Protective effects of angiopoietin-like 4 on cerebrovascular and functional damages in ischaemic stroke

AIMS: Given the impact of vascular injuries and oedema on brain damage caused during stroke, vascular protection represents a major medical need. We hypothesized that angiopoietin-like 4 (ANGPTL4), a regulator of endothelial barrier integrity, might exert a protective effect during ischaemic stroke. METHODS AND RESULTS: Using a murine transient ischaemic stroke model, treatment with recombinant ANGPTL4 led to significantly decreased infarct size and improved behaviour. Quantitative characteristics of the vascular network (density and branchpoints) were preserved in ANGPTL4-treated mice. Integrity of tight and adherens junctions was also quantified and ANGPTL4-treated mice displayed increased VE-cadherin and claudin-5-positive areas. Brain oedema was thus significantly decreased in ANGPTL4-treated mice. In accordance, vascular damage and infarct severity were increased in angptl4-deficient mice thus providing genetic evidence that ANGPTL4 preserves brain tissue from ischaemia-induced alterations. Altogether, these data show that ANGPTL4 protects not only the global vascular network, but also interendothelial junctions and controls both deleterious inflammatory response and oedema. Mechanistically, ANGPTL4 counteracted VEGF signalling and thereby diminished Src-signalling downstream from VEGFR2. This led to decreased VEGFR2-VE-cadherin complex disruption, increased stability of junctions and thus increased endothelial cell barrier integrity of the cerebral microcirculation. In addition, ANGPTL4 prevented neuronal loss in the ischaemic area. CONCLUSION: These results, therefore, show ANGPTL4 counteracts the loss of vascular integrity in ischaemic stroke, by restricting Src kinase signalling downstream from VEGFR2. ANGPTL4 treatment thus reduces oedema, infarct size, neuronal loss, and improves mice behaviour. These results suggest that ANGPTL4 constitutes a relevant target for vasculoprotection and cerebral protection during stroke

Infections in Dupilumab Clinical Trials in Atopic Dermatitis : A Comprehensive Pooled Analysis

Background: Patients with moderate-to-severe atopic dermatitis (AD) have increased infection risk, including skin infections and systemic infections. Immunomodulators (e.g., anti-tumor necrosis factors, anti-interleukin [anti-IL]-23, anti-IL-17, Janus kinase inhibitors) increase risk of infections. Dupilumab (a monoclonal antibody blocking the shared receptor component for IL-4 and IL-13) is approved for inadequately controlled moderate-to-severe AD and for moderate-to-severe eosinophilic or oral corticosteroid-dependent asthma. Objective: The aim was to determine the impact of dupilumab on infection rates in patients with moderate-to-severe AD. Methods: This analysis pooled data from seven randomized, placebo-controlled dupilumab trials in adults with moderate-to-severe AD. Exposure-adjusted analyses assessed infection rates. Results: Of 2932 patients, 1091 received placebo, 1095 dupilumab 300 mg weekly, and 746 dupilumab 300 mg every 2 weeks. Treatment groups had similar infection rates overall per 100 patient-years (placebo, 155; dupilumab weekly, 150; dupilumab every 2 weeks, 156; dupilumab combined, 152), and similar non-skin infection rates. Serious/severe infections were reduced with dupilumab (risk ratio 0.43; p < 0.05), as were bacterial and other non-herpetic skin infections (risk ratio 0.44; p < 0.001). Although herpesviral infection rates overall were slightly higher with dupilumab than placebo, clinically important herpesviral infections (eczema herpeticum, herpes zoster) were less common with dupilumab (risk ratio 0.31; p < 0.01). Systemic anti-infective medication use was lower with dupilumab. Conclusions: Dupilumab is associated with reduced risk of serious/severe infections and non-herpetic skin infections and does not increase overall infection rates versus placebo in patients with moderate-to-severe AD. ClinicalTrials.gov Identifiers: NCT01548404, NCT02210780, NCT01859988, NCT02277743, NCT02277769, NCT02260986, and NCT02755649

Two Phase 3 Trials of Dupilumab versus Placebo in Atopic Dermatitis.

BACKGROUND Dupilumab, a human monoclonal antibody against interleukin-4 receptor alpha, inhibits signaling of interleukin-4 and interleukin-13, type 2 cytokines that may be important drivers of atopic or allergic diseases such as atopic dermatitis. METHODS In two randomized, placebo-controlled, phase 3 trials of identical design (SOLO 1 and SOLO 2), we enrolled adults with moderate-to-severe atopic dermatitis whose disease was inadequately controlled by topical treatment. Patients were randomly assigned in a 1:1:1 ratio to receive, for 16 weeks, subcutaneous dupilumab (300 mg) or placebo weekly or the same dose of dupilumab every other week alternating with placebo. The primary outcome was the proportion of patients who had both a score of 0 or 1 (clear or almost clear) on the Investigator’s Global Assessment and a reduction of 2 points or more in that score from baseline at week 16. RESULTS We enrolled 671 patients in SOLO 1 and 708 in SOLO 2. In SOLO 1, the primary outcome occurred in 85 patients (38%) who received dupilumab every other week and in 83 (37%) who received dupilumab weekly, as compared with 23 (10%) who received placebo (P<0.001 for both comparisons with placebo). The results were similar in SOLO 2, with the primary outcome occurring in 84 patients (36%) who received dupilumab every other week and in 87 (36%) who received dupilumab weekly, as compared with 20 (8%) who received placebo (P<0.001 for both comparisons). In addition, in the two trials, an improvement from baseline to week 16 of at least 75% on the Eczema Area and Severity Index was reported in significantly more patients who received each regimen of dupilumab than in patients who received placebo (P<0.001 for all comparisons). Dupilumab was also associated with improvement in other clinical end points, including reduction in pruritus and symptoms of anxiety or depression and improvement in quality of life. Injection-site reactions and conjunctivitis were more frequent in the dupilumab groups than in the placebo groups. CONCLUSIONS In two phase 3 trials of identical design involving patients with atopic dermatitis, dupilumab improved the signs and symptoms of atopic dermatitis, including pruritus, symptoms of anxiety and depression, and quality of life, as compared with placebo. Trials of longer duration are needed to assess the long-term effectiveness and safety of dupilumab. (Funded by Sanofi and Regeneron Pharmaceuticals; SOLO 1 ClinicalTrials.gov number, NCT02277743; SOLO 2 ClinicalTrials .gov number, NCT02277769.

Efficacy and safety of dupilumab with concomitant topical corticosteroids in children 6 to 11 years old with severe atopic dermatitis: a randomized, double-blinded, placebo-controlled phase 3 trial

Background Children with severe atopic dermatitis (AD) have limited treatment options. Objective We report efficacy and safety of dupilumab + topical corticosteroids (TCS) in children aged 6–11 years with severe AD inadequately controlled with topical therapies. Methods In this double-blind, 16-week, phase 3 trial (NCT03345914), 367 patients were randomized 1:1:1 to 300mg dupilumab every 4 weeks (300mg-q4w), a weight-based regimen of dupilumab every 2 weeks (100mg-q2w, baseline weight <30kg; 200mg-q2w, ≥30kg), or placebo; with concomitant medium-potency TCS. Results Both the q4w and q2w dupilumab+TCS regimens resulted in clinically meaningful and statistically significant improvement in signs, symptoms, and quality of life (QoL) versus placebo+TCS in all prespecified endpoints. For q4w/q2w/placebo, 32.8%/29.5%/11.4% of patients achieved Investigator’s Global Assessment scores of 0/1; 69.7%/67.2%/26.8% achieved ≥75% improvement in Eczema Area and Severity Index scores; and 50.8%/58.3%/12.3% achieved ≥4-point reduction in worst itch score. Response to therapy was weight-dependent: optimal dupilumab doses for efficacy and safety were 300mg-q4w in children <30kg and 200mg-q2w in children ≥30kg. Conjunctivitis and injection-site reactions were more common with dupilumab+TCS than placebo+TCS. Limitations Short-term 16-week treatment period; severe AD only. Conclusion Dupilumab+TCS is efficacious and well tolerated in children with severe AD, significantly improving signs, symptoms, and QoL

Subcutaneous REGEN-COV Antibody Combination to Prevent Covid-19

BACKGROUND REGEN-COV (previously known as REGN-COV2), a combination of the monoclonal antibodies casirivimab and imdevimab, has been shown to markedly reduce the risk of hospitalization or death among high-risk persons with coronavirus disease 2019 (Covid-19). Whether subcutaneous REGEN-COV prevents severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and subsequent Covid-19 in persons at high risk for infection because of household exposure to a person with SARS-CoV-2 infection is unknown. METHODS We randomly assigned, in a 1:1 ratio, participants (=12 years of age) who were enrolled within 96 hours after a household contact received a diagnosis of SARSCoV- 2 infection to receive a total dose of 1200 mg of REGEN-COV or matching placebo administered by means of subcutaneous injection. At the time of randomization, participants were stratified according to the results of the local diagnostic assay for SARS-CoV-2 and according to age. The primary efficacy end point was the development of symptomatic SARS-CoV-2 infection through day 28 in participants who did not have SARS-CoV-2 infection (as measured by reverse-transcriptase- quantitative polymerase-chain-reaction assay) or previous immunity (seronegativity). RESULTS Symptomatic SARS-CoV-2 infection developed in 11 of 753 participants in the REGEN-COV group (1.5%) and in 59 of 752 participants in the placebo group (7.8%) (relative risk reduction [1 minus the relative risk], 81.4%; P104 copies per milliliter) was shorter (0.4 weeks and 1.3 weeks, respectively). No dose-limiting toxic effects of REGEN-COV were noted. CONCLUSIONS Subcutaneous REGEN-COV prevented symptomatic Covid-19 and asymptomatic SARS-CoV-2 infection in previously uninfected household contacts of infected persons. Among the participants who became infected, REGEN-COV reduced the duration of symptomatic disease and the duration of a high viral load

Neurotrophic factor receptors: Just like other growth factor and cytokine receptors?

As the actions of neurotrophic factors appear so strikingly different from those of growth factors and cytokines operating elsewhere in the body, it was long thought that neurotrophic factors might in some way be fundamentally different from traditional growth factors and cytokines. Recent advances in the understanding of the structure of the receptors for neurotrophic factors reveals them to be much more like the receptors used by other cytokines and growth factors than was perhaps first anticipated. These findings suggest that neurotrophic factors display distinctive actions not because they utilize novel receptor systems, but rather because they activate these receptors in neurons

Neurotrophic factors and their receptors

Development of the nervous system depends on signals that instruct neurons when to divide, differentiate, survive, or die. There are now two known distinct classes of factors noted for their neurotrophic activities-the family of factors collectively known as the neurotrophins, and ciliary neurotrophic factor. Neurotrophin-mediated signaling pathways initiate by autophosphorylation of Trk receptors, which are receptor tyrosine kinases similar to the receptors for traditional growth factors such as fibroblast growth factor. In contrast, ciliary neurotrophic factor employs a receptor system that shares components with the receptor complexes for a subclass of distantly related hematopoietic cytokines. These two distinct classes of neurotrophic factors, utilizing distinct signaling pathways, can interact to effect the growth and differentiation of neuronal progenitors during neuropoiesis in a way analogous to that exhibited by the cytokines during hematopoiesis

The neurotrophins and CNTF: Two families of collaborative neurotrophic factors

Because the actions of neurotrophic factors appear distinct from those of traditional growth factors and cytokines, it was long assumed that the neurotrophic factors utilized receptors and signaling systems fundamentally different from those used by growth factors operating elsewhere in the body. Recent advances in the understanding of the structure of the receptors for neurotrophic factors have unexpectedly revealed that they are in fact similar to the receptors used by the traditional growth factors and cytokines. The expression of the receptors for the neurotrophic factors is exclusively or predominantly in the nervous system; activation of these receptors in the context of the neuron allows these factors to display distinctive actions. While the precise roles of the neurotrophic factors and their therapeutic potential in various disease slates still remain to be elucidated, this review describes studies on their receptor systems, their notable biological activities in the nervous system, and recent insights provided by targeted gene disruptions