Cardiac Safety of Ozanimod, a Novel Sphingosine-1-Phosphate Receptor Modulator: Results of a Thorough QT/QTc Study

Targeting the Sphingosine-1-Phosphate Pathway: New Opportunities in Inflammatory Bowel Disease Management

Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC) are chronic immune-mediated diseases which primarily target the intestines. In recent years, the development and regulatory approval of various immunotherapies, both biological agents and small molecules, that target specific pathways of the IBD-associated inflammatory cascade have revolutionized the treatment of IBD. Small molecules offer the advantages of oral administration and short wash-out times. Sphingosine-1-phosphate (S1P) is a bioactive metabolite of ceramide, which exerts its functions after binding to five G-protein-coupled receptors (S1PR1-S1PR5). Concerning IBD, S1P participates in the egress of lymphocytes from the secondary lymphoid tissue and their re-circulation to sites of inflammation, mainly through S1PR1 binding. In addition, this system facilitates the differentiation of T-helper cells towards proinflammatory immunophenotypes. Recently, S1P modulators have offered a valuable addition to the IBD treatment armamentarium. They exert their anti-inflammatory function via sequestration of T cell subsets in the lymphoid tissues and prevention of gut homing. In this review, we revisit the role of the S1P/S1PR axis in the pathogenesis of IBD and discuss efficacy and safety data from clinical trials and real-world reports on the two S1PR modulators, ozanimod and etrasimod, that are currently approved for IBD treatment, and comment on their potential positioning in the IBD day-to-day management. We also present recent data on emerging S1P modulators. Finally, based on the successes and failures of S1PR modulators in IBD, we discuss future avenues of IBD treatments targeting the S1P/S1PR axis.

Pharmacokinetics of S1P receptor modulators in the treatment of ulcerative colitis

INTRODUCTION

Ulcerative colitis is a chronic inflammatory bowel disease, affecting the colorectal mucosae, with a relapsing-remitting course, characterized by the trafficking and gathering of lymphocytes in the inflammatory intestinal mucosa. Sphingosine-1-phosphate (S1P) receptor modulators preventing lymphocytes egress from lymphoid tissues to the active inflammation site is an alternative therapeutic option in this condition.

AREA COVERED

We carried out a comprehensive review of the literature available on Medline, Scopus and Embase regarding the pharmacokinetics of S1P receptor modulators. For each compound, we reviewed the mechanism of action, pharmacokinetic data and efficacy and safety data from phase 3 studies and real-life studies when available.

EXPERT OPINION

S1P receptor modulators, including ozanimod and etrasimod (both currently on the market) as well as VTX002 (under development), are a new class of drugs for the treatment of moderate to severe ulcerative colitis, inducing and maintaining the remission. Due to its pharmacokinetic features, this class of drugs has certain advantages such as an oral administration, a short half-life, a high volume of distribution, and no immunogenicity. On the other hand, there are risks of cardiological and ophthalmological side-effects, as well as drug-drug interactions risk, that require special attention from the healthcare providers.

Concomitant Administration of Ozanimod and Serotonergic Antidepressants in Patients With Ulcerative Colitis or Relapsing Multiple Sclerosis

BACKGROUND

Ozanimod, approved for the treatment of moderately to severely active ulcerative colitis (UC) and relapsing multiple sclerosis (RMS), is a weak in vitro monoamine oxidase B (MAO-B) inhibitor. MAO-B inhibitors can cause serotonin accumulation with concomitant use of selective serotonin reuptake inhibitors (SSRIs) or serotonin and norepinephrine reuptake inhibitors (SNRIs). We evaluated the incidence of treatment-emergent adverse events (TEAEs) potentially associated with serotonin accumulation during ozanimod and concomitant SSRI/SNRI use in this post hoc analysis of pooled UC studies and the open-label extension RMS DAYBREAK.

METHODS

Data for ozanimod 0.92 mg from pooled UC studies (n = 1158; cutoff: January 10, 2022) and RMS DAYBREAK (n = 2257; cutoff: February 1, 2022) were analyzed. Concomitant SSRI/SNRI use was allowed in the UC (n = 67) and RMS (n = 274) studies. A narrow Medical Dictionary for Regulatory Activities search ("serotonin syndrome," "neuroleptic malignant syndrome," and "malignant hyperthermia") and a broad search including terms potentially associated with serotonin accumulation were conducted. The percentages of patients with TEAEs in both searches were analyzed by concomitant SSRI/SNRI use when the TEAE occurred.

RESULTS

No patients had TEAEs matching the narrow search criteria. No differences were observed in the percentages of patients with ≥1 TEAE matching the broad search regardless of SSRI/SNRI use in UC (with: 25.4% [n = 17 of 67]; without: 15.0% [n = 164 of 1091]) and RMS (with: 12.4% [n = 34 of 274]; without: 15.6% [n = 310 of 1982]) studies.

CONCLUSIONS

No evidence of increased TEAEs potentially associated with serotonin accumulation was observed with concurrent use of ozanimod and SSRIs/SNRIs.

CLINICAL TRIAL REGISTRATION

NCT01647516, NCT02531126, NCT02435992, NCT02576717.

A Gastroenterologist's guide to drug interactions of small molecules for inflammatory bowel disease

Small molecule drugs are becoming increasingly used in the treatment of inflammatory bowel diseases (IBD). However, unlike monoclonal antibody drugs, which have few interactions with other medications, the pharmacokinetics of small molecule drugs are complex and may be influenced by a myriad of drug-drug interactions (DDI) as well as by patient characteristics and food intake. This review aims to provide a concise practical guide to small molecule drug interactions for the use of IBD physicians. It starts with a brief overview of the main metabolizing enzymes and transporters involved in drug interactions and the Food and Drug Administration's (FDA) approach to determining drug-interaction hazard thresholds. It is then followed by a more detailed review of the pharmacokinetics of five novel small molecules approved in IBD: Tofacitinib, Upadacitinib, Filgotinib, Ozanimod, and Etrasimod, including their known interactions and specific warnings. This review will also inform readers on challenges in determining the actual magnitude of interactions and their clinical relevance, including the arbitrary nature of some hazard thresholds, the inference of the impact on metabolizing enzymes and transporters from single-drug assays which may not reflect poly-pharmaceutical regimens, and other challenges in this field which the IBD physician needs to be cognizant of. In practice, before administering a small molecule drug, it is advisable to evaluate any potential interactions with other medications the patient is receiving. An increased awareness by health care professionals and patients, may reduce the possible risks associated with DDI of small molecule IBD drugs.

Cardiovascular Safety of Ozanimod in Patients With Ulcerative Colitis: True North and Open-Label Extension Analyses

BACKGROUND & AIMS

Evaluating cardiovascular safety of sphingosine 1-phosphate (S1P) receptor modulators is warranted due to S1P receptor expression on cardiomyocytes and vascular endothelial cells. This analysis reports the cardiovascular safety of ozanimod, an S1P receptor modulator, in patients with moderately to severely active ulcerative colitis from the phase 3 True North (TN) and open-label extension (OLE).

METHODS

All patients who received ozanimod in TN (n = 796) and all eligible TN patients who entered the OLE (n = 823) were included. Cardiovascular-related adverse events were evaluated in patients with up to 146 weeks of ozanimod exposure (2219 patient-years), which included 52 weeks during TN.

RESULTS

On TN day 1, first-dose ozanimod resulted in a 0.2 beats per minute mean decrease in heart rate from pretreatment to hour 6; 2 patients experienced bradycardia, which resolved without treatment modification. Mean systolic and diastolic blood pressure increases of 5.1 and 2.2 mm Hg, respectively, were observed at TN week 52. No second-degree Mobitz type II atrioventricular block events were reported; 1 third-degree atrioventricular block unrelated to ozanimod occurred in the OLE. Cardiac and vascular treatment-emergent adverse events were infrequent (3.8% [31 of 823] and 8.5% [70 of 823]); no ozanimod-related cardiovascular deaths occurred. The incidences of deep-vein thrombosis (0.2%; 2 of 823), pulmonary embolism (0.2%; 2 of 823), and ischemic stroke (0.4%; 3 of 823) in the OLE were low.

CONCLUSIONS

No new cardiovascular safety signals were identified, consistent with findings from previous ozanimod studies. There were few major adverse cardiovascular events or thromboembolic events, which were unrelated or unlikely related to ozanimod. Ozanimod has a well-tolerated cardiovascular safety profile when prescribed in accordance with the label. Clinical trial registry website and trial numbers: ClinicalTrials.gov numbers: NCT02435992 and NCT02531126.

Ozanimod Therapy in Patients With COVID-19 Requiring Oxygen Support: A Randomized Open-Label Pilot Trial

BACKGROUND

Sphingosine-1-phosphate receptor ligands (SRLs) dampen immunopathologic damages in models of viral pneumonia.

RESEARCH QUESTION

Is it feasible to administer an SRL therapy, here ozanimod (OZA), to acutely ill patients infected with SARS-CoV-2?

STUDY DESIGN AND METHODS

The prospective randomized open-label COVID-19 Ozanimod Intervention (COZI) pilot trial was conducted in three Canadian hospitals. Patients admitted for COVID-19 requiring oxygen were eligible. Randomization was stratified for risk factors of poor outcome and oxygen needs at inclusion. Participants were allocated to standard of care or to standard of care plus OZA. OZA (oral, once daily, incremental dosage) was administered for a maximum of 14 days. Primary end point investigated for size effect and variance over time was the assessment of safety and efficacy, evaluated by the daily score on the World Health Organization-adapted six-point ordinal scale for clinical improvement analyzed under the intention-to-treat principle.

RESULTS

Twenty-three patients were randomized to the standard of care arm, and 20 were randomized to the OZA arm from September 2020 to February 2022. Evaluation of efficacy showed nonsignificant reductions of median (interquartile range) duration of respiratory support (6 [3-10] vs 9 [4-12] days; P = .34), median duration of hospitalization (9 [6-12] vs 10 [6-18] days; P = .20), and median time to clinical improvement (4 [3-7] vs 7 [3-11] days; P = .12) for OZA compared with standard of care, respectively. Heart rate was significantly lower with OZA (65 [ 63-67] vs 71 [69-72] beats/min; P < .0001). However, QT and PR intervals were not affected. No severe adverse drug reaction was reported.

INTERPRETATION

To our knowledge, SRL utility in severe pneumonia has never been tested in patients. This study shows for the first time that this new pharmacologic agent may safely be administered to patients hospitalized for viral pneumonia, with potential clinical benefits. Bradycardia was frequent but well tolerated.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT04405102; URL: www.

CLINICALTRIALS

gov.

Reversible oxidation/reduction steps in the metabolic degradation of the glycerol side chain of the S1P1 modulator ponesimod

1. Ponesimod is a selective modulator of the sphingosine 1-phosphate receptor 1 (S1P1) approved for the treatment of active relapsing forms of multiple sclerosis. The chemical structure of ponesimod contains a glycerol side chain which is the major target of drug metabolism in humans.

2.  The two major metabolic pathways give the acids M12 (-OCH2CH(OH)COOH) and M13 (-OCH2COOH). While the former results from oxidation of the terminal alcohol, the mechanism yielding the chain-shortened acid M13 is less obvious. A detailed mechanistic study with human liver microsomes and hepatocytes using ponesimod, M12 and some of the suspected intermediates revealed an unexpectedly complex pattern of enzyme-mediated and chemical reactions.

3. Metabolic pathways for both acids were not independent and several of the transformations were reversible, depending on reaction conditions. Formation of M13 occurred either via initial oxidation of the secondary alcohol, or as a downstream process starting from M12.

4. The phenol metabolite M32 was produced as part of several pathways. Control experiments at various pH values and in the absence of metabolising enzymes support the conclusion that its formation resulted from chemical degradation rather than from metabolic processes.

Cardiovascular Evaluation of Etrasimod, a Selective Sphingosine 1-phosphate Receptor Modulator, in Healthy Adults: Results of a Randomized, Thorough QT/QTc Study

Etrasimod is an investigational, once-daily, oral, selective sphingosine 1-phosphate receptor 1,4,5 modulator used as an oral treatment option for immune-mediated inflammatory disorders. This randomized, double-blind, placebo- and positive-controlled, parallel-group, healthy adult study investigated etrasimod's effect on the QT interval and other electrocardiogram parameters. All participants received etrasimod-matched placebo on day 1. Group A received once-daily, multiple ascending doses of etrasimod (2-4 mg) on days 1-14 and moxifloxacin-matched placebo on days 1 and 15. Group B received etrasimod-matched placebo on days 1-14 and either moxifloxacin 400 mg or moxifloxacin-matched placebo on days 1 and 15. The primary analysis was a concentration-QTc analysis using a corrected QT interval by Fridericia (QTcF). The etrasimod concentration-QTc analysis predicted placebo-corrected change from baseline QTcF (ΔΔQTcF) values and associated 90% confidence intervals remained <10 milliseconds over the observed etrasimod plasma concentration range (≤279 ng/mL). Etrasimod was associated with mild, transient, asymptomatic heart rate slowing that was most pronounced on day 1 (2 mg, first dose). The largest-by-time point mean placebo-corrected changes in heart rate from time-matched day -1 baseline (∆∆HR) on days 1, 7 (2 mg, last dose), and 14 (4 mg, last dose) were -15.1, -8.5, and -6.0 bpm, respectively. Etrasimod's effects on PR interval were small, with the largest least squares mean placebo-corrected change from baseline in PR interval (∆∆PR) being 6.6 milliseconds. No episodes of atrioventricular block were observed. Thus, multiple ascending doses of etrasimod were not associated with clinically relevant QT/QTc effects in healthy adults and only had a mild, transient, and asymptomatic impact on heart rate.

Structural determinants of sphingosine-1-phosphate receptor selectivity

Fingolimod, the prodrug of fingolimod-1-phosphate (F1P), was the first sphingosine-1-phosphate receptor (S1PR) modulator approved for multiple sclerosis. F1P unselectively targets all five S1PR subtypes. While agonism (functional antagonism via receptor internalization) at S1PR1 leads to the desired immune modulatory effects, agonism at S1PR3 is associated with cardiac adverse effects. This motivated the development of S1PR3 -sparing compounds and led to a second generation of S1PR1,5 -selective ligands like siponimod and ozanimod. Our method combines molecular dynamics simulations and three-dimensional pharmacophores (dynophores) and enables the elucidation of S1PR subtype-specific binding site characteristics, visualizing also subtle differences in receptor-ligand interactions. F1P and the endogenous ligand sphingosine-1-phosphate bind to the orthosteric pocket of all S1PRs, but show different binding mode dynamics, uncovering potential starting points for the development of subtype-specific ligands. Our study contributes to the mechanistic understanding of the selectivity profile of approved drugs like ozanimod and siponimod and pharmaceutical tool compounds like CYM5541.

Ozanimod differentially preserves human cerebrovascular endothelial barrier proteins and attenuates matrix metalloproteinase-9 activity following in vitro acute ischemic injury

Endothelial integrity is critical in mitigating a vicious cascade of secondary injuries following acute ischemic stroke (AIS). Matrix metalloproteinase-9 (MMP-9), a contributor to endothelial integrity loss, is elevated during stroke and is associated with worsened stroke outcome. We investigated the FDA-approved selective sphingosine-1-phosphate receptor 1 (S1PR1) ligand, ozanimod, on the regulation/activity of MMP-9 as well as endothelial barrier components [platelet endothelial cell adhesion molecule 1 (PECAM-1), claudin-5, and zonula occludens 1 (ZO-1)] in human brain microvascular endothelial cells (HBMECs) following hypoxia plus glucose deprivation (HGD). We previously reported that S1PR1 activation improves HBMEC integrity; however, mechanisms underlying S1PR1 involvement in endothelial cell barrier integrity have not been clearly elucidated. We hypothesized that ozanimod would attenuate an HGD-induced increase in MMP-9 activity that would concomitantly attenuate the loss of integral barrier components. Male HBMECs were treated with ozanimod or vehicle and exposed to 3 h of normoxia (21% O2) or HGD (1% O2). Immunoblotting, zymography, qRT-PCR, and immunocytochemical labeling techniques assessed processes related to MMP-9 and barrier markers. We observed that HGD acutely increased MMP-9 activity and reduced claudin-5 and PECAM-1 levels, and ozanimod attenuated these responses. In situ analysis, via PROSPER, suggested that attenuation of MMP-9 activity may be a primary factor in maintaining these integral barrier proteins. We also observed that HGD increased intracellular mechanisms associated with augmented MMP-9 activation; however, ozanimod had no effect on these select factors. Thus, we conclude that ozanimod has the potential to attenuate HGD-mediated decreases in HBMEC integrity in part by decreasing MMP-9 activity as well as preserving barrier properties.NEW & NOTEWORTHY We have identified a potential novel mechanism by which ozanimod, a selective sphingosine-1-phosphate receptor 1 (S1PR1) agonist, attenuates hypoxia plus glucose deprivation (HGD)-induced matrix metalloproteinase-9 (MMP-9) activity and disruptions in integral human brain endothelial cell barrier proteins. Our results suggest that ischemic-like injury elicits increased MMP-9 activity and alterations of barrier integrity proteins in human brain microvascular endothelial cells (HBMECs) and that ozanimod via S1PR1 attenuates these HGD-induced responses, adding to its therapeutic potential in cerebrovascular protection during the acute phase of ischemic stroke.

Recruitment and Residence of Intestinal T Cells - Lessons for Therapy in Inflammatory Bowel Disease

Targeting leukocyte trafficking in the management of inflammatory bowel disease [IBD] has been a significant therapeutic advance over the past 15 years. However, as with other advanced therapies, phase III clinical trials report response to trafficking inhibitors in only a proportion of patients, with fewer achieving clinical remission or mucosal healing. Additionally, there have been significant side effects, most notably progressive multifocal leukoencephalopathy in association with the α4 inhibitor natalizumab. This article reviews the mechanisms underpinning T cell recruitment and residence, to provide a background from which the strength and limitations of agents that disrupt leukocyte trafficking can be further explored. The therapeutic impact of trafficking inhibitors is underpinned by the complexity and plasticity of the intestinal immune response. Pathways essential for gut homing in health may be bypassed in the inflamed gut, thus providing alternative routes of entry when conventional homing molecules are targeted. Furthermore, there is conservation of trafficking architecture between proinflammatory and regulatory T cells. The persistence of resident memory cells within the gut gives rise to local established pro-inflammatory populations, uninfluenced by inhibition of trafficking. Finally, trafficking inhibitors may give rise to effects beyond the intended response, such as the impact of vedolizumab on innate immunity, as well as on target side effects. With significant research efforts into predictive biomarkers already underway, it is ultimately hoped that a better understanding of trafficking and residence will help us predict which patients are most likely to respond to inhibition of leukocyte trafficking, and how best to combine therapies.

Efficacy and Safety of S1P1 Receptor Modulator Drugs for Patients with Moderate-to-Severe Ulcerative Colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) that negatively impacts patients' quality of life. In the last decades, the therapeutic options available for the management of patients with moderate to severe UC have increased significantly, including not only biological drugs but also small molecules. However, there is a persistent need to develop new drugs that act on new targets while minimizing the risk of adverse events. Sphingosine-1-phosphate (S1P) is a membrane-derived lysophospholipid. The S1P gradient between tissues and the circulatory system has a key role in regulating the trafficking of immune cells as autoreactive B and T lymphocytes. S1P receptor modulators could be a safe and efficacious alternative mechanism for reducing inflammation in immune-mediated disorders, including UC, by reducing lymphocyte egress from the lymph nodes to the bloodstream. Several S1P receptor modulators have been developed and tested in UC. Ozanimod is already approved by Food and Drug Administration (FDA) and European Medical Agency (EMA), while etrasimod and VTX002 are still under approval. Oral administration route, rapidity and reliable safety profile are the main advantages of this class of drugs. The aim of this review is to summarize the available evidence for the efficacy, safety, and pharmacokinetics of ozanimod, etrasimod, and VTX002 in UC.

Molecular and neuroimmune pharmacology of S1P receptor modulators and other disease-modifying therapies for multiple sclerosis

Multiple sclerosis (MS) is a neurological, immune-mediated demyelinating disease that affects people in the prime of life. Environmental, infectious, and genetic factors have been implicated in its etiology, although a definitive cause has yet to be determined. Nevertheless, multiple disease-modifying therapies (DMTs: including interferons, glatiramer acetate, fumarates, cladribine, teriflunomide, fingolimod, siponimod, ozanimod, ponesimod, and monoclonal antibodies targeting ITGA4, CD20, and CD52) have been developed and approved for the treatment of MS. All the DMTs approved to date target immunomodulation as their mechanism of action (MOA); however, the direct effects of some DMTs on the central nervous system (CNS), particularly sphingosine 1-phosphate (S1P) receptor (S1PR) modulators, implicate a parallel MOA that may also reduce neurodegenerative sequelae. This review summarizes the currently approved DMTs for the treatment of MS and provides details and recent advances in the molecular pharmacology, immunopharmacology, and neuropharmacology of S1PR modulators, with a special focus on the CNS-oriented, astrocyte-centric MOA of fingolimod.

S1PR1 modulators in multiple sclerosis: Efficacy, safety, comparison, and chemical structure insights

Multiple sclerosis (MS) is a neurological disease that leads to severe physical and cognitive disabilities. Drugs used in the treatment of MS vary from small synthetic molecules to large macromolecules such as antibodies. Sphingosine 1-phosphate receptor modulators are frequently used for the treatment of MS. These medicines prevent the egress of lymphocytes from secondary lymphoid organs leading to immune system suppression. Currently, four S1PR modulators are on the market and several potential drug candidates are in clinical trials for the treatment of MS. These compounds differ in chemical structure, adverse effects, and efficacy points of view. The current article reviews the latest studies on S1PR1 modulators and compares them with other MS drugs in terms of efficacy, tolerability, and safety. A special focus was dedicated to discussing the structure-activity relationships of these compounds and performing a three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis to gain better insight into the ligand-receptor interaction mode.

Safety and Monitoring of the Treatment with Disease-Modifying Therapies (DMTs) for Multiple Sclerosis (MS)

BACKGROUND

Disease-Modifying Therapies (DMTs) for Multiple Sclerosis (MS) are widely used given their proven efficacy in the relapsing form of the disease, while recently, Siponimod and Ocrelizumab have been approved for the progressive forms of the disease. Currently, 22 diseasemodifying drugs are approved by the FDA, while in 2012, only nine were present in the market. From March 2019 until August 2020, six new drugs were approved. This rapid development of new DMTs highlighted the need to update our knowledge about their short and long-term safety.

OBJECTIVE

This review summarizes the available safety data for all the Disease-Modifying Therapies for Multiple Sclerosis and presents the monitoring plan before and during the treatment.

METHODS

A literature search was conducted using PUBMED and COCHRANE databases. Key journals and abstracts from major annual meetings of Neurology, references of relevant reviews, and relative articles were also manually searched. We prioritized systematic reviews, large randomized controlled trials (RCTs), prospective cohort studies, and other observational studies. Special attention was paid to guidelines and papers focusing on the safety and monitoring of DMTs.

CONCLUSION

Data for oral (Sphingosine 1-phosphate (S1P) receptor modulators, Fumarates, Teriflunomide, Cladribine), injectables (Interferons, Glatiramer acetate, Ofatumumab), and infusion therapies (Natalizumab, Ocrelizumab, Alemtuzumab) are presented.

A Literature Review of Ozanimod Therapy in Inflammatory Bowel Disease: From Concept to Practical Application

Inflammatory bowel disease (IBD), namely Ulcerative Colitis (UC) and Crohn's Disease (CD), is believed to be due to a dysregulation of the innate immune response. The complexity of the immune cascade offers both a challenge and an opportunity to researchers seeking out new treatments for IBD, as various points along the inflammatory pathways can be targeted for interruption. Sphinogosine-1-phosphate (S1P) is a phospholipid molecule with wide ranging biological effects caused by binding five known S1P receptor subtypes. Ozanimod is a small molecule drug that selectively targets S1P receptors 1 and 5 which play a crucial role in lymphocyte trafficking. In clinical trials for both UC and CD, it has been shown to induce a reversible lymphopenia which correlates with response to therapy. Reported adverse events include infection, anemia, and elevated liver enzymes. Rare instances of bradycardia, heart block, and macular edema were also reported. As a newly available therapy approved for UC patients, we aim to summarize ozanimod's novel mechanism of action, pre-clinical and clinical trial results, and to give context to this newly available drug that gastroenterologists may utilize in their treatment algorithm.

Ozanimod: A Review in Ulcerative Colitis

Ozanimod (Zeposia®) is the first sphingosine-1-phosphate receptor (S1PR) modulator to be approved for the treatment of adults with moderately to severely active ulcerative colitis in the USA, and in adults with moderately to severely active ulcerative colitis who have had an inadequate or lost response to, or were intolerant of, either conventional therapy or a biologic in the EU. An oral agent, ozanimod is administered once daily as induction and maintenance therapy. In the randomized, double-blind, multinational phase 2 Touchstone and phase 3 True North clinical trials, ozanimod was effective in inducing clinical remission and maintaining remission relative to placebo in adults with moderately to severely active ulcerative colitis. Ozanimod was generally well tolerated in these studies, with manageable or transient adverse events (AEs). Current data from the Touchstone and True North open-label extensions are consistent with the primary studies with respect to therapeutic efficacy and tolerability, with no new safety signals observed. Although further data will be beneficial, ozanimod expands the treatment options for adults with moderately to severely active ulcerative colitis.

Efficacy and Safety of Multiple Sclerosis Drugs Approved Since 2018 and Future Developments

Multiple sclerosis treatment made substantial headway during the last two decades with the implementation of therapeutics with new modes of action and routes of application. We are now in the situation that second-generation molecules, approved since 2018, are on the market, characterized by reduced side effects using a more tailored therapeutic approach. Diroximel fumarate is a second-generation fumarate with reduced gastrointestinal side effects. Moreover, several novel, selective, sphingosine-1-phosphate receptor modulators with reduced off-target effects have been developed; namely siponimod, ozanimod, and ponesimod; all oral formulations. B-cell-targeted therapies such as ocrelizumab, given intravenously, and since 2021 ofatumumab, applied subcutaneously, complement the spectrum of novel therapies. The glycoengineered antibody ublituximab is the next anti-CD20 therapy about to be approved. Within the next years, oral inhibitors of Bruton's tyrosine kinase, currently under investigation in several phase III trials, may be licensed for multiple sclerosis. Those developments currently offer an individualized multiple sclerosis therapy, targeting patient needs with substantial effects on relapses, disability progression, and implications for daily life. In this up-to-date review, we provide a holistic overview about novel developments of the therapeutic landscape and upcoming approaches for multiple sclerosis treatment.

Sphingosine 1-phosphate modulation and immune cell trafficking in inflammatory bowel disease

Immune cell trafficking is a critical element of the intestinal immune response, both in homeostasis and in pathological conditions associated with inflammatory bowel disease (IBD). This process involves adhesion molecules, chemoattractants and receptors expressed on immune cell surfaces, blood vessels and stromal intestinal tissue as well as signalling pathways, including those modulated by sphingosine 1-phosphate (S1P). The complex biological processes of leukocyte recruitment, activation, adhesion and migration have been targeted by various monoclonal antibodies (vedolizumab, etrolizumab, ontamalimab). Promising preclinical and clinical data with several oral S1P modulators suggest that inhibition of lymphocyte egress from the lymph nodes to the bloodstream might be a safe and efficacious alternative mechanism for reducing inflammation in immune-mediated disorders, including Crohn's disease and ulcerative colitis. Although various questions remain, including the potential positioning of S1P modulators in treatment algorithms and their long-term safety, this novel class of compounds holds great promise. This Review summarizes the critical mediators and mechanisms involved in immune cell trafficking in IBD and the available evidence for efficacy, safety and pharmacokinetics of S1P receptor modulators in IBD and other immune-mediated disorders. Further, it discusses potential future approaches to incorporate S1P modulators into the treatment of IBD.

A critical review of ozanimod for the treatment of adults with moderately to severely active ulcerative colitis

INTRODUCTION

Ozanimod is a sphingosine-1-phosphate (S1P) modulator that inhibits lymphocyte trafficking from lymph nodes to the circulation. It is approved by the US Food and Drug Administration (FDA) for the treatment of relapsing multiple sclerosis and most recently for the management of moderate-severe ulcerative colitis (UC).

AREAS COVERED

Here we review the status of drugs approved for moderate-severe UC, the unmet needs in the management of UC, proposed mechanisms of action of S1P modulators, clinical data regarding ozanimod in UC, and emerging S1P modulators being evaluated in inflammatory bowel disease.

EXPERT OPINION

Ozanimod is superior to placebo in inducing and maintaining clinical and endoscopic remission in UC. Adverse events include transient asymptomatic bradycardia, first-degree atrioventricular blocks, transient asymptomatic hepatotoxicity, macular edema in patients with preexisting risk factors, and increased risk of nasopharyngitis. Ozanimod is contraindicated in patients with clinically significant cardiovascular diseases, type II second-, or third-degree atrioventricular blocks, and females of childbearing age who do not use contraception. Ozanimod is the first S1P modulator to be approved for UC, offering a new therapeutic class option for patients. It has the advantages of being convenient with a once-daily oral administration, non-immunogenic, and overall safe when used in patients without contraindications.

Review article: the sphingosine 1 phosphate/sphingosine 1 phosphate receptor axis - a unique therapeutic target in inflammatory bowel disease

BACKGROUND

Ozanimod, a high selective sphingosine 1 phosphate (S1P) receptor (S1PR) 1/5 modulator was approved by the Food and Drug Administration for the treatment of adult patients with moderately to severely active ulcerative colitis. Additional S1PR modulators are being tested in clinical development programmes for both ulcerative colitis and Crohn's disease.

AIM

To provide an overview of advances in understanding S1PRs biology and summarise preclinical and clinical investigations of S1P receptor modulators in chronic inflammatory disease with special emphasis on inflammatory bowel diseases (IBD).

METHODS

We performed a narrative review using PubMed and ClinicalTrials.gov.

RESULTS

Through S1PRs, S1P regulates multiple cellular processes, including proliferation, migration, survival, and vascular barrier integrity. The S1PRs function of regulating lymphocyte trafficking is well known, but new functions of S1PRs expand our knowledge of S1PRs biology. Several S1PR modulators are in clinical development for both ulcerative colitis and Crohn's disease and have shown promise in phase II and III studies with ozanimod now being approved for ulcerative colitis.

CONCLUSIONS

S1P receptor modulators constitute a novel, promising, safe, and convenient strategy for the treatment of IBD.

Discovery of Novel Sphingosine-1-Phosphate-1 Receptor Agonists for the Treatment of Multiple Sclerosis

The sphingosine-1-phosphate-1 (S1P₁) receptor agonists have great potential for the treatment of multiple sclerosis (MS) because they can inhibit lymphocyte egress through receptor internalization. We designed and synthesized triazole and isoxazoline derivatives to discover a novel S1P₁ agonist for MS treatment. Of the two scaffolds, the isoxazoline derivative was determined to have excellent in vitro efficacy and drug-like properties. Among them, compound 21l was found to have superior drug-like properties as well as excellent in vitro efficacies (EC₅₀ = 7.03 nM in β-arrestin recruitment and EC₅₀ = 11.8 nM in internalization). We also confirmed that 21l effectively inhibited lymphocyte egress in the peripheral lymphocyte count test and significantly improved the clinical score in the experimental autoimmune encephalitis MS mouse model.

Risk for Cardiovascular Adverse Events Associated With Sphingosine-1-Phosphate Receptor Modulators in Patients With Multiple Sclerosis: Insights From a Pooled Analysis of 15 Randomised Controlled Trials

Background

All agents engaging sphongosine-1-phospate receptors (S1PRs) will have some cardiovascular effect. This study aimed to elucidate the risk of cardiovascular adverse events (AEs) in patients with multiple sclerosis (MS) treated with S1PR modulators (S1PRMs).

Methods

We systematically searched the PubMed, EMBASE, and Cochrane Library databases for randomised controlled trials (RCTs) published through January 5, 2021. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated using the random-effects model. Sensitivity analyses and meta-regression were performed.

Results

Seventeen RCTs (12 for fingolimod; 3 for ozanimod; 2 for siponimod) involving 13,295 patients were included. Compared with the control treatment, S1PRMs significantly increased the risk of cardiovascular AEs (RR, 2.21; 95% CI, 1.58–3.10; I², 75.6%). Notably, the high-risk cardiovascular AEs associated with S1PRMs were primarily bradyarrhythmia (RR, 2.92; 95% CI, 1.91–4.46; I², 30.8%) and hypertension (RR, 2.00; 95% CI, 1.49–2.67; I², 56.5%). Subgroup analysis results were consistent with the primary outcomes except that ozanimod was associated with a higher risk of hypertension only (RR, 1.76; 95% CI, 1.10–2.82; I², 0.0%), while siponimod was associated with a higher risk of bradyarrhythmia only (RR, 2.75; 95% CI, 1.75–4.31; I², 0.0%). No significant inter-subgroup differences were observed (P_interaction > 0.05).

Conclusions

S1PRM use increased the risk of cardiovascular AEs by 1.21 times in patients with MS, and increased risks for bradyarrhythmia and hypertension were at 2.92- and 2.00-fold, respectively. These findings can help clinicians assess the risk of cardiovascular AEs in patients treated with S1PRMs.

Systematic Review Registration

The PROSPERO ID is CRD42020183215.

Targeting Leukocyte Trafficking in Inflammatory Bowel Disease

In the last two decades, understanding of inflammatory bowel disease (IBD) immunopathogenesis has expanded considerably. Histopathological examination of the intestinal mucosa in IBD demonstrates the presence of a chronic inflammatory cell infiltrate. Research has focused on identifying mechanisms of immune cell trafficking to the gastrointestinal tract that may represent effective gut-selective targets for IBD therapy whilst avoiding systemic immunosuppression that may be associated with off-target adverse effects such as infection and malignancy. Integrins are cell surface receptors that can bind to cellular adhesion molecules to mediate both leukocyte homing and retention. In 2014, Vedolizumab (Entyvio^®) was the first anti-integrin (anti-α4ß7 monoclonal antibody) treatment to be approved for use in IBD. Several other anti-integrin therapies are currently in advanced stages of development, including novel orally administered small-molecule drugs. Drugs targeting alternative trafficking mechanisms such as mucosal addressin cellular adhesion molecule-1 and sphingosine-1-phosphate receptors are also being evaluated. Here, we summarise key established and emerging therapies targeting leukocyte trafficking that may play an important role in realising the goal of stratified precision medicine in IBD care.

Sphingosine 1-phosphate receptor modulators in multiple sclerosis and other conditions

The sphingosine 1-phosphate (S1P) signalling pathways have important and diverse functions. S1P receptors (S1PRs) have been proposed as a therapeutic target for various diseases due to their involvement in regulation of lymphocyte trafficking, brain and cardiac function, vascular permeability, and vascular and bronchial tone. S1PR modulators were first developed to prevent rejection by the immune system following renal transplantation, but the only currently approved indication is multiple sclerosis. The primary mechanism of action of S1PR modulators in multiple sclerosis is through binding S1PR subtype 1 on lymphocytes resulting in internalisation of the receptor and loss of responsiveness to the S1P gradient that drives lymphocyte egress from lymph nodes. The reduction in circulating lymphocytes presumably limits inflammatory cell migration into the CNS. Four S1PR modulators (fingolimod, siponimod, ozanimod, and ponesimod) have regulatory approval for multiple sclerosis. Preclinical evidence and ongoing and completed clinical trials support development of S1PR modulators for other therapeutic indications.

Biased and allosteric modulation of bone cell-expressing G protein-coupled receptors as a novel approach to osteoporosis therapy

On the cellular level, osteoporosis (OP) is a result of imbalanced bone remodeling, in which osteoclastic bone resorption outcompetes osteoblastic bone formation. Currently available OP medications include both antiresorptive and bone-forming drugs. However, their long-term use in OP patients, mainly in postmenopausal women, is accompanied by severe side effects. Notably, the fundamental coupling between bone resorption and formation processes underlies the existence of an undesirable secondary outcome that bone anabolic or anti-resorptive drugs also reduce bone formation. This drawback requires the development of anti-OP drugs capable of selectively stimulating osteoblastogenesis and concomitantly reducing osteoclastogenesis. We propose that the application of small synthetic biased and allosteric modulators of bone cell receptors, which belong to the G-protein coupled receptors (GPCR) family, could be the key to resolving the undesired anti-OP drug selectivity. This approach is based on the capacity of these GPCR modulators, unlike the natural ligands, to trigger signaling pathways that promote beneficial effects on bone remodeling while blocking potentially deleterious effects. Under the settings of OP, an optimal anti-OP drug should provide fine-tuned regulation of downstream effects, for example, intermittent cyclic AMP (cAMP) elevation, preservation of Ca²⁺ balance, stimulation of osteoprotegerin (OPG) and estrogen production, suppression of sclerostin secretion, and/or preserved/enhanced canonical β-catenin/Wnt signaling pathway. As such, selective modulation of GPCRs involved in bone remodeling presents a promising approach in OP treatment. This review focuses on the evidence for the validity of our hypothesis.

Ozanimod for the treatment of relapsing forms of multiple sclerosis

Multiple sclerosis (MS) is an inflammatory disease that causes chronic neurological disability in young adults. Modulation of sphingosine 1-phosphate (S1P) receptors, a group of receptors that, among other things, regulate egression of lymphocytes from lymph nodes, has proven to be effective in treating relapsing MS. Fingolimod, the first oral S1P receptor modulator, has demonstrated potent efficacy and tolerability, but can cause undesirable side effects due to its interaction with a wide range of S1P receptor subtypes. This review will focus on ozanimod, a more selective S1P receptor modulator, which has recently received approval for relapsing MS. We summarize ozanimod's mechanism of action, and efficacy and safety from clinical trials that demonstrate its utility as another treatment option for relapsing MS.

Ozanimod, an S1PR1 ligand, attenuates hypoxia plus glucose deprivation-induced autophagic flux and phenotypic switching in human brain VSM cells

Vascular smooth muscle (VSM) cell phenotypic expression and autophagic state are dynamic responses to stress. Vascular pathologies, such as hypoxemia and ischemic injury, induce a synthetic VSM phenotype and autophagic flux resulting in a loss of vascular integrity and VSM cell death respectfully. Both clinical pilot and experimental stroke studies demonstrate that sphingosine-1-phosphate receptor (S1PR) modulation improves stroke outcome; however, specific mechanisms associated with a beneficial outcome at the level of the cerebrovasculature have not been clearly elucidated. We hypothesized that ozanimod, a selective S1PR type 1 ligand, will attenuate VSM synthetic phenotypic expression and autophagic flux in primary human brain VSM cells following acute hypoxia plus glucose deprivation (HGD; in vitro ischemic-like injury) exposure. Cells were treated with ozanimod and exposed to normoxia or HGD. Crystal violet staining, standard immunoblotting, and immunocytochemical labeling techniques assessed cellular morphology, vacuolization, phenotype, and autophagic state. We observed that HGD temporally decreased VSM cell viability and concomitantly increased vacuolization, both of which ozanimod reversed. HGD induced a simultaneous elevation and reduction in levels of pro- and antiautophagic proteins respectfully, and ozanimod attenuated this response. Protein levels of VSM phenotypic biomarkers, smoothelin and SM22, were decreased following HGD. Furthermore, we observed an HGD-induced epithelioid and synthetic morphological appearance accompanied by disorganized cytoskeletal filaments, which was rescued by ozanimod. Thus, we conclude that ozanimod, a selective S1PR₁ ligand, protects against acute HGD-induced phenotypic switching and promotes cell survival, in part, by attenuating HGD-induced autophagic flux thus improving vascular patency in response to acute ischemia-like injury.

Selective sphingosine-1-phosphate receptor 1 modulation ameliorates TBI-induced neurological deficit after CCI

BACKGROUND AND PURPOSE

The inflammatory response after traumatic brain injury (TBI) can contribute to secondary brain injury. RP101075, a sphingosine-1-phosphate receptor modulator, can attenuate various inflammatory responses. Here, we hypothesized that consecutive administration of RP101075 over 3 days could broadly suppress the TBI-induced inflammatory response and ameliorate the outcomes of TBI.

METHODS AND RESULTS

Young C57/BL6 mice were subjected to a controlled cortical impact (CCI) model. RP101075-treated mice exhibited significantly reduced scores on the modified neurological severity score (mNSS) test on days 3, 7, 14, and 21 after TBI, in comparison to TBI mice that received the vehicle. RP101075-treated mice had a remarkably decreased percentage of foot faults on the foot fault test on days 7, 14, and 21 after surgery, in comparison to TBI mice that received the vehicle. Using the wet brain weight/dry brain weight method, we found that RP101075 attenuated brain edema at 3 days post-TBI. According to the results of the Morris water maze (MWM), TBI mice treated with RP101075 exhibited reduced latency time and an increased percentage of target quadrant time from day 24 to day 25 after TBI, in comparison to TBI mice that received the vehicle. In addition, flow cytometry and immunohistochemistry showed that RP101075 markedly decreased the number of infiltrated T cells, B cells and NK cells at 3 days after TBI. Analysis of Western blot data showed that RP101075 lowered the expression of proinflammatory factors on day 3 after TBI.

CONCLUSIONS

Our study demonstrated that consecutive administration of RP101075 over 3 days suppressed the TBI-induced inflammatory response and ameliorated neurological deficits after TBI. Thus, this procedure may be a potential treatment strategy for TBI in the clinical setting.

Sphingosine 1-phosphate Receptor Modulator Therapy for Multiple Sclerosis: Differential Downstream Receptor Signalling and Clinical Profile Effects

Lysophospholipids are a class of bioactive lipid molecules that produce their effects through various G protein-coupled receptors (GPCRs). Sphingosine 1-phosphate (S1P) is perhaps the most studied lysophospholipid and has a role in a wide range of physiological and pathophysiological events, via signalling through five distinct GPCR subtypes, S1PR1 to S1PR5. Previous and continuing investigation of the S1P pathway has led to the approval of three S1PR modulators, fingolimod, siponimod and ozanimod, as medicines for patients with multiple sclerosis (MS), as well as the identification of new S1PR modulators currently in clinical development, including ponesimod and etrasimod. S1PR modulators have complex effects on S1PRs, in some cases acting both as traditional agonists as well as agonists that produce functional antagonism. S1PR subtype specificity influences their downstream effects, including aspects of their benefit:risk profile. Some S1PR modulators are prodrugs, which require metabolic modification such as phosphorylation via sphingosine kinases, resulting in different pharmacokinetics and bioavailability, contrasting with others that are direct modulators of the receptors. The complex interplay of these characteristics dictates the clinical profile of S1PR modulators. This review focuses on the S1P pathway, the characteristics and S1PR binding profiles of S1PR modulators, the mechanisms of action of S1PR modulators with regard to immune cell trafficking and neuroprotection in MS, together with a summary of the clinical effectiveness of the S1PR modulators that are approved or in late-stage development for patients with MS. Sphingosine 1-phosphate receptor modulator therapy for multiple sclerosis: differential downstream receptor signalling and clinical profile effects (MP4 65540 kb).

Long-Term Efficacy and Safety of Ozanimod in Moderately to Severely Active Ulcerative Colitis: Results From the Open-Label Extension of the Randomized, Phase 2 TOUCHSTONE Study

BACKGROUND AND AIMS

This analysis examined the long-term safety and efficacy of ozanimod in patients with moderately to severely active ulcerative colitis [UC] with ≥ 4 years of follow-up in the phase 2 TOUCHSTONE open-label extension [OLE].

METHODS

Patients receiving placebo or ozanimod HCl 0.5 mg or 1 mg during the double-blind period could enter the OLE [ozanimod HCl 1 mg daily]. Partial Mayo score [pMS] clinical response and remission were assessed through OLE week 200 and summarized descriptively using observed cases [OC] and non-responder imputation [NRI]. Endoscopy was required at OLE week 56 and the end of treatment. Parameters associated with endoscopy were summarized at weeks 56 and 104 [OC], and week 56 [NRI]. C-reactive protein and faecal calprotectin were assessed. Adverse events were monitored throughout the study.

RESULTS

Of 197 patients receiving double-blind treatment, 170 entered the OLE. Discontinuation rates were 28% at year 1 and 15-18% annually through year 4. Partial Mayo measures indicated clinical response and remission rates at OLE week 200 of 93.3% and 82.7%, respectively, using OC and 41% and 37% with the more conservative NRI analysis. At weeks 56 and 104, respectively, histological remission rates were 46.3% and 38.5%, and endoscopic improvement rates were 46.4% and 46.5% [OC]. No new safety signals were identified during ≥ 4 years of follow-up.

CONCLUSIONS

There was a high rate of continued study participation and long-term benefit with ozanimod HCl 1 mg daily based on clinical, histological and biomarker measures in patients with moderately to severely active UC in the TOUCHSTONE OLE. [NCT02531126].

Ozanimod: First Approval

Ozanimod (ZEPOSIA^®; Celgene Corporation) is a novel, orally administered sphingosine 1-phosphate (S1P) receptor modulator. In March 2020, the US FDA approved ozanimod capsules for use in the treatment of relapsing forms of multiple sclerosis, to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. In the same month, ozanimod received a positive CHMP opinion recommending approval in the EU for the treatment of adult patients with relapsing-remitting multiple sclerosis with active disease defined by clinical or imaging features. Ozanimod is currently being evaluated for use in ulcerative colitis and Crohn's disease in multinational phase III trials. This article summarizes the milestones in the development of ozanimod leading to its first approval for relapsing forms of multiple sclerosis.

Concentration-QTc Modeling of Ozanimod's Major Active Metabolites in Adult Healthy Subjects

Ozanimod, approved by regulatory agencies in multiple countries for the treatment of adults with relapsing multiple sclerosis, is a sphingosine 1-phosphate (S1P) receptor modulator, which binds with high affinity selectively to S1P receptor subtypes 1 and 5. The relationships between plasma concentrations of ozanimod and its major active metabolites, CC112273 and CC1084037, and the QTc interval (C-QTc) from a phase I multiple-dose study in healthy subjects were analyzed using nonlinear mixed effects modeling. QTc was modeled linearly as the sum of a sex-related fixed effect, baseline, and concentration-related random effects that incorporated interindividual and residual variability. Common linear, power, and maximum effect (E_max ) functions were assessed for characterizing the relationship of QTc with concentrations. Model goodness-of-fit and performance were evaluated by standard diagnostic tools, including a visual predictive check. The placebo-corrected change from baseline in QTc (ΔΔQTc) was estimated based on the developed C-QTc model using a nonparametric bootstrapping approach. QTc was better derived using a study-specific population formula (QTcP). Among the investigated functions, an E_max function most adequately described the relationship of QTcP with concentrations. Separate models for individual analytes characterized the C-QTcP relationship better than combined analytes models. Attributing QT prolongation independently to CC1084037 or CC112273, the upper bound of the 95% confidence interval of the predicted ΔΔQTcP was ~ 4 msec at the plateau of the E_max curves. Therefore, ΔΔQTcP is predicted to remain below 10 msec at the supratherapeutic concentrations of the major active metabolites.

Ozanimod to Treat Relapsing Forms of Multiple Sclerosis: A Comprehensive Review of Disease, Drug Efficacy and Side Effects

Multiple sclerosis (MS) is a prevalent and debilitating neurologic condition characterized by widespread neurodegeneration and the formation of focal demyelinating plaques in the central nervous system. Current therapeutic options are complex and attempt to manage acute relapse, modify disease, and manage symptoms. Such therapies often prove insufficient alone and highlight the need for more targeted MS treatments with reduced systemic side effect profiles. Ozanimod is a novel S1P (sphingosine-1-phosphate) receptor modulator used for the treatment of clinically isolated syndrome, relapsing–remitting, and secondary progressive forms of multiple sclerosis. It selectively modulates S1P1 and S1P5 receptors to prevent autoreactive lymphocytes from entering the CNS where they can promote nerve damage and inflammation. Ozanimod was approved by the US Food and Drug Administration (US FDA) for the management of multiple sclerosis in March 2020 and has been proved to be both effective and well tolerated. Of note, ozanimod is associated with the following complications: increased risk of infections, liver injury, fetal risk, increased blood pressure, respiratory effects, macular edema, and posterior reversible encephalopathy syndrome, among others. Further investigation including head-to-head clinical trials is warranted to evaluate the efficacy of ozanimod compared with other S1P1 receptor modulators.

PK, PD, and interactions: the new scenario with JAK inhibitors and S1P receptor modulators, two classes of small molecule drugs, in IBD

INTRODUCTION

Inflammatory bowel diseases (IBDs) are immune-mediated chronic inflammatory disorders of the gastrointestinal tract whose pathogenesis is not yet fully understood. Despite the advent of biological agents, there are still unmet needs for IBD patients, due to suboptimal rate of sustained remission achieved. Small molecule drugs (SMDs), the next generation of selective drugs in IBD, show promising results in ongoing trials.

AREAS COVERED

We describe the pharmacodynamics and pharmacokinetic features of novel SMDs and their main differences with biologic agents.

EXPERT OPINION

Small molecule drugs are a promising class of drugs for the treatment of ulcerative colitis and Crohn's disease with good results in inducing and maintaining remission. Hence, over the next few years physicians will have numerous options of small molecule drugs for the treatment of patients with IBD. This group of drugs are potentially easier to use over biological agents due to pharmacokinetic features such as oral administration, short half-life, high volume of distribution, and lack of immunogenicity. On the other hand, drug-drug interactions can happen with small-molecule drugs, principally due to competitive metabolic and clearance mechanisms.

Cardiac Autonomic Dysfunction in Multiple Sclerosis: A Systematic Review of Current Knowledge and Impact of Immunotherapies

Cardiac autonomic dysfunction (CAD) has been reported in patients with multiple sclerosis (MS). This systematic review summarizes the evidence for the types and prevalence of CAD in MS patients, as well as its association with MS type, disease characteristics, fatigue and immunotherapies used to treat MS. The analysis revealed that CAD is correlated with pathophysiological processes of MS, can trigger serious cardiovascular complications that may reduce life expectancy, and may have implications for treatment with immunotherapies, especially fingolimod. Numerous mainly small case-control or cohort studies have reported various measures of CAD (particularly heart rate variation) in MS patients, showing higher rates of abnormality versus controls. A smaller number of studies have reported on cardiac autonomic symptoms in MS, including orthostatic intolerance/dizziness in around 50% of patients. CAD also appears to be associated with disease duration and to be more common in progressive than relapsing-remitting MS. However, although a substantial evidence base suggests that assessing CAD in people with MS may be important, standardised methods to evaluate CAD in these patients have not yet been established. In addition, no studies have yet looked at whether treating CAD can reduce the burden of MS symptoms, disease activity or the rate of progression.

Clinical Pharmacology in Adult and Pediatric Inflammatory Bowel Disease

This review describes the clinical pharmacology of the major drugs used for the treatment of patients with inflammatory bowel disease (IBD). Pharmacokinetics, drug metabolism, mechanism of action, efficacy, and safety profile are discussed. Some small molecules were developed to act systemically (eg, ozanimod) or locally (eg, aminosalicylates) and thus have disparate pharmacokinetic properties. In addition, locally acting compounds have been optimized to mitigate systemic exposure-eg, budesonide, which undergoes extensive first-pass metabolism-thereby reducing systemic bioavailability and side effects. Other small molecules such as thiopurines are precursors of their active metabolites and differences in genotype or phenotype of metabolizing enzymes may affect efficacy and safety, requiring therapeutic drug monitoring (TDM). Monoclonal antibodies (MAs) are large molecules administered parenterally, and their pharmacokinetics may be influenced not only by the general immunoglobulin (Ig) G metabolism and recycling pathways but also by antigen properties such as antigen distribution and antigen concentration. In addition, antibody structure, host factors, concurrent medications, and immunogenicity may contribute to the substantial inter- and intrapatient variability in drug exposure and response observed for MAs. Current guidelines recommend reactive TDM of tumor necrosis factor antagonists at the time of loss of response. Evidence for proactive TDM and for the role of TDM for biologics with a different mechanism of action is emerging. Although small molecules offer potential benefits over biologics with oral administration and lack of immunogenicity, there may be risk for more systemic side effects due to off-target binding. Understanding drug metabolism, pharmacokinetic characteristics, and mechanism of action are important in selecting the right drug at the right time at the right dose for patients with IBD.10.1093/ibd/izy189_video1izy189.video15786062223001.

Ozanimod for the treatment of relapsing remitting multiple sclerosis

INTRODUCTION

Ozanimod is a selective sphingosine 1-phosphate receptor 1 and 5 modulator under development by Celgene, for the treatment of relapsing remitting multiple sclerosis. Extensive clinical experience has become available for the related compound fingolimod, favoring the sphingosine 1-phosphate therapeutic concept. Off-target effects have been attributed to its low receptor specificity and have prompted the development of next generation sphingosine 1-phosphate receptor modulators. Areas covered: The authors evaluate the literature of ozanimod, using the PubMed database as well as repositories of the European Committee for Treatment and Research in Multiple Sclerosis and the American and European Academy of Neurology. Specifically, the authors cover and discuss the preclinical data on ozanimod, pharmacokinetics and dynamics, and data on efficacy and safety from the pivotal trials. Expert opinion: Superiority of ozanimod over intramuscular interferon β-1a with regard to reduction in annualized relapse rate and magnetic resonance imaging outcomes has been shown in two phase III trials. The beneficial effect on brain volume and gray matter loss are encouraging and in line with data on other newer immunomodulators. Ozanimod is a valuable contribution to the therapeutic armamentarium in MS, although the effect on disability progression is unclear and requires further investigations.

Drug-induced Proarrhythmia and Torsade de Pointes: A Primer for Students and Practitioners of Medicine and Pharmacy

Multiple marketing withdrawals due to proarrhythmic concerns occurred in the United States, Canada, and the United Kingdom in the late 1980s to early 2000s. This primer reviews the clinical implications of a drug's identified proarrhythmic liability, the issues associated with these safety-related withdrawals, and the actions taken by the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) and by regulatory agencies in terms of changing drug development practices and introducing new nonclinical and clinical tests to asses proarrhythmic liability. ICH Guidelines S7B and E14 were released in 2005. Since then, they have been adopted by many regional regulatory authorities and have guided nonclinical and clinical proarrhythmic cardiac safety assessments during drug development. While this regulatory paradigm has been successful in preventing drugs with unanticipated potential for inducing the rare but potentially fatal polymorphic ventricular arrhythmia torsade de pointes from entering the market, it has led to the termination of drug development programs for other potentially useful medicines because of isolated results from studies with limited predictive value. Research efforts are now exploring alternative approaches to better predict potential proarrhythmic liabilities. For example, in the domain of human electrocardiographic assessments, concentration-response modeling conducted during phase 1 clinical development has recently become an accepted alternate primary methodology to the ICH E14 "thorough QT/QTc" study for defining a drug's corrected QT interval prolongation liability under certain conditions. When a drug's therapeutic benefit is considered important at a public health level but there is also an identified proarrhythmic liability that may result from administration of the single drug in certain individuals and/or drug-drug interactions, marketing approval will be accompanied by appropriate directions in the drug's prescribing information. Health-care professionals in the fields of medicine and pharmacy need to consider the prescribing information in conjunction with individual patients' clinical characteristics and concomitant medications when prescribing and dispensing such drugs.