Anti-immunoglobulin E therapy for asthma

PM2.5 exposure promotes asthma in aged Brown-Norway rats: Implication of multiomics analysis

Children are disproportionately represented among those who suffer asthma, which is a kind of chronic airway inflammation. Asthma symptoms might worsen when exposed to the air pollutant particulate matter 2.5 (PM2.5). However, it is becoming more prevalent among older adults, with more asthma-related deaths occurring in this pollution than in any other age group, and symptoms caused by asthma can reduce the quality of life of the elderly, whose asthma is underdiagnosed due to physiological factors. Therefore, in an effort to discover a therapy for older asthma during exposure to air pollution, we sought to ascertain the effects of pre-exposure (PA) and persistent exposure (PAP) to PM2.5 in aged asthma rats. In this study, we exposed aged rats to PM2.5 at different times (PA and PAP) and established an ovalbumin-mediated allergic asthma model. The basic process of elderly asthma caused by PM2.5 exposure was investigated by lung function detection, enzyme-linked immunosorbent assay (ELISA), histopathology, cytology, cytokine microarray, untargeted metabolomics, and gut microbiota analysis. Our findings demonstrated that in the PA and PAP groups, exposure to PM2.5 reduced lung function and exacerbated lung tissue damage, with varying degrees of effect on immunoglobulin levels, the findings of a cytological analysis, cytokines, and chemokines. The PA and PAP rats had higher amounts of polycyclic aromatic hydrocarbons (PAHs), such as naphthalene, 2-methylNaphthalene, 1-methylNaphthalene and flourene. Moreover, exposure to PM2.5 at different times showed different effects on plasma metabolism and gut microbiota. Bioinformatics analysis showed a strong correlation between PAHs, cytokines, and gut microbiota, and PAHs may cause metabolic disorders through the gut microbiota. These findings point to a possible mechanism for the development of asthma in older people exposure to PM2.5 that may be related to past interactions between PAHs, cytokines, gut microbiota, and plasma metabolites.

Long-term efficacy and safety of omalizumab in patients with persistent uncontrolled allergic asthma: a systematic review and meta-analysis

Currently, limited information is available to clinicians regarding the long-term efficacy of omalizumab treatment for allergic asthma. In this report, we aimed to (i) systematically review the evidence regarding the long-term efficacy of omalizumab in patients with persistent uncontrolled allergic asthma, and to (ii) discuss the cost-effectiveness evidence published for omalizumab in this patient population. A comprehensive search for randomized controlled trials (RCTs; ≥52 weeks) was performed, and six studies met our final inclusion criteria (n = 2,749). Omalizumab was associated with significant improvements in quality of life and the Global Evaluation of Treatment Effectiveness. Omalizumab also allowed patients to completely withdraw from inhaled corticosteroid therapy and did not increase the overall incidence of adverse events. However, there was insufficient evidence that omalizumab reduced the incidence of exacerbations, and the cost-effectiveness of omalizumab varied across studies. Our data indicated that omalizumab use for at least 52 weeks in patients with persistent uncontrolled allergic asthma was accompanied by an acceptable safety profile, but it lacked effect on the asthma exacerbations. Use of omalizumab was associated with a higher cost than conventional therapy, but these increases may be cost-effective if the medication is used in patients with severe allergic asthma.

Profile of patients treated with omalizumab in routine clinical practice in Spain

BACKGROUND

Omalizumab is indicated in patients with severe allergic asthma not controlled by high-dose inhaled glucocorticoids and long-acting beta-agonists. Few data are available on the profile of patients treated with this drug in routine clinical practice in Spain.

OBJECTIVE

To describe the profile of patients with severe allergic asthma treated with omalizumab and the course of the disease after a period of treatment.

METHODS

Retrospective, multicentre study, recording the data on patients of either sex and ≥12 years with uncontrolled severe allergic asthma, previously treated with omalizumab. Data were evaluated in relation to pulmonary function, symptoms, quality of life, and concomitant anti-asthma treatment before the prescription of omalizumab and at the time of the study visit.

RESULTS

214 patients were evaluable (mean age=48.2±17.7 years; mean age at the time of diagnosis=26.6±16.5 years). 90.7% had experienced exacerbations the year before receiving omalizumab, and the mean total IgE level was 273±205.4IU/ml. The mean monthly dose was 380.5±185.4mg. Compared with the baseline situation, differences were observed after treatment with omalizumab in mean FEV1 (62.7±15.9% vs. 70.8±18.7%), in the proportion of patients requiring oral corticosteroids (47.7% vs. 14.0%), and in the ACQ and AQLQ scores. 32.7% of the patients received doses not recommended by the Summary of Product Characteristics (SPC).

CONCLUSIONS

Profile of asthmatic patients treated with omalizumab predominantly corresponds to uncontrolled severe asthma cases, in accordance with SPC's indications. The results of the study suggest a favourable clinical course similar to that observed in other studies.

Pharmacokinetics and concentration–effect relationships of therapeutic monoclonal antibodies and fusion proteins

Although monoclonal antibodies (mAbs) constitute a major advance in therapeutics, their pharmacokinetic (PK) and pharmacodynamic (PD) properties are not fully understood. Saturable mechanisms are thought to occur in distribution and elimination of mAbs, which are protected from degradation by the Brambell's receptor (FcRn). The binding of mAbs to their target antigen explains part of their nonlinear PK and PD properties. The interindividual variability in mAb PK can be explained by several factors, including immune response against the biodrug and differences in the number of antigenic sites. The concentration-effect relationships of mAbs are complex and dependent on their mechanism of action. Interindividual differences in mAb PD can be explained by factors such as genetics and clinical status. PK and concentration-effect studies are necessary to design optimal dosing regimens. Because of their above-mentioned characteristics, the interindividual variability in their dose-response relationships must be studied by PK-PD modelling.

JTP-27536 [(+)-1,3-dihydroxy-2-hydroxymethylpropyl-2-ammonium 2-[(R)-3-cyclo-hexyl-1-phenylpropyl]-1,3-dioxo-2,3-dihydro-1H-isoindole-5-carboxylate monohydrate], a novel inhibitor of immunoglobulins and interleukin-5 with anti-inflammatory properties in mouse allergic dermatitis model

We report a novel synthetic compound JTP-27536 [(+)-1,3-dihydroxy-2-hydroxymethylpropyl-2-ammonium 2-[(R)-3-cyclohexyl-1-phenylpropyl]-1,3-dioxo-2,3-dihydro-1H-isoindole-5-carboxylate monohydrate] as an inhibitor of immunoglobulins (Igs) and interleukin (IL)-5 production in vitro and in vivo. JTP-27536 inhibited IgE production in mouse and human B cells with IC50 values of 2.5 and 2.1 microM, respectively, and the inhibition was stronger than that on IgG1 and IgM production (IC50 > 10 microM). JTP-27536 also inhibited IL-5 production in mouse splenocytes and human peripheral blood mononuclear cells with IC50 values of 3.3 and 1.3 microM, respectively, without affecting mouse interferon (IFN)-gamma, IL-2, IL-4, IL-10, or human IL-4 production. In contrast, prednisolone not only inhibited mouse IgE production but also mouse IFN-gamma, IL-2, IL-4, and IL-10 and human IL-4 and IL-5 production in vitro. The effect of suplatast tosilate, a Th2 cytokine inhibitor, on antibody and cytokine production was less potent than that of JTP-27536. In vivo animal experiments using dinitrophenylated ascaris-sensitized mice and 2,4,6-trinitro-1-chrolobenzene-induced chronic dermatitis mice showed that JTP-27536 was more potent than suplatast tosilate and comparable with prednisolone in inhibiting ear swelling, antigen-specific IgE and IL-5 production, and cell infiltrations into the inflamed tissue. These results indicate that JTP-27536 is an inhibitor of Igs, in particular IgE, and of IL-5, which has antiallergic properties in mouse dermatitis model, and suggest that an inhibitor of Igs and IL-5 like JTP-27536 may be useful as a drug for the treatment of allergic diseases.

Convergent Recognition of the IgE Binding Site on the High-Affinity IgE Receptor

Two structurally distinct classes of peptides were recently identified by phage display that bind the high-affinity IgE receptor, FcepsilonRI, and block IgE binding and subsequent receptor activation. Both classes adopt highly stable structures in solution, one forming a beta hairpin, with the other forming a helical "zeta" structure. Despite these differences, the two classes bind competitively to the same site on the receptor. Structural analyses of both peptide-receptor complexes by NMR spectroscopy and/or X-ray crystallography reveal that the unrelated peptide scaffolds have nevertheless converged to present a similar three-dimensional surface to interact with FcepsilonRI and that their modes of interaction share a key feature of the IgE-FcepsilonRI complex, the proline/tryptophan sandwich.

Omalizumab is effective in the long-term control of severe allergic asthma

BACKGROUND

Previous reports show that addition of omalizumab to standard therapy reduces asthma exacerbations and simultaneously decreases use of inhaled corticosteroids (ICSs) and rescue medication in patients with allergic asthma.

OBJECTIVE

To determine the effect of omalizumab on long-term disease control in patients with severe allergic asthma.

METHODS

The present study concerns the 24-week, double-blind extension phase to a previous 28-week core study in which patients received subcutaneous omalizumab or matching placebo (at least 0.016 mg/kg/IgE [IU/mL] every 4 weeks) for 16 weeks in addition to their existing ICS therapy (beclomethasone dipropionate [BDP]; steroid-stable phase), followed by a 12-week phase in which controlled attempts were made to gradually reduce ICS therapy (steroid-reduction phase). During the extension phase patients were maintained on randomized treatment (omalizumab or placebo) and the lowest sustainable dose of BDP. The use of other asthma medications was permitted during the extension phase. Investigators were also allowed to switch patients from BDP to other ICS medications if considered necessary.

RESULTS

A total of 460 patients (omalizumab, n = 245; placebo, n = 215) entered the extension phase. Overall, omalizumab-treated patients experienced significantly fewer exacerbations vs placebo during the extension phase (0.60 and 0.83 exacerbations per patient, respectively; P = 0.023), despite a sustained significant reduction in their use of ICS (mean BDP equivalent dose: omalizumab, 227 microg/d; placebo, 335 microg/d; P < 0.001). Treatment with omalizumab was well tolerated and the incidence of adverse events was similar in both treatment groups.

CONCLUSIONS

These results indicate that omalizumab is effective in the long-term control of severe allergic asthma.