Evaluation of ustekinumab trough levels during induction and maintenance therapy with regard to disease activity status in difficult to treat Crohn disease patients

Ustekinumab (UST) is approved for the treatment of moderate and severe Crohn disease (CD). Therapeutic drug monitoring (TDM) can help monitor the therapeutic effects of biologics. Therefore, the aim of this study was to evaluate the clinical outcomes of UST-treated CD patients and to determine the UST trough level in clinical and corticosteroid-free remission.This retrospective study included patients with moderate and severe active disease (AD) treated intravenously with a weight-adapted induction dose of UST. The maintenance therapy consisted of 90 mg UST subcutaneously at week 8 and thereafter every 8 or 12 weeks, depending on the clinical response. Clinical and corticosteroid-free remission, Harvey-Bradshaw-Index (HBI), UST trough level, and further laboratory parameters were measured just before the injection of UST at each follow-up evaluation until week 40.37 CD patients with a median HBI of 9 at week 0 were included in the study. Starting from 24% at the beginning of the monitoring period, and 38% of patients at the end of the monitoring period were treated with an 8-week interval (P = .18). There was a significant improvement in clinical (P = .0004), corticosteroid-free remission (P = .03), and HBI (P < .0001) from week 0 until the end of the observation period. The serum UST trough level decreased significantly from 2.0 at week 8 to 0.3, in the maintenance therapy and 0.4 μg/ml at the end of the therapy (P < .0001). Neither UST trough level nor levels of C-reactive protein (CRP) or fecal calprotectin (FC) were associated with disease outcome. Concomitant immunomodulator therapy did not appear to affect the UST trough level or clinical course.UST is an effective treatment option for difficult-to-treat patients with CD. UST trough levels may not be associated with treatment efficacy or the prediction of treatment outcomes in patients with CD. Further prospective randomized trials should be conducted to evaluate whether UST trough levels are associated with treatment outcomes in patients with CD.

Suppression of Serum Interferon-γ Levels as a Potential Measure of Response to Ustekinumab Treatment in Patients With Systemic Lupus Erythematosus

OBJECTIVE

In a previously reported phase II randomized, placebo-controlled, interventional trial, we demonstrated that treatment with ustekinumab, an anti-interleukin-12 (IL-12)/IL-23 p40 neutralizing monoclonal antibody, improved global and organ-specific measures of disease activity in patients with active systemic lupus erythematosus (SLE). Utilizing the biomarker data from this phase II clinical study, we sought to determine whether modulation of the expression of IL-12, IL-23, or both cytokines by ustekinumab is associated with clinical efficacy in patients with SLE.

METHODS

This phase II randomized, placebo-controlled study enrolled 102 patients with autoantibody-positive SLE whose disease remained active despite standard-of-care therapy. Patients were randomized at a 3:2 ratio to receive ~6 mg/kg ustekinumab intravenously or placebo at week 0, followed by subcutaneous injections of 90 mg ustekinumab or placebo every 8 weeks, with placebo crossover to 90 mg ustekinumab every 8 weeks. The SLE Responder Index 4 (SRI-4) at week 24 was used to determine which patients could be classified as ustekinumab responders and which could be classified as nonresponders. In addition to measurements of p40 and IL-23, serum levels of interferon-γ (IFNγ), IL-17A, IL-17F, and IL-22, as a proxy for the IL-12 and IL-23 pathways, were quantified by immunoassay.

RESULTS

Changes in the serum levels of IL-17A, IL-17F, and IL-22 at different time points after treatment were not consistently significantly associated with an SRI-4 clinical response to ustekinumab in patients with SLE. In contrast, an SRI-4 response to ustekinumab was significantly associated (P < 0.01) with durable reductions in the serum IFNγ protein levels at several time points relative to baseline, which was not observed in ustekinumab nonresponders or patients who received placebo.

CONCLUSION

While not diminishing a potential role of IL-23, these serum biomarker assessments indicate that IL-12 blockade has an important role in the mechanism of action of ustekinumab treatment in patients with SLE.

[Inhibitory effect of bispecific antibody targeting IL-12 p40 and TNF-α simultaneously on psoriasis in mice]

Objective To construct bispecific antibodies, which can block interleukin 12 (IL-12)/IL-23 p40 subunit and tumor necrosis factor α (TNF-α) simultaneously, and identify their biological function and inhibitory effect on psoriasis formation in mice. Methods Based on the sequences of adalimumab and ustekinumab, three kinds of bispecific antibodies were designed, named BiAU003, BiAU022 and BiAU023. The specificity and binding capacity of bispecific antibodies were determined by ELISA. After co-treated with bispecific antibodies and TNF-α, the level of endothelial leukocyte adhesion molecule-1 (ELMA-1) labeled with fluorescein isothiocyanate (FITC) in human umbilical vein endothelial cells (HUVECs) were examined by flow cytometry. Human peripheral blood mononuclear cells (PBMCs) were purified and cultured in the medium containing IL-2 and IL-12 in the absence or presence of bispecific antibodies. Commercial ELISA kit was used to detect interferon γ (IFN-γ) concentration in the supernatant. BALB/c mice were used for psoriasis model construction through injection of IL-12 and TNF-α subcutaneously. Then they were treated with the bispecific antibodies. Psoriasic skin was measured in thickness and scale under microscopy after H&E staining. Results The three kinds of bispecific antibodies could specifically recognize IL-12/23 p40 and TNF-α protein, and inhibit IFN-γ secretion and the expression of ELAM-1 protein. Data also indicated that bispecific antibodies inhibited the formation of psoriasic skin, and showed an equal or superior effect to control antibody drug. Conclusion The novel bispecific antibodies, BiAU003, BiAU022 and BiAU023, can serve as an antagonist of TNF-α and IL-12/23 p40, and have a blocking effect on mouse psoriasis formation.

Antibodies in the Treatment of Psoriasis: IL-12/23 p40 and IL-17a

The anti-tumor necrosis factor (TNF)-α agents represent the second generation of psoriasis therapy. Research has produced a third generation of biologic treatments, some of which offer greater efficacy than the TNF-α inhibitors. This article reviews the data documenting the efficacy and safety of three types of biologics.

In the pipeline for psoriasis: upcoming psoriasis treatments

Psoriasis is a chronic debilitating disease in which dermatologists take a frontline role in improving the quality of life of affected patients. Although recent years have seen the advent of numerous new medications for the treatment of psoriasis, there still is considerable room for improvement in our treatment of this condition. Novel insights into the underlying mechanisms of psoriasis have yielded exciting new potential medications, many with promising preliminary efficacy data. The upcoming systemic agents for the treatment of psoriasis are presented in this article, encompassing novel biologics and small-molecule medicines (eg, IL-17 receptor blockers, Janus kinase [Jak] inhibitors). The underlying mechanisms and currently available data for each drug will be discussed to impart a working knowledge of these new treatment options to dermatology residents, as these drugs may soon be added to our armamentarium for treating psoriasis.

Diarylheptanoids and flavonoids from viscum album inhibit LPS-stimulated production of pro-inflammatory cytokines in bone marrow-derived dendritic cells

Three new diarylheptanoids, (3S,5R)-3-hydroxy-5-methoxy-1,7-bis(4-hydroxyphenyl)-6E-heptene (1), (3S,5S)-3-hydroxy-5-methoxy-1,7-bis(4-hydroxyphenyl)-6E-heptene (2), and (3S)-3-hydroxy-1,7-bis(4-hydroxyphenyl)-6E-hepten-5-one (3), four new flavonoid glycosides, 3,7,3'-tri-O-methylquercetin-4'-O-β-d-apiofuranosyl-(1→2)-O-β-d-glucopyranoside (4), 7,3'-di-O-methylquercetin-4'-O-β-d-glucopyranosyl-3-O-[6‴-(3-hydroxy-3-methylglutaroyl)]-α-d-glucopyranoside (5), 7,3'-di-O-methylquercetin-4'-O-β-d-glucopyranosyl-3-O-[(6'''''→5'''')-O-1'''''-(sinap-4-yl)-β-d-glucopyranosyl-6‴-(3-hydroxy-3-methylglutaroyl)]-α-d-glucopyranoside (6), and (2S)-5-hydroxy-7,3'-dimethoxyflavanone-4'-O-β-d-apiofuranosyl-(1→5)-O-β-d-apiofuranosyl-(1→2)-O-β-d-glucopyranoside (9), and 17 known compounds were isolated from the leaves and twigs of Viscum album. Compounds 1, 4, and 19 significantly inhibited LPS-stimulated production of TNF-α, IL-6, and IL-12p40 with IC50 values ranging from 0.09 ± 0.01 to 8.96 ± 0.45 μM. (+)-Medioresinol (13) showed inhibitory effects on LPS-stimulated production of IL-12p40 with an IC50 value of 2.00 ± 0.15 μM.

Psoriasis and cardiovascular disorders

There is considerable evidence to show that patients with moderate-to-severe psoriasis have a significantly increased risk of cardiovascular disease and cardiovascular risk factors such as obesity, diabetes mellitus, the metabolic syndrome and smoking compared to the general population. The mechanistic link between psoriasis and this observed increase in cardiovascular co-morbidities has not been fully defined. It is clear, however, that common inflammatory pathways are at play in the pathophysiology of psoriasis, obesity and coronary artery disease. It had been proposed that the control of systemic inflammation in psoriasis could help reduce cardiovascular morbidity, and retrospective studies of methotrexate and anti-TNF-a agents have suggested a cardio-protective effect with use of these agents. More recently, however, there have been concerns regarding a potential excess of cardiovascular events with the newer generation of anti-interleukin-12p40 antibodies. In this article we review the association of psoriasis with cardiovascular disorders and the effects of current psoriasis therapies on cardiovascular risk.

Psoriasis and cardiovascular comorbidities with emphasis in Asia

Psoriasis is traditionally considered a skin-specific disease with the exception of coexisting psoriatic arthritis. However, growing evidence suggests a link between psoriasis and other comorbidities. Cardiovascular comorbidity, in particular, is the focus of considerable research, due in part to the associated mortality and possible intervention. A common mechanism that may explain both psoriasis and atherosclerosis pathogenesis is of great interest and utility. The increase of Th1 and Th17 leading to chronic inflammation is thought to be a patho-denominator for both diseases. In addition, progressive adiposity and resultant metabolic syndrome are but the beginning steps in the "psoriatic march". In this article, we review the recent publications on cardiovascular risks in patients with psoriasis. We also examine the effects of psoriasis treatment, including the new biologics, on cardiovascular comorbidities. Although there is generally a lack of Asian research on this issue, we present the most recent pertinent findings from Taiwan.

IL-22 is required for Th17 cell-mediated pathology in a mouse model of psoriasis-like skin inflammation

Psoriasis is a chronic skin disease resulting from the dysregulated interplay between keratinocytes and infiltrating immune cells. We report on a psoriasis-like disease model, which is induced by the transfer of CD4(+)CD45RB(hi)CD25(-) cells to pathogen-free scid/scid mice. Psoriasis-like lesions had elevated levels of antimicrobial peptide and proinflammatory cytokine mRNA. Also, similar to psoriasis, disease progression in this model was dependent on the p40 common to IL-12 and IL-23. To investigate the role of IL-22, a Th17 cytokine, in disease progression, mice were treated with IL-22-neutralizing antibodies. Neutralization of IL-22 prevented the development of disease, reducing acanthosis (thickening of the skin), inflammatory infiltrates, and expression of Th17 cytokines. Direct administration of IL-22 into the skin of normal mice induced both antimicrobial peptide and proinflammatory cytokine gene expression. Our data suggest that IL-22, which acts on keratinocytes and other nonhematopoietic cells, is required for development of the autoreactive Th17 cell-dependent disease in this model of skin inflammation. We propose that IL-22 antagonism might be a promising therapy for the treatment of human psoriasis.

Dectin-1 interaction with Mycobacterium tuberculosis leads to enhanced IL-12p40 production by splenic dendritic cells

Dectin-1 is a fungal pattern recognition receptor that binds to beta-glucans and triggers cytokine production by facilitating interaction with TLR2 or by directly activating spleen tyrosine kinase (Syk). To assess the possible role of Dectin-1 in the innate response to mycobacteria, we used an in vitro system in which IL-12p40 production is measured in splenic dendritic cells (SpDC) following exposure to live Mycobacterium tuberculosis bacilli. Treatment of SpDC with laminarin or glucan phosphate, two molecules known to block Dectin-1-dependent activity, led to a reduction in M. tuberculosis-induced IL-12p40 as well as IL-12p70 production. Moreover, SpDC from Dectin-1-/- chimeric mice displayed reduced IL-12p40 production in response to mycobacteria when compared with Dectin-sufficient DC. Laminarin treatment also inhibited mycobacterial-induced IL-12p40 production in DC from TLR2-/- mice, arguing that Dectin-1 functions independently of TLR2 signaling in this system. Importantly, a Dectin-1 fusion protein was found to directly bind to live mycobacteria in a laminarin-inhibitable manner indicating the presence of ligands for the receptor in the bacterium and laminarin pretreatment resulted in reduced association of mycobacteria to SpDC. In additional experiments, mycobacterial stimulation was shown to be associated with increased phosphorylation of Syk and this response was inhibited by laminarin. Furthermore, pharmacologic inhibition of Syk reduced the M. tuberculosis-induced IL-12p40 response. Together, these findings support a role for Dectin-1 in promoting M. tuberculosis-induced IL-12p40 production by DC in which the receptor augments bacterial-host cell interaction and enhances the subsequent cytokine response through an unknown mechanism involving Syk signaling.

Neonatal B cells suppress innate toll-like receptor immune responses and modulate alloimmunity

It has been known for decades that neonates are susceptible to transplant tolerance, but the immunological mechanisms involved remain to be fully elucidated. Recent evidence indicates that the maturation state of DCs responding to an allograft may have a profound impact on whether immunity or tolerance ensues. Given that TLR activation is a key process leading to DC maturation, we hypothesized that DCs from neonates have defective TLR immune responses. Contrary to our hypothesis, we found that murine neonatal DCs demonstrated enhanced TLR responses in comparison to adult counterparts in vitro. However, we found that neonatal B cells possess unique immunoregulatory functions as they impaired DC responses to TLR activation in an IL-10-dependent fashion. Functionally, we demonstrated that TLR-activated neonatal, but not adult, B cells impaired Th1, but not Th2, T cell alloimmune responses in vitro and in vivo, in models of alloimmune priming and allotransplantation. We conclude that neonatal B cells possess unique immunoregulatory properties that inhibit DC function and modulate alloimmunity in our murine experimental systems.

Negative Regulation of TLR-Signaling Pathways by Activating Transcription Factor-3

Activating transcription factor-3 (ATF3) is rapidly induced by LPS in mouse macrophages and regulates TLR4 responses. We show that ATF3 is rapidly induced by various TLRs in mouse macrophages and plasmacytoid dendritic cells (DCs), as well as plasmacytoid and myeloid subsets of human DCs. In primary macrophages from mice with a targeted deletion of the atf3 gene (ATF3-knockout (KO)), TLR-stimulated levels of IL-12 and IL-6 were elevated relative to responses in wild-type macrophages. Similarly, targeted deletion of atf3 correlated with enhanced responsiveness of myeloid DCs to TLR activation as measured by IL-12 secretion. Ectopic expression of ATF3 antagonized TLR-stimulated IL-12p40 activation in a reporter assay. In vivo, CpG-oligodeoxynucleotide, a TLR9 agonist, given i.p. to ATF3-KO mice resulted in enhanced cytokine production from splenocytes. Furthermore, while ATF3-KO mice challenged with a sublethal dose of PR8 influenza virus were delayed in body weight recovery in comparison to wild type, the ATF3-KO mice showed higher titers of serum neutralizing Ab against PR8 5 mo postinfection. Thus, ATF3 behaves as a negative regulatory transcription factor in TLR pathways and, accordingly, deficiency in atf3 alters responses to immunological challenges in vivo. ATF3 dysregulation merits further exploration in diseases such as type I diabetes and cancer, where altered innate immunity has been implicated in their pathogenesis.

IL-12 contributes to allergen-induced airway inflammation in experimental asthma

Lack of sufficient IL-12 production has been suggested to be one of the basic underlying mechanisms in atopy, but a potential role of IL-12 in established allergic airway disease remains unclear. We took advantage of a mouse model of experimental asthma to study the role of IL-12 during the development of bronchial inflammation. Administration of anti-IL-12p35 or anti-IL-12p40 mAb to previously OVA-sensitized BALB/c mice concomitantly with exposure to nebulized OVA, abolished both the development of bronchial hyperresponsiveness to metacholine as well as the eosinophilia in bronchoalveolar lavage fluid and peripheral blood. Anti-IL-12 treatment reduced CD4(+) T cell numbers and IL-4, IL-5, and IL-13 levels in the bronchoalveolar lavage fluid and the mRNA expression of IL-10, eotaxin, RANTES, MCP-1, and VCAM-1 in the lung. Anti-IL-12p35 treatment failed to show these effects in IFN-gamma knockout mice pointing to the essential role of IFN-gamma in IL-12-induced effects. Neutralization of IL-12 during the sensitization process aggravated the subsequent development of allergic airway inflammation. These data together with recent information on the role of dendritic cells in both the sensitization and effector phase of allergic respiratory diseases demonstrate a dual role of IL-12. Whereas IL-12 counteracts Th2 sensitization, it contributes to full-blown allergic airway disease upon airway allergen exposure in the postsensitization phase, with enhanced recruitment of CD4(+) T cells and eosinophils and with up-regulation of Th2 cytokines, chemokines, and VCAM-1. IFN-gamma-producing cells or cells dependent on IFN-gamma activity, play a major role in this unexpected proinflammatory effect of IL-12 in allergic airway disease.