Anti-Interleukin 5 (IL-5) and IL-5Ra Biological Drugs: Efficacy, Safety, and Future Perspectives in Severe Eosinophilic Asthma

The North-Western Italian experience with anti IL-5 therapy amd comparison with regulatory trials

BACKGROUND

The severe forms of asthma represent a major burden, because of severity of symptoms, costs and impact on everyday life. Recently, Mepolizumab (MEP) was approved and marketed for the treatment of hypereosinophilic severe asthma. This anti-IL-5 monoclonal antibody reduced exacerbation rates and oral corticosteroid (OCS) use in well selected patients. The aim of this study was to evaluate the characteristics of patients receiving MEP in a real-life setting. Thus, we describe a retrospective analysis of patients treated with MEP in six centres in North Western Italy, including those who participated in the main regulatory trials.

METHODS

The baseline data, before prescription, from six North Western Italy severe asthma clinics, between June 1st 2017 and December 31st 2017, were evaluated. The collected real-life data were then compared with those of SIRUS, MENSA, DREAM and MUSCA trials.

RESULTS

Sixty-five patients were included (45% female; mean age 56 years; age range 19-84). Main observed differences with regulatory trials could be observed in eosinophils blood count at baseline, where the mean of our real-life patients (653 cells/μL) was overall higher than the one of all trials (240 cells/μL, 296 cells/μL, 253 cells/μL; p <  0.0001). The incidence of polyposis was also significantly higher in our sample (72% vs. 24%, 49%, 10%, 19%; p <  0.0001). The daily average dose of OCS was lower in our real-life patients (9 mg), if compared with SIRIUS (13.7 mg), MENSA (13.2) and MUSCA (13), and similar to the data published in DREAM (10.8).

CONCLUSIONS

The comparison of real-life patients' characteristics with regulatory trials, displayed several apparent discrepancies. The demographic and clinical aspects were similar in all groups, whereas other features (eosinophil count, pulmonary function FEV1%) differed. These data, for the first time, could represent a basis for a more accurate prescription of the drug.

Anti-IL-5 and IL-5Ra: Efficacy and Safety of New Therapeutic Strategies in Severe Uncontrolled Asthma

The current developments of the new biological drugs targeting interleukin 5 (IL-5) and IL-5 receptor allowed to expand the treatment options for severe hypereosinophilic asthma. Clinicians will then be able to choose between antibodies targeting either circulating IL-5 or its receptor expressed on eosinophils and basophils. The available clinical trials consistently reported favorable results about the reduction of exacerbations rate, improvement in quality of life, and sparing of the systemic steroid use, with a favorable safety profile. Two of these new drugs are administered subcutaneously, mepolizumab every 4 weeks and benralizumab every 8 weeks, whereas reslizumab is given intravenously monthly on a weigh-based dose. In the future, the research actions will be involved in the identification of a single biomarker or multiple biomarkers for the optimal choice of biological agents to be properly prescribed.

The Severe Asthma Network in Italy: Findings and Perspectives

BACKGROUND

Severe Asthma Network in Italy (SANI) is a registry of patients recruited by accredited centers on severe asthma.

OBJECTIVE

To analyze epidemiological, clinical, inflammatory, functional, and treatment characteristics of severe asthmatics from the SANI registry.

METHODS

All consecutive patients with severe asthma were included into the registry, without exclusion criteria to have real-life data on demographics, asthma control, treatments (including biologics), inflammatory biomarkers, and comorbidities.

RESULTS

A total of 437 patients (mean age: 54.1 years, 57.2% females, 70.7% atopics, 94.5% in Global Initiative for Asthma severity step V) were enrolled into the study. The mean annual exacerbation rate was 3.75. The mean blood eosinophil level was 536.7 cells/mcL, and the average serum total IgE was 470.3 kU/L. Approximately 64% of patients were on regular oral corticosteroid treatment, 57% with omalizumab and 11.2% with mepolizumab. Most common comorbidities were rhinitis, nasal polyposis, and bronchiectasis. Patients with nasal polyposis had higher age of disease onset, higher blood eosinophil count, and lower frequency of atopy and atopic eczema. Bronchiectasis was associated with more frequent severe exacerbations, higher blood eosinophils, and total IgE. Stratifying patients, those with late-onset asthma were less frequently atopic (with less frequent allergic rhinitis and food allergy), and more frequently with nasal polyposis and higher serum total IgE levels.

CONCLUSIONS

This study revealed a high frequency of relevant comorbidities and that a substantial proportion of patients have late-onset asthma; all these features define specific different disease phenotypes. Severe asthma complexity and comorbidities require multidisciplinary approaches, led by specifically trained pulmonologists and allergists.

Targeting JAK-STAT signal transduction in IBD

An unmet medical need exists for novel targeted therapies for inflammatory bowel disease (IBD) as many patients experience inadequate responses to antibody-based biologics. An oral drug formulation with reduced production costs and redundancy for healthcare staff to administer therapy ideally should result in diminished healthcare expenses and improved patient compliance. A new drug class of small molecules, the Janus kinase (JAK) inhibitors (jakinibs), fulfills these criteria and has recently shown efficacy in IBD. Here we provide an overview of the mode of action of jakinibs and provide a comprehensive overview of existing clinical studies. Convincing clinical data show that a complex cytokine-driven inflammation can efficiently be modulated by therapeutic inhibition of the JAK proteins.

Anticalin® Proteins as Therapeutic Agents in Human Diseases

Anticalin proteins are an emerging class of clinical-stage biopharmaceuticals with high potential as an alternative to antibodies. Anticalin molecules are generated by combinatorial design from natural lipocalins, which are abundant plasma proteins in humans, and reveal a simple, compact fold dominated by a central β-barrel, supporting four structurally variable loops that form a binding site. Reshaping of this loop region results in Anticalin proteins that can recognize and tightly bind a wide range of medically relevant targets, from small molecules to peptides and proteins, as validated by X-ray structural analysis. Their robust format allows for modification in several ways, both as fusion proteins and by chemical conjugation, for example, to tune plasma half-life. Antagonistic Anticalin therapeutics have been developed for systemic administration (e.g., PRS-080: anti-hepcidin) or pulmonary delivery (e.g. PRS-060/AZD1402: anti-interleukin [IL]-4-Rα). Moreover, Anticalin proteins allow molecular formatting as bi- and even multispecific fusion proteins, especially in combination with antibodies that provide a second specificity. For example, PRS-343, which has recently entered clinical-stage development, combines an agonistic Anticalin targeting the costimulatory receptor 4-1BB with an antibody directed against the cancer antigen human epidermal growth factor receptor 2 (HER2), thus offering a novel treatment option in immuno-oncology.

Tralokinumab for severe, uncontrolled asthma (STRATOS 1 and STRATOS 2): two randomised, double-blind, placebo-controlled, phase 3 clinical trials

BACKGROUND

Tralokinumab is an anti-interleukin-13 human monoclonal antibody developed for the treatment of severe, uncontrolled asthma. These clinical trials aimed to assess the efficacy and safety of tralokinumab in this population.

METHODS

STRATOS 1 and STRATOS 2 were randomised, double-blind, parallel-group, placebo-controlled, phase 3 clinical trials that enrolled participants aged 12-75 years with severe asthma that was inadequately controlled despite use of inhaled corticosteroids (≥500 μg per day fluticasone or equivalent) and a long-acting β₂ agonist (but not oral corticosteroids). STRATOS 1 was done at 246 sites in 14 countries, and STRATOS 2 was done at 242 sites in 13 countries. In STRATOS 1, participants were randomly assigned (2:1) to receive tralokinumab 300 mg or matching placebo subcutaneously every 2 weeks or every 4 weeks for 52 weeks. In STRATOS 2, participants were randomly assigned (1:1) to receive tralokinumab 300 mg or matching placebo subcutaneously every 2 weeks for 52 weeks. STRATOS 1 attempted to identify a biomarker-positive population with enhanced tralokinumab benefit, which was then tested in STRATOS 2. The primary endpoint was the annualised asthma exacerbation rate (AAER) reduction at week 52 in the all-comers population for STRATOS 1 and in the biomarker-positive population for STRATOS 2. All efficacy analyses for both trials were done on the full analysis set by an intention-to-treat approach. The safety analysis set comprised any participant who received the investigational drug and was categorised by treatment received. These trials are registered with ClinicalTrials.gov, numbers NCT02161757 (STRATOS 1) and NCT02194699 (STRATOS 2), and with the EU Clinical Trials Register, EudraCT 2013-005614-35 (STRATOS 1) and EudraCT 2013-005615-27 (STRATOS 2).

FINDINGS

STRATOS 1 was done between June 13, 2014, and Feb 28, 2017. 1207 participants were randomly assigned and 1202 treated as follows: tralokinumab every 2 weeks (n=398), tralokinumab every 4 weeks (n=404), or placebo (n=400). STRATOS 2 was done between Oct 30, 2014, and Sept 21, 2017. 856 participants were randomly assigned and 849 treated as follows: tralokinumab every 2 weeks (n=427) and placebo every 2 weeks (n=422). In the STRATOS 1 all-comers population, tralokinumab every 2 weeks did not significantly reduce AAER compared with placebo (7·0% reduction [95% CI -20·8 to 28·4]; rate ratio 0·93 [95% CI 0·72 to 1·21]; p=0·59). Baseline fractional exhaled nitric oxide (FENO) 37 ppb or greater was identified as the preferred biomarker in STRATOS 1; in FENO-high participants, tralokinumab every 2 weeks (n=97) reduced AAER by 44·0% (95% CI 6·0 to 66·0; rate ratio 0·56 [95% CI 0·34 to 0·94]; p=0·028) compared with placebo (n=102). In the STRATOS 2 FENO-high population, tralokinumab every 2 weeks (n=108) did not significantly improve AAER (15·8% reduction [95% CI -33·7 to 47·0]; rate ratio 0·84 [95% CI 0·53 to 1·34]; p=0·47) compared with placebo (n=121). The safety profile was consistent with that of previous tralokinumab trials.

INTERPRETATION

Tralokinumab reduced AAER in participants with severe asthma with baseline FENO 37 ppb or higher in STRATOS 1, but not in STRATOS 2. These inconsistent effects on AAER do not support a key role for interleukin 13 in severe asthma exacerbations.

FUNDING

AstraZeneca.

Transcriptional profiling of eosinophil subsets in interleukin-5 transgenic mice

Eosinophils are important in fighting parasitic infections and are implicated in the pathogenesis of asthma and allergy. IL‐5 is a critical regulator of eosinophil development, controlling proliferation, differentiation, and maturation of the lineage. Mice that constitutively express IL‐5 have in excess of 10‐fold more eosinophils in the hematopoietic organs than their wild type (WT) counterparts. We have identified that much of this expansion is in a population of Siglec‐F high eosinophils, which are rare in WT mice. In this study, we assessed transcription in myeloid progenitors, eosinophil precursors, and Siglec‐F medium and Siglec‐F high eosinophils from IL‐5 transgenic mice and in doing so have created a useful resource for eosinophil biologists. We have then utilized these populations to construct an eosinophil trajectory based on gene expression and to identify gene sets that are associated with eosinophil lineage progression. Cell cycle genes were significantly associated with the trajectory, and we experimentally demonstrate an increasing trend toward quiescence along the trajectory. Additionally, we found gene expression changes associated with constitutive IL‐5 signaling in eosinophil progenitors, many of which were not observed in eosinophils.

Eosinophils in Interleukin‐5 transgenic mice can be subdivided by Siglec‐F expression, and are transcriptionally distinct.

Diabetes Downregulates Allergen-Induced Airway Inflammation in Mice

Previous studies described that allergic diseases, including asthma, occur less often than expected in patients with type 1 diabetes. Here, we investigated the influence of diabetes on allergic airway inflammation in a model of experimental asthma in mice. Diabetes was induced by intravenous injection of alloxan into 12 h-fasted A/J mice, followed by subcutaneous sensitization with ovalbumin (OVA) and aluminum hydroxide (Al(OH)₃), on days 5 and 19 after diabetes induction. Animals were intranasally challenged with OVA (25 μg), from day 24 to day 26. Alloxan-induced diabetes significantly attenuated airway inflammation as attested by the lower number of total leukocytes in the bronchoalveolar lavage fluid, mainly neutrophils and eosinophils. Suppression of eosinophil infiltration in the peribronchiolar space and generation of eosinophilotactic mediators, such as CCL-11/eotaxin, CCL-3/MIP-1α, and IL-5, were noted in the lungs of diabetic sensitized mice. In parallel, reduction of airway hyperreactivity (AHR) to methacholine, mucus production, and serum IgE levels was also noted under diabetic conditions. Our findings show that alloxan diabetes caused attenuation of lung allergic inflammatory response in A/J mice, by a mechanism possibly associated with downregulation of IgE antibody production.

Eosinophilic Granulomatosis With Polyangiitis: Newer Therapies

PURPOSE OF REVIEW

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic disseminated vasculitis associated with extravascular granulomas in patients suffering from asthma and tissue eosinophilia. Current therapies to achieve remission and prevent relapse include glucocorticoids and immunosuppressants like cyclophosphamide.

RECENT FINDINGS

With the right treatment, clinical prognosis is favorable, so concerted efforts have been made in recent years to find new alternatives for treating severe EGPA. Monoclonal antibodies such as omalizumab, rituximab, and mepolizumab are among these new options. This review summarizes the pathogenesis and clinical manifestations of EGPA and critically examines current and emerging therapies.

Eosinophils from Physiology to Disease: A Comprehensive Review

Despite being the second least represented granulocyte subpopulation in the circulating blood, eosinophils are receiving a growing interest from the scientific community, due to their complex pathophysiological role in a broad range of local and systemic inflammatory diseases as well as in cancer and thrombosis. Eosinophils are crucial for the control of parasitic infections, but increasing evidence suggests that they are also involved in vital defensive tasks against bacterial and viral pathogens including HIV. On the other side of the coin, eosinophil potential to provide a strong defensive response against invading microbes through the release of a large array of compounds can prove toxic to the host tissues and dysregulate haemostasis. Increasing knowledge of eosinophil biological behaviour is leading to major changes in established paradigms for the classification and diagnosis of several allergic and autoimmune diseases and has paved the way to a "golden age" of eosinophil-targeted agents. In this review, we provide a comprehensive update on the pathophysiological role of eosinophils in host defence, inflammation, and cancer and discuss potential clinical implications in light of recent therapeutic advances.