Tocilizumab, a humanized anti-interleukin-6 receptor antibody, for treatment of rheumatoid arthritis

Bone-muscle crosstalk under physiological and pathological conditions

Anatomically connected bones and muscles determine movement of the body. Forces exerted on muscles are then turned to bones to promote osteogenesis. The crosstalk between muscle and bone has been identified as mechanotransduction previously. In addition to the mechanical features, bones and muscles are also secretory organs which interact closely with one another through producing myokines and osteokines. Moreover, besides the mechanical features, other factors, such as nutrition metabolism, physiological rhythm, age, etc., also affect bone-muscle crosstalk. What's more, osteogenesis and myogenesis within motor system occur almost in parallel. Pathologically, defective muscles are always detected in bone associated diseases and induce the osteopenia, inflammation and abnormal bone metabolism, etc., through biomechanical or biochemical coupling. Hence, we summarize the study findings of bone-muscle crosstalk and propose potential strategies to improve the skeletal or muscular symptoms of certain diseases. Altogether, functional improvement of bones or muscles is beneficial to each other within motor system.

Clinical Outcomes among Hospitalized COVID-19 Patients Who Received Baricitinib or Tocilizumab in Addition to Standard of Care

COVID-19 infection is caused by the novel severe acute respiratory syndrome coronavirus 2 (SAR-CoV-2). This novel virus has transformed into different resistant variants (e.g., omicron; delta; alpha; epsilon) since its first emergence in 2019. The National Institutes of Health and Infectious Diseases Society of America guidelines currently recommend adding either baricitinib or tocilizumab to the standard of care for severe COVID-19 treatment. An outcome comparison between baricitinib and tocilizumab is needed to determine which agent is more appropriate and safer in clinical practice when deciding treatment. We aimed to compare mortality and clinical outcomes between tocilizumab and baricitinib in the management of severe COVID-19 infection. A total of 5638 adult patients from 16 acute care hospitals in a large healthcare system in Texas were included in this multicentered retrospective cohort study. The median age of the patients was 56 years and 46.67% of them were female. Severe COVID-19 patients were treated with standard of care and either tocilizumab or baricitinib. The primary outcome of hospital admission mortality rates was found to be higher with tocilizumab (odd ratio (OR) of 1.56; p = 0.001; 95% CI 1.19 to 2.008) compared to that with baricitinib (OR 0.65; p = 0.001; 95% CI 0.50 to 0.84). For one of the secondary outcomes, patients who received tocilizumab were 3.75 times more likely to be admitted to the ICU than those receiving baricitinib (p = 0.001; 95% CI 2.89 to 4.85). Among the 1199 COVID-19 patients who were admitted to the ICU, the ICU length of stay was shorter among patients receiving baricitinib with a mean difference of 4.42 days and a median difference of 2.54 days, compared to those receiving tocilizumab (p < 0.0001; 95% CI -5.97 to -2.62) as another secondary outcome. Our large retrospective observational study showed that baricitinib reduced mortality; the likelihood of ICU admission; and the ICU length of stay compared to tocilizumab in patients with severe COVID-19 infection.

Nonspecific Orbital Inflammation (NSOI): Unraveling the Molecular Pathogenesis, Diagnostic Modalities, and Therapeutic Interventions

Nonspecific orbital inflammation (NSOI), colloquially known as orbital pseudotumor, sometimes presents a diagnostic and therapeutic challenge in ophthalmology. This review aims to dissect NSOI through a molecular lens, offering a comprehensive overview of its pathogenesis, clinical presentation, diagnostic methods, and management strategies. The article delves into the underpinnings of NSOI, examining immunological and environmental factors alongside intricate molecular mechanisms involving signaling pathways, cytokines, and mediators. Special emphasis is placed on emerging molecular discoveries and approaches, highlighting the significance of understanding molecular mechanisms in NSOI for the development of novel diagnostic and therapeutic tools. Various diagnostic modalities are scrutinized for their utility and limitations. Therapeutic interventions encompass medical treatments with corticosteroids and immunomodulatory agents, all discussed in light of current molecular understanding. More importantly, this review offers a novel molecular perspective on NSOI, dissecting its pathogenesis and management with an emphasis on the latest molecular discoveries. It introduces an integrated approach combining advanced molecular diagnostics with current clinical assessments and explores emerging targeted therapies. By synthesizing these facets, the review aims to inform clinicians and researchers alike, paving the way for molecularly informed, precision-based strategies for managing NSOI.

Effect of plant produced Anti-hIL-6 receptor antibody blockade on pSTAT3 expression in human peripheral blood mononuclear cells

As a response to invasion by pathogens, the secretion of interleukin 6 (IL-6) which is a cytokine, activates IL-6/JAKs/STAT3 intracellular signaling via., phosphorylation. Over expression of pSTAT3 induces IL-6 positive feedback loop causing cytokine release syndrome or cytokine storm. Plants have gained momentum as an alternative expression system. Hence, this study aims to produce mAb targeting human IL-6 receptor (hIL-6R) in Nicotiana benthamiana for down regulating its cellular signaling thus, decreasing the expression of pSTAT3. The variable regions of heavy and light chains of anti-hIL-6R mAb were constructed in pBYK2e geminiviral plant expression vector and transiently co-expressed in N. benthamiana. The results demonstrate the proper protein assembly of anti-hIL-6R mAb with highest expression level of 2.24 mg/g FW at 5 dpi, with a yield of 21.4 µg/g FW after purification. The purity and N-glycosylation of plant produced antibody was analyzed, including its specificity to human IL-6 receptor by ELISA. Additionally, we investigated the effect to pSTAT3 expression in human PBMC's by flow cytometry wherein, the results confirmed lower expression of pSTAT3 with increasing concentrations of plant produced anti-hIL-6R mAb. Although, further in vivo studies are key to unveil the absolute functionality of anti-hIL-6R, we hereby show the potential of the plant platform and its suitability for the production of this therapeutic antibody.

Outcomes and Adverse Effects of Baricitinib Versus Tocilizumab in the Management of Severe COVID-19

OBJECTIVES

The National Institutes of Health and Infectious Diseases Society of America guidelines recommend tocilizumab or baricitinib in the management of severe COVID-19. Despite clinical trials on the individual agents, there are no large-scale studies comparing the two agents to guide the selection of one versus the other. The purpose of this study was to compare the outcomes and adverse effects of baricitinib versus tocilizumab in the management of severe COVID-19.

DESIGN

Retrospective, observational cohort study.

SETTING

Eleven acute care hospitals in a large health system in Georgia.

PATIENTS

Adult patients with severe COVID-19 who received at least one dose of either baricitinib or tocilizumab between June 2021 and October 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was in-hospital mortality. The key secondary outcome was occurrence rate of adverse effects. A total of 956 patients were identified. The median age was 57 years, and 53% were of male sex. The median body mass index was 33.5, and more than 94% of the population was unvaccinated. Propensity score matching by baseline characteristics resulted in a total of 582 patients, 291 in each group. There was no difference in mortality between the two groups; however, the occurrence rate of adverse effects was significantly higher in the tocilizumab group compared with baricitinib: secondary infections (32% vs 22%; p < 0.01); thrombotic events (24% vs 16%; p < 0.01); and acute liver injury (8% vs 3%; p < 0.01).

CONCLUSIONS

Our propensity score-matched, retrospective, observational study in patients hospitalized with severe COVID-19 showed no difference in mortality but significantly fewer adverse effects with baricitinib compared with tocilizumab. Our data suggest that baricitinib may be a better choice when treating patients with severe COVID-19, but additional prospective, randomized trials are needed to help clinicians choose the most optimal drug.

A Computational Model of Cytokine Release Syndrome during CAR T-cell Therapy

Cytokine release syndrome (CRS) is a lethal adverse event in chimeric antigen receptor (CAR) T-cell therapy, hindering this promising therapy for cancers, such as B-cell acute lymphoblastic leukemia (B-ALL). Clinical management of CRS requires a better understanding of its underlying mechanisms. In this study, a computational model of CRS during CAR T-cell therapy is built to depict how the cellular interactions among CAR T-cells, B-ALL cells, and bystander monocytes, as well as the accompanying molecular interactions among various inflammatory cytokines, influence the severity of CRS. The model successfully defines the factors related to severe CRS and studied the effects of immunomodulatory therapy on CRS. The use of the model is also demonstrated as a precision medicine tool to optimize the treatment scheme, including personalized choice of CAR T-cell products and control of switchable CAR T-cell activity, for a more efficient and safer immunotherapy. This new computational oncology model can serve as a precision medicine tool to guide the clinical management of CRS during CAR T cell therapy.

The delicate relation between melanocytes and skin immunity: A game of hide and seek

Melanocytes exhibit a complex and intriguing relationship with the skin immune response, leading to several clinical conditions. In some disorders, inappropriate melanocyte destruction (e.g., vitiligo, halo naevi) is problematic, while in others, immune tolerance should be broken (melanoma). Important parts of the dysregulated pathways have been unraveled in pigment disorders, ranging from upregulated interferon (IFN)-γ signaling to memory T cells, regulatory T cells, and immune checkpoints. Although a network of many factors is involved, targeting key players such as IFN-γ or checkpoint inhibitors (e.g., programmed death-ligand 1 (PD-L1)] can shift the balance and lead to impressive outcomes. In this review, we focus on the immunological mechanisms of the most common inflammatory disorders where the interaction of the immune system with melanocytes plays a crucial role. This can provide new insights into the current state of melanocyte research.

Contributions of Immune Cells and Stromal Cells to the Pathogenesis of Systemic Sclerosis: Recent Insights

Systemic sclerosis (SSc) is a multisystem rheumatic disease characterized by vascular dysfunction, autoimmune abnormalities, and progressive organ fibrosis. A series of studies in SSc patients and fibrotic models suggest that immune cells, fibroblasts, and endothelial cells participate in inflammation and aberrant tissue repair. Furthermore, the growing number of studies on single-cell RNA sequencing (scRNA-seq) technology in SSc elaborate on the transcriptomics and heterogeneities of these cell subsets significantly. In this review, we summarize the current knowledge regarding immune cells and stromal cells in SSc patients and discuss their potential roles in SSc pathogenesis, focusing on recent advances in the new subtypes by scRNA-seq.

Molecular Therapy in Myasthenia Gravis

Myasthenia gravis (MG) is an autoimmune disorder caused by antibodies that act against the myoneural junction. Conventional immunosuppressants such as corticosteroids, azathioprine and mycophenolate are associated with long-term side effects and many patients do not achieve remission and may become refractory. Thus, there is an unmet need for target-specific therapies that act faster, have fewer side effects and lead to stable disease remission. However, many of the novel therapeutic agents being described are not meeting their primary endpoints. We reviewed the current status of novel immunotherapies for MG, their mechanisms of action, along with the side effect profiles. Fast onset of action, sustained disease remission and relatively low frequency of side effects of the new agents are attractive. However, the unknown long-term safety and high cost are precluding factors. Better preclinical studies and more randomized trials are needed before novel agents are routinely employed.

Tocilizumab Induces IL-10-Mediated Immune Tolerance in Invasive Candidiasis

The existence of a hyperinflammatory state has been observed in patients with invasive fungal infections (IFI). It is being postulated whether morbidity from IFI may, in part, be a consequence of an unnecessarily prolonged or exaggerated proinflammatory immune response including interleukin 6 (IL-6) post-infection, in a host with dysregulated or compromised immunity. This, in turn, induces collateral host injury at the tissue and organ level, leading to adverse outcomes. Tocilizumab has become widely used as an immunomodulator in the treatment of inflammatory conditions. Here, we evaluated the use of tocilizumab to curb post-infective inflammatory flare in the setting of an in-vivo mouse model for invasive candidiasis. Following Candida infection, the tocilizumab-treated mice showed improved short-term survival compared with the saline-treated control mice. There was a reduced inflammatory response mounted by the host, coupled with reduced IL-6 but increased IL-10 levels. TNF-α and IFN-γ responses were not affected. Tocilizumab facilitated immune tolerance by selectively inducing IL-10, producing CD8α+ conventional dendritic cells (DCs) and peripheral T-regulatory cells, over CD11b+ conventional DCs and plasmacytoid DCs. We demonstrate here the sequelae from immunomodulatory manipulation and the basis whereby the use of monoclonal antibodies may be further explored in IFI.

Interleukin-6 blockade, a potential adjunct therapy for post-burn hypermetabolism

Severe burns remain a leading cause of death and disability worldwide. Despite advances in patient care, the excessive and uncontrolled hypermetabolic stress response induced by this trauma inevitably affects every organ system causing substantial morbidity and mortality. Recent evidence suggests interleukin-6 (IL-6) is a major culprit underlying post-burn hypermetabolism. Indeed, genetic deletion of IL-6 alleviates various complications associated with poor clinical outcomes including the adverse remodeling of adipose tissue, cachexia and hepatic steatosis. Thus, pharmacological blockade of IL-6 may be a more favorable treatment option to fully restore metabolic function after injury. To test this, we investigated the safety and effectiveness of blocking IL-6 for post-burn hypermetabolism using a validated anti-IL-6 monoclonal antibody (mAb) in our experimental murine model. Here, we show daily anti-IL-6 mAb administration protects against burn-induced weight loss (P < .0001) without any adverse effect on mortality. At the organ level, post-burn treatment with the IL-6 blocker suppressed the thermogenic activation of adipose tissue (P < .01) and its associated wasting (P < .05). The reduction of browning-induced lipolysis (P < .0001) indirectly decreased hepatic lipotoxicity (P < .01) which improved liver dysfunction (P < .05). Importantly, the beneficial effects of this anti-IL-6 agent extended to the skin, reflected by the decrease in excessive collagen deposition (P < .001) and genes involved in pathologic fibrosis and scarring (P < .05). Together, our results indicate that post-burn IL-6 blockade leads to significant improvements in systemic hypermetabolism by inhibiting pathological alterations in key immunometabolic organs. These findings support the therapeutic potential of anti-IL-6 interventions to improve care, quality of life, and survival in burned patients.

Anti-Inflammatory Therapy for Atherosclerosis: Focusing on Cytokines

Atherosclerosis is a well-known global health problem. Despite the high prevalence of the disease, numerous aspects of pathogenesis remain unclear. Subsequently, there are still no cure or adequate preventive measures available. Atherogenesis is now considered a complex interplay between lipid metabolism alterations, oxidative stress, and inflammation. Inflammation in atherogenesis involves cellular elements of both innate (such as macrophages and monocytes) and adaptive immunity (such as B-cells and T-cells), as well as various cytokines cascades. Because inflammation is, in general, a well-investigated therapeutic target, and strategies for controlling inflammation have been successfully used to combat a number of other diseases, inflammation seems to be the preferred target for the treatment of atherosclerosis as well. In this review, we summarized data on targeting the most studied inflammatory molecular targets, CRP, IL-1β, IL-6, IFN-γ, and TNF-α. Studies in animal models have shown the efficacy of anti-inflammatory therapy, while clinical studies revealed the incompetence of existing data, which blocks the development of an effective atheroprotective drug. However, all data on cytokine targeting give evidence that anti-inflammatory therapy can be a part of a complex treatment.

Critical Determinants of Cytokine Storm and Type I Interferon Response in COVID-19 Pathogenesis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), a rapidly evolving pandemic worldwide with at least 68 million COVID-19-positive cases and a mortality rate of about 2.2%, as of 10 December 2020. About 20% of COVID-19 patients exhibit moderate to severe symptoms. Severe COVID-19 manifests as acute respiratory distress syndrome (ARDS) with elevated plasma proinflammatory cytokines, including interleukin 1β (IL-1β), IL-6, tumor necrosis factor α (TNF-α), C-X-C motif chemokine ligand 10 (CXCL10/IP10), macrophage inflammatory protein 1 alpha (MIP-1α), and chemokine (C-C motif) ligand 2 (CCL2), with low levels of interferon type I (IFN-I) in the early stage and elevated levels of IFN-I during the advanced stage of COVID-19. Most of the severe and critically ill COVID-19 patients have had preexisting comorbidities, including hypertension, diabetes, cardiovascular diseases, and respiratory diseases. These conditions are known to perturb the levels of cytokines, chemokines, and angiotensin-converting enzyme 2 (ACE2), an essential receptor involved in SARS-CoV-2 entry into the host cells. ACE2 downregulation during SARS-CoV-2 infection activates the angiotensin II/angiotensin receptor (AT1R)-mediated hypercytokinemia and hyperinflammatory syndrome. However, several SARS-CoV-2 proteins, including open reading frame 3b (ORF3b), ORF6, ORF7, ORF8, and the nucleocapsid (N) protein, can inhibit IFN type I and II (IFN-I and -II) production. Thus, hyperinflammation, in combination with the lack of IFN responses against SARS-CoV-2 early on during infection, makes the patients succumb rapidly to COVID-19. Therefore, therapeutic approaches involving anti-cytokine/anti-cytokine-signaling and IFN therapy would favor the disease prognosis in COVID-19. This review describes critical host and viral factors underpinning the inflammatory "cytokine storm" induction and IFN antagonism during COVID-19 pathogenesis. Therapeutic approaches to reduce hyperinflammation and their limitations are also discussed.

Nanomedicine: A Diagnostic and Therapeutic Approach to COVID-19

The SARS-CoV-2 virus is causing devastating morbidity and mortality worldwide. Nanomedicine approaches have a high potential to enhance conventional diagnostics, drugs and vaccines. In fact, lipid nanoparticle/mRNA vaccines are already widely used to protect from COVID-19. In this review, we present an overview of the taxonomy, structure, variants of concern, epidemiology, pathophysiology and detection methods of SARS-CoV-2. The efforts of repurposing, tailoring, and adapting pre-existing medications to battle COVID-19 and the state of vaccine developments are presented. Next, we discuss the broad concepts and limitations of how nanomedicine could address the COVID-19 threat. Nanomaterials are particles in the nanometer scale (10-100 nm) which possess unique properties related to their size, polarity, structural and chemical composition. Nanoparticles can be composed of precious metals (copper, silver, gold), inorganic materials (graphene, silicon), proteins, carbohydrates, lipids, RNA/DNA, or conjugates, combinations and polymers of all of the aforementioned. The advanced biochemical features of these nanoscale particles allow them to directly interact with virions and irreversibly disrupt their structure, which can render a virus incapable of replicating within the host. Virus-neutralizing coats and surfaces impregnated with nanomaterials can enhance personal protective equipment, hand sanitizers and air filter systems. Nanoparticles can enhance drug-based therapies by optimizing uptake, stability, target cell-specific delivery, and magnetic properties. In fact, recent studies have highlighted the potential of nanoparticles in different aspects of the fight against SARS-CoV-2, such as enhancing biosensors and diagnostic tests, drug therapies, designing new delivery mechanisms, and optimizing vaccines. This article summarizes the ongoing research on diagnostic strategies, treatments, and vaccines for COVID-19, while emphasizing the potential of nanoparticle-based pharmaceuticals and vaccines.

Pharmacokinetics under the COVID-19 storm

AIMS

The storm-like nature of the health crises caused by COVID-19 has led to unconventional clinical trial practices such as the relaxation of exclusion criteria. The question remains: how can we conduct diverse trials without exposing subgroups of populations to potentially harmful drug exposure levels? The aim of this study was to build a knowledge base of the effect of intrinsic/extrinsic factors on the disposition of several repurposed COVID-19 drugs.

METHODS

Physiologically based pharmacokinetic (PBPK) models were used to study the change in the pharmacokinetics (PK) of drugs repurposed for COVID-19 in geriatric patients, different race groups, organ impairment and drug-drug interactions (DDIs) risks. These models were also used to predict epithelial lining fluid (ELF) exposure, which is relevant for COVID-19 patients under elevated cytokine levels.

RESULTS

The simulated PK profiles suggest no dose adjustments are required based on age and race for COVID-19 drugs, but dose adjustments may be warranted for COVID-19 patients also exhibiting hepatic/renal impairment. PBPK model simulations suggest ELF exposure to attain a target concentration was adequate for most drugs, except for hydroxychloroquine, azithromycin, atazanavir and lopinavir/ritonavir.

CONCLUSION

We demonstrate that systematically collated data on absorption, distribution, metabolism and excretion, human PK parameters, DDIs and organ impairment can be used to verify simulated plasma and lung tissue exposure for drugs repurposed for COVID-19, justifying broader patient recruitment criteria. In addition, the PBPK model developed was used to study the effect of age and ethnicity on the PK of repurposed drugs, and to assess the correlation between lung exposure and relevant potency values from in vitro studies for SARS-CoV-2.

Interleukin-6 neutralization ameliorates symptoms in prematurely aged mice

Hutchinson-Gilford progeria syndrome (HGPS) causes premature aging in children, with adipose tissue, skin and bone deterioration, and cardiovascular impairment. In HGPS cells and mouse models, high levels of interleukin-6, an inflammatory cytokine linked to aging processes, have been detected. Here, we show that inhibition of interleukin-6 activity by tocilizumab, a neutralizing antibody raised against interleukin-6 receptors, counteracts progeroid features in both HGPS fibroblasts and Lmna^{G609G / G609G} progeroid mice. Tocilizumab treatment limits the accumulation of progerin, the toxic protein produced in HGPS cells, rescues nuclear envelope and chromatin abnormalities, and attenuates the hyperactivated DNA damage response. In vivo administration of tocilizumab reduces aortic lesions and adipose tissue dystrophy, delays the onset of lipodystrophy and kyphosis, avoids motor impairment, and preserves a good quality of life in progeroid mice. This work identifies tocilizumab as a valuable tool in HGPS therapy and, speculatively, in the treatment of a variety of aging-related disorders.

IL-6/STAT3 and adipokine modulation using tocilizumab in rats with fructose-induced metabolic syndrome

Metabolic syndrome (MetS) is a low-grade inflammation state that results from an interplay between genetic and environmental factors. The incidence of MetS among individuals with insulin resistance, dyslipidemia, elevated blood pressure, and obesity, which constitute the syndrome, is 40% in the Middle East. The absence of an approved therapeutic agent for MetS is one reason to investigate tocilizumab (TCZ), which might be effective in the treatment of MetS. Results have implicated interleukin 6 (IL-6) in the development of MetS, identifying inflammation as a critical factor in its etiology and offering hope for new therapeutic approaches development. Here, we evaluate whether tocilizumab can be used for metabolic syndrome treatment. We assigned rats to three groups, 8 rats each: a negative-control group, provided with standard rodent chow and water; a fructose-fed group, provided with standard rodent chow and 10% fructose in drinking water for 22 weeks; and a treatment group, fed as per the metabolic syndrome group but treated with tocilizumab (5 mg/kg/week, intraperitoneal) for the final 5 weeks. Treatment with TCZ successfully ameliorated the damaging effects of fructose by stabilizing body weight gain and through the normalization of serum biochemical parameters and histopathological examination. Significant differences in adipokine levels were perceived, resulting in a significant decline in serum leptin and interleukin 6 (IL-6) levels concurrent with adiponectin normalization. Tocilizumab might be an effective agent for the treatment of metabolic syndrome. However, further investigations on human subjects are needed before the clinical application of tocilizumab for this indication.

Bi-directional communication: Conversations between fibroblasts and immune cells in systemic sclerosis

Systemic Sclerosis (SSc) is an autoimmune idiopathic connective tissue disease, characterized by aberrant fibro-proliferative and inflammatory responses, causing fibrosis of multiple organs. In recent years the interactions between innate and adaptive immune cells with resident fibroblasts have been uncovered. Cross-talk between immune and stromal cells mediates activation of stromal cells to myofibroblasts; key cells in the pathophysiology of fibrosis. These cells and their cytokines appear to mediate their effects in both a paracrine and autocrine fashion. This review examines the role of innate and adaptive immune cells in SSc, focusing on recent advances that have illuminated our understanding of ongoing bi-directional communication between immune and stromal cells. Finally, we appraise current and future therapies and how these may be useful in a disease that currently has no specific disease modifying treatment.

Model based approach for estimating the dosage regimen of indomethacin a potential antiviral treatment of patients infected with SARS CoV-2

To face SARS-CoV-2 pandemic various attempts are made to identify potential effective treatments by repurposing available drugs. Among them, indomethacin, an anti-inflammatory drug, was shown to have potent in-vitro antiviral properties on human SARS-CoV-1, canine CCoV, and more recently on human SARS-CoV-2 at low micromolar range. Our objective was to show that indomethacin could be considered as a promising candidate for the treatment of SARS-CoV-2 and to provide criteria for comparing benefits of alternative dosage regimens using a model-based approach. A multi-stage model-based approach was developed to characterize % of recovery and viral load in CCoV-infected dogs, to estimate the PK of indomethacin in dog and human using published data after administration of immediate (IR) and sustained-release (SR) formulations, and to estimate the expected antiviral activity as a function of different assumptions on the effective exposure in human. Different dosage regimens were evaluated for IR formulation (25 mg and 50 mg three-times-a-day, and 25 mg four-times-a-day), and SR formulation (75 mg once and twice-a-day). The best performing dosing regimens were: 50 mg three-times-a-day for the IR formulation, and 75 mg twice-a-day for the SR formulation. The treatment with the SR formulation at the dose of 75 mg twice-a-day is expected to achieve a complete response in three days for the treatment in patients infected by the SARS-CoV-2 coronavirus. These results suggest that indomethacin could be considered as a promising candidate for the treatment of SARS-CoV-2 whose potential therapeutic effect need to be further assessed in a prospective clinical trial.

Update on the Pathomechanism, Diagnosis, and Treatment Options for Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that involves multiple joints bilaterally. It is characterized by an inflammation of the tendon (tenosynovitis) resulting in both cartilage destruction and bone erosion. While until the 1990s RA frequently resulted in disability, inability to work, and increased mortality, newer treatment options have made RA a manageable disease. Here, great progress has been made in the development of disease-modifying anti-rheumatic drugs (DMARDs) which target inflammation and thereby prevent further joint damage. The available DMARDs are subdivided into (1) conventional synthetic DMARDs (methotrexate, hydrochloroquine, and sulfadiazine), (2) targeted synthetic DMARDs (pan-JAK- and JAK1/2-inhibitors), and (3) biologic DMARDs (tumor necrosis factor (TNF)-α inhibitors, TNF-receptor (R) inhibitors, IL-6 inhibitors, IL-6R inhibitors, B cell depleting antibodies, and inhibitors of co-stimulatory molecules). While DMARDs have repeatedly demonstrated the potential to greatly improve disease symptoms and prevent disease progression in RA patients, they are associated with considerable side-effects and high financial costs. This review summarizes our current understanding of the underlying pathomechanism, diagnosis of RA, as well as the mode of action, clinical benefits, and side-effects of the currently available DMARDs.

Secukinumab Immunogenicity over 52 Weeks in Patients with Psoriatic Arthritis and Ankylosing Spondylitis

Objective.

Secukinumab, a fully human antiinterleukin 17A monoclonal antibody, is efficacious for the treatment of psoriatic arthritis (PsA) and ankylosing spondylitis (AS). This study examined the immunogenicity of secukinumab in patients with PsA and AS exposed to secukinumab for up to 52 weeks.

Methods.

Antibody bridging assays were used to assess the immunogenicity of secukinumab in patients with PsA [FUTURE 1–3 studies, and AS (MEASURE 1–4 studies)]. Evaluations were at baseline and at weeks 16 (AS only), 24, and 52. Treatment-emergent antidrug antibodies (TE-ADA) were defined as a positive ADA signal in ≥ 1 posttreatment sample in patients negative at baseline. Positive samples were analyzed for drug-neutralizing potential, and effect of TE-ADA on secukinumab pharmacokinetics, immunogenicity-related adverse events (AE), and efficacy through Week 52 were assessed.

Results.

Of 1414 treated PsA and 1164 treated AS patients with samples available for immunogenicity evaluation, 5 (0.35%) and 8 (0.69%), respectively, developed TE-ADA. All but 1 PsA patient were biologic-naive; two of the 5 PsA and one of the 8 AS patients received concomitant methotrexate, and two of the 8 AS patients received concomitant sulfasalazine. Associations between TE-ADA and secukinumab dose, frequency, or administration mode were not observed. Other than one PsA patient, all TE-ADA were non-neutralizing. No TE-ADA were associated with any AE. All TE-ADA were associated with normal secukinumab pharmacokinetics and none were associated with loss of secukinumab efficacy.

Conclusion.

Secukinumab treatment was associated with a low (< 1%) incidence of immunogenicity in patients with PsA or AS. (clinicaltrials.gov: NCT01392326; NCT01752634; NCT01989468; NCT01358175; NCT01649375; NCT02008916; NCT02159053)

An Overview of VPAC Receptors in Rheumatoid Arthritis: Biological Role and Clinical Significance

The axis comprised by the Vasoactive Intestinal Peptide (VIP) and its G protein-coupled receptors (GPCRs), VPAC1, and VPAC2, belong to the B1 family and signal through Gs or Gq proteins. VPAC receptors seem to preferentially interact with Gs in inflammatory cells, rather than Gq, thereby stimulating adenylate cyclase activity. cAMP is able to trigger various downstream pathways, mainly the canonical PKA pathway and the non-canonical cAMP-activated guanine nucleotide exchange factor (EPAC) pathway. Classically, the presence of VPACs has been confined to the plasma membrane; however, VPAC1 location has been described in the nuclear membrane in several cell types such as activated Th cells, where they are also functional. VPAC receptor signaling modulates a number of biological processes by tipping the balance of inflammatory mediators in macrophages and other innate immune cells, modifying the expression of TLRs, and inhibiting MMPs and the expression of adhesion molecules. Receptor signaling also downregulates coagulation factors and acute-phase proteins, promotes Th2 over Th1, stimulates Treg abundance, and finally inhibits a pathogenic Th17 profile. Thus, the VIP axis signaling regulates both the innate and adaptive immune responses in several inflammatory/autoimmune diseases. Rheumatoid arthritis (RA) is a complex autoimmune disease that develops on a substrate of genetically susceptible individuals and under the influence of environmental factors, as well as epigenetic mechanisms. It is a heterogeneous disease with different pathogenic mechanisms and variable clinical forms between patients with the same diagnosis. The knowledge of VIP signaling generated in both animal models and human ex vivo studies can potentially be translated to clinical reality. Most recently, the beneficial effects of nanoparticles of VIP self-associated with sterically stabilized micelles have been reported in a murine model of RA. Another novel research area is beginning to define the receptors as biomarkers in RA, with their expression levels shown to be associated with the activity of the disease and patients-reported impairment. Therefore, VPAC expression together VIP genetic variants could allow patients to be stratified at the beginning of the disease with the purpose of guiding personalized treatment decisions.

Intravenous tocilizumab: a review of its use in adults with rheumatoid arthritis

Tocilizumab (Actemra®, RoActemra®) is a humanized monoclonal antibody that acts as an interleukin-6 receptor antagonist. Intravenous tocilizumab as monotherapy or in combination with disease-modifying anti-rheumatic drugs (DMARDs) is indicated for the treatment of adult patients with moderate to severe active rheumatoid arthritis (RA) who had an inadequate response to one or more DMARDs or tumor necrosis factor (TNF) α antagonists (the specific indication varies between countries); it may also be used as monotherapy in patients for whom continued methotrexate use is inappropriate. This article reviews the efficacy and tolerability of tocilizumab in these patients and briefly summarizes its pharmacology. Several large well-designed clinical trials and routine clinical practice studies showed that tocilizumab was an effective and generally well tolerated biologic for the treatment of adults with RA, including those with an inadequate response to DMARDs or TNFα antagonists. In these studies, tocilizumab as monotherapy or in combination with DMARDs (including methotrexate) had beneficial effects on the signs and symptoms of disease, health-related quality of life/physical function, and/or radiologic disease progression. In addition, tocilizumab monotherapy was more effective than adalimumab monotherapy in improving the signs and symptoms of disease in patients for whom continued methotrexate use was inappropriate. As with other biologic DMARDS, infections were the most common adverse event associated with tocilizumab therapy. Pooled and meta-analyses demonstrated that the efficacy and tolerability profile of tocilizumab was sustained during long-term (up to 9 years) therapy. Although additional comparative data are needed to position tocilizumab more definitively with respect to other biologic DMARDs, current evidence indicates that tocilizumab is effective as a first- or subsequent-line biologic in patients with moderate to severe RA.