OX40 in the Pathogenesis of Atopic Dermatitis-A New Therapeutic Target.

Atopic dermatitis (AD) is a chronic, heterogeneous, inflammatory disease characterized by skin lesions, pruritus, and pain. Patients with moderate-to-severe AD experience chronic symptoms, intensified by unpredictable flares, and often have comorbidities and secondary complications, which can result in significant clinical burden that impacts the patient's overall quality of life. The complex interplay of immune dysregulation and skin barrier disruption drives AD pathogenesis, of which T-cell-dependent inflammation plays a critical role in patients with AD. Despite new targeted therapies, many patients with moderate-to-severe AD fail to achieve or sustain their individual treatment goals and/or may not be suitable for or tolerate these therapies. There remains a need for a novel, efficacious, well-tolerated therapeutic option that can deliver durable benefits across a heterogeneous AD patient population. Expression of OX40 [tumor necrosis factor receptor superfamily, member 4 (TNFRSF4)], a prominent T-cell co-stimulatory molecule, and its ligand [OX40L; tumor necrosis factor superfamily, member 4 (TNFSF4)] is increased in AD. As the OX40 pathway is critical for expansion, differentiation, and survival of effector and memory T cells, its targeting might be a promising therapeutic approach to provide sustained inhibition of pathogenic T cells and associated inflammation and broad disease control. Antibodies against OX40 [rocatinlimab (AMG 451/KHK4083) and telazorlimab (GBR 830)] or OX40L [amlitelimab (KY1005)] have shown promising results in early-phase clinical studies of moderate-to-severe AD, highlighting the importance of OX40 signaling as a new therapeutic target in AD.

Summary of Research: An Anti-OX40 Antibody to Treat Moderate-to-Severe Atopic Dermatitis: A Multicentre, Double-Blind, Placebo-Controlled Phase 2b Study.

This is a summary of the original article "An Anti-OX40 Antibody to Treat Moderate-to-Severe Atopic Dermatitis: a Multicentre, Double-blind, Placebo-Controlled Phase 2b Study". Atopic dermatitis (AD) is an inflammatory skin disease caused by a complex interplay of genetic factors, alterations to the skin microenvironment, and immune dysregulation, including T cells that have become uncontrolled. Rocatinlimab is an investigational agent that blocks OX40, a receptor on activated T cells that has an important role in inflammatory conditions such as AD. This summary of research provides an overview of a previously published article on the results of a phase 2b study of patients with moderate-to-severe AD who were treated with different doses of rocatinlimab or placebo and followed for up to 56 weeks. Rocatinlimab significantly improved the symptoms of AD and was well tolerated. The most common adverse events were fever, nasopharyngitis, and chills. This study supports rocatinlimab as a potentially safe and effective treatment for moderate-to-severe AD.

An anti-OX40 antibody to treat moderate-to-severe atopic dermatitis: a multicentre, double-blind, placebo-controlled phase 2b study.

BACKGROUND: OX40 is crucial for T-cell differentiation and memory induction. The anti-OX40 antibody, rocatinlimab inhibits the OX40 pathway. We evaluated the efficacy and safety of rocatinlimab in adults with moderate-to-severe atopic dermatitis. METHODS: This multicentre, double-blind, placebo-controlled phase 2b study was done at 65 secondary and tertiary sites in the USA, Canada, Japan, and Germany. Eligible patients were adults (aged 18 years or older) with confirmed atopic dermatitis (American Academy of Dermatology Consensus Criteria or local diagnostic criteria) with moderate-to-severe disease activity, as defined by an Eczema Area and Severity Index (EASI) score of 16 or more, validated Investigator's Global Assessment for Atopic Dermatitis score of 3 (moderate) or 4 (severe), and affected body surface area 10% or higher at both screening and baseline, with documented history (within 1 year) of inadequate response to topical medications or if topical treatments were medically inadvisable. Patients were randomly assigned (1:1:1:1:1) to receive subcutaneous rocatinlimab every 4 weeks (150 mg or 600 mg) or every 2 weeks (300 mg or 600 mg) or subcutaneous placebo up to week 18, with an 18-week active-treatment extension and 20-week follow-up. Percentage change from baseline in EASI score was assessed as the primary endpoint at week 16 and during the active extension and follow-up in all randomly assigned patients exposed to study drug with a post-baseline EASI score at week 16 or earlier according to the group they were randomly assigned to. Safety was assessed in all randomly assigned patients exposed to study drug; patients were analysed according to the group they were randomly assigned to. The study is registered with ClinicalTrials.gov, NCT03703102. FINDINGS: Between Oct 22, 2018, and Oct 21, 2019, 274 patients (114 [42%] women, 160 [58%] men; mean age 38·0 years [SD 14·5]) were randomly assigned to one of the rocatinlimab groups (217 [79%] patients) or to the placebo group (57 [21%] patients). Compared with placebo (-15·0 [95% CI -28·6 to -1·4]), significant least-squares mean percent reductions in EASI score at week 16 were observed in all rocatinlimab groups (rocatinlimab 150 mg every 4 weeks -48·3 [-62·2 to -34·0], p=0·0003; rocatinlimab 600 mg every 4 weeks -49·7 [-64·3 to -35·2], p=0·0002; rocatinlimab 300 mg every 2 weeks -61·1 [-75·2 to -47·0], p<0·0001; and rocatinlimab 600 mg every 2 weeks -57·4 [-71·3 to -43·4], p<0·0001). The most common adverse events during the double-blind period in patients receiving rocatinlimab (adverse events ≥5% of patients in the total rocatinlimab group and more common than the placebo group) were pyrexia (36 [17%] patients), nasopharyngitis (30 [14%] patients), chills (24 [11%] patients), headache (19 [9%] patients), aphthous ulcer (15 [7%] patients), and nausea (13 [6%] patients). There were no deaths. INTERPRETATION: Patients treated with rocatinlimab had progressive improvements in atopic dermatitis, which was maintained in most patients after treatment discontinuation. Treatment was well tolerated. FUNDING: Kyowa Kirin.

A Phase I, Randomized, Double-Blind, Placebo-Controlled, Single-Dose and Multiple-Rising-Dose Study of the BTK Inhibitor TAK-020 in Healthy Subjects.

Bruton's tyrosine kinase (BTK) is a target for treatment of hematologic malignancies and autoimmune diseases. TAK-020 is a highly selective covalent BTK inhibitor that inhibits both B cell receptor and fragment crystallizable receptor signaling. We assessed the safety/tolerability and pharmacokinetics/pharmacodynamics (PDs) of TAK-020 in healthy subjects. Each cohort of the single-rising dose (n = 72; 9 cohorts) and the multiple-rising dose (n = 48; 6 cohorts) portions of the study comprised six TAK-020-treated and two placebo-treated, subjects aged 18-55 years (inclusive). The PD effects were assessed by measuring BTK occupancy and the inhibition of fragment crystallizable epsilon receptor 1 (FcεRI)-mediated activation of basophils. Overall, treatment-emergent adverse events (TEAEs) were similar to placebo; there were no serious TEAEs or no TEAEs leading to discontinuation. TAK-020 was rapidly absorbed (median time to maximum plasma concentration (Tmax ) 45-60 minutes) with a half-life of ~ 3-9 hours at doses ≥ 2.5 mg. TAK-020 exposure was generally dose proportional for single doses ≤ 70 mg and after multiple doses of ≤ 60 mg once daily. Target occupancy was dose dependent, with doses ≥ 2.5 mg yielding maximum and sustained occupancy > 70% for > 96 hours. Single doses ≥ 4.4 mg reduced FcεRI-mediated activation of basophils by > 80% and comparable inhibition was observed with daily dosing ≥3.75 mg for 9 days. Inhibition persisted for 24-72 hours postdose and the duration generally increased with dose. TAK-020 was generally well-tolerated in healthy subjects after single and multiple doses and demonstrated target engagement and pathway modulation. The PD effects outlasted drug exposures, as expected for covalent inhibition of BTK.

Defining Phenotypes in Diabetic Nephropathy: a novel approach using a cross-sectional analysis of a single centre cohort.

The global increase in Diabetes Mellitus (DM) has led to an increase in DM-Chronic Kidney Disease (DM-CKD). In this cross-sectional observational study we aimed to define phenotypes for patients with DM-CKD that in future may be used to individualise treatment We report 4 DM-CKD phenotypes in 220 patients recruited from Imperial College NHS Trust clinics from 2004-2012. A robust principal component analysis (PCA) was used to statistically determine clusters with phenotypically different patients. 163 patients with complete data sets were analysed: 77 with CKD and 86 with DM-CKD. Four different clusters were identified. Phenotypes 1 and 2 are entirely composed of patients with DM-CKD and phenotypes 3 and 4 are predominantly CKD (non-DM-CKD). Phenotype 1 depicts a cardiovascular phenotype; phenotype 2: microvascular complications with advanced DM-CKD; phenotype 3: advanced CKD with less anaemia, lower weight and HbA1c; phenotype 4: hypercholesteraemic, younger, less severe CKD. We are the first group to describe different phenotypes in DM-CKD using a PCA approach. Identification of phenotypic groups illustrates the differences and similarities that occur under the umbrella term of DM-CKD providing an opportunity to study phenotypes within these groups thereby facilitating development of precision/personalised targeted medicine.

Effect of therapeutic plasma exchange on immunoglobulins in myasthenia gravis.

An integrated understanding of therapeutic plasma exchange (TPE) effects on immunoglobulins, autoantibodies, and natural or acquired (vaccine) protective antibodies in patients with autoimmune myasthenia gravis (MG) is lacking. Prior studies measured TPE effects in healthy volunteers or heterogeneous autoimmune disease populations. We prospectively profiled plasma IgA, IgM, IgG, IgG subclasses (IgG1-4), acetylcholine receptor autoantibodies (AChR+), and protective antibodies in patients with AChR + MG receiving TPE for an exacerbation. TPE was performed according to institutional practice and patients were profiled for up to 12 weeks. Ten patients were enrolled (median age = 72.9 years; baseline MG-Composite = 21; median TPE treatments = 6 during their first course) and all improved. The maximum decrease in all immunoglobulins, including AChR autoantibodies, was achieved on the final day of the first TPE course (∼60-70% reduction). Three weeks post-TPE, mean AChR autoantibody, total IgG, IgG1, and IgG2 titers were below the reference range and had not recovered within 20% of baseline, whereas other measured immunoglobulins approached baseline values. We did not generally observe an "overshoot" of immunoglobulins above pre-TPE levels or accelerated recovery of pathologic AChR autoantibodies. Protective antibody profiles showed similar patterns as other IgGs and were detectable at levels associated with protection from infection. A slow return to baseline for IgGs (except IgG3) was observed, and we did not observe any obvious effect of concomitant medications on this recovery. Collectively, these findings enhance our understanding of the immunological effects of TPE and further support the concept of rapid immunoglobulin depletion for the treatment of patients with MG.

Efficacy and safety of mavrilimumab in subjects with rheumatoid arthritis.

OBJECTIVES: Mavrilimumab, a human monoclonal antibody targeting the alpha subunit of the granulocyte-macrophage colony-stimulating factor receptor, was evaluated in a phase 2 randomised, double-blind, placebo-controlled study to investigate efficacy and safety in subjects with rheumatoid arthritis (RA). METHODS: Subcutaneous mavrilimumab (10 mg, 30 mg, 50 mg, or 100 mg) or placebo was administered every other week for 12 weeks in subjects on stable background methotrexate therapy. The primary endpoint was the proportion of subjects achieving a ≥1.2 decrease from baseline in Disease Activity Score (DAS28-CRP) at week 12. RESULTS: 55.7% of mavrilimumab-treated subjects met the primary endpoint versus 34.7% placebo (p=0.003) at week 12; for the 10 mg, 30 mg, 50 mg, and 100 mg groups, responses were 41.0% (p=0.543), 61.0% (p=0.011), 53.8% (p=0.071), and 66.7% (p=0.001) respectively. Response rate differences from placebo were observed at week 2 and increased throughout the treatment period. The 100 mg dose demonstrated a significant effect versus placebo on DAS28-CRP<2.6 (23.1% vs 6.7%, p=0.016), all categories of the American College of Rheumatology (ACR) criteria (ACR20: 69.2% vs 40.0%, p=0.005; ACR50: 30.8% vs 12.0%, p=0.021; ACR70: 17.9% vs 4.0%, p=0.030), and the Health Assessment Questionnaire Disability Index (-0.48 vs -0.25, p=0.005). A biomarker-based disease activity score showed a dose-dependent decrease at week 12, indicating suppression of disease-related biological pathways. Adverse events were generally mild or moderate in intensity. No significant hypersensitivity reactions, serious or opportunistic infections, or changes in pulmonary parameters were observed. CONCLUSIONS: Mavrilimumab induced rapid clinically significant responses in RA subjects, suggesting that inhibiting the mononuclear phagocyte pathway may provide a novel therapeutic approach for RA.

Induction of cartilage integration by a chondrocyte/collagen-scaffold implant.

The integration of implanted cartilage is a major challenge for the success of tissue engineering protocols. We hypothesize that in order for effective cartilage integration to take place, matrix-free chondrocytes must be induced to migrate between the two tissue surfaces. A chondrocyte/collagen-scaffold implant system was developed as a method of delivering dividing cells at the interface between two cartilage surfaces. Chondrocytes were isolated from bovine nasal septum and seeded onto both surfaces of a collagen membrane to create the chondrocyte/collagen-scaffold implant. A model of two cartilage discs and the chondrocyte/collagen-scaffold sandwiched in between was used to effect integration in vitro. The resulting tissue was analysed histologically and biomechanically. The cartilage-implant-cartilage sandwich appeared macroscopically as one continuous piece of tissue at the end of 40 day cultures. Histological analysis showed tissue continuum across the cartilage-scaffold interface. The integration was dependent on both cells and scaffold. Fluorescent labeling of implanted chondrocytes demonstrated that these cells invade the surrounding mature tissue and drive a remodelling of the extracellular matrix. Using cell-free scaffolds we also demonstrated that some chondrocytes migrated from the natural cartilage into the collagen scaffold. Quantification of integration levels using a histomorphometric repair index showed that the chondrocyte/collagen-scaffold implant achieved the highest repair index compared to controls, reflected functionally through increased tensile strength. In conclusion, cartilage integration can be achieved using a chondrocyte/collagen-scaffold implant that permits controlled delivery of chondrocytes to both host and graft mature cartilage tissues. This approach has the potential to be used therapeutically for implantation of engineered tissue.

TRACP Influences Th1 pathways by affecting dendritic cell function.

UNLABELLED: TRACP, a marker of osteoclasts, is also expressed by cells of the immune system. We identified a novel function for TRACP in the dendritic cell. DCs from TRACP knockout mice have impaired maturation and trigger reduced Th1 responses in vivo. We postulate that TRACP has an important role in the presentation of antigens to T cells. INTRODUCTION: TRACP is highly expressed by osteoclasts, activated macrophages, and dendritic cells (DCs). Knockout mice lacking TRACP have an intrinsic defect in osteoclastic resorption and macrophages that display abnormal immunomodulatory responses and cytokine secretion profiles. Our aim in this study was to investigate the significance of TRACP in the inductive phase of the immune response by examining dendritic cells from TRACP(-/-) mice. MATERIALS AND METHODS: Maturational state and function of leukocyte subsets in mice was assessed by flow cytometry. The ability of the immune system to respond to nonspecific activation and to specific antigen was assessed by delayed type hypersensitivity and the presence of isotype-specific serum antibody in vivo and T-cell proliferation and cytokine production in vitro. RESULTS: The ability of lipopolysaccharide (LPS) to upregulate MHC II and CD80 in DCs from TRACP(-/-) mice was reduced compared with wildtype mice, although production of IL-10 by DCs from TRACP-deficient animals was increased. T- and B-cell responses not involving antigen presentation (anti-CD3, TNP-ficoll) were normal in TRACP(-/-) mice, but responses to T-dependent antigens were impaired. Specifically, TRACP(-/-) mice had defective delayed hypersensitivity responses to picryl chloride and reduced proliferative responses to ovalbumin compared with wildtype mice. In response to ovalbumin, but not anti-CD3, T cells from TRACP(-/-) mice produced less interferon-gamma (IFN-gamma), but there was no difference in IL-4 production: TRACP(-/-) mice also produced less ovalbumin (OVA)-specific IgG2a after immunization. CONCLUSIONS: The finding that DCs from TRACP(-/-) mice have impaired maturation and defective Th1 responses shows that TRACP is important for polarizing responses in naïve T cells to antigen-presented dendritic cells.