Trial of Anti-BDCA2 Antibody Litifilimab for Systemic Lupus Erythematosus.

BACKGROUND: Antibody-binding of blood dendritic cell antigen 2 (BDCA2), which is expressed exclusively on plasmacytoid dendritic cells, suppresses the production of type I interferon that is involved in the pathogenesis of systemic lupus erythematosus (SLE). The safety and efficacy of subcutaneous litifilimab, a humanized monoclonal antibody that binds to BDCA2, in patients with SLE have not been extensively studied. METHODS: We conducted a phase 2 trial of litifilimab involving participants with SLE. The initial trial design called for randomly assigning participants to receive litifilimab (at a dose of 50, 150, or 450 mg) or placebo administered subcutaneously at weeks 0, 2, 4, 8, 12, 16, and 20, with the primary end point of evaluating cutaneous lupus activity. The trial design was subsequently modified; adults with SLE, arthritis, and active skin disease were randomly assigned to receive either litifilimab at a dose of 450 mg or placebo. The revised primary end point was the change from baseline in the total number of active joints (defined as the sum of the swollen joints and the tender joints) at week 24. Secondary end points were changes in cutaneous and global disease activity. Safety was also assessed. RESULTS: A total of 334 adults were assessed for eligibility, and 132 underwent randomization (64 were assigned to receive 450-mg litifilimab, 6 to receive 150-mg litifilimab, 6 to receive 50-mg litifilimab, and 56 to receive placebo). The primary analysis was conducted in the 102 participants who had received 450-mg litifilimab or placebo and had at least four tender and at least four swollen joints. The mean (±SD) baseline number of active joints was 19.0±8.4 in the litifilimab group and 21.6±8.5 in the placebo group. The least-squares mean (±SE) change from baseline to week 24 in the total number of active joints was -15.0±1.2 with litifilimab and -11.6±1.3 with placebo (mean difference, -3.4; 95% confidence interval, -6.7 to -0.2; P = 0.04). Most of the secondary end points did not support the results of the analysis of the primary end point. Receipt of litifilimab was associated with adverse events, including two cases of herpes zoster and one case of herpes keratitis. CONCLUSIONS: In a phase 2 trial involving participants with SLE, litifilimab was associated with a greater reduction from baseline in the number of swollen and tender joints than placebo over a period of 24 weeks. Longer and larger trials are required to determine the safety and efficacy of litifilimab for the treatment of SLE. (Funded by Biogen; LILAC ClinicalTrials.gov number, NCT02847598.).

Effect of Dimethyl Fumarate vs Interferon ß-1a in Patients With Pediatric-Onset Multiple Sclerosis: The CONNECT Randomized Clinical Trial.

Importance: With few approved multiple sclerosis therapies in the pediatric population, there is a need for further approved treatment options. Limited data exist for dimethyl fumarate (DMF) treatment in pediatric-onset multiple sclerosis (POMS). Objective: To compare the efficacy, safety, and tolerability of DMF vs intramuscular interferon ß-1a (IFNß-1a) in POMS. Design, Setting, and Participants: The CONNECT study was an active-controlled, open-label, rater-blinded 96-week randomized clinical trial in patients with POMS aged 10 to less than 18 years treated between August 2014 and November 2020. Data were analyzed from January through October 2021. Interventions: Patients were randomized to DMF or IFNß-1a. Main Outcomes and Measures: The primary end point was the proportion of patients free of new or newly enlarging (N or NE) T2 hyperintense lesions at week 96 among trial completers. Secondary end points included number of N or NE T2 lesions, proportion of patients free of relapse, annualized relapse rate (ARR), and safety. The estimated proportion of participants who were relapse free up to week 96 was calculated based on the Kaplan-Meier method. Adjusted ARR was obtained from a negative binomial regression adjusted for baseline relapse rate, baseline Expanded Disability Status Scale (EDSS) score, and age group. Results: Among 150 patients with POMS in the intention-to-treat (ITT) population (median [range] age, 15 [10-17] years; 101 [67.3%] female patients), 78 individuals received DMF and 72 individuals received IFNß-1a. At week 96, the proportion of patients with no N or NE T2 hyperintense lesions among 103 trial completers was 16.1% (95% CI, 8.0%-27.7%) for DMF vs 4.9% (95% CI, 0.6%-16.5%) for IFNß-1a, and in a sensitivity analysis among the ITT population, the proportions were 10 patients receiving DMF (12.8%) vs 2 patients receiving IFNß-1a (2.8%). The estimated proportion of patients who remained relapse free at week 96 was 66.2% for DMF vs 52.3% for IFNß-1a. Adjusted ARR (95% CI) at week 96 was 0.24 (95% CI, 0.15-0.39) for DMF vs 0.53 (95% CI, 0.33-0.84) for IFNß-1a; the rate ratio for DMF vs IFNß-1a was 0.46 (95% CI, 0.26-0.80; P = .006). The number of treatment-emergent adverse events (TEAEs; 74 patients [94.9%] vs 69 patients [95.8%]), serious TEAEs (18 patients [23.1%] vs 21 patients [29.2%]), and treatment discontinuations due to TEAEs (5 patients [6.4%] vs 8 patients [11.1%]) was similar for DMF vs IFNß-1a. Conclusions and Relevance: This study found that more pediatric patients with POMS treated with DMF were free of new or newly enlarging T2 lesions and that the adjusted ARR was lower among these patients compared with those treated with interferon ß-1a. DMF was well tolerated. Trial Registration: ClinicalTrials.gov Identifier: NCT02283853.

Trial of Anti-BDCA2 Antibody Litifilimab for Cutaneous Lupus Erythematosus.

BACKGROUND: Blood dendritic cell antigen 2 (BDCA2) is a receptor that is exclusively expressed on plasmacytoid dendritic cells, which are implicated in the pathogenesis of lupus erythematosus. Whether treatment with litifilimab, a humanized monoclonal antibody against BDCA2, would be efficacious in reducing disease activity in patients with cutaneous lupus erythematosus has not been extensively studied. METHODS: In this phase 2 trial, we randomly assigned adults with histologically confirmed cutaneous lupus erythematosus with or without systemic manifestations in a 1:1:1:1 ratio to receive subcutaneous litifilimab (at a dose of 50, 150, or 450 mg) or placebo at weeks 0, 2, 4, 8, and 12. We used a dose-response model to assess whether there was a response across the four groups on the basis of the primary end point, which was the percent change from baseline to 16 weeks in the Cutaneous Lupus Erythematosus Disease Area and Severity Index-Activity score (CLASI-A; scores range from 0 to 70, with higher scores indicating more widespread or severe skin involvement). Safety was also assessed. RESULTS: A total of 132 participants were enrolled; 26 were assigned to the 50-mg litifilimab group, 25 to the 150-mg litifilimab group, 48 to the 450-mg litifilimab group, and 33 to the placebo group. Mean CLASI-A scores for the groups at baseline were 15.2, 18.4, 16.5, and 16.5, respectively. The difference from placebo in the change from baseline in CLASI-A score at week 16 was -24.3 percentage points (95% confidence interval [CI] -43.7 to -4.9) in the 50-mg litifilimab group, -33.4 percentage points (95% CI, -52.7 to -14.1) in the 150-mg group, and -28.0 percentage points (95% CI, -44.6 to -11.4) in the 450-mg group. The least squares mean changes were used in the primary analysis of a best-fitting dose-response model across the three drug-dose levels and placebo, which showed a significant effect. Most of the secondary end points did not support the results of the primary analysis. Litifilimab was associated with three cases each of hypersensitivity and oral herpes infection and one case of herpes zoster infection. One case of herpes zoster meningitis occurred 4 months after the participant received the last dose of litifilimab. CONCLUSIONS: In a phase 2 trial involving participants with cutaneous lupus erythematosus, treatment with litifilimab was superior to placebo with regard to a measure of skin disease activity over a period of 16 weeks. Larger and longer trials are needed to determine the effect and safety of litifilimab for the treatment of cutaneous lupus erythematosus. (Funded by Biogen; LILAC ClinicalTrials.gov number, NCT02847598.).

Chronic lesion activity and disability progression in secondary progressive multiple sclerosis.

Objective: Slowly expanding lesions (SELs), a subgroup of chronic white matter lesions that gradually expand over time, have been shown to predict disability accumulation in primary progressive multiple sclerosis (MS) disease. However, the relationships between SELs, acute lesion activity (ALA), overall chronic lesion activity (CLA) and disability progression are not well understood. In this study, we examined the ASCEND phase III clinical trial, which compared natalizumab with placebo in secondary progressive MS (SPMS). Methods: Patients with complete imaging datasets between baseline and week 108 (N=600) were analysed for SEL prevalence (the number and volume of SELs), disability progression, ALA (assessed by gadolinium-enhancing lesions and new T2-hyperintense lesions) and CLA (assessed by T1-hypointense lesion volume increase within baseline T2-non-enhancing lesions identified as SELs and non-SELs). Results: CLA in both SELs and non-SELs was greater in patients with SPMS with confirmed disability progression than in those with no progression. In the complete absence of ALA at baseline and on study, SEL prevalence was significantly lower, while CLA within non-SELs remained associated with disability progression. Natalizumab decreased SEL prevalence and CLA in SELs and non-SELs compared with placebo. Conclusions: This study shows that CLA in patients with SPMS is decreased but persists in the absence of ALA and is associated with disability progression, highlighting the need for therapeutics targeting all mechanisms of CLA, including smouldering inflammation and neurodegeneration. Trial registration number: NCT01416181.

Abnormalities in normal-appearing white matter from which multiple sclerosis lesions arise.

Normal-appearing white matter is far from normal in multiple sclerosis; little is known about the precise pathology or spatial pattern of this alteration and its relation to subsequent lesion formation. This study was undertaken to evaluate normal-appearing white matter abnormalities in brain areas where multiple sclerosis lesions subsequently form, and to investigate the spatial distribution of normal-appearing white matter abnormalities in persons with multiple sclerosis. Brain MRIs of pre-lesion normal-appearing white matter were analysed in participants with new T2 lesions, pooled from three clinical trials: SYNERGY (NCT01864148; n = 85 with relapsing multiple sclerosis) was the test data set; ASCEND (NCT01416181; n = 154 with secondary progressive multiple sclerosis) and ADVANCE (NCT00906399; n = 261 with relapsing-remitting multiple sclerosis) were used as validation data sets. Focal normal-appearing white matter tissue state was analysed prior to lesion formation in areas where new T2 lesions later formed (pre-lesion normal-appearing white matter) using normalized magnetization transfer ratio and T2-weighted (nT2) intensities, and compared with overall normal-appearing white matter and spatially matched contralateral normal-appearing white matter. Each outcome was analysed using linear mixed-effects models. Follow-up time (as a categorical variable), patient-level characteristics (including treatment group) and other baseline variables were treated as fixed effects. In SYNERGY, nT2 intensity was significantly higher, and normalized magnetization transfer ratio was lower in pre-lesion normal-appearing white matter versus overall and contralateral normal-appearing white matter at all time points up to 24 weeks before new T2 lesion onset. In ASCEND and ADVANCE (for which normalized magnetization transfer ratio was not available), nT2 intensity in pre-lesion normal-appearing white matter was significantly higher compared to both overall and contralateral normal-appearing white matter at all pre-lesion time points extending up to 2 years prior to lesion formation. In all trials, nT2 intensity in the contralateral normal-appearing white matter was also significantly higher at all pre-lesion time points compared to overall normal-appearing white matter. Brain atlases of normal-appearing white matter abnormalities were generated using measures of voxel-wise differences in normalized magnetization transfer ratio of normal-appearing white matter in persons with multiple sclerosis compared to scanner-matched healthy controls. We observed that overall spatial distribution of normal-appearing white matter abnormalities in persons with multiple sclerosis largely recapitulated the anatomical distribution of probabilities of T2 hyperintense lesions. Overall, these findings suggest that intrinsic spatial properties and/or longstanding precursory abnormalities of normal-appearing white matter tissue may contribute to the risk of autoimmune acute demyelination in multiple sclerosis.

Next-generation Bruton's tyrosine kinase inhibitor BIIB091 selectively and potently inhibits B cell and Fc receptor signaling and downstream functions in B cells and myeloid cells.

OBJECTIVES: Bruton's tyrosine kinase (BTK) plays a non-redundant signaling role downstream of the B-cell receptor (BCR) in B cells and the receptors for the Fc region of immunoglobulins (FcR) in myeloid cells. Here, we characterise BIIB091, a novel, potent, selective and reversible small-molecule inhibitor of BTK. METHODS: BIIB091 was evaluated in vitro and in vivo in preclinical models and in phase 1 clinical trial. RESULTS: In vitro, BIIB091 potently inhibited BTK-dependent proximal signaling and distal functional responses in both B cells and myeloid cells with IC50s ranging from 3 to 106 nm, including antigen presentation to T cells, a key mechanism of action thought to be underlying the efficacy of B cell-targeted therapeutics in multiple sclerosis. BIIB091 effectively sequestered tyrosine 551 in the kinase pocket by forming long-lived complexes with BTK with t 1/2 of more than 40 min, thereby preventing its phosphorylation by upstream kinases. As a key differentiating feature of BIIB091, this property explains the very potent whole blood IC50s of 87 and 106 nm observed with stimulated B cells and myeloid cells, respectively. In vivo, BIIB091 blocked B-cell activation, antibody production and germinal center differentiation. In phase 1 healthy volunteer trial, BIIB091 inhibited naïve and unswitched memory B-cell activation, with an in vivo IC50 of 55 nm and without significant impact on lymphoid or myeloid cell survival after 14 days of dosing. CONCLUSION: Pharmacodynamic results obtained in preclinical and early clinical settings support the advancement of BIIB091 in phase 2 clinical trials.

MOG autoantibodies trigger a tightly-controlled FcR and BTK-driven microglia proliferative response.

Autoantibodies are a hallmark of numerous neurological disorders, including multiple sclerosis, autoimmune encephalitides and neuromyelitis optica. Whilst well understood in peripheral myeloid cells, the pathophysiological significance of autoantibody-induced Fc receptor signalling in microglia remains unknown, in part due to the lack of a robust in vivo model. Moreover, the application of therapeutic antibodies for neurodegenerative disease also highlights the importance of understanding Fc receptor signalling in microglia. Here, we describe a novel in vivo experimental paradigm that allows for selective engagement of Fc receptors within the CNS by peripherally injecting anti-myelin oligodendrocyte glycoprotein (MOG) monoclonal antibodies into normal wild-type mice. MOG antigen-bound immunoglobulins were detected throughout the CNS and triggered a rapid and tightly regulated proliferative response in both brain and spinal cord microglia. This microglial response was abrogated when anti-MOG antibodies were deprived of Fc receptor effector function or injected into Fcγ receptor knockout mice and was associated with the downregulation of Fc receptors in microglia, but not peripheral myeloid cells, establishing that this response was dependent on central Fc receptor engagement. Downstream of the Fc receptors, BTK was a required signalling node for this response, as microglia proliferation was amplified in BtkE41K knock-in mice expressing a constitutively active form of the enzyme and blunted in mice treated with a CNS-penetrant small molecule inhibitor of BTK. Finally, this response was associated with transient and stringently regulated changes in gene expression predominantly related to cellular proliferation, which markedly differed from transcriptional programs typically associated with Fc receptor engagement in peripheral myeloid cells. Together, these results establish a physiologically-meaningful functional response to Fc receptor and BTK signalling in microglia, while providing a novel in vivo tool to further dissect the roles of microglia-specific Fc receptor and BTK-driven responses to both pathogenic and therapeutic antibodies in CNS homeostasis and disease.

RNA tape sampling in cutaneous lupus erythematosus discriminates affected from unaffected and healthy volunteer skin.

OBJECTIVE: Punch biopsy, a standard diagnostic procedure for patients with cutaneous lupus erythematosus (CLE) carries an infection risk, is invasive, uncomfortable and potentially scarring, and impedes patient recruitment in clinical trials. Non-invasive tape sampling is an alternative that could enable serial evaluation of specific lesions. This cross-sectional pilot research study evaluated the use of a non-invasive adhesive tape device to collect messenger RNA (mRNA) from the skin surface of participants with CLE and healthy volunteers (HVs) and investigated its feasibility to detect biologically meaningful differences between samples collected from participants with CLE and samples from HVs. METHODS: Affected and unaffected skin tape samples and simultaneous punch biopsies were collected from 10 participants with CLE. Unaffected skin tape and punch biopsies were collected from 10 HVs. Paired samples were tested using quantitative PCR for a candidate immune gene panel and semi-quantitative immunohistochemistry for hallmark CLE proteins. RESULTS: mRNA collected using the tape device was of sufficient quality for amplification of 94 candidate immune genes. Among these, we found an interferon (IFN)-dominant gene cluster that differentiated CLE-affected from HV (23-fold change; p<0.001) and CLE-unaffected skin (sevenfold change; p=0.002), respectively. We found a CLE-associated gene cluster that differentiated CLE-affected from HV (fourfold change; p=0.005) and CLE-unaffected skin (fourfold change; p=0.012), respectively. Spearman's correlation between per cent area myxovirus 1 protein immunoreactivity and IFN-dominant mRNA gene cluster expression was highly significant (dermis, rho=0.86, p<0.001). In total, skin tape-derived RNA expression comprising both IFN-dominant and CLE-associated gene clusters correlated with per cent area immunoreactivity of some hallmark CLE-associated proteins in punch biopsies from the same lesions. CONCLUSIONS: A non-invasive tape RNA collection technique is a potential tool for repeated skin biomarker measures throughout a clinical trial.

Differential accumulation of storage bodies with aging defines discrete subsets of microglia in the healthy brain.

To date, microglia subsets in the healthy CNS have not been identified. Utilizing autofluorescence (AF) as a discriminating parameter, we identified two novel microglia subsets in both mice and non-human primates, termed autofluorescence-positive (AF+) and negative (AF-). While their proportion remained constant throughout most adult life, the AF signal linearly and specifically increased in AF+ microglia with age and correlated with a commensurate increase in size and complexity of lysosomal storage bodies, as detected by transmission electron microscopy and LAMP1 levels. Post-depletion repopulation kinetics revealed AF- cells as likely precursors of AF+ microglia. At the molecular level, the proteome of AF+ microglia showed overrepresentation of endolysosomal, autophagic, catabolic, and mTOR-related proteins. Mimicking the effect of advanced aging, genetic disruption of lysosomal function accelerated the accumulation of storage bodies in AF+ cells and led to impaired microglia physiology and cell death, suggestive of a mechanistic convergence between aging and lysosomal storage disorders.

Microglia are a unique type of immune cell found in the brain and spinal cord. Their job is to support neurons, defend against invading microbes, clear debris and remove dying neurons by engulfing them. Despite these diverse roles, scientists have long believed that there is only a single type of microglial cell, which adapts to perform whatever task is required. But more recent evidence suggests that this is not the whole story. Burns et al. now show that we can distinguish two subtypes of microglia based on a property called autofluorescence. This is the tendency of cells and tissues to emit light of one color after they have absorbed light of another. Burns et al. show that about 70% of microglia in healthy mouse and monkey brains display autofluorescence. However, about 30% of microglia show no autofluorescence at all. This suggests that there are two subtypes of microglia: autofluorescence-positive and autofluorescence-negative. But does this difference have any implications for how the microglia behave? Autofluorescence occurs because specific substances inside the cells absorb light. In the case of microglia, electron microscopy revealed that autofluorescence was caused by structures within the cell called lysosomal storage bodies accumulating certain materials. The stored material included fat molecules, cholesterol crystals and other substances that are typical of disorders that affect these compartments. Burns et al. show that autofluorescent microglia contain larger amounts of proteins involved in storing and digesting waste materials than their non-autofluorescent counterparts. Moreover, as the brain ages, lysosomal storage material builds up inside autofluorescent microglia, which increase their autofluorescence as a result. Unfortunately, this accumulation of cellular debris also makes it harder for the microglia to perform their tasks. Increasing evidence suggests that the accumulation of waste materials inside the brain contributes to diseases of aging. Future work should examine how autofluorescent microglia behave in animal models of neurodegenerative diseases. If these cells do help protect the brain from the effects of aging, targeting them could be a new strategy for treating aging-related diseases.

Organotypic Brain Slice Culture Microglia Exhibit Molecular Similarity to Acutely-Isolated Adult Microglia and Provide a Platform to Study Neuroinflammation.

Microglia are central nervous system (CNS) resident immune cells that have been implicated in neuroinflammatory pathogenesis of a variety of neurological conditions. Their manifold context-dependent contributions to neuroinflammation are only beginning to be elucidated, which can be attributed in part to the challenges of studying microglia in vivo and the lack of tractable in vitro systems to study microglia function. Organotypic brain slice cultures offer a tissue-relevant context that enables the study of CNS resident cells and the analysis of brain slice microglial phenotypes has provided important insights, in particular into neuroprotective functions. Here we use RNA sequencing, direct digital quantification of gene expression with nCounter® technology and targeted analysis of individual microglial signature genes, to characterize brain slice microglia relative to acutely-isolated counterparts and 2-dimensional (2D) primary microglia cultures, a widely used in vitro surrogate. Analysis using single cell and population-based methods found brain slice microglia exhibited better preservation of canonical microglia markers and overall gene expression with stronger fidelity to acutely-isolated adult microglia, relative to in vitro cells. We characterized the dynamic phenotypic changes of brain slice microglia over time, after plating in culture. Mechanical damage associated with slice preparation prompted an initial period of inflammation, which resolved over time. Based on flow cytometry and gene expression profiling we identified the 2-week timepoint as optimal for investigation of microglia responses to exogenously-applied stimuli as exemplified by treatment-induced neuroinflammatory changes observed in microglia following LPS, TNF and GM-CSF addition to the culture medium. Altogether these findings indicate that brain slice cultures provide an experimental system superior to in vitro culture of microglia as a surrogate to investigate microglia functions, and the impact of soluble factors and cellular context on their physiology.

Unique Sjögren's syndrome patient subsets defined by molecular features.

OBJECTIVE: To address heterogeneity complicating primary SS (pSS) clinical trials, research and care by characterizing and clustering patients by their molecular phenotypes. METHODS: pSS patients met American-European Consensus Group classification criteria and had at least one systemic manifestation and stimulated salivary flow of ⩾0.1 ml/min. Correlated transcriptional modules were derived from gene expression microarray data from blood (n = 47 with appropriate samples). Patients were clustered based on this molecular information using an unbiased random forest modelling approach. In addition, multiplex, bead-based assays and ELISAs were used to assess 30 serum cytokines, chemokines and soluble receptors. Eleven autoantibodies, including anti-Ro/SSA and anti-La/SSB, were measured by Bio-Rad Bioplex 2200. RESULTS: Transcriptional modules distinguished three clusters of pSS patients. Cluster 1 showed no significant elevation of IFN or inflammation modules. Cluster 2 showed strong IFN and inflammation modular network signatures, as well as high plasma protein levels of IP-10/CXCL10, MIG/CXCL9, BLyS (BAFF) and LIGHT. Cluster 3 samples exhibited moderately elevated IFN modules, but with suppressed inflammatory modules, increased IP-10/CXCL10 and B cell-attracting chemokine 1/CXCL13 and trends toward increased MIG/CXCL9, IL-1α, and IL-21. Anti-Ro/SSA and anti-La/SSB were present in all three clusters. CONCLUSION: Molecular profiles encompassing IFN, inflammation and other signatures can be used to separate patients with pSS into distinct clusters. In the future, such profiles may inform patient selection for clinical trials and guide treatment decisions.

Effect of in vivo Hydroxychloroquine and ex vivo Anti-BDCA2 mAb Treatment on pDC IFNα Production From Patients Affected With Cutaneous Lupus Erythematosus.

Objective: Plasmacytoid dendritic cells (pDCs) are a major source of Type-I Interferon (IFN-I), a key driver in cutaneous lupus erythematosus (CLE). Currently evaluated in Phase II clinical trial, 24F4A (BIIB059) is an antibody targeting BDCA2, an inhibitory receptor expressed on pDCs. Given that Hydroxychloroquine (HCQ), a widely-used CLE therapy, and 24F4A are both able to inhibit pDC-derived IFN-I production; this study aimed to determine whether 24F4A would show an additional inhibitory effect on pDC response after ex vivo or in vivo treatment with HCQ. Methods: The effect of 24F4A on pDC-derived IFNα was measured from peripheral blood mononuclear cells (PBMC) either from healthy donors in presence or absence of HCQ or from CLE patients clinically exposed to various levels of HCQ. TLR7, TLR7/8, and TLR9 agonists (ssRNA, R848, and CpG-A) were used for pDC stimulation. Results: PDCs were the only producers of IFNα in response to CpG-A, R848, and ssRNA stimulation in PBMC cultures. CLE patients with higher levels of blood HCQ showed lower ex vivo pDC responses to CpG-A, but not R848 or ssRNA. In contrast, 24F4A reduced the amount of IFNα produced by pDCs from CLE patients in response to all TLR agonists, irrespective of the blood HCQ level. Conclusion: Our findings reveal that clinically-relevant HCQ concentrations partially inhibit the pDC response to TLR9 and weakly affect the response to TLR7/8 stimulation. 24F4A robustly inhibits pDC responses even in the presence of HCQ, highlighting its unique potential to disrupt pDC disease relevant biology, which could provide additional therapeutic benefit for CLE patients.

Monoclonal antibody targeting BDCA2 ameliorates skin lesions in systemic lupus erythematosus.

BACKGROUND: Plasmacytoid DCs (pDC) produce large amounts of type I IFN (IFN-I), cytokines convincingly linked to systemic lupus erythematosus (SLE) pathogenesis. BIIB059 is a humanized mAb that binds blood DC antigen 2 (BDCA2), a pDC-specific receptor that inhibits the production of IFN-I and other inflammatory mediators when ligated. A first-in-human study was conducted to assess safety, tolerability, and pharmacokinetic (PK) and pharmacodynamic (PD) effects of single BIIB059 doses in healthy volunteers (HV) and patients with SLE with active cutaneous disease as well as proof of biological activity and preliminary clinical response in the SLE cohort. METHODS: A randomized, double-blind, placebo-controlled clinical trial was conducted in HV (n = 54) and patients with SLE (n = 12). All subjects were monitored for adverse events. Serum BIIB059 concentrations, BDCA2 levels on pDCs, and IFN-responsive biomarkers in whole blood and skin biopsies were measured. Skin disease activity was determined using the Cutaneous Lupus Erythematosus Disease Area and Severity Index Activity (CLASI-A). RESULTS: Single doses of BIIB059 were associated with favorable safety and PK profiles. BIIB059 administration led to BDCA2 internalization on pDCs, which correlated with circulating BIIB059 levels. BIIB059 administration in patients with SLE decreased expression of IFN response genes in blood, normalized MxA expression, reduced immune infiltrates in skin lesions, and decreased CLASI-A score. CONCLUSIONS: Single doses of BIIB059 were associated with favorable safety and PK/PD profiles and robust target engagement and biological activity, supporting further development of BIIB059 in SLE. The data suggest that targeting pDCs may be beneficial for patients with SLE, especially those with cutaneous manifestations. TRIAL REGISTRATION: ClinicalTrials.gov NCT02106897. FUNDING: Biogen Inc.

Citrullinated vimentin and biglycan protein fingerprints as candidate serological biomarkers for disease activity in systemic sclerosis: a pilot study.

Purpose: Extracellular matrix (ECM) deposition and remodelling in skin and lungs of systemic sclerosis (SSc) subjects lead to release of metabolites/biomarkers into circulation. We investigated if biomarkers of ECM degradation (biglycan and elastin) and macrophage activation (citrullinated vimentin) could identify diffuse SSc (dSSc) subjects from controls and the biomarkers discriminative power. Methods: DSSc subjects (n = 40) fulfilling the 2013 EULAR/ACR classification criteria were divided in early (<2years of symptoms) and late (≥10 years of symptoms). Early were subdivided into intermediate and rapid skin thickness progression rate (STPR). Twenty controls were included. Citrullinated and matrix metalloproteinase (MMP)-2/8-degraded vimentin (VICM), MMP-9/12-degraded biglycan (BGM) and MMP-7-degraded elastin (ELM-7) were assessed in serum. Analysis between groups was by Kruskal-Wallis and ROC AUC for discriminative power. Results: VICM and BGM levels were increased in early compared with late dSSc (p< =0.023). VICM was increased in rapid and intermediate STPR compared with controls (p< =0.025). No differences in ELM-7 levels were observed. AUC of VICM was 0.71 for early versus late dSSc and BGM had an AUC of 0.79 for dSSc versus controls. Conclusion: This pilot study found differences in biomarker levels between early and late dSSc. This study offers new perspectives of ECM metabolites as potential biomarkers of dSSc.

Serum biomarkers of collagen turnover as potential diagnostic tools in diffuse systemic sclerosis: A cross-sectional study.

BACKGROUND: Systemic sclerosis (SSc) is characterized by excessive fibrosis throughout the body. This leads to the release of extracellular matrix (ECM) fragments into circulation, where they may be quantified as biomarkers. The objectives were to investigate levels of ECM turnover biomarkers and the diagnostic power of these. METHODS: Diffuse SSc patients (n = 40) fulfilling the ACR/EULAR 2013 classification criteria and asymptomatic controls were included. Patients were divided into early (<2 years of symptoms; n = 20) and late (>10 years of symptoms; n = 20) diffuse SSc. Biomarkers of type I (C1M), III (C3A, C3M), IV (C4M), V (C5M) and VI (C6M) collagen degradation and type I (PRO-C1), II (PRO-C2), III (PRO-C3), IV (PRO-C4), V (PRO-C5) and VI (PRO-C6) collagen formation were measured in serum. Repeated measures ANOVA was used to test for differences in biomarker levels and the area under the receiver operating characteristic curve (AUC) was used to investigate the ability of the biomarkers to separate groups. RESULTS: In early diffuse SSc, formation biomarkers of type III, IV, V and VI collagen were significantly increased compared to asymptomatic controls (p<0.0001). Moreover, in early diffuse SSc formation biomarkers of type III, V and VI collagen were significantly increased compared to late diffuse SSc (p = 0.0006, 0.003 and 0.004, respectively). Type I (p<0.0001), III (C3M: p = 0.001, and C3A: p = 0.02), IV (p<0.0001) and VI (p<0.0001) collagen degradation biomarkers significantly increased in early diffuse SSc compared to controls. C4M, C6M, PRO-C4, PRO-C5 and PRO-C6 had an AUC of >0.85 when assessing asymptomatic controls vs. diffuse SSc. Biomarkers of type VI collagen (PRO-C6 and C6M) turnover had the best separation with an AUC's of >0.90. CONCLUSION: Formation biomarkers of ECM turnover were shown to be significantly different between asymptomatic controls and diffuse SSc. This pilot study suggest that serological biomarkers of the ECM turnover is potentially applicable in SSc.

Clinical Efficacy and Safety of Baminercept, a Lymphotoxin ß Receptor Fusion Protein, in Primary Sjögren's Syndrome: Results From a Phase II Randomized, Double-Blind, Placebo-Controlled Trial.

OBJECTIVE: To evaluate the clinical efficacy and safety of baminercept, a lymphotoxin ß receptor IgG fusion protein (LTßR-Ig), for the treatment of primary Sjögren's syndrome (SS), and to explore the possible mechanisms of action of this treatment. METHODS: In this multicenter trial, 52 patients with primary SS were randomized in a 2:1 ratio to receive subcutaneous injections of 100 mg of baminercept every week for 24 weeks or matching placebo. The primary end point was the change between screening and week 24 in the stimulated whole salivary flow (SWSF) rate. Secondary end points included the European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (ESSDAI), as well as measurements of select chemokines and cytokines and enumeration of peripheral blood B and T cell subsets. RESULTS: The change from baseline to week 24 in the SWSF rate was not significantly different between the baminercept and placebo treatment groups (baseline-adjusted mean change -0.01 versus 0.07 ml/minute; P = 0.332). The change in the ESSDAI during treatment was also not significantly different between the treatment groups (baseline-adjusted mean change -1.23 versus -0.15; P = 0.104). Although the incidence of adverse events was similar between the treatment groups, baminercept therapy was associated with a higher incidence of liver toxicity, including 2 serious adverse events. Baminercept also produced a significant decrease in plasma levels of CXCL13 and significant changes in the number of circulating B and T cells, consistent with its known inhibitory effects on LTßR signaling. CONCLUSION: In this trial, treatment with baminercept failed to significantly improve glandular and extraglandular disease in patients with primary SS, despite evidence from mechanistic studies showing that it blocks LTßR signaling.

Development of a Neo-Epitope Specific Assay for Serological Assessment of Type VII Collagen Turnover and Its Relevance in Fibroproliferative Disorders.

Type VII collagen is the main component of the anchoring fibrils connecting the basement membrane to the underlying interstitial matrix. Mutations in the type VII collagen gene cause dystrophic epidermolysis bullosa. Increased levels of type VII collagen in the skin have been reported in patients with systemic sclerosis (SSc), whereas reduced levels in the airways have been related to asthma. This indicates that type VII collagen plays an important part in upholding tissue integrity and that its remodeling may lead to pathological states. The aim of this study was to investigate the role of type VII collagen remodeling in fibroproliferative disorders. We produced monoclonal antibody targeting a specific fragment of type VII collagen (C7M) released to the systemic circulation and developed a neo-epitope specific competitive enzyme-linked immunosorbent assay (ELISA). Biological relevance was evaluated in serum from patients with SSc or chronic obstructive pulmonary disease (COPD). The C7M ELISA was technically robust and specific for the C7M neo-epitope. Serum C7M levels were significantly elevated in two cohorts of patients with SSc and in patients with COPD as compared with healthy individuals (P < 0.0001). The C7M ELISA enabled quantification of type VII collagen turnover in serum. Elevated serum C7M levels indicated that the turnover rate of type VII collagen was significantly increased in patients with SSc or COPD, suggesting a pathological role. Thus, the C7M ELISA may become useful in future investigations of type VII collagen turnover in fibroproliferative disorders, and it may prove a valuable tool for evaluating novel anti-fibrotic drugs.

RANKL inhibition with denosumab does not influence 3-year progression of aortic calcification or incidence of adverse cardiovascular events in postmenopausal women with osteoporosis and high cardiovascular risk.

Atherosclerosis and osteoporosis are chronic diseases that progress with age, and studies suggest aortic calcification, an indicator of atherosclerosis, is inversely associated with bone mineral density (BMD). The osteoprotegerin (OPG)/receptor activator of NF-κB (RANK)/RANK ligand (RANKL) system has been proposed as a shared regulatory system for bone and vasculature. Denosumab (DMAb), a monoclonal antibody against RANKL, improved BMD and reduced fracture risk in the Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) trial. We evaluated whether or not treatment with DMAb influenced progression of aortic calcification (AC) and incidence of cardiovascular (CV) adverse events. We included 2363 postmenopausal women with osteoporosis (1142 placebo, 1221 DMAb), selected from 7808 participants in the FREEDOM trial (3906 placebo, 3902 DMAb), at high risk of CV events according to modified Raloxifene Use for the Heart (RUTH) criteria. CV adverse events were reported by participants. AC scores were assessed using a semiquantitative method from lateral spine X-rays. Change in AC score from baseline to 12 (n = 1377), 24 (n = 1231), and 36 months (n = 1045) was calculated as AC score at follow-up minus AC score at baseline. AC progression was defined as change in AC score >0. Baseline characteristics, CV risk factors, and AC scores were similar between treatment groups. Mean age of participants was 74 years (range, 60-90), 88% were white, and 77% had AC score >0 at baseline. Frequency of AC progression over 3 years did not differ between women in placebo (22%) and DMAb (22%) groups (p = 0.98). AC progression did not differ between treatment groups when analyzed by baseline estimated glomerular filtration rate or by baseline AC scores. Frequency of CV adverse events did not differ between placebo (40%) and DMAb (38%) groups (p = 0.26). In conclusion, DMAb treatment had no effect on progression of AC or incidence of CV adverse events compared to placebo.