Single- and Multiple-Dose Pharmacokinetics and Pharmacodynamics of PN-943, a Gastrointestinal-Restricted Oral Peptide Antagonist of α4β7, in Healthy Volunteers

SPH7854, a gut-limited RORγt antagonist, ameliorates TNBS-induced experimental colitis in rat

Multiple lines of evidence suggest that Retinoic Acid Related Orphan Nuclear Receptor gamma t (RORγt) is a potent therapeutic target for inflammatory bowel disease (IBD). However, systemic blockade of RORγt easily leads to thymic lymphoma and aberrant liver function. Therefore, the development of gut-limited RORγt antagonists may lead to the development of innovative IBD therapeutics that improve safety and retain effectiveness. We discovered SPH7854, a potent and selective RORγt antagonist. The effect of SPH7854 on the differentiation of T helper 1 (Th1)/Th17/regulatory T (Treg) cells was evaluated in mouse and human primary cells. SPH7854 (2-(4-(ethylsulfonyl)phenyl)-N- (6-(2-methyl-2-(pyridin-2-yl) propanoyl)pyridin-3-yl)acetamide) dose-dependently inhibited interleukin-17A (IL-17A) secretion from mouse CD4 + T cells and human peripheral blood mononuclear cells (PBMC). Additionally, SPH7854 strongly suppressed Th17 cell differentiation and considerably promoted Treg cell differentiation while slightly affected Th1 cell differentiation from mouse CD4 + T cells. The pharmacokinetic (PK) studies indicated that SPH7854 was restricted to the gut: the bioavailability and maximal plasma concentration of SPH7854 after oral administration (6 mg/kg) were 1.24 ± 0.33 % and 4.92 ± 11.81 nM, respectively, in rats. Strikingly, oral administration of SPH7854 (5 mg/kg and 15 mg/kg) twice daily significantly alleviated 2, 4, 6-trinitrobenzensulfonic acid (TNBS)-induced colitis in rats. SPH7854, especially at 15 mg/kg, significantly alleviated symptoms and improved macroscopic signs and microscopic structure in rat colitis, with decreased colonic mucosal levels of IL-17A, IL-6, tumor necrosis factor α (TNFα), monocyte chemoattractant protein-1 (MCP-1) and myeloperoxidase (MPO). These evidences indicated that blockade of RORγt activity via a gut-limited antagonist may be an effective and safe therapeutic strategy for IBD treatment.

[Old and New Biologics and Small Molecules in Inflammatory Bowel Disease: Anti Integrins]

Recently, novel biologics or small molecular drugs have been introduced for overcoming the unmet needs associated with anti-tumor necrosis factor α agents for inflammtory bowel disease (IBD) treatment. Among these novel drugs, anti integrin agents block leukocyte trafficking to the intestine by blocking the interaction between integrin and cell adhesion molecules. Vedolizumab (anti-α4β7) is most widely used anti-integrin approved in both ulcerative colitis and Crohn's disease .It has been shown to be effective in both induction and maintenance therapy with a favorable safety profile due to gut selectivity. Several models incorporating clinical, genetic, immune and gut microbial markers to predict response to vedolizumab in IBD have been developed. Etrolizumab (anti-β7) blocks leukocyte trafficking via α4β7 and cell adhesion via αEβ7 integrins. In addition, the introduction of subcutaneous vedolizumab showed similar efficacy and safety with improved patients' convenience. Other investigational anti-integrin therapies include abrilumab (anti-α4β7 IgG2), PN-943 (orally administered and gut-restricted α4β7 antagonist peptide), AJM300 (orally active small molecule inhibitor of α4), and ontamalimab (anti-MAdCAM-1 IgG).

The coming of age of cyclic peptide drugs: an update on discovery technologies

INTRODUCTION

Cyclic peptides are an established class of pharmaceuticals, with the ability to bind to a broader range of protein targets than traditional small molecules while also being capable of oral availability and cell penetration. Historically, cyclic peptide drugs have been discovered almost exclusively through natural product mining approaches; however, the last two decades have seen the development of display screening approaches capable of rapidly identifying de novo (i.e. not natural product derived) cyclic peptide ligands to targets of interest.

AREAS COVERED

In this review, the authors describe the current clinical landscape for cyclic peptide pharmaceuticals. This article focuses on the discovery approaches that have led to the development of different classes of molecules and how the development of newer technologies, particularly phage and mRNA display, has broadened the clinical applicability of such molecules.

EXPERT OPINION

The field of de novo cyclic peptide drug discovery is reaching maturity, with the first drugs identified through display screening approaches reaching the market in recent years. Many more are in clinical trials; however, significant technical challenges remain. Technological improvements will be required over the coming years to facilitate the identification of membrane permeable cyclic peptides capable of oral availability and targeting intracellular proteins.

Targeting T-cell integrins in autoimmune and inflammatory diseases

The recruitment of T cells to tissues and their retention there are essential processes in the pathogenesis of many autoimmune and inflammatory diseases. The mechanisms regulating these processes have become better understood over the past three decades and are now recognized to involve temporally and spatially specific interactions between cell-adhesion molecules. These include integrins, which are heterodimeric molecules that mediate in-to-out and out-to-in signalling in T cells, other leukocytes, and most other cells of the body. Integrin signalling contributes to T-cell circulation through peripheral lymph nodes, immunological synapse stability and function, extravasation at the sites of inflammation, and T-cell retention at these sites. Greater understanding of the contribution of integrin signalling to the role of T cells in autoimmune and inflammatory diseases has focused much attention on the development of therapeutics that target T-cell integrins. This literature review describes the structure, activation, and function of integrins with respect to T cells, then discusses the use of integrin-targeting therapeutics in inflammatory bowel disease, multiple sclerosis, and psoriasis. Efficacy and safety data from clinical trials and post-marketing surveillance are presented for currently approved therapeutics, therapeutics that have been withdrawn from the market, and novel therapeutics currently in clinical trials. This literature review will inform the reader of the current means of targeting T-cell integrins in autoimmune and inflammatory diseases, as well as recent developments in the field.

Emerging Therapies for Ulcerative Colitis: Updates from Recent Clinical Trials

Ulcerative colitis (UC) is a chronic and progressive inflammatory disorder that affects the colon. The advent of advanced therapies such as biologic agents and small molecules has revolutionized the management of UC. Despite the expanding therapeutic armamentarium of advanced therapies to treat UC, the overall net remission rates and durability of currently available agents are relatively low. This highlights the need for further drug development and more innovative clinical trial design. There are currently multiple emerging agents in the pipeline for the management of UC. This includes agents with alternative routes of administration such as oral or subcutaneous tumor necrosis factor inhibitors or novel mechanisms of action such as toll-like receptor 9 (TLR9) agonist cobitolimod and phosphodiesterase 4 inhibitor apremilast. In this review, we will highlight novel and emerging advanced therapies currently in the pipeline for the management of UC.

Cyclic Peptides in Pipeline: What Future for These Great Molecules?

Cyclic peptides are molecules that are already used as drugs in therapies approved for various pharmacological activities, for example, as antibiotics, antifungals, anticancer, and immunosuppressants. Interest in these molecules has been growing due to the improved pharmacokinetic and pharmacodynamic properties of the cyclic structure over linear peptides and by the evolution of chemical synthesis, computational, and in vitro methods. To date, 53 cyclic peptides have been approved by different regulatory authorities, and many others are in clinical trials for a wide diversity of conditions. In this review, the potential of cyclic peptides is presented, and general aspects of their synthesis and development are discussed. Furthermore, an overview of already approved cyclic peptides is also given, and the cyclic peptides in clinical trials are summarized.

Exploring the Pipeline of Novel Therapies for Inflammatory Bowel Disease; State of the Art Review

Crohn’s disease (CD) and ulcerative colitis (UC), known as inflammatory bowel diseases (IBD), are characterized by chronic inflammation of the gastrointestinal tract. Over the last two decades, numerous medications have been developed and repurposed to induce and maintain remission in IBD patients. Despite the approval of multiple drugs, the major recurring issues continue to be primary non-response and secondary loss of response, as well as short- and long-term adverse events. Most clinical trials show percentages of response under 60%, possibly as a consequence of strict inclusion criteria and definitions of response. That is why these percentages appear to be more optimistic in real-life studies. A therapeutic ceiling has been used as a term to define this invisible bar that has not been crossed by any drug yet. This review highlights novel therapeutic target agents in phases II and III of development, such as sphingosine-1-phosphate receptor modulators, selective Janus kinase inhibitors, anti-interleukins, and other small molecules that are currently under research until 1 January 2023. Emerging treatments for CD and UC that have just received approval or are undergoing phase III clinical trials are also discussed in this review.

Controlling in and out - the future of interfering with immune cell trafficking in inflammatory bowel disease

INTRODUCTION

Immune cell trafficking is a key requirement in the pathogenesis of inflammatory bowel diseases. Consistently, therapeutic strategies to target immune cell trafficking have been established and continue to be developed for the treatment of ulcerative colitis and Crohn's disease.

AREAS COVERED

In this review, we briefly summarize the most important checkpoints of intestinal immune cell trafficking and their importance during IBD. Moreover, we provide an overview of associated therapeutic targets and previous as well as current efforts on treatment strategies related to these targets.

EXPERT OPINION

Finally, we comment on potential future developments that might shape the field of immune cell trafficking in the context of IBD.

Anti-Integrins for the Treatment of Inflammatory Bowel Disease: Current Evidence and Perspectives

Leukocyte trafficking to the gastrointestinal tract is recognized to play a role in the pathogenesis of inflammatory bowel disease (IBD). Integrins are expressed on immune cells and interact with cell adhesion molecules (CAM) to mediate leukocyte trafficking. Blockade of the gut-tropic integrin α4β7 and its subunits has been exploited as a therapeutic target in IBD. Natalizumab (anti-α4) is approved for moderate to severe Crohn's disease (CD), but its use is limited due to potential risk of progressive multifocal leukoencephalopathy. Vedolizumab (anti-α4β7) is approved for the treatment of ulcerative colitis (UC) and CD. It is the most widely used anti-integrin therapy in IBD and has been shown to be effective in both induction and maintenance therapy, with a favorable safety profile. Several models incorporating clinical, genetic, immune, gut microbial, and vitamin D markers to predict response to vedolizumab in IBD have been developed. Etrolizumab (anti-β7) blocks leukocyte trafficking via α4β7 and cell adhesion via αEβ7 integrins. Large phase 3 clinical trials evaluating efficacy of etrolizumab in the induction and maintenance of patients with IBD are underway. Other investigational anti-integrin therapies include abrilumab (anti-α4β7 IgG2), PN-943 (orally administered and gut-restricted α4β7 antagonist peptide), AJM300 (orally active small molecule inhibitor of α4), and ontamalimab (anti-MAdCAM-1 IgG).

Small Molecule Drugs in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBDs), mainly represented by Crohn’s disease (CD) and Ulcerative Colitis (UC), are chronic disorders with an unclear pathogenesis. This incurable and iterative intestinal mucosal inflammation requires the life-long use of anti-inflammatory drugs to prevent flares or relapses, which are the major providers of complications, such as small bowel strictures and intestinal perforations. The introduction of tumor necrosis factor (TNF)-alpha inhibitors and other compounds, such as anti-IL12/23 and anti-alpha4/beta7 integrin monoclonal antibodies, has considerably improved the clinical management of IBDs. They are now the standard of care, being the first-line therapy in patients with aggressive disease and in patients with moderate to severe disease with an inadequate response to conventional therapy. However, for approximately one third of all patients, their efficacy remains insufficient by a lack or loss of response due to the formation of anti-drug antibodies or compliance difficulties with parenteral formulations. To address these issues, orally administered Small Molecules Drugs (SMDs) that use a broad range of novel pharmacological pathways, such as JAK inhibitors, sphingosine-1-phosphate receptor modulators, and phosphodiesterase 4 inhibitors, have been developed for CD and UC. This article provides an updated and complete review of the most recently authorized SMDs and SMDs in phase II/III development.