Insight into the mechanism of laquinimod action

Disease-modifying therapy in progressive multiple sclerosis: a systematic review and network meta-analysis of randomized controlled trials

Background

Currently, disease-modifying therapies (DMTs) for progressive multiple sclerosis (PMS) are widely used in clinical practice. At the same time, there are a variety of drug options for DMTs, but the effect of the drugs that can better relieve symptoms and improve the prognosis are still inconclusive.

Objectives

This systematic review aimed to evaluate the efficacy and safety of DMTs for PMS and to identify the best among these drugs.

Methods

MEDLINE, EMBASE, the Cochrane Library, and clinicaltrials.gov were systematically searched to identify relevant studies published before 30 January, 2023. We assessed the certainty of the evidence using the confidence in the network meta-analysis (CINeMA) framework. We estimated the summary risk ratio (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes with 95% credible intervals (CrIs).

Results

We included 18 randomized controlled trials (RCTs) involving 9,234 patients in the study. DMT can effectively control the disease progression of MS. Among them, mitoxantrone, siponimod, and ocrelizumab are superior to other drug options in delaying disease progression (high certainty). Mitoxantrone was the best (with high certainty) for mitigating deterioration (progression of disability). Ocrelizumab performed best on the pre- and post-treatment Timed 25-Foot Walk test (T25FW; low certainty), as did all other agents (RR range: 1.12-1.05). In the 9-Hole Peg Test (9HPT), natalizumab performed the best (high certainty), as did all other agents (RR range: 1.59-1.09). In terms of imaging, IFN-beta-1b performed better on the new T2 hypointense lesion on contrast, before and after treatment (high certainty), while siponimod performed best on the change from baseline in the total volume of lesions on T2-weighted image contrast before and after treatment (high certainty), and sWASO had the highest area under the curve (SUCRA) value (100%). In terms of adverse events (AEs), rituximab (RR 1.01), and laquinimod (RR 1.02) were more effective than the placebo (high certainty). In terms of serious adverse events (SAEs), natalizumab (RR 1.09), and ocrelizumab (RR 1.07) were safer than placebo (high certainty).

Conclusion

DMTs can effectively control disease progression and reduce disease deterioration during the treatment of PMS.

Systematic review registration

https://inplasy.com/?s=202320071, identifier: 202320071.

Methyl-CpG-Binding Protein 2 Emerges as a Central Player in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders

MECP2 and its product methyl-CpG binding protein 2 (MeCP2) are associated with multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), which are inflammatory, autoimmune, and demyelinating disorders of the central nervous system (CNS). However, the mechanisms and pathways regulated by MeCP2 in immune activation in favor of MS and NMOSD are not fully understood. We summarize findings that use the binding properties of MeCP2 to identify its targets, particularly the genes recognized by MeCP2 and associated with several neurological disorders. MeCP2 regulates gene expression in neurons, immune cells and during development by modulating various mechanisms and pathways. Dysregulation of the MeCP2 signaling pathway has been associated with several disorders, including neurological and autoimmune diseases. A thorough understanding of the molecular mechanisms underlying MeCP2 function can provide new therapeutic strategies for these conditions. The nervous system is the primary system affected in MeCP2-associated disorders, and other systems may also contribute to MeCP2 action through its target genes. MeCP2 signaling pathways provide promise as potential therapeutic targets in progressive MS and NMOSD. MeCP2 not only increases susceptibility and induces anti-inflammatory responses in immune sites but also leads to a chronic increase in pro-inflammatory cytokines gene expression (IFN-γ, TNF-α, and IL-1β) and downregulates the genes involved in immune regulation (IL-10, FoxP3, and CX3CR1). MeCP2 may modulate similar mechanisms in different pathologies and suggest that treatments for MS and NMOSD disorders may be effective in treating related disorders. MeCP2 regulates gene expression in MS and NMOSD. However, dysregulation of the MeCP2 signaling pathway is implicated in these disorders. MeCP2 plays a role as a therapeutic target for MS and NMOSD and provides pathways and mechanisms that are modulated by MeCP2 in the regulation of gene expression.

Repurposing MS immunotherapies for CIDP and other autoimmune neuropathies: unfulfilled promise or efficient strategy?

Despite advances in the treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and other common autoimmune neuropathies (AN), still-many patients with these diseases do not respond satisfactorily to the available treatments. Repurposing of disease-modifying therapies (DMTs) from other autoimmune conditions, particularly multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), is a promising strategy that may accelerate the establishment of novel treatment choices for AN. This approach appears attractive due to homologies in the pathogenesis of these diseases and the extensive post-marketing experience that has been gathered from treating MS and NMOSD patients. The idea is also strengthened by a number of studies that explored the efficacy of DMTs in animal models of AN but also in some CIDP patients. We here review the available preclinical and clinical data of approved MS therapeutics in terms of their applicability to AN, especially CIDP. Promising therapeutic approaches appear to be B cell-directed and complement-targeting strategies, such as anti-CD20/anti-CD19 agents, Bruton's tyrosine kinase inhibitors and anti-C5 agents, as they exert their effects in the periphery. This is a major advantage because, in contrast to MS, their action in the periphery is sufficient to exert significant immunomodulation.

Therapeutic Strategies in Huntington’s Disease: From Genetic Defect to Gene Therapy

Despite the identification of an expanded CAG repeat on exon 1 of the huntingtin gene located on chromosome 1 as the genetic defect causing Huntington’s disease almost 30 years ago, currently approved therapies provide only limited symptomatic relief and do not influence the age of onset or disease progression rate. Research has identified various intricate pathogenic cascades which lead to neuronal degeneration, but therapies interfering with these mechanisms have been marked by many failures and remain to be validated. Exciting new opportunities are opened by the emerging techniques which target the mutant protein DNA and RNA, allowing for “gene editing”. Although some issues relating to “off-target” effects or immune-mediated side effects need to be solved, these strategies, combined with stem cell therapies and more traditional approaches targeting specific pathogenic cascades, such as excitotoxicity and bioavailability of neurotrophic factors, could lead to significant improvement of the outcomes of treated Huntington’s disease patients.

Carboxamide Derivatives Are Potential Therapeutic AHR Ligands for Restoring IL-4 Mediated Repression of Epidermal Differentiation Proteins

Atopic dermatitis (AD) is a common T-helper 2 (Th2) lymphocyte-mediated chronic inflammatory skin disease characterized by disturbed epidermal differentiation (e.g., filaggrin (FLG) expression) and diminished skin barrier function. Therapeutics targeting the aryl hydrocarbon receptor (AHR), such as coal tar and tapinarof, are effective in AD, yet new receptor ligands with improved potency or bioavailability are in demand to expand the AHR-targeting therapeutic arsenal. We found that carboxamide derivatives from laquinimod, tasquinimod, and roquinimex can activate AHR signaling at low nanomolar concentrations. Tasquinimod derivative (IMA-06504) and its prodrug (IMA-07101) provided full agonist activity and were most effective to induce FLG and other epidermal differentiation proteins, and counteracted IL-4 mediated repression of terminal differentiation. Partial agonist activity by other derivatives was less efficacious. The previously reported beneficial safety profile of these novel small molecules, and the herein reported therapeutic potential of specific carboxamide derivatives, provides a solid rationale for further preclinical assertation.

Manipulating Macrophage/Microglia Polarization to Treat Glioblastoma or Multiple Sclerosis

Macrophages and microglia are implicated in several diseases with divergent roles in physiopathology. This discrepancy can be explained by their capacity to endorse different polarization states. Theoretical extremes of these states are called M1 and M2. M1 are pro-inflammatory, microbicidal, and cytotoxic whereas M2 are anti-inflammatory, immunoregulatory cells in favor of tumor progression. In pathological states, these polarizations are dysregulated, thus restoring phenotypes could be an interesting treatment approach against diseases. In this review, we will focus on compounds targeting macrophages and microglia polarization in two very distinctive pathologies: multiple sclerosis and glioblastoma. Multiple sclerosis is an inflammatory disease characterized by demyelination and axon degradation. In this case, macrophages and microglia endorse a M1-like phenotype inducing inflammation. Promoting the opposite M2-like polarization could be an interesting treatment strategy. Glioblastoma is a brain tumor in which macrophages and microglia facilitate tumor progression, spreading, and angiogenesis. They are part of the tumor associated macrophages displaying an anti-inflammatory phenotype, thereby inhibiting anti-tumoral immunity. Re-activating them could be a method to limit and reduce tumor progression. These two pathologies will be used to exemplify that targeting the polarization of macrophages and microglia is a promising approach with a broad spectrum of applications deserving more attention.

Recent advances in clinical trials targeting the kynurenine pathway

The kynurenine pathway (KP) is the major catabolic pathway for the essential amino acid tryptophan leading to the production of nicotinamide adenine dinucleotide. In inflammatory conditions, the activation of the KP leads to the production of several bioactive metabolites including kynurenine, 3-hydroxykynurenine, 3-hydroxyanthranilic acid, kynurenic acid and quinolinic acid. These metabolites can have redox and immune suppressive activity, be neurotoxic or neuroprotective. While the activity of the pathway is tightly regulated under normal physiological condition, it can be upregulated by immunological activation and inflammation. The dysregulation of the KP has been implicated in wide range of neurological diseases and psychiatric disorders. In this review, we discuss the mechanisms involved in KP-mediated neurotoxicity and immune suppression, and its role in diseases of our expertise including cancer, chronic pain and multiple sclerosis. We also provide updates on the clinical trials evaluating the efficacy of KP inhibitors and/or analogues in each respective disease.

Laquinimod Modulates Human Astrocyte Function and Dampens Astrocyte-Induced Neurotoxicity during Inflammation

Astrocytes greatly participate to inflammatory and neurotoxic reactions occurring in neurodegenerative diseases and are valuable pharmacological targets to support neuroprotection. Here we used human astrocytes generated from reprogrammed fibroblasts as a cellular model to study the effect of the compound Laquinimod and its active metabolite de-Laquinimod on astrocyte functions and the astrocyte-neuron interaction. We show that human iAstrocytes expressed the receptor for the inflammatory mediator IL1 and responded to it via nuclear translocation of NFκB, an event that did not occur if cells were treated with Laquinimod, indicating a direct anti-inflammatory activity of the drug on the human astrocyte. Similarly, while exposure to IL1 downregulated glial glutamate transporters GLAST and GLT1, treatment with Laquinimod supported maintenance of physiological levels of these proteins despite the inflammatory milieu. Laquinimod also induced nuclear translocation of the aryl hydrocarbon receptor (AHR), suggesting that drug action was mediated by activation of the AHR pathway. However, the drug was effective despite AHR inhibition via CH223191, indicating that AHR signaling in the astrocyte is dispensable for drug responses. Finally, in vitro experiments with rat spinal neurons showed that laquinimod did not exert neuroprotection directly on the neuron but dampened astrocyte-induced neurodegeneration. Our findings indicate that fibroblast-derived human astrocytes represent a suitable model to study astrocyte-neuron crosstalk and demonstrate indirect, partial neuroprotective efficacy for laquinimod.

Kynurenines in the Pathogenesis of Multiple Sclerosis: Therapeutic Perspectives

Over the past years, an increasing amount of evidence has emerged in support of the kynurenine pathway’s (KP) pivotal role in the pathogenesis of several neurodegenerative, psychiatric, vascular and autoimmune diseases. Different neuroactive metabolites of the KP are known to exert opposite effects on neurons, some being neuroprotective (e.g., picolinic acid, kynurenic acid, and the cofactor nicotinamide adenine dinucleotide), while others are toxic to neurons (e.g., 3-hydroxykynurenine, quinolinic acid). Not only the alterations in the levels of the metabolites but also disturbances in their ratio (quinolinic acid/kynurenic acid) have been reported in several diseases. In addition to the metabolites, the enzymes participating in the KP have been unearthed to be involved in modulation of the immune system, the energetic upkeep of neurons and have been shown to influence redox processes and inflammatory cascades, revealing a sophisticated, intertwined system. This review considers various methods through which enzymes and metabolites of the kynurenine pathway influence the immune system, the roles they play in the pathogenesis of neuroinflammatory diseases based on current evidence with a focus on their involvement in multiple sclerosis, as well as therapeutic approaches.

Molecular Effects of FDA-Approved Multiple Sclerosis Drugs on Glial Cells and Neurons of the Central Nervous System

Multiple sclerosis (MS) is characterized by peripheral and central inflammatory features, as well as demyelination and neurodegeneration. The available Food and Drug Administration (FDA)-approved drugs for MS have been designed to suppress the peripheral immune system. In addition, however, the effects of these drugs may be partially attributed to their influence on glial cells and neurons of the central nervous system (CNS). We here describe the molecular effects of the traditional and more recent FDA-approved MS drugs Fingolimod, Dimethyl Fumarate, Glatiramer Acetate, Interferon-β, Teriflunomide, Laquinimod, Natalizumab, Alemtuzumab and Ocrelizumab on microglia, astrocytes, neurons and oligodendrocytes. Furthermore, we point to a possible common molecular effect of these drugs, namely a key role for NFκB signaling, causing a switch from pro-inflammatory microglia and astrocytes to anti-inflammatory phenotypes of these CNS cell types that recently emerged as central players in MS pathogenesis. This notion argues for the need to further explore the molecular mechanisms underlying MS drug action.

The Effect of CYP3A Induction and Inhibition on the Pharmacokinetics of Laquinimod, a Novel Neuroimmunomodulator

Laquinimod, a neuroimmunomodulator, is extensively metabolized by cytochrome P450 (CYP) 3A4, and modulations of CYP3A4 activity may lead to alterations in the pharmacokinetics and/or clinical effects of laquinimod. To determine the drug-drug interaction potential of laquinimod with CYP3A inhibitors and inducers, interaction assessments were conducted in healthy volunteers using single-dose administration of laquinimod before and after multiple dosing of CYP3A inhibitors (ketoconazole, fluconazole, and cimetidine) or a CYP3A4 inducer (rifampin). For ketoconazole, subjects (n = 14) received laquinimod 0.6 mg following 1 day of ketoconazole (400 mg daily) pretreatment, a single concomitant dose, and 28 additional days. For fluconazole, subjects (n = 14) received laquinimod 0.6 mg after a single fluconazole dose of 400 mg followed by 200-mg daily fluconazole administration for 20 additional days. For cimetidine, subjects (n = 14) received laquinimod 0.6 mg following 1 day of cimetidine (800 mg twice daily) pretreatment, a single concomitant dose, and 21 additional days. For rifampin, subjects (n = 14) received laquinimod 0.6 mg following 9 days of rifampin (600 mg daily) pretreatment, a single concomitant dose, and 12 additional days. Coadministration of laquinimod with CYP3A inhibitors, ketoconazole, fluconazole, and cimetidine increased laquinimod area under the plasma concentration-time curve from time zero to infinity by approximately 3.1-, 2.5-, and 1.1-fold, respectively. Coadministration of laquinimod with rifampin decreased laquinimod area under the plasma concentration-time curve from time zero to infinity by 5-fold. These results indicate that coadministration of laquinimod with moderate to strong inhibitors of CYP3A or strong inducers of CYP3A may give rise to significant pharmacokinetic drug interactions.

Laquinimod Mitigated IL-1β-Induced Impairment of the Cartilage Extracellular Matrix in Human ATDC5 Chondrocytes

To date, a safe and reliable treatment of osteoarthritis (OA) has not yet been announced. Inflammatory response and degradation of the articular extracellular matrix (ECM) induced by IL-1β are important pathological characteristics of OA. Laquinimod is a quinoline-3-carboxamide and a novel oral immunomodulatory compound in clinical use. However, whether laquinimod has a beneficial effect in OA is not known. In our research, we found that laquinimod could ameliorate IL-1β-induced generation of ROS and improve mitochondrial function by increasing mitochondrial membrane potential (ΔΨm). Furthermore, treatment with laquinimod suppressed IL-1β-induced production of TNF-α and IL-6. Notably, laquinimod prevented the degradation of type II collagen by inhibiting MMP-3 and MMP-13. Meanwhile, the presence of laquinimod attenuated the reduction in aggrecan by mediating ADAMTS-4 and ADAMTS-5. Mechanistically, laquinimod ameliorated IL-1β-induced inflammation and degeneration of ECM by suppressing the activation of NF-κB. Taken together, our findings reveal that laquinimod possesses a beneficial effect against IL-1β insults in human chondrocytes, implying an important role of laquinimod in OA.

Immunotherapies in Huntington's disease and α-Synucleinopathies

Modulation of immune activation using immunotherapy has attracted considerable attention for many years as a potential therapeutic intervention for several inflammation-associated neurodegenerative diseases. However, the efficacy of single-target immunotherapy intervention has shown limited or no efficacy in alleviating disease burden and restoring functional capacity. Marked immune system activation and neuroinflammation are important features and prodromal signs in polyQ repeat disorders and α-synucleinopathies. This review describes the current status and future directions of immunotherapies in proteinopathy-induced neurodegeneration with emphasis on preclinical and clinical efficacies of several anti-inflammatory compounds and antibody-based therapies for the treatment of Huntington's disease and α-synucleinopathies. The review concludes with how disease modification and functional restoration could be achieved by using targeted multimodality therapy to target multiple factors.

Cortical and meningeal pathology in progressive multiple sclerosis: a new therapeutic target?

Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease that involves an intricate interaction between the central nervous system and the immune system. Nevertheless, its etiology is still unknown. MS exhibits different clinical courses: recurrent episodes with remission periods ('relapsing-remitting') that can evolve to a 'secondary progressive' form or persistent progression from the onset of the disease ('primary progressive'). The discovery of an effective treatment and cure has been hampered due to the pathological and clinical heterogeneity of the disease. Historically, MS has been considered as a disease exclusively of white matter. However, patients with progressive forms of MS present with cortical lesions associated with meningeal inflammation along with physical and cognitive disabilities. The pathogenesis of the cortical lesions has not yet been fully described. Animal models that represent both the cortical and meningeal pathologies will be critical in addressing MS pathogenesis as well as the design of specific treatments. In this review, we will address the state-of-the-art diagnostic and therapeutic alternatives and the development of strategies to discover new therapeutic approaches, especially for the progressive forms.

New biologics and small molecules in inflammatory bowel disease: an update

Inflammatory bowel disease (IBD) is a spectrum of immune-mediated inflammatory disorders with a complex multifactorial pathogenesis, where different pathways may predominate in different individuals. This complexity will most likely require a panoply of drugs targeting different pathways if one wants to treat to steroid-free sustained remission and mucosal healing. Presently, the mainstay of medical management of IBD is based on 5-aminosalicylates, corticosteroids, thiopurines, methotrexate, antitumor necrosis factor, anti-alpha4 beta7 (α4β7) integrin and anti-interleukin (IL)-12/IL-23 therapies. The discovery of new pathways involved in the pathogenesis of IBD resulted in new drugs targeting Janus kinase/signal transducers and activators of transcription, IL-6, spingosine-1-phosphate, and phosphodiesterase 4, among others. These new therapies might result in more advantageous safety profiles. Several of these new drugs have already been successfully tested in other inflammatory disorders, such as psoriasis or rheumatoid arthritis. In this review, evidence from phase II and phase III randomized controlled clinical trials in patients with IBD involving new biologicals and small molecules are summarized.

Are immunotherapies for Huntington's disease a realistic option?

There is compelling evidence that the pathophysiology of many neurodegenerative diseases includes dysregulation of the immune system, with some elements that precede disease onset. However, if these alterations are prominent, why have clinical trials targeting this system failed to translate into long-lasting meaningful benefits for patients? This review focuses on Huntington's disease, a genetic disorder marked by notable cerebral and peripheral inflammation. We summarize ongoing and completed clinical trials that have involved pharmacological approaches to inhibit various components of the immune system and their pre-clinical correlates. We then discuss new putative treatment strategies using more targeted immunotherapies such as vaccination and intrabodies and how these may offer new hope in the treatment of Huntington's disease as well as other neurodegenerative diseases.

Emerging small-molecule treatments for multiple sclerosis: focus on B cells

Multiple sclerosis (MS) is a major cause of disability in young adults. Following an unknown trigger (or triggers), the immune system attacks the myelin sheath surrounding axons, leading to progressive nerve cell death. Antibodies and small-molecule drugs directed against B cells have demonstrated good efficacy in slowing progression of the disease. This review focusses on small-molecule drugs that can affect B-cell biology and may have utility in disease management. The risk genes for MS are examined from the drug target perspective. Existing small-molecule therapies for MS with B-cell actions together with new drugs in development are described. The potential for experimental molecules with B-cell effects is also considered. Small molecules can have diverse actions on B cells and be cytotoxic, anti-inflammatory and anti-viral. The current B cell-directed therapies often kill B-cell subsets, which can be effective but lead to side effects and toxicity. A deeper understanding of B-cell biology and the effect on MS disease should lead to new drugs with better selectivity, efficacy, and an improved safety profile. Small-molecule drugs, once the patent term has expired, provide a uniquely sustainable form of healthcare.

Oral Therapies for Multiple Sclerosis

Multiple sclerosis treatment faces tremendous changes owing to the approval of new medications, some of which are available as oral formulations. Until now, the four orally available medications, fingolimod, dimethylfumarate (BG-12), teriflunomide, and cladribine have received market authorization, whereas laquinimod is still under development. Fingolimod is a sphingosine-1-phosphate inhibitor, which is typically used as escalation therapy and leads to up to 60% reduction of the annualized relapse rate, but might also have neuroprotective properties. In addition, there are three more specific S1P agonists in late stages of development: siponimod, ponesimod, and ozanimod. Dimethylfumarate has immunomodulatory and cytoprotective functions and is used as baseline therapy. Teriflunomide, the active metabolite of the rheumatoid arthritis medication leflunomide, targets the dihydroorotate dehydrogenase, thus inhibiting the proliferation of lymphocytes by depletion of pyrimidines. Here we will review the mechanisms of action, clinical trial data, as well as data about safety and tolerability of the compounds.

Laquinimod protects the optic nerve and retina in an experimental autoimmune encephalomyelitis model

BACKGROUND

The oral immunomodulatory agent laquinimod is currently evaluated for multiple sclerosis (MS) treatment. Phase II and III studies demonstrated a reduction of degenerative processes. In addition to anti-inflammatory effects, laquinimod might have neuroprotective properties, but its impact on the visual system, which is often affected by MS, is unknown. The aim of our study was to investigate potential protective effects of laquinimod on the optic nerve and retina in an experimental autoimmune encephalomyelitis (EAE) model.

METHODS

We induced EAE in C57/BL6 mice via MOG_35-55 immunization. Animals were divided into an untreated EAE group, three EAE groups receiving laquinimod (1, 5, or 25 mg/kg daily), starting the day post-immunization, and a non-immunized control group. Thirty days post-immunization, scotopic electroretinograms were carried out, and mice were sacrificed for histopathology (HE, LFB), immunohistochemistry (MBP, Iba1, Tmem119, F4/80, GFAP, vimentin, Brn-3a, cleaved caspase 3) of the optic nerve and retina, and retinal qRT-PCR analyses (Brn-3a, Iba1, Tmem119, AMWAP, CD68, GFAP). To evaluate the effect of a therapeutic approach, EAE animals were treated with 25 mg/kg laquinimod from day 16 when 60% of the animals had developed clinical signs of EAE.

RESULTS

Laquinimod reduced neurological EAE symptoms and improved the neuronal electrical output of the inner nuclear layer compared to untreated EAE mice. Furthermore, cellular infiltration, especially recruited phagocytes, and demyelination in the optic nerve were reduced. Microglia were diminished in optic nerve and retina. Retinal macroglial signal was reduced under treatment, whereas in the optic nerve macroglia were not affected. Additionally, laquinimod preserved retinal ganglion cells and reduced apoptosis. A later treatment with laquinimod in a therapeutic approach led to a reduction of clinical signs and to an improved b-wave amplitude. However, no changes in cellular infiltration and demyelination of the optic nerves were observed. Also, the number of retinal ganglion cells remained unaltered.

CONCLUSION

From our study, we deduce neuroprotective and anti-inflammatory effects of laquinimod on the optic nerve and retina in EAE mice, when animals were treated before any clinical signs were noted. Given the fact that the visual system is frequently affected by MS, the agent might be an interesting subject of further neuro-ophthalmic investigations.

Immunotherapy in inflammatory bowel disease: Novel and emerging treatments

Inflammatory bowel disease (IBD) is a chronic disabling inflammatory process that affects young individuals, with growing incidence. The etiopathogenesis of IBD remains poorly understood. A combination of genetic and environmental factors triggers an inadequate immune response against the commensal intestinal flora in IBD patients. Thus, a better understanding of the immunological mechanisms involved in IBD pathogenesis is central to the development of new therapeutic options.

Current pharmacological treatments used in clinical practice like thiopurines or anti-TNF are effective but can produce significant side effects and their efficacy may diminish over time. In fact, up to one third of the patients do not have a satisfactory response to these therapies. Consequently, the search for new therapeutic strategies targeting alternative immunological pathways has intensified. Several new oral and parenteral substances are in the pipeline for IBD.

In this review we discuss novel therapies targeting alternative pro-inflammatory pathways like IL-12/23 axis, IL-6 pathway or Janus Kinase inhibitors; as well as others modulating anti-inflammatory signalling pathways like transforming growth factor-β1 (TGF-β1). We also highlight new emerging therapies targeting the adhesion and migration of leukocytes into the inflamed intestinal mucosa by blocking selectively different subunits of α₄β₇ integrins or binding alternative adhesion molecules like MAdCAM-1. Drugs reducing the circulating lymphocytes by sequestering them in secondary lymphoid organs (sphingosine-1-phosphate (S1P) receptor modulators) are also discussed. Finally, the latest advances in cell therapies using mesenchymal stem cells or engineered T regs are reviewed. In addition, we provide an update on the current status in clinical trials of these new immune-regulating therapies that open a new era in the treatment of IBD.

Preservation of neuronal function as measured by clinical and MRI endpoints in relapsing-remitting multiple sclerosis: how effective are current treatment strategies?

INTRODUCTION

Approved medications for relapsing-remitting multiple sclerosis have shown to be effective in terms of their anti-inflammatory potential. However, it is also crucial to evaluate what long-term effects a patient can expect from current MS drugs in terms of preventing neurodegeneration. Here we aim to provide an overview of the current treatment strategies in MS with a specific focus on potential neuroprotective effects. Areas covered: Randomized, double-blind and placebo or referral-drug controlled phase 2a/b and phase 3 trials were examined; non-blinded phase 4 studies (extension studies) were included to provide long-term data, if not otherwise available. Endpoints considered were expanded disability status scale, various neuropsychological tests, percent brain volume change and T1-hypointense lesions as well as multiple sclerosis functional composite, confirmed disease progression, and no evidence of disease activity. Expert commentary: Overall, neuroprotective functions of classical MS therapeutics are not sufficiently investigated, but available data show limited effects. Thus, further research and development in neuroprotection are warranted. When counselling patients, potential long-term beneficial effects should be presented more conservatively.

Laquinimod ameliorates excitotoxic damage by regulating glutamate re-uptake

Background

Laquinimod is an immunomodulatory drug under clinical investigation for the treatment of the progressive form of multiple sclerosis (MS) with both anti-inflammatory and neuroprotective effects. Excitotoxicity, a prominent pathophysiological feature of MS and of its animal model, experimental autoimmune encephalomyelitis (EAE), involves glutamate transporter (GluT) dysfunction in glial cells.

The aim of this study was to assess whether laquinimod might exert direct neuroprotective effects by interfering with the mechanisms of excitotoxicity linked to GluT function impairments in EAE.

Methods

Osmotic minipumps allowing continuous intracerebroventricular (icv) infusion of laquinimod for 4 weeks were implanted into C57BL/6 mice before EAE induction. EAE cerebella were taken to perform western blot and qPCR experiments. For ex vivo experiments, EAE cerebellar slices were incubated with laquinimod before performing electrophysiology, western blot, and qPCR.

Results

In vivo treatment with laquinimod attenuated EAE clinical score at the peak of the disease, without remarkable effects on inflammatory markers. In vitro application of laquinimod to EAE cerebellar slices prevented EAE-linked glutamatergic alterations without mitigating astrogliosis and inflammation. Moreover, such treatment induced an increase of Slcla3 mRNA coding for the glial glutamate–aspartate transporter (GLAST) without affecting the protein content. Concomitantly, laquinimod significantly increased the levels of the glial glutamate transporter 1 (GLT-1) protein and pharmacological blockade of GLT-1 function fully abolished laquinimod anti-excitotoxic effect.

Conclusions

Overall, our results suggest that laquinimod protects against glutamate excitotoxicity of the cerebellum of EAE mice by bursting the expression of glial glutamate transporters, independently of its anti-inflammatory effects.

Safety and in vivo immune assessment of escalating doses of oral laquinimod in patients with RRMS

Background

Laquinimod is an oral immunomodulator in clinical development to treat relapsing-remitting multiple sclerosis (RRMS). Laquinimod is in clinical development for the treatment of multiple sclerosis and Huntington Disease (HD). The objective of this study is to assess the safety, tolerability, pharmacokinetics (PK) and cytoimmunologic effects following escalating doses of laquinimod in patients with RRMS.

Methods

One hundred twelve patients were randomly assigned to laquinimod/placebo in a series of separate dose-escalating cohorts starting from a daily oral dose of 0.9 mg/1.2 mg escalating to 2.7 mg, in 0.3 mg increments.

Results

Twenty-eight patients received placebo and 84 received laquinimod ranging from 0.9 to 2.7 mg. No deaths occurred. One serious adverse event (SAE) of perichondritis was reported, which was unrelated to laquinimod (0.9 mg). There was no increased incidence of adverse events (AEs) with escalating doses. Laquinimod-treated patients showed more abnormal laboratory levels in liver enzymes, P-amylase, C-reactive protein (CRP), and fibrinogen, but most shifts were clinically non-significant. The exposure of laquinimod was dose proportional and linear in the tested dose range. An immunological substudy showed significant dose-dependent decreases in 6-sulpho LacNAc + dendritic cell (slanDC) frequency following laquinimod compared to placebo.

Conclusion

Laquinimod doses up to 2.7 mg were safely administered to patients with RRMS. An in vivo effect of laquinimod on the innate immune system was demonstrated.

Trial registration

EudraCT Number: 2009-011234-99. Registered 23 June 2009.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-017-0945-z) contains supplementary material, which is available to authorized users.

Laquinimod treatment in the R6/2 mouse model

The transgenic mouse model R6/2 exhibits Huntington's disease (HD)-like deficits and basic pathophysiological similarities. We also used the pheochromocytoma-12 (PC12)-cell-line-model to investigate the effect of laquinimod on metabolic activity. Laquinimod is an orally administered immunomodulatory substance currently under development for the treatment of multiple sclerosis (MS) and HD. As an essential effect, increased levels of BDNF were observed. Therefore, we investigated the therapeutic efficacy of laquinimod in the R6/2 model, focusing on its neuroprotective capacity. Weight course and survival were not influenced by laquinimod. Neither were any metabolic effects seen in an inducible PC12-cell-line model of HD. As a positive effect, motor functions of R6/2 mice at the age of 12 weeks significantly improved. Preservation of morphologically intact neurons was found after treatment in the striatum, as revealed by NeuN, DARPP-32, and ubiquitin. Biochemical analysis showed a significant increase in the brain-derived neurotrophic factor (BDNF) level in striatal but not in cortical neurons. The number of mutant huntingtin (mhtt) and inducible nitric oxide synthase (iNOS) positive cells was reduced in both the striatum and motor cortex following treatment. These findings suggest that laquinimod could provide a mild effect on motor function and striatal histopathology, but not on survival. Besides influences on the immune system, influence on BDNF-dependent pathways in HD are discussed.

Laquinimod has no effects on brain volume or cellular CNS composition in the F1 3xTg-AD/C3H mouse model of Alzheimer's disease

BACKGROUND

Laquinimod is an anti-inflammatory agent with good central nervous system (CNS) bioavailability, and neuroprotective and myelorestorative properties. A clinical trial in patients with multiple sclerosis demonstrated that laquinimod significantly reduced loss of brain volume. The cellular substrate or molecular events underlying that treatment effect are unknown. In this study, we aimed to explore laquinimod's potential effects on brain volume, animal behavior, cellular numbers and composition of CNS-intrinsic cells and mononuclear cells within the CNS, amyloid beta (Aβ) accumulation and tau phosphorylation in the F1 3xTg-AD/C3H mouse model of Alzheimer's disease.

METHODS

Utilizing a dose response study design, four months old F1 3xTg-AD/C3H mice were treated for 10months between ages 4 and 14months with laquinimod (5, 10, or 25mg/kg), or PBS administered by oral gavage. Brain volumes were measured in a 7 Tesla magnetic resonance imager (MRI) at ages 4 and 14months. Behavioral testing included locomotor and rearing activity and the Morris water maze task. Cell numbers and immunophenotypes were assessed by multiparameter flow cytometry. Aβ deposition and tau phosphorylation were determined by immunohistochemistry.

RESULTS

In the F1 3xTg-AD/C3H animal model of AD, there was no detectable reduction of brain volume over a period of 10months of treatment, as there was not brain atrophy in any of the placebo or treatment groups. Laquinimod had no detectable effects on most neurobehavioral outcomes. The number or composition of CNS intrinsic cells and mononuclear subsets isolated from the CNS were not altered by laquinimod.

CONCLUSION

This is the first demonstration that there are no age-associated brain volume changes in the F1 3xTg-AD/C3H mouse model of Alzheimer's disease. Consequently, laquinimod had no effect on that outcome of this study. Most secondary outcomes on the effects of laquinimod on behavior and the number and composition of CNS-intrinsic cells and mononuclear cells within the CNS were also negative.

Laquinimod enhances central nervous system barrier functions

Laquinimod is currently being tested as a therapeutic drug in multiple sclerosis. However, its exact mechanism of action is still under investigation. Tracking of fluorescently-tagged encephalitogenic T cells during experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, revealed that laquinimod significantly reduces the invasion of pathogenic effector T cells into the CNS tissue. T-cell activation, differentiation and amplification within secondary lymphoid organs after immunization with myelin antigen, their migratory capacity and re-activation within the nervous tissue were either only mildly affected or remained unchanged. Instead, laquinimod directly impacted the functionality of the CNS vasculature. The expression of tight junction proteins p120 and ZO-1 in human brain endothelial cells was up-regulated upon laquinimod treatment, resulting in a significant increase in the transendothelial electrical resistance of confluent monolayers of brain endothelial cells. Similarly, expression of the adhesion molecule activated leukocyte cell adhesion molecule (ALCAM) and inflammatory chemokines CCL2 and IP-10 was suppressed, leading to a significant reduction in the migration of memory T_H1 and T_H17 lymphocytes across the blood brain barrier (BBB). Our data indicate that laquinimod exerts its therapeutic effects by tightening the BBB and limiting parenchymal invasion of effector T cells, thereby reducing CNS damage.

Laquinimod Safety Profile: Pooled Analyses from the ALLEGRO and BRAVO Trials

BACKGROUND

Laquinimod 0.6 mg is a once-daily, oral, disease-modifying therapy in development for the treatment of multiple sclerosis (MS) that was investigated in two double-blind, placebo-controlled, phase 3 trials: ALLEGRO and BRAVO.

METHODS

Data from these studies were pooled to assess the safety profile of laquinimod versus placebo. Adverse events (AEs), laboratory value changes, and potential risks identified in preclinical studies were evaluated in participants in ALLEGRO and BRAVO treated with at least one dose of laquinimod or matching placebo (1:1 random assignment).

RESULTS

In total, 1988 patients received at least one dose of study drug (laquinimod: n = 983 [mean ± SD duration, 639 ± 190 days]; placebo: n = 1005 [mean ± SD duration, 627 ± 198 days]). Early terminations due to AEs were infrequent (laquinimod: 6.4%; placebo: 4.7%). Death was reported in four patients (laquinimod: n = 1; placebo: n = 3). Rates of serious AEs (including malignancies, infections, and cardiovascular AEs) were similar between groups. The most common AEs identified with laquinimod use were back and neck pain and appendicitis. Laquinimod was also associated with asymptomatic changes in liver enzyme levels, fibrinogen levels, and hematologic parameters that followed a consistent temporal pattern: mild, nonprogressive, and occurring within 90 days of treatment initiation, then stabilizing or reverting to baseline levels during continued treatment.

CONCLUSIONS

Data from these pivotal laquinimod studies demonstrate a safety profile comprising benign or manageable AEs and asymptomatic laboratory findings with a clear temporal pattern. Potential risks noted in preclinical studies were not observed.

Treatment of spontaneous EAE by laquinimod reduces Tfh, B cell aggregates, and disease progression

Objective:

To evaluate the influence of oral laquinimod, a candidate multiple sclerosis (MS) treatment, on induction of T follicular helper cells, development of meningeal B cell aggregates, and clinical disease in a spontaneous B cell–dependent MS model.

Methods:

Experimental autoimmune encephalomyelitis (EAE) was induced in C57BL/6 mice by immunization with recombinant myelin oligodendrocyte glycoprotein (rMOG) protein. Spontaneous EAE was evaluated in C57BL/6 MOG p35-55–specific T cell receptor transgenic (2D2) × MOG-specific immunoglobulin (Ig)H-chain knock-in (IgH^MOG-ki [Th]) mice. Laquinimod was administered orally. T cell and B cell populations were examined by flow cytometry and immunohistochemistry.

Results:

Oral laquinimod treatment (1) reduced CD11c⁺CD4⁺ dendritic cells, (2) inhibited expansion of PD-1⁺CXCR5⁺BCL6⁺ T follicular helper and interleukin (IL)-21–producing activated CD4⁺CD44⁺ T cells, (3) suppressed B cell CD40 expression, (4) diminished formation of Fas⁺GL7⁺ germinal center B cells, and (5) inhibited development of MOG-specific IgG. Laquinimod treatment not only prevented rMOG-induced EAE, but also inhibited development of spontaneous EAE and the formation of meningeal B cell aggregates. Disability progression was prevented when laquinimod treatment was initiated after mice developed paralysis. Treatment of spontaneous EAE with laquinimod was also associated with increases in CD4⁺CD25^hiFoxp3⁺ and CD4⁺CD25⁺IL-10⁺ regulatory T cells.

Conclusions:

Our observations that laquinimod modulates myelin antigen–specific B cell immune responses and suppresses both development of meningeal B cell aggregates and disability progression in spontaneous EAE should provide insight regarding the potential application of laquinimod to MS treatment. Results of this investigation demonstrate how the 2D2 × Th spontaneous EAE model can be used successfully for preclinical evaluation of a candidate MS treatment.

NF-κB Pathways in the Pathogenesis of Multiple Sclerosis and the Therapeutic Implications

Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways are involved in cell immune responses, apoptosis and infections. In multiple sclerosis (MS), NF-κB pathways are changed, leading to increased levels of NF-κB activation in cells. This may indicate a key role for NF-κB in MS pathogenesis. NF-κB signaling is complex, with many elements involved in its activation and regulation. Interestingly, current MS treatments are found to be directly or indirectly linked to NF-κB pathways and act to adjust the innate and adaptive immune system in patients. In this review, we will first focus on the intricacies of NF-κB signaling, including the activating pathways and regulatory elements. Next, we will theorize about the role of NF-κB in MS pathogenesis, based on current research findings, and discuss some of the associated therapeutic implications. Lastly, we will review four new MS treatments which interrupt NF-κB pathways—fingolimod, teriflunomide, dimethyl fumarate (DMF) and laquinimod (LAQ)—and explain their mechanisms, and the possible strategy for MS treatments in the future.

Further understanding of the immunopathology of multiple sclerosis: impact on future treatments

INTRODUCTION

The understanding of the immunopathogenesis of multiple sclerosis (MS) has expanded with more research into T-cell subtypes, cytokine contributors, B-cell participation, mitochondrial dysfunction, and more. Treatment options have rapidly expanded with three relatively recent oral therapy alternatives entering the arena.

AREAS COVERED

In the following review, we discuss current mechanisms of immune dysregulation in MS, how they relate to current treatments, and the impact these findings will have on the future of therapy. Expert commentary: The efficacy of these medications and understanding their mechanisms of actions validates the immunopathogenic mechanisms thought to underlie MS. Further research has exposed new targets, while new promising therapies have shed light on new aspects into the pathophysiology of MS.

Laquinimod dampens hyperactive cytokine production in Huntington's disease patient myeloid cells

Huntington's disease (HD) is a neurodegenerative condition characterized by pathology in the brain and peripheral tissues. Hyperactivity of the innate immune system, due in part to NFκB pathway dysregulation, is an early and active component of HD. Evidence suggests targeting immune disruption may slow disease progression. Laquinimod is an orally active immunomodulator that down-regulates proinflammatory cytokine production in peripheral blood mononuclear cells, and in the brain down-regulates astrocytic and microglial activation by modulating NFκB signalling. Laquinimod had beneficial effects on inflammation, brain atrophy and disease progression in multiple sclerosis (MS) in two phase III clinical trials. This study investigated the effects of laquinimod on hyperactive proinflammatory cytokine release and NFκB signalling in HD patient myeloid cell cultures. Monocytes from manifest (manHD) and pre-manifest (preHD) HD gene carriers and healthy volunteers (HV) were treated with laquinimod and stimulated with lipopolysaccharide. After 24 h pre-treatment with 5 μM laquinimod, manHD monocytes released lower levels of IL-1β, IL-5, IL-8, IL-10, IL-13 and TNFα in response to stimulation. PreHD monocytes released lower levels of IL-8, IL-10 and IL-13, with no reduction observed in HV monocytes. The effects of laquinimod on dysfunctional NFκB signalling in HD was assessed by inhibitor of kappa B (IκB) degradation kinetics, nuclear translocation of NFκB and interactions between IκB kinase (IKK) and HTT, in HD myeloid cells. No differences were observed between laquinimod-treated and untreated conditions. These results provide evidence that laquinimod dampens hyper-reactive cytokine release from manHD and preHD monocytes, with a much reduced effect on HV monocytes. Evidence suggests targeting CNS and peripheral immune disruption may slow Huntington's disease (HD) neurodegenerative processes. The effects of laquinimod, an orally active immunomodulator, on hyperactive cytokine release and dysfunctional NFκB signalling in stimulated myeloid cell cultures from pre-manifest and manifest HD gene carriers and healthy volunteers were investigated. Laquinimod dampened cytokine release but did not impact NFκB signalling. Read the Editorial Highlight for this article on page 670.

Laquinimod prevents cuprizone-induced demyelination independent of Toll-like receptor signaling

Objective:

To test whether Toll-like receptor (TLR) signaling plays a key role for reduced nuclear factor B (NF-κB) activation after laquinimod treatment in the model of cuprizone-induced demyelination, oligodendrocyte apoptosis, inflammation, and axonal damage.

Methods:

Ten-week-old C57BL/6J, TLR4^−/−, and MyD88^−/− mice received 0.25% cuprizone for 6 weeks and were treated daily with 25 mg/kg laquinimod or vehicle. After 6 weeks of demyelination, extent of demyelination, oligodendrocyte density, microglia infiltration, and axonal damage were analyzed in the corpus callosum. Additionally, we analyzed primary mouse astrocytes from C57BL/6J, TLR4^−/−, MyD88^−/−, and TRIF^−/− mice for alteration in NF-κB signaling.

Results:

Vehicle-treated controls from C57BL/6J, TLR4^−/−, and MyD88^−/− mice displayed extensive callosal demyelination as well as microglial activation. In contrast, mice treated with 25 mg/kg laquinimod showed mainly intact callosal myelin. The demyelination score was significantly higher in all untreated mice compared to mice treated with laquinimod. There were significantly fewer APP-positive axonal spheroids, Mac3-positive macrophages/microglia, and less oligodendrocyte apoptosis in the corpus callosum of laquinimod-treated mice in comparison to untreated controls. Stimulated primary mouse astrocytes from laquinimod-treated groups show reduced NF-κB activation compared to vehicle-treated controls.

Conclusions:

Our results confirm that laquinimod prevents demyelination in the cuprizone mouse model for multiple sclerosis via downregulation of NF-κB activation. This laquinimod effect, however, does not involve upstream Toll-like receptor signaling.

Laquinimod in the treatment of relapsing remitting multiple sclerosis

INTRODUCTION

Laquinimod is a new once-daily oral administrable agent, which is under investigation in a phase 3 clinical trial for relapsing remitting multiple sclerosis (RRMS) and in a phase 2 clinical trial for primary progressive MS (PPMS).

AREAS COVERED

The pharmacokinetic, pharmacodynamic and the safety profiles of laquinimod are covered in this review. In preclinical studies, the ability to prevent both experimental autoimmune encephalomyelitis and experimental autoimmune neuritis has been demonstrated. Reduced cell infiltration, demyelination, axonal damage and a shift of T-helper cell responses have been shown. Accordingly, in human studies, a decrease of pro-inflammatory and an increase of anti-inflammatory cytokines have been measured and a significant reduction of disease progression and a decrease in brain volume loss has been demonstrated. During all clinical studies a favorable safety profile was observed for 0.6mg laquinimod. New information about cardiovascular events is prompting the discontinuation of higher dosing regimens in both ongoing trials.

EXPERT OPINION

Laquinimod is a first in class oral agent with high potential to reduce disease progression in RRMS and PPMS. Owing to its favorable safety profile, a combination with 0.6mg laquinimod and other disease modifying therapies could be an option in future MS therapy.

Laquinimod in the treatment of multiple sclerosis: a review of the data so far

Laquinimod (ABR-215062) is a new orally available carboxamide derivative, which is currently developed for relapsing remitting (RR) and chronic progressive (CP) forms of multiple sclerosis (MS; RRMS or CPMS) as well as neurodegenerative diseases. Its mechanism of action may comprise immunomodulatory effects on T-cells, monocytes, and dendritic cells as well as neuroprotective effects with prominent actions on astrocytes. Laquinimod was tested in Phase II and III clinical trials in RRMS at different dosages ranging from 0.1 to 0.6 mg/day. The compound was well tolerated, yet at the dosages tested only led to moderate effects on the reduction of relapse rates as primary study endpoint in Phase III trials. In contrast, significant effects on brain atrophy and disease progression were observed. While there were no significant safety signals in the clinical trials, the Committee for Medicinal Products for Human Use (CHMP) refused marketing authorization for RRMS based on the assessment of the risk–benefit ratio with regard to data from animal studies. At present, the compound is further tested in RRMS as well as CPMS and Huntington’s disease at different concentrations. Results from these trials will further inform about the clinical benefit of laquinimod in patient cohorts with a persisting, but still insufficiently met need for safe and at the same time effective oral compounds with neuroprotective effects.

Pridopidine for the treatment of Huntington's disease

INTRODUCTION

Huntington's disease is a rare dominantly-inherited neurodegenerative disease with motor, cognitive and behavioral manifestations. It results from an expanded unstable trinucleotide repeat in the coding region of the huntingtin gene. Treatment is symptomatic, but a poor evidence baseguides selection of therapeutic agents. Non-choreic derangements in voluntary movement contribute to overall motor disability and are poorly addressed by current therapies. Pridopidine is a novel agent in the dopidine class believed to have 'state dependent' effects at dopamine receptors, thus show promise in the treatment of these disorders of voluntary movement.

AREAS COVERED

This review discusses the pharmacokinetics and pharmacodynamics of pridopidine and reviews clinical trials supporting development of the drug for HD. This information was culled from literature searches for dopidines, pridopidine, and HD experimental therapeutics in PubMed and at http://www.clinicaltrials.org .

EXPERT OPINION

There is a compelling need to discover new treatments for motor disability in HD, particularly for non-choreic motor symptoms. While pridopidine failed to achieve its primary efficacy outcomes in 2 large trials, reproducible effects on secondary motor outcomes have fueled an ongoing trial studying higher doses and more focused clinical endpoints. This and phase III trials will define define the utility of pridopidine for HD.

Synaptopathy connects inflammation and neurodegeneration in multiple sclerosis

Multiple sclerosis (MS) has long been regarded as a chronic inflammatory disease of the white matter that leads to demyelination and eventually to neurodegeneration. In the past decade, several aspects of MS pathogenesis have been challenged, and degenerative changes of the grey matter, which are independent of demyelination, have become a topic of interest. CNS inflammation in MS and experimental autoimmune encephalomyelitis (EAE; a disease model used to study MS in rodents) causes a marked imbalance between GABAergic and glutamatergic transmission, and a loss of synapses, all of which leads to a diffuse 'synaptopathy'. Altered synaptic transmission can occur early in MS and EAE, independently of demyelination and axonal loss, and subsequently causes excitotoxic damage. Inflammation-driven synaptic abnormalities are emerging as a prominent pathogenic mechanism in MS-importantly, they are potentially reversible and, therefore, represent attractive therapeutic targets. In this Review, we focus on the connection between inflammation and synaptopathy in MS and EAE, which sheds light not only on the pathophysiology of MS but also on that of primary neurodegenerative disorders in which inflammatory processes contribute to disease progression.

Current stage in inflammatory bowel disease: What is next?

In recent years, the incidence of inflammatory bowel disease (IBD) has been on the rise, extending to countries where it was infrequent in the past. As a result, the gap between high and low incidence countries is decreasing. The disease, therefore, has an important economic impact on the healthcare system. Advances in recent years in pharmacogenetics and clinical pharmacology have allowed for the development of treatment strategies adjusted to the patient profile. Concurrently, new drugs aimed at inflammatory targets have been developed that may expand future treatment options. This review examines advances in the optimization of existing drug treatments and the development of novel treatment options for IBD.