti-α4 integrin; vedolizumab, anti-α4β7 integrin), and several other agents in the same class currently under development., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Antisense oligonucleotide (AON)-mediated exon skipping is a promising therapeutic approach for Duchenne muscular dystrophy that is currently being tested in various clinical trials. This approach is based on restoring the open reading frame of dystrophin transcripts resulting in shorter but partially functional dystrophin proteins as found in patients with Becker muscular dystrophy. After systemic administration, a large proportion of AONs ends up in the liver and kidneys. Therefore, enhancing AON uptake by skeletal and cardiac muscle would improve the AONs' therapeutic effect. For phosphorodiamidate morpholino oligomer, AONs use nonspecific positively charged cell penetrating peptides to enhance efficacy. However, this is challenging for negatively charged 2'-O-methyl phosphorothioate oligomer. Therefore, we screened a 7-mer phage display peptide library to identify muscle and heart homing peptides in vivo in the mdx mouse model and found a promising candidate peptide capable of binding muscle cells in vitro and in vivo. Upon systemic administration in dystrophic mdx mice, conjugation of a 2'-O-methyl phosphorothioate AON to this peptide indeed improved uptake in skeletal and cardiac muscle, and resulted in higher exon skipping levels with a significant difference in heart and diaphragm. Based on these results, peptide conjugation represents an interesting strategy to enhance the therapeutic effect of exon skipping with 2'-O-methyl phosphorothioate AONs for Duchenne muscular dystrophy.

Background: Many experimental and clinical studies have focused on the antisense strategy. In this context phosphorothioate oligonucleotides are compounds addressed to hybridize to a targeted mRNA inducing a variety of effects including inhibition of the expression of proteins involved in different pathological processes and preventing translation., Methods: In this review, we provide an update on clinical efficacy and toxicological profile of phosphorothioate oligonucleotides used in experimental and clinical studies, also focusing on the use of the antisense strategy in the context of Duchenne muscular dystrophy which is a key pathology to study different aspects of this therapy. Pubmed/Medline was searched using the keyword "Phosphorotioate" combined with "Antisense", "Oligonucleotide" and "Duchenne muscular dystrophy"., Conclusions: Phosphorothioate oligonucleotide transient activation of the complement cascade represents the most evident toxicological response, as showed by in vivo studies. It is also known that many of these compounds induce a prolongation of activated partial thromboplastin time, a reaction which is often highly transient and proportional to the oligonucleotide plasma concentrations, making that effect clinically insignificant for the current treatment regimens. In summary, current evidence shows limited untoward effects and reversibility of the damage induced, at least for some of those compounds, with promising effectiveness for treatment of various pathologies.

Background: The antisense ICAM-1 inhibitor alicaforsen has been studied in four phase 2 studies in ulcerative colitis (UC). Recruited patients varied as to the extent of their colitis and in the severity of disease at entry., Aim: To investigate the efficacy of alicaforsen enema in specific UC populations. Efficacy was analysed for short-term (week 6-10) and long-term (week 30) outcomes compared with either placebo or a high-dose mesalazine (mesalamine) enema in patients with disease extent up to 40 cm from the anal verge in patients with moderate or severe disease, and in patients with both of these features., Methods: Individual patient data meta-analyses of 200 patients from four phase 2 studies evaluating nightly alicaforsen 240 mg enema and comparators. Patient data were pooled and analysed in a single data set. Continuous outcomes were evaluated using anova; dichotomous outcomes were evaluated using Pearson chi-square or Fisher's exact tests., Results: Alicaforsen showed superior efficacy vs. placebo in: patients with disease extent up to 40 cm, patients with moderate and severe disease and especially when both those conditions were satisfied. In these patient groups, mesalazine also showed short-term efficacy. At week 30, however, the efficacy of mesalazine waned and alicaforsen became significantly more efficacious., Conclusions: This post hoc meta-analysis showed that alicaforsen is effective in patients with active UC, especially in patients with distal disease, which is of moderate/severe activity. The efficacy of alicaforsen was durable in these sub-groups, suggesting a disease-modifying effect. This analysis suggests that alicaforsen enema may offer an effective, potentially durable response in moderate/severe distal active UC., (© 2013 John Wiley & Sons Ltd.)

Aeroallergens are the most common triggers for the development of asthma. Recent birth cohort studies have identified viral infections occurring against a background of aeroallergen sensitization as a potent risk factor for initiation of asthma. Viral infection enhances immunopathogenic potential of pre-existing inhalant allergy via modulating airway mucosal dendritic cells. By using an allergen inhalation challenge clinical model, studies have shown that the late asthma response (LAR) is associated with more pronounced allergen-induced airway inflammation and airway hyperresponsiveness. The degree of airway eosinophilia, regulated by bone marrow progenitor cells and interleukin-5 level, correlates with the magnitude of the LAR and the increase in hyperresponsiveness. Both myeloid and plasmacytoid dendritic cell subsets have been involved in the pathogenesis of allergen-induced LAR. Myeloid dendritic cells are responsible for the allergen presentation and induction of inflammation and plasmacytoid dendritic cells play a role in the resolution of allergen-induced inflammation. A variety of potential new classes of asthma medication has also been evaluated with the allergen inhalation challenge in mild asthmatic subjects. Examples are TPI ASM8, an inhaled anti-sense oligonucleotide drug product, which attenuated both early and LARs via inhibition of the target gene mRNA of chemokine receptor 3, and the common β chain of interleukin-3, interleukin-5 and granulocyte-macrophage colony-stimulating factor receptor. Anti-human antibody interleukin-13 (IM-638) significantly attenuated both early and late allergen-induced asthma response. Pitrakinra, which targets both interleukin-4 and interleukin-13, substantially diminishes allergen-induced airway responses. Allergen-induced airway responses are a valuable way to evaluate the activity of possible new therapies in asthmatic airways.

Persistent production of type I interferon (IFN) by activated plasmacytoid dendritic cells (pDC) is a leading model to explain chronic immune activation in human immunodeficiency virus (HIV) infection but direct evidence for this is lacking. We used a dual antagonist of Toll-like receptor (TLR) 7 and TLR9 to selectively inhibit responses of pDC but not other mononuclear phagocytes to viral RNA prior to and for 8 weeks following pathogenic simian immunodeficiency virus (SIV) infection of rhesus macaques. We show that pDC are major but not exclusive producers of IFN-α that rapidly become unresponsive to virus stimulation following SIV infection, whereas myeloid DC gain the capacity to produce IFN-α, albeit at low levels. pDC mediate a marked but transient IFN-α response in lymph nodes during the acute phase that is blocked by administration of TLR7 and TLR9 antagonist without impacting pDC recruitment. TLR7 and TLR9 blockade did not impact virus load or the acute IFN-α response in plasma and had minimal effect on expression of IFN-stimulated genes in both blood and lymph node. TLR7 and TLR9 blockade did not prevent activation of memory CD4+ and CD8+ T cells in blood or lymph node but led to significant increases in proliferation of both subsets in blood following SIV infection. Our findings reveal that virus-mediated activation of pDC through TLR7 and TLR9 contributes to substantial but transient IFN-α production following pathogenic SIV infection. However, the data indicate that pDC activation and IFN-α production are unlikely to be major factors in driving immune activation in early infection. Based on these findings therapeutic strategies aimed at blocking pDC function and IFN-α production may not reduce HIV-associated immunopathology.

Lymphocyte infiltration into the intestinal tract in inflammatory bowel disease (IBD) is mediated by interaction between α4 integrin and its specific ligands. Development of monoclonal antibodies against α4 integrin allowed targeting of lymphocyte trafficking into the intestine as a novel therapeutic intervention. Natalizumab, vedolizumab, alicaforsen AJM300, rhuMAb β7, CCX282-B, and PF-00547,659 are few of monoclonal antibodies that have shown high promise in trials with the potential for more attractive benefit:risk ratio than currently available therapies. In this review, an attempt is made to underline the therapeutic potential and the safety of anti-adhesion molecule treatment in IBD.

The eosinophil is a multifunctional granulocyte best known for providing host defense against parasites. Paradoxically, eosinophils are also implicated in the pathogenesis of allergic inflammation, asthma, and hypereosinophilic syndromes. Emerging evidence also supports the potential for harnessing the cytotoxic power of eosinophils and redirecting it to kill solid tumors. Central to eosinophil physiology is interleukin-5 (IL-5) and its receptor (IL-5R) which is composed of a ligand-specific alpha chain (IL-5Rα) and the common beta chain (βc). Eosinophil activation can lead to their degranulation, resulting in rapid release of an arsenal of tissue-destructive proinflammatory mediators and cytotoxic proteins that can be both beneficial and detrimental to the host. This review discusses eosinophil immunobiology and therapeutic strategies for targeting of IL-5 and IL-5R, as well as the potential for harnessing eosinophil cytotoxicity as a tumoricide.

Hypereosinophilic syndromes (HESs) are a diverse group of conditions characterized by clinical manifestations attributable to eosinophilia and eosinophilic infiltration of tissues. HESs are chronic disorders with significant morbidity and mortality. Although the availability of targeted chemotherapeutic agents, including imatinib, has improved quality of life and survival in some patients with HESs, additional agents with increased efficacy and decreased toxicity are sorely needed. The purpose of this review is to provide an overview of eosinophil biology with an emphasis on potential targets of pharmacotherapy and to provide a summary of potential eosinophil-targeting agents, including those in development, in clinical trials, or approved for other disorders., (Published by Mosby, Inc.)

Inflammatory bowel diseases (IBD) are chronic relapsing and remitting disorders that have varying degrees of severity. However multiple studies have confirmed that a large proportion of patients on maintenance treatment lose response to anti-TNF therapy. This has led to increasing interest in the concept of 'switching therapy out-of-class' i.e. a nonanti- TNF antibody when patients either fail to respond (primary non-response, develop secondary non-response) or do not tolerate anti-TNF therapies. The most widely known and studied alternative class of antibodies therapies at present are the selective adhesion molecule inhibitors. Several antibodies exist which constitute selection adhesion molecule inhibitors, including Natalizumab, MLN-0002 (Vedolizumab) and ISIS 2302 (Alicaforsen) will be discussed in this review.

Elevated numbers of blood and tissue eosinophils are present in allergic diseases and experimental evidence suggests that eosinophils play an important pathogenic role in these conditions. Regulation of eosinophil maturation, recruitment, and survival is under the control of a small group of factors, including interleukin-5 (IL-5). Given the probable importance of eosinophils to allergy and other associated disorders, IL-5 has been proposed as a potential molecular target in the treatment of these diseases. IL-5 antagonist therapies in current development include two monoclonal anti-IL-5 antibodies (mepolizumab, reslizumab), a monoclonal antibody directed at the IL-5 receptor (benralizumab), and anti-sense oligonucleotide therapy (TPI ASM8). Anti-IL5 antibody therapy has been the most extensively studied of these agents, and trials have been performed in patients with bronchial asthma, nasal polyposis, atopic dermatitis, eosinophilic esophagitis, hypereosinophilic syndrome, and Churg-Strauss syndrome. In studies of asthmatics, anti-IL-5 showed minimal efficacy in patients with moderate, controlled asthma. In patients with severe, refractory asthma associated with eosinophilia, however, clinical trials have demonstrated significant reductions in asthma exacerbations. Clinical studies in other disorders, particularly eosinophilic esophagitis and hypereosinophilic syndrome, have also shown significant improvements in blood and/or tissue eosinophilia and variable alterations in clinical disease activity. Strategies aimed at the inhibition of IL-5 may hold great promise in the treatment of eosinophilic diseases.

Here, we discuss three RNA-based therapeutic technologies exploiting various oligonucleotides that bind to RNA by base pairing in a sequence-specific manner yet have different mechanisms of action and effects. RNA interference and antisense oligonucleotides downregulate gene expression by inducing enzyme-dependent degradation of targeted mRNA. Steric-blocking oligonucleotides block the access of cellular machinery to pre-mRNA and mRNA without degrading the RNA. Through this mechanism, steric-blocking oligonucleotides can redirect alternative splicing, repair defective RNA, restore protein production or downregulate gene expression. Moreover, they can be extensively chemically modified to acquire more drug-like properties. The ability of RNA-blocking oligonucleotides to restore gene function makes them best suited for the treatment of genetic disorders. Positive results from clinical trials for the treatment of Duchenne muscular dystrophy show that this technology is close to achieving its clinical potential.

The decoy oligodeoxynucleotide (ODN) serves as a decoy sequence for a target transcription factor, then inhibiting its binding to the authentic sequence at the promoter, and consequently hinders the gene expression. ODNs should be properly up taken by the cell and tissue, be specific for one nuclear factor, and be stable against intracellular and serum nucleases. Since phosphodiester oligos are easily degradated by nucleases, chemical modification such as phosphorothioation, and structural modification by ligation of the extremities of two single-strand phosphodiester sequence resulting in a dumbbell shaped ODN (Ribbon-type decoy ODN) are performed to increase the stability of ODNs. In combination, phosphorothioation of specific regions in Ribbon-type decoy has further increased its stability, and the introduction of saturated hydrocarbon polymer spacer linking the two double strands also improved the stability and reduced the production cost. The cellular delivery has been optimized by using the biodegradable polymer D,L-lactide-co-glycolide (PLGA) as a carrier to ODN. The nuclear factor-kappa B (NF-κB) is a convergent point of different pathways, with main role in many pathologies, and poses as an ideal target for decoy ODN strategy. Following this we have designed ODN targeting NF-κB, and in this review, we are going to discuss the various modification performed in an attempt to improve the ODN efficacy, and some promising pre-clinical data and clinical trials using NF-κB decoy ODN.

We have taken an empirical approach in designing splice-switching oligomers to induce targeted dystrophin exon skipping. The nucleotide sequence of the exon under examination is first analyzed for potential exon recognition motifs and then a set of oligomers complementary to the acceptor and donor splice sites, as well as intra-exonic regions predicted to contain exon splice enhancers, are designed and synthesized as 2'-O-methyl-modified bases on a phosphorothioate backbone (2OMeAOs). The 2OMeAOs can be readily transfected into cultured normal myogenic cells as cationic lipoplexes, and are incubated for 24 h before total RNA extraction and subsequent analysis by semi-quantitative RT-PCR. The amplification conditions used for each dystrophin transcript region under investigation minimize preferential production of shorter amplicons and do not exaggerate the level of induced RT-PCR products, compared to the endogenous dystrophin transcript product. It is imperative that the test oligomers are transfected over a range of concentrations and that the target exon is excised in a reproducible and dose-dependent manner.Once it has been demonstrated that an oligomer can induce some degree of exon skipping, that target region of the pre-mRNA is assumed to be involved in splicing of the exon. A series of overlapping oligomers are prepared and evaluated by transfection into normal myogenic cells at lower concentrations to identify the more effective compounds. Clinical application requires antisense compounds that efficiently modulate splicing at low dosages, delivering the greatest benefits in terms of efficacy, safety, and cost.

Background: TPI ASM8 contains two modified phosphorothioate antisense oligonucleotides (AON), one targeting the common beta chain (βc) of the IL-3/IL-5/GM-CSF receptors and the other targeting the chemokine receptor CCR3. Inhalation of TPI ASM8 significantly improves lung function and sputum eosinophilia after allergen inhalation challenge in asthmatics., Objective: This study assessed whether TPI ASM8 reduces airway levels of haemopoietic progenitor cells., Methods: This open-label study was conducted in 14 stable, allergic mild asthmatic subjects with early- and late-phase allergen-induced bronchoconstriction. Subjects underwent allergen challenges after 4-day treatment with placebo, 4 mg b.i.d. and 8 mg o.d. of TPI ASM8. Sputum was induced before, 7 and 24 h after allergen challenges for progenitor measurements. Treatments were separated by 2-3 weeks., Results: TPI ASM8 reduced allergen-induced sputum eosinophils, and the early and late asthmatic responses (P<0.05). TPI ASM8 also reduced the number of CD34(+) CCR3(+) cells (P=0.004) and CD34(+) IL-5Rα(+) cells (P=0.016), and the proportion of CD34(+) cells expressing IL-5Rα (P=0.036)., Conclusions and Clinical Relevance: TPI ASM8 was safe and well tolerated. The results of this study demonstrate blocking of CCR3 and βc expression by TPI ASM8 significantly inhibits the accumulation of eosinophils and eosinophil progenitors in the airways after allergen challenge. Inhibition of airway progenitor cell accumulation presents a novel therapeutic target., (© 2011 Blackwell Publishing Ltd.)

A promising strategy based on the antisense oligonucleotides against the Plasmodium falciparum topoisomerase II has been considered using cationic nanoemulsion as oligonucleotide delivery system. Phosphodiester and chemically modified phosphorothioate oligonucleotides bearing negative charges were adsorbed on positively charged emulsion composed of medium chain triglycerides, egg lecithin, 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), and water, at different +/- charge ratios (positive charges from cationic lipid/negative charges from oligonucleotide): +0.5/-, +2/-, +4/- and +6/-. The physicochemical properties of the complexes were determined, as well as their stability in culture medium. Their interaction with erythrocytes through hemolysis, binding experiments and confocal microscopy were also evaluated. Finally, the in vitro evaluation of parasite growth and reinfection capacity was performed. The overall results showed that antisense oligonucleotides against P. falciparum topoisomerase II gene can be efficiently adsorbed onto a cationic nanoemulsion forming complexes. Whereas unloaded nanoemulsion displayed an hemolytic effect due to the presence of the cationic lipid, this was not the case of loaded nanoemulsion at low +/- ratios. Oligonucleotide-loaded nanoemulsions were found to be located inside the infected erythrocytes, inhibiting efficiently parasite growth (until 80%) and causing a delay in P. falciparum life cycle., (Copyright © 2011. Published by Elsevier B.V.)

Background: TPI ASM8 contains two modified antisense oligonucleotides (AON) targeting the beta subunit (β(c) ) of the IL-3, IL-5, GM-CSF receptors and the chemokine receptor CCR3. A previous study suggested that TPI ASM8 had broader effects than just inhibition of eosinophils in asthmatics., Objective: We assessed whether TPI ASM8 caused a dose-dependent attenuation in the inflammatory and physiological changes after inhaled allergen challenge (AIC)., Methods: This single-center, open-label, stepwise-ascending dose study was conducted in fourteen stable, mild allergic asthmatics. Following placebo AIC, subjects underwent AIC after 4 days treatment with 1, 2, and 4 mg BID and finally 8 mg once daily (OD) of TPI ASM8, inhaled via the I-Neb™ nebuliser. Treatments were separated by 2-3-week washout periods., Results: TPI ASM8 was safe and well tolerated at all doses. TPI ASM8 8 mg OD reduced eosinophils in sputum after AIC (by 60.9% at 7 h and 68.4% at 24 h post-AIC, P=0.016 and P=0.007, respectively). Additionally, TPI ASM8 8 mg OD significantly attenuated the early and late airway responses as shown by the reduction in the area under the curve by 45% (P=0.016) and 59%, (P=0.0015), respectively, the increase in eosinophil cationic protein (ECP) by up to 57% (P=0.021), and airway responsiveness to methacholine by more than 1 doubling dose (P=0.012). A dose-response relationship was noted, and efficacy was maintained with once per day administration., Conclusions: TPI ASM8 attenuated a broad range of inflammatory and physiological changes after AIC, suggesting that CCR3, IL-3, and GM-CSF also are important targets for the management of asthma., (© 2011 John Wiley & Sons A/S.)

Hepatitis C virus infection is the main cause of liver disease worldwide, often leading to chronic hepatitis. Recent studies have demonstrated that miRNA-122, a liver-specific miRNA, is required for HCV replication in hepatocytes by its binding to the 5' UTR of HCV. Down-regulation of miRNA-122 in vitro and in vivo has led to significant inhibition of viral replication. In the present article, we report the major recent findings on the potential therapeutic role of anti-miRNA-122 molecules.

Numerous chemically modified oligonucleotides have been developed so far and show their own unique chemical properties and pharmacodynamic/pharmacokinetic characteristics. Among all non-natural nucleotides, to the best of our knowledge, only five chemistries are currently being tested in clinical trials: phosphorothioate, 2´-O-methyl RNA, 2´-O-methoxyethyl RNA, 2´,4´-bridged nucleic acid/locked nucleic acid and the phosphorodiamidate morpholino oligomer. Since phosphorothioate modification can improve the pharmacokinetics of oligonucleotides, this modification is currently used in combination with all other modifications except phosphorodiamidate morpholino oligomer. For the treatment of metabolic, cardiovascular, cancer and other systemic diseases, the phosphorothioate class of drugs is obviously helpful, while superior efficacies can be observed in phosphorodiamidate morpholino oligomer compared to other classes of oligonucleotides for the treatment of Duchenne muscular dystrophy. Which properties of antisense molecules are actually essential for clinical applications? In this article, we provide an overview of the medicinal chemistry of existing non-natural antisense molecules, as well as their clinical applications, to discuss which properties of antisense oligonuculeotides affect therapeutic potency.

Previous studies have suggested that the caspase 8 inhibitor FLIP is a promising anti-cancer therapeutic target. In this study, we characterised a novel FLIP-targeted antisense phosphorothioate oligonucleotide (AS PTO). FLIP AS and control PTOs were assessed in vitro in transient transfection experiments and in vivo using xenograft models in Balb/c nude mice. FLIP expression was assessed by QPCR and Western. Apoptosis induction was determined by flow cytometry and Western. Of 5 sequences generated, one potently down-regulated FLIP. AS PTO-mediated down-regulation of FLIP resulted in caspase 8 activation and apoptosis induction in non-small cell lung (NSCLC) cells but not in normal lung cells. Similar results were observed in colorectal and prostate cancer cells. Furthermore, the FLIP AS PTO sensitized cancer cells but not normal lung cells to apoptosis induced by rTRAIL. Moreover, the FLIP AS PTO enhanced chemotherapy-induced apoptosis in NSCLC cells. Importantly, compared to a control non-targeted PTO, intra-peritoneal delivery of FLIP AS PTO inhibited the growth of NSCLC xenografts and enhanced the in vivo antitumour effects of cisplatin. We have identified a novel FLIP-targeted AS PTO that has in vitro and in vivo activity and which therefore has potential for further pre-clinical development.

The liver-expressed microRNA-122 (miR-122) is essential for hepatitis C virus (HCV) RNA accumulation in cultured liver cells, but its potential as a target for antiviral intervention has not been assessed. We found that treatment of chronically infected chimpanzees with a locked nucleic acid (LNA)-modified oligonucleotide (SPC3649) complementary to miR-122 leads to long-lasting suppression of HCV viremia, with no evidence of viral resistance or side effects in the treated animals. Furthermore, transcriptome and histological analyses of liver biopsies demonstrated derepression of target mRNAs with miR-122 seed sites, down-regulation of interferon-regulated genes, and improvement of HCV-induced liver pathology. The prolonged virological response to SPC3649 treatment without HCV rebound holds promise of a new antiviral therapy with a high barrier to resistance.

CpG-Oligodeoxynucleotide (ODN) has two backbones. Phosphorothioate backbone (PS) shows a strong immunostimulating effect while phosphodiester (PE) shows little in vivo. 3' hexameric deoxyriboguanosine-run (3' dG(6)-run) conjugation to PE CpG-ODN has been reported to enhance immunostimulation and to protect against asthma when injected at the time of sensitization in mice. We evaluated the treatment effects of PE and PS CpG-ODN with or without 3' dG(6)-run on asthma in presensitized mice. BALB/c mice sensitized with ovalbumin and alum were challenged with 1% ovalbumin on three days. CpG-ODNs (100 microg) or PBS were injected 4 times; 27 hr before challenge and 3 hr before each challenge (CpG-dG(6): CpG-ODN with 3' dG(6)-run, PE*-CpG-dG(6): PE-CpG-dG(6) with two PS backbones at the 5' terminus). PE-CpG showed no treatment effect. PE-CpG-dG(6) only increased ovalbumin-specific IgG2a. PE*-CpG-dG(6) increased ovalbumin-specific IgG2a but also reduced BAL fluid eosinophils and airway hyperresponsiveness. PS-CpG increased ovalbumin-specific IgG2a, reduced airway inflammation and airway hyperresponsiveness. PS-CpG-dG(6) was less effective than PS-CpG on airway inflammation and airway hyperresponsiveness. In pre-sensitized mice, PE-CpG required not only 3' dG(6)-run but also the modification of two PS linkages at 5' terminus to inhibit features of asthma. PS-CpG was strong enough to inhibit asthma but PS-CpG-dG(6) was less effective.

Synthetic oligodeoxynucleotides (ODN) capable of "neutralizing" or "inhibiting" immune responses have been described. This review will focus on the properties of phosphorothioate ODN that mimic the immunosuppressive activity of the repetitive TTAGGG motifs present in mammalian telomeres. These TTAGGG multimers block the production of pro-inflammatory and T helper type 1 cytokines elicited when immune cells are activated by a wide variety of Toll-like receptor ligands, polyclonal activators, and antigens. Several mechanisms contribute to the suppressive activity of such ODN. Ongoing microarray studies indicate that suppressive ODN interfere with the phosphorylation of signal transducer and activator of transcription 1 (STAT1) and STAT4, thereby blocking the inflammation mediated by STAT-associated signaling cascades. In animal models, suppressive ODN can be used to prevent or treat diseases characterized by persistent immune activation, including collagen-induced arthritis, inflammatory arthritis, systemic lupus erythematosus, silicosis, and toxic shock. These findings suggest that TTAGGG multimers may find broad use in the treatment of diseases characterized by over-exuberant/persistent immune activation.

Nuclear factor-kappaB (NF-kappaB) plays a key role in the expression of several genes involved in the immune and inflammatory process. Previously, we demonstrated that NF-kappaB activation can be significantly inhibited by a double stranded oligodeoxynucleotide (ODN). Nevertheless, the therapeutic use of ODN requires a delivery system able to improve poor crossing of cell membranes and rapid in vivo enzymatic degradation. Poly(D,L-lactide-co-glycolide) (PLGA) microspheres can increase ODN stability in biological environment and release the encapsulated drug in long time frames. Here, we used a decoy ODN against NF-kappaB and we investigated its effect, when administered in naked form or when delivered by PLGA microspheres, in a rat model of chronic inflammation. The subcutaneous implant of lambda-carrageenin-soaked sponges caused leukocyte infiltration and formation of granulation tissue which were inhibited up to 15 days by co-injection of microspheres releasing decoy ODN whereas naked decoy ODN showed this effect only up to 5 days. Molecular analysis performed on granulation tissue demonstrated an inhibition of NF-kappaB activation correlated to a decrease of tumor necrosis factor-alpha (TNF-alpha) and inducible nitric oxide synthase (iNOS) expression. Our results suggest that microspheres could be an useful tool to improve pharmacokinetics of decoy ODN and may represent a strategy to inhibit NF-kappaB activation in chronic inflammation.

Background: We have previously shown that short-course treatment with Amb a 1-immunostimulatory phosphorothioate oligonucleotide conjugate (AIC) before the ragweed season modifies the response of the nasal mucosa to allergen challenge in ragweed-sensitive patients by increasing Th1 cytokines and decreasing both Th2 cytokines and eosinophilia after the ragweed season. The effect of AIC immunotherapy on CD4+CD25+ T cell expression in the nasal mucosa is unknown., Objective: To determine the in vivo effect of short-course AIC immunotherapy on CD4+CD25+ regulatory T cells in the nasal mucosa of ragweed-sensitive subjects., Methods: 19 ragweed-sensitive patients with allergic rhinitis were randomly assigned to receive either 6 escalating doses of AIC (0.06-12microg; n = 12) or placebo (n = 7) at weekly intervals immediately before the 2001 ragweed season. Nasal biopsies were taken at baseline prior to immunization and again post immunization 24 hours after ragweed allergen challenge at the start and end of the ragweed season. The expression of T regulatory cells, IL-10 and TGF-beta was assessed at each time point by immunohistochemistry., Results: The numbers of allergen-induced CD4+-, CD4+CD25+-, IL-10- and TGF-beta-positive cells in the nasal mucosa after AIC immunization before the ragweed season did not differ between the two groups. Repeat challenge after the ragweed season led to a significant increase in CD4+CD25+ cells in AIC-compared with placebo-treated subjects. A trend toward an increase in IL-10-positive cells in the AIC-treated group did not reach statistical significance., Conclusions: Short-course AIC immunotherapy increases CD4+CD25+ regulatory T cell infiltration in the nasal mucosa following allergen challenge after seasonal ragweed-pollen exposure.

Background: Alicaforsen (ISIS 2302), an antisense to intercellular adhesion molecule-1 (ICAM-1) (CD54), was designed to inhibit ICAM-1 expression. ICAM-1 seems to play a role in cell-mediated inflammation, specifically cell trafficking. For this reason, it may be useful in a variety of immune-mediated diseases, including inflammatory bowel disease., Objective: To evaluate the use of alicaforsen in clinical trials to understand its efficacy and side effects, as well as assess for evidence that may offer insight into disease pathways., Methods: We evaluate all of the available, published trials, with a focus on the prospective, randomized trials., Results/conclusions: Systemic treatment for Crohn's disease has not revealed significant effect. Topical enemas for ulcerative colitis have demonstrated some effect in secondary outcomes, and initial studies in pouchitis are promising. In general, the compound has been well tolerated and safe.

Protein kinase C (PKC) are cytoplasmic serine-threonine kinases, analysis of their involvement in oncogenesis is complex. Deregulated expressions of certain PKC can be observed in various tumors, but there is great variability in the roles of these enzymes according isoform or cell type (pro- or anti-proliferative action). Although understanding of the role of PKC in tumor development is still incomplete, different agents are currently evaluated. This review discusses the available data, with special emphasis on clinical outcomes.

Rationale: The drug product TPI ASM8 contains two modified phosphorothioate antisense oligonucleotides designed to inhibit allergic inflammation by down-regulating human CCR3 and the common beta chain (beta(c)) of IL-3, IL-5, and granulocyte-macrophage colony-stimulating factor receptors., Objectives: This study examined the effects of inhaled TPI ASM8 on sputum cellular influx, CCR3 and beta(c) mRNA and protein levels, and the airway physiologic response after inhaled allergen., Methods: Seventeen subjects with mild atopic asthma were randomized in a crossover study to inhale 1,500 microg TPI ASM8 or placebo by nebulizer, once daily for 4 days. On Day 3, subjects underwent allergen inhalation challenge. Sputum samples were collected before and after allergen. CCR3 and beta(c) protein levels were measured by flow cytometry, mRNA was measured using real-time quantitative polymerase chain reaction, and the FEV1 was measured over 7 hours after challenge., Measurements and Main Results: Compared with placebo, TPI ASM8 inhibited sputum eosinophil influx by 46% (P = 0.02) and blunted the increase in total cells (63%) after allergen challenge. TPI ASM8 significantly reduced the early asthmatic response (P = 0.04) with a trend for the late asthmatic response (P = 0.08). The allergen-induced (Day 2 to Day 3) levels of beta(c) mRNA and CCR3 mRNA in sputum-derived cells were inhibited by TPI ASM8 (P = 0.039 and P = 0.054, respectively), with no significant effects on the cell surface protein expression of CCR3 and beta(c) (P > 0.05). No serious adverse events were reported., Conclusions: TPI ASM8 attenuates the allergen-induced increase in target gene mRNA and airway responses in subjects with mild asthma. Clinical trial registered with www.clinicaltrials.gov (NCT 00264966).

The last few years have been highlighted by further knowledge and optimism regarding the use of biologic therapy in Crohn disease. The introduction of anti-tumor necrosis factor (TNF) therapy into clinical practice in the form of the murine chimeric monoclonal antibody infliximab, and more recently the fully human monoclonal antibody adalimumab, has significantly advanced treatment for Crohn disease. Despite the introduction of the anti-TNF agents, 20-40% of patients will fail to respond to initial induction therapy, and of the initial responders only 60-70% will have a sustained response at 1 year. Therefore, there remains a significant unmet need in the treatment of patients with Crohn disease. A novel approach in suppressing inflammation is to intervene in the mechanisms responsible for the migration of leukocytes into inflamed tissue. One such method is by selective adhesion molecule inhibition. Several agents based on this strategy have been evaluated in the treatment of inflammatory bowel disease. It is expected that these agents will offer an alternative to the anti-TNF agent class in patients with moderate to severe Crohn disease.