Oral disease-modifying treatments for multiple sclerosis: the story so far

Investigating drug-induced urinary retention: a pharmacovigilance analysis of FDA adverse event reports from 2004 to 2024

BACKGROUND

Drug-induced urinary retention (DIUR) can severely impact patient quality of life and complicate treatment. This study investigates the incidence and characteristics of DIUR using data from the FDA Adverse Event Reporting System (FAERS) over 20 years.

METHODS

FAERS reports related to urinary retention (UR) from Q1 2004 to Q1 2024 were analyzed. Potential causative drugs were identified, and the top 30 drugs with the most UR reports were ranked. Statistical disproportionality analyses, including Proportional Reporting Ratio (PRR) and Reporting Odds Ratio (ROR), were conducted to detect significant safety signals.

RESULTS

Out of 17,703,515 reports in the FAERS database 28,423 cases of UR were identified. Anticholinergics, antidepressants, and opioids were the most frequently implicated drug classes. The highest ROR and PRR values were observed for drugs like ezogabine. Additionally, less commonly associated drugs, such as adalimumab and others, were implicated, suggesting potential under-recognition of this adverse effect. However, these associations should be interpreted with caution, as they do not confirm a direct causal relationship.

CONCLUSION

This study underscores the importance of pharmacovigilance in identifying and understanding DIUR. Further research is needed to confirm these findings and develop strategies to manage and reduce the risk, improving patient outcomes.

Lossen rearrangement by Rh(III)-catalyzed C-H activation/annulation of aryl hydroxamates with alkynes: access to quinolone-containing amino acid derivatives

A convenient and robust method for the preparation of new CF₃-containing 2-quinolones has been developed via a Rh(III)-catalyzed C-H activation/Lossen rearrangement/annulation cascade of N-pivaloyloxy-arylamides with internal alkynes bearing an α-CF₃-α-amino acid moiety on the triple bond. This work expands the scope of valuable products that are available through C-H activation/annulation reactions of arylamides in organic synthesis.

Minocycline for the management of multiple sclerosis: repositioning potential, opportunities, and challenges

INTRODUCTION

Multiple sclerosis (MS) is a chronic demyelinating inflammatory disorder with variable clinical and pathologic characteristics reflecting multiple underlying pathophysiologic mechanisms. Repositioning of existing drugs for the new indications offers several advantages including significant reduction in the cost and time of drug development and exemption from early phase clinical trials. Minocycline has been reported to exhibit immunomodulation in several pre-clinical and clinical studies through suppression of migratory inflammatory cells, modulation of peripheral immune response, and inhibition of microglial activation within the CNS.

AREAS COVERED

Here, the authors review the repositioning potential of minocycline for the treatment of MS along with appraisal of the evidence obtained from preclinical and clinical research. The authors also discuss the advantages and potential safety concerns related to the use of minocycline for the management of MS.

EXPERT OPINION

Minocycline offers several distinct advantages in terms of well-known safety profile, lower cost of therapy, widespread availability, and being available as an oral formulation. The authors call upon the public and private funders to facilitate well designed and adequately powered randomized clinical trials that can provide conclusive evidence regarding the safety and efficacy of minocycline in patients with MS.

Synthesis of 3-substituted quinolin-2(1H)-ones via the cyclization of o-alkynylisocyanobenzenes

A facile synthesis of various functionalized 3-substituted quinolin-2(1H)-ones through Ag(i) nitrate-catalyzed cyclization of o-alkynylisocyanobenzenes is described. The reaction allows rapid and convenient access to 3-substituted quinolin-2(1H)-one scaffolds in moderate to good yields.

Synthesis of 1,2-dihydro-2-oxo-4-quinolinyl phosphates from 2-acyl-benzoic acids

We report a facile synthesis of 1,2-dihydro-2-oxo-4-quinolinyl phosphates (1a-l) starting from 2-acyl-benzoic acids (2a-l) in the presence of phosphoryl azides via a one-pot cascade reaction involving a Curtius rearrangement, an intramolecular nucleophilic addition of the enol carbon to the isocyanate intermediate, and an addition-elimination of the enol oxygen to the phosphoryl azide. During the reaction three new bonds are formed under mild conditions to yield 1,2-dihydro-2-oxo-4-quinolinyl phosphates in modest yields.

Solid-phase synthesis of quinolinone library

Quinolinones have various biological activities, including antibacterial, anticancer, and antiviral properties. The 3-substituted amide quinolin-2(1H)-ones not only show antibacterial activity, but also act as immunomodulators, 5-HT4 receptor agonists, cannabinoid receptor inverse agonists, and AchE and, BuchE inhibitors. To investigate the potent biological activity of 3-substituted amide quinolin-2(1H)-ones, a large number of 3,5-amide substituted-2-oxoquinolinones were prepared by parallel solid-phase synthesis. The compound 5-amino-1-(4-methoxybenzyl)-2-oxo-1,2-dihydroquinoline-3-carboxylic acid was loaded onto 4-formyl-3,5-dimethoxyphenoxy (PL-FDMP) resin by reductive amination with high efficiency. Various building blocks were attached to the 3 and 5 positions to yield 3,5-disubstituted-2-oxoquinolinones with high purity and good yield. The ability some of these compound to inhibit the release of IL-1β, a cytokine involved in the immune response was measured, and they showed about 50% inhibition at 10 μM.

Effects of Panax ginseng in Neurodegenerative Diseases

Ginseng, the root of the Panax ginseng, has been a popular and widely-used traditional herbal medicine in Korea, China, and Japan for thousands of years. Now it has become popular as a functional health food and is used globally as a natural medicine. Evidence is accumulating in the literature on the physiological and pharmacological effects of P. ginseng on neurodegenerative diseases. Possible ginseng- or ginsenosides-mediated neuroprotective mechanisms mainly involve maintaining homeostasis, and anti-inflammatory, anti-oxidant, anti-apoptotic, and immune-stimulatory activities. This review considers publications dealing with the various actions of P. ginseng that are indicative of possible neurotherapeutic efficacies in neurodegenerative diseases and neurological disorders such as Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, and amyotrophic lateral sclerosis and multiple sclerosis.

Fingolimod: a review of its use in the management of relapsing-remitting multiple sclerosis

Oral fingolimod (Gilenya™), a sphingosine 1-phosphate (S1P) receptor agonist, is the first oral agent and the first in a novel class of disease-modifying therapies (DMTs) to be approved for use in the US for the treatment of relapsing forms of multiple sclerosis (MS). In the EU, fingolimod is approved for use as a single-agent DMT in selected patients with highly-active, relapsing-remitting (RR) MS. This article reviews the pharmacological properties and clinical use of the drug in patients with RRMS. Fingolimod is rapidly converted in vivo to the active moiety S-fingolimod-phosphate, which binds with high affinity to S1P receptors, thereby sequestering lymphocytes in the lymph nodes and preventing their egress into the peripheral circulation. As a consequence, there is a reduction in the infiltration of autoaggressive lymphocytes into the CNS. Fingolimod-phosphate also acts as a functional antagonist, as its binding to S1P receptors results in their internalization and degradation, thereby downregulating S1P receptors on the lymphocyte cell surface. Since fingolimod crosses the blood : brain barrier, it also potentially acts at S1P receptors on neural cells in the CNS to mitigate neuropathological processes associated with MS. In large multinational trials in adult patients with RRMS, oral fingolimod 0.5 mg/day was more effective than oral placebo (FREEDOMS) and recommended dosages of intramuscular interferon-β (IFNβ)-1a (TRANSFORMS) in reducing the annualized relapse rate and was also generally more effective at slowing progression of neurological disability and at reducing the burden and activity of disease. Fingolimod was generally well tolerated in these trials of up to 2 years' duration, with most adverse events being manageable and of mild to moderate severity; there were two deaths from opportunistic infections, albeit these occurred with fingolimod 1.25 mg/day (higher than the recommended dosage). Limited long-term data indicated that no new safety concerns had arisen after 5 years of fingolimod treatment. However, further clinical experience is required to fully determine the long-term safety profile of fingolimod, particularly with regard to any potentially serious or life-threatening adverse events. In the absence of robust pharmacoeconomic studies and of head-to-head trials comparing fingolimod with other formulations of IFNβ and glatiramer acetate, the relative position of fingolimod with respect to other DMTs remains to be fully determined. In the meantime, given its convenient once-daily oral treatment regimen and better efficacy than intramuscular IFNβ-1a, fingolimod is a valuable emerging option for the treatment of adult patients with relapsing forms of MS.

Pathophysiology of multiple sclerosis and the place of teriflunomide

Significant progress in multiple sclerosis (MS) treatment has been made over the last two decades, including the emergence of disease-modifying therapy (DMT). However, substantial unmet medical need persists and has stimulated the search for new therapeutics. Teriflunomide, one of the several oral DMTs under investigation, is a selective inhibitor of de novo pyrimidine synthesis which exerts a cytostatic effect on proliferating T- and B lymphocytes in the periphery and thus has both antiproliferative and anti-inflammatory properties. Anti-inflammatory effects have been demonstrated in rodent MS models, with reductions in macrophage and B- and T-cell infiltration in the central nervous system and preservation of myelin and oligodendrocytes. Delays in disease onset, reductions in disease relapses and improvements in clinical symptoms were also observed. A proof-of-concept clinical trial in patients with relapsing MS demonstrated that teriflunomide significantly reduced magnetic resonance imaging (MRI) activity and improved clinical endpoints, with both effects maintained with longer-term treatment. Additional studies have shown that teriflunomide can be safely added to beta interferon or glatiramer acetate therapy, with some evidence of additional improvements in MRI disease burden and clinical signs. Teriflunomide has an acceptable and manageable safety and tolerability profile. A large clinical programme is underway to further elucidate the role of teriflunomide in the treatment of MS.

Escalating immunotherapy of multiple sclerosis

Basic disease-modifying treatment for relapsing forms of active multiple sclerosis (MS) is now available in many countries with high prevalence rates, for this chronic inflammatory disease of the central nervous system. Several lines of evidence support early immunomodulatory treatment with either recombinant interferon-beta or glatiramer acetate, and positive results from phase III trials encourage start of treatment even in patients with clinically isolated syndromes (CIS). However, currently available drugs for basic therapy are only partially effective and patients may still encounter relapses or disease progression. As treatment-refractory, clinically active MS can quickly lead to irreversible neurological disability there is an urgent need for effective escalating strategies. Patients with suboptimal treatment response to basic therapy have been treated with combination therapies, cytotoxic drugs (such as mitoxantrone and cyclophosphamide) or autologous hematopoietic stem cell transplantation. Recently, the monoclonal antibody, natalizumab, was added to this armamentarium. None of these strategies have been vigorously evaluated in large randomized, controlled phase III trials with patients who failed basic therapy. Therefore, the decision to escalate immunotherapy is still based on limited evidence. This article will review potential candidates for intensified immunosuppression and call for innovative study designs to better evaluate escalating immunotherapy in MS.

Cladribine tablets: in relapsing-remitting multiple sclerosis

Cladribine, an immunosuppressant that selectively reduces peripheral lymphocyte levels, has potential as an oral therapy for relapsing-remitting multiple sclerosis. An oral (tablet) formulation is being investigated in clinical trials. In the large, well designed, phase III CLARITY trial, short-course treatment with oral cladribine (cumulative dose of 3.5 or 5.25 mg/kg) resulted in a significantly greater reduction in annualized relapse rates at 96 weeks compared with placebo in patients with relapsing-remitting multiple sclerosis. Improvements in the annualized relapse rate with oral cladribine were independent of key baseline patient characteristics which included age, sex, previous treatment with disease-modifying drugs and the number of relapses in the previous 12 months. In addition, a significantly higher proportion of patients were relapse-free at 96 weeks and there were significant reductions in the risk of 3-month sustained progression of disability in cladribine recipients compared with placebo recipients. The mean numbers of brain lesions on magnetic resonance imaging were also significantly reduced with cladribine compared with placebo in the CLARITY trial. Lymphocytopenia, herpes zoster infections and neoplasms (including malignancies) were more common in cladribine than placebo recipients.

Animal models of multiple sclerosis--potentials and limitations

Experimental autoimmune encephalomyelitis (EAE) is still the most widely accepted animal model of multiple sclerosis (MS). Different types of EAE have been developed in order to investigate pathogenetic, clinical and therapeutic aspects of the heterogenic human disease. Generally, investigations in EAE are more suitable for the analysis of immunogenetic elements (major histocompatibility complex restriction and candidate risk genes) and for the study of histopathological features (inflammation, demyelination and degeneration) of the disease than for screening of new treatments. Recent studies in new EAE models, especially in transgenic ones, have in connection with new analytical techniques such as microarray assays provided a deeper insight into the pathogenic cellular and molecular mechanisms of EAE and potentially of MS. For example, it was possible to better delineate the role of soluble pro-inflammatory (tumor necrosis factor-α, interferon-γ and interleukins 1, 12 and 23), anti-inflammatory (transforming growth factor-β and interleukins 4, 10, 27 and 35) and neurotrophic factors (ciliary neurotrophic factor and brain-derived neurotrophic factor). Also, the regulatory and effector functions of distinct immune cell subpopulations such as CD4+ Th1, Th2, Th3 and Th17 cells, CD4+FoxP3+ Treg cells, CD8+ Tc1 and Tc2, B cells and γδ+ T cells have been disclosed in more detail. The new insights may help to identify novel targets for the treatment of MS. However, translation of the experimental results into the clinical practice requires prudence and great caution.

Identification of targets and new developments in the treatment of multiple sclerosis--focus on cladribine

Orally available disease-modifying drugs for relapsing-remitting multiple sclerosis (MS) represent an unmet need for this chronic and debilitating disease. Among 5 currently investigated drugs at phase 3 clinical stage, promising efficacy data for fingolimod and oral cladribine have recently been published. However, benefits need to be weighed against the risks to define the role of these compounds within current treatment regimens. In this review, data on the efficacy of a promising compound, oral cladribine, are discussed and balanced with known and anticipated risks in a postmarketing era, and finally gives an outlook on the potential place of this drug in treatment algorithms for MS in the future.

Immunotherapy of multiple sclerosis

Multiple sclerosis (MS) is regarded as a prototypic inflammatory autoimmune central nervous system disorder causing neurological disability in young adults. Recommended basic immunomodulatory therapies of MS are currently interferon beta and glatiramer acetate. Both have proven to be clinically and paraclinically effective and clinical evidence suggests that treatment should be initiated as early as possible. However, despite the fact that therapeutic options for MS have significantly been widened over the past decade there is still tremendous activity in the search for new treatment options for MS. One important development in the field is reflected by the substantial number of promising results for oral therapies. Various phase III clinical trials are currently being initiated or are already underway evaluating the efficacy of a variety of orally administered agents, including cladribine, teriflunomide, laquinimod, fingolimod and fumaric acid. It is hoped that these oral therapies for MS further broaden our armament for MS therapy.

Animal models of multiple sclerosis for the development and validation of novel therapies - potential and limitations

Various types of experimental autoimmune encephalomyelitis (EAE) reflect some of the pathogenetic, clinical, and therapeutic features of the different forms of multiple sclerosis (MS), thereby, providing some, albeit limited, insight into the molecular and cellular basis of the human disease. Specific questions of MS therapy including the search for new therapeutic targets and strategies and their validation require investigations in different available EAE models. A survey is given of experimental therapeutic approaches that are currently under study with the most promising examples of monoclonal antibodies, gene therapy, stem cell transplantation and orally applied small molecular weight disease-modifying drugs. Reasons for therapy failure and adverse side-effects of some experimental trials are discussed. Precaution is advised, if results of new experimental approaches are translated into clinical practice.

Teriflunomide reduces behavioral, electrophysiological, and histopathological deficits in the Dark Agouti rat model of experimental autoimmune encephalomyelitis

Teriflunomide is an orally available anti-inflammatory drug that prevents T and B cell proliferation and function by inhibition of dihydroorotate dehydrogenase. It is currently being developed for the treatment of multiple sclerosis (MS). We report here for the first time the anti-inflammatory effects of teriflunomide in the Dark Agouti rat model of experimental autoimmune encephalomyelitis (EAE). Neurological evaluation demonstrated that prophylactic dosing of teriflunomide at 3 and 10 mg/kg delayed disease onset and reduced maximal and cumulative scores. Therapeutic administration of teriflunomide at doses of 3 or 10 mg/kg at disease onset significantly reduced maximal and cumulative disease scores as compared to vehicle treated rats. Dosing teriflunomide at disease remission, at 3 and 10 mg/kg, reduced the cumulative scores for the remaining course of the disease. Teriflunomide at 10 mg/kg significantly reduced inflammation, demyelination, and axonal loss when dosed prophylactically or therapeutically. In electrophysiological somatosensory evoked potential studies, therapeutic administration of teriflunomide, at the onset of disease, prevented both a decrease in waveform amplitude and an increase in the latency to waveform initiation in EAE animals compared to vehicle. Therapeutic dosing with teriflunomide at disease remission prevented a decrease in evoked potential amplitude, prevented an increase in latency, and enhanced recovery time within the CNS.

Treating multiple sclerosis with monoclonal antibodies

Therapeutic monoclonal antibodies (mAbs) are potent new tools for a molecular targeted approach to modify the course of multiple sclerosis (MS). Besides natalizumab, which was approved in 2006, three other mAbs (alemtuzumab, rituximab and daclizumab) were successfully tested in Phase II MS trials. In this review, introductory notes on the development and systematic nomenclature of therapeutic mAbs in general, set the stage for a detailed discussion of the four mAbs mentioned. We summarize non-MS indications, expression and function of target antigens, scientific rationales for MS therapy, putative modes of action and pharmacological aspects. Particularly, we provide a critical discussion of clinical MS trials, including protocols and interim analyses of trials currently underway. The natalizumab section pays special attention to the clinical handling of safety issues and the diagnostic use of neutralizing antibodies. We finally develop a scenario for how each of the four mAbs might evolve into the market of MS therapeutics within the coming years.

Emerging oral therapies for multiple sclerosis

BACKGROUND

Current disease-modifying drugs (DMDs) have positively affected the treatment of relapsing-remitting multiple sclerosis (RRMS); however, the requirement for long-term injections imposes a burden on patients and may lead to reduced adherence in some cases. Furthermore, not all patients respond adequately to current DMDs, suggesting that certain patients require different therapeutic approaches. Therefore, alternative MS treatments with less invasive routes of administration and new modes of action are needed to expand the current treatment repertoire, increase patient satisfaction and adherence, and thereby improve efficacy.

DISCUSSION

This review discusses the current unmet need for an orally administered treatment for RRMS, including potential benefits of this route of administration, and implications for improved treatment outcomes. Oral drugs that are currently in Phase II/III clinical development are discussed.