Biologics for the Treatments of Allergic Conditions: Severe Asthma

Dupilumab Efficacy on Asthma Functional, Inflammatory, and Patient-Reported Outcomes across Different Disease Phenotypes and Severity: A Real-Life Perspective

Dupilumab is currently approved for the treatment of Type 2 severe asthma and chronic rhinosinusitis with nasal polyps (CRSwNP). Few studies have specifically reported on dupilumab efficacy on asthma outcomes as a primary objective in a real-life setting, in patients with and without CRSwNP. Our study aimed to explore the efficacy of dupilumab on functional, inflammatory, and patient-reported outcomes in asthma patients across different disease phenotypes and severity, including mild-to-moderate asthma coexisting with CRSwNP. Data from 3, 6, and 12 months follow-up were analyzed. Asthma (FEV1%, Tiffeneau%, ACT, FeNO, oral steroid use, exacerbation rate, and blood eosinophilia) and polyposis (SNOT22, VAS, NPS) outcomes showed a rapid (3 months) and sustained (6 and 12 months) significant change from baseline, despite most of the patients achieving oral steroid withdrawal. According to the sensitivity analysis, the improvement was not conditioned by either the presence of polyposis or severity of asthma at baseline. Of note, even in the case of milder asthma forms, a significant further improvement was recorded during dupilumab treatment course. Our report provides short-, medium-, and long-term follow-up data on asthma outcomes across different diseases phenotypes and severity, contributing to the real-world evidence related to dupilumab efficacy on upper and lower airways T2 inflammation.

Remission in Type 2 Inflammatory Diseases: Current Evidence, Unmet Needs, and Suggestions for Defining Remission in Chronic Rhinosinusitis with Nasal Polyps

PURPOSE OF REVIEW

The development of biological therapies for type 2 inflammatory diseases raises the possibility of addressing remission in those dis-immune conditions. No consensus exists for a definition of remission in chronic rhinosinusitis with nasal polyps (CRSwNP). This review aims to critically evaluate the published data to provide the basis for defining remission in CRSwNP.

RECENT FINDINGS

The published evidence has yet to provide an unequivocal definition on remission in type 2 inflammatory diseases, in part reflecting differences in approaches to diagnosis and follow-up. A multidimensional evaluation is necessary when considering complete remission, including clinical, inflammatory, and histologic criteria, but how to combine or tailor the three perspectives according to disease severity at baseline or timing of assessment of treatment category is yet to reach consensus. We suggest defining remission starting from the approach taken in asthma and eosinophilic esophagitis, that is, including the resolution of symptoms and improvements in objective parameters of disease severity and/or inflammatory activity. Future studies and consensuses should provide validated criteria with cutoffs for the day-to-day definition of remission. The definition of remission in CRSwNP should include the following criteria, to be verified and maintained for a period of ≥ 12 months: absence of symptoms (nasal obstruction, loss of smell, rhinorrhea as the main ones); no impact of symptoms on quality of life; no need of surgery; no chronic or rescue medications (systemic corticosteroids or antibiotics); and recovery of smell function, possibly evaluated by objective test. Assessment of underlying inflammation should also be considered once accurate and feasible biomarkers are available in clinical practice.

Benralizumab Efficacy in Late Non-Responders to Mepolizumab and Variables Associated with Occurrence of Switching: A Real-Word Perspective

Overlapping eligibility to different biologics for severe asthma is still challenging, especially when addressing the same target. We aimed to characterize severe eosinophilic asthma patients according to their maintained or reduced response to mepolizumab over time and to explore baseline variables significantly associated with the occurrence of switching to benralizumab. We performed a multicentre retrospective observational study evaluating OCS reduction, exacerbation rate, lung function, exhaled nitric oxide levels (FeNO), Asthma control test (ACT), and blood eosinophil concentrations at baseline and before and after switching occurrence among 43 female and 25 male patients with severe asthma aged 23 to 84 years. Younger age, higher OCS daily dose and lower blood eosinophils at baseline were associated with a significantly higher risk (odds) for switching occurrence. All the patients showed an optimal response to mepolizumab, up to six months. The need for switching, according to the above-mentioned criterion, occurred for 30 out of 68 patients after a median time of 21 months (Q1-Q3: 12-24) from mepolizumab initiation. At the follow-up time-point after the switch (median time: 31 months, Q-Q3: 22-35), all the outcomes substantially improved and no cases of poor clinical response to benralizumab were detected. Although the small sample size and the retrospective design represent major limitations, to our knowledge, our study provides the first real-word focus on clinical variables potentially predicting a better response to anti IL-5r in patients fully eligible for both mepolizumab and benralizumab and suggests that in late non responder patients to mepolizumab, more robustly targeting the IL-5 axis may be effective.

Biologics for eosinophilic granulomatosis with polyangiitis

PURPOSE OF REVIEW

The link between severe asthma and eosinophilic granulomatosis with polyangiitis (EGPA) in terms of pathophysiological background, clinical manifestations and disease evolution has leaded to investigate the relevance of anti T2 monoclonal antibodies licensed for severe asthma patients as a treatment option for EGPA. The present review aimed to provide un update on EGPA pathophysiology and to critically summarize the most robust evidence coming from trials and real-life setting on the use of anti T2 biologics in EGPA patients.

RECENT FINDINGS

Mepolizumab, an anti-interleukin-5 monoclonal antibody, is the only biologic drug targeting eosinophilic inflammation currently approved for EGPA treatment at the dose of 300 mg/4 weeks. Its use is restricted by the American College of Rheumatology guidelines to specific diseases phases and severity grades. However the most appropriate mepolizumab positioning and dose is still under investigation in the real life practice, which is providing an increasing amount of evidence confirming its efficacy, alone or in combination with other options in different disease stages. The relevance of other monoclonal antibodies interfering with T2 inflammation, including omalizumab and benralizumab, is under investigation but the evidence is still scarce.

SUMMARY

Taking into account the suboptimal medium-long term safety profile of conventional EGPA treatments, the opportunity of selectively targeting eosinophilic inflammation certainly represents a revolutionary approach. However, further real-word evidence is required to effectively position the new treatments in the light of the disease complexity, including different immunological drivers, and individual variability.

Severe asthma in the era of COVID-19: A narrative review

INTRODUCTION AND OBJECTIVES

Severe asthma management during the coronavirus disease 2019 (COVID-19) pandemic is a challenge and will continue to be, at least in the next few months, as herd immunity is still a mirage. A lot has to be learned about how COVID-19 affects underlying diseases, and severe asthma is no exception.

METHODS

Narrative review of papers available until February 2021 in PubMed and Google Scholar, relating severe asthma and COVID-19. Four main research topics were reviewed: SARS-CoV-2 infection: immunology and respiratory pathology; interrelationship of severe asthma endotypes and COVID-19 disease mechanisms; severe asthma epidemiology and COVID-19; and biologics for severe asthma in the context of COVID-19.

RESULTS

COVID-19 disease mechanisms start with upper respiratory cell infection, and afterwards several immunological facets are activated, contributing to disease severity, namely cell-mediated immunity and antibody production. Although infrequent in the COVID-19 course some patients develop a cytokine storm that causes organ damage and may lead to acute respiratory distress syndrome or multiorgan failure. Regarding severe asthma endotypes, type2-high might have a protective role both in infection risk and disease course. There is conflicting data regarding the epidemiological relationship between COVID-19 among severe asthma patients, with some studies reporting increased risk of infection and disease course, whereas others the other way round. Biologics for severe asthma do not seem to increase the risk of infection and severe COVID-19, although further evidence is needed.

CONCLUSIONS

Globally, in the era of COVID-19, major respiratory societies recommend continuing the biologic treatment, preferably in a self-home administration program.

G Protein-Coupled Receptor Kinase 2 (GRK2) Regulates T Cell Response in a Murine Model of House Dust Mite-Induced Asthma

G protein-coupled receptor kinase 2 (GRK2) is an adapter protein that modulates G protein-coupled receptor (GPCR) signaling. It also regulates the functions and activity of other intracellular proteins in many cell types. Accordingly, GRK2 is thought to contribute to disease progression by a variety of mechanisms related to its multifunctional roles. Indeed, GRK2 levels are enhanced in patient samples as well as in preclinical models of several diseases. We have previously shown that GRK2 regulates mast cell functions, and thereby contributes to exacerbated inflammation during allergic reactions. In the current study, we observed that GRK2 levels are enhanced in the lungs of human asthma patients and in mice sensitized to house dust mite extract (HDME) allergen. Consistent with these findings, interleukin (IL)-4 and IL-13 levels were reduced in the lungs of GRK2+/- mice in a HMDE mouse model of asthma. Because Th2 cells are the major source of these cytokines during asthma, we determined the role of GRK2 in regulating T cell-specific responses in our HMDE mouse model. We observed a significant reduction of airway hyperresponsiveness (AHR), lung eosinophil and lymphocyte counts, serum IgE, Th2 cytokines (IL-4 and IL-13), goblet cell hyperplasia and mucus production in mice that had reduced GRK2 expression specifically in T cells. Collectively, our studies reveal an important role for GRK2 in regulating T cell response during asthma pathogenesis and further elucidation of the mechanisms through which GRK2 modulates airway inflammation will lead to the development of new therapeutic strategies for asthma.

Uncontrolled Asthma: Unmet Needs in the Management of Patients

The recent scientific research has provided clinicians with the tools for substantially upgrading the standard of care in the field of bronchial asthma. Nevertheless, satisfactory asthma control still remains an unmet need worldwide. Identifying the major determinants of poor control in different asthma severity levels represents the first step towards the improvement of the overall patients' management. The present review aims to provide an overview of the main unmet needs in asthma control and of the potential tools for overcoming the issue. Implementing a personalized medicine approach is essential, not only in terms of pharmacological treatments, biologic drugs or sophisticated biomarkers. In fact, exploring the complex profile of each patient, from his inflammation phenotype to his preferences and expectations, may help in filling the gap between the big potential of currently available treatments and the overall unsatisfactory asthma control. Telemedicine and e-health technologies may provide a strategy to both optimize disease assessment on a regular basis and enhance patients' empowerment in managing their asthma. Increasing patients' awareness as well as the physicians' knowledge about asthma phenotypes and treatment options besides corticosteroid probably represent the key and more difficult goals of all the players involved in asthma management at every level.

Imperatorin ameliorates mast cell-mediated allergic airway inflammation by inhibiting MRGPRX2 and CamKII/ERK signaling pathway

BACKGROUND

Allergic asthma is a common inflammatory lung disease associated with complex pathogenesis. Mast cell (MC) is one of the key drivers of allergic asthma, Mas-related G protein-coupled receptor X2 (MRGPRX2) on the MC could mediate MC activation and trigger a pseudo-allergic reaction. Imperatorin (IMP), the main active compound of Radix Angelicae Dahuricae, has been reported to exert various pharmacological effects. In this study, we focused on the therapeutical mechanism of IMP on MRGPRX2-induced pseudo-allergy and allergic asthma.

METHODS

We examined the effect of IMP on MRGPRX2 related mast cell activation in mouse peritoneal MC (MPMC), Human Laboratory of Allergic Disease 2 MCs (LAD2 cells) and Mrgprx2-expressing HEK293 cells. Molecular docking and Surface plasmon resonance (SPR) were taken to reveal the binding character between IMP and MRPGRX2. MRGPRX2 downstream proteins were also detected by western blotting. IgE-independent responses was evaluated by using passive cutaneous anaphylaxis (PCA) and active systemic anaphylaxis (ASA) models. The therapeutic effect of IMP on asthma was evaluated by a lung inflammation mouse model which was induced by ovalbumin (OVA).

RESULTS

IMP was found to reduce substance P (SP) induced calcium flux and suppressed degranulation of MC. SP can promote the phosphorylation of ERK and CamKII, which regulates the synthesis of inflammatory factors such as MIP-2 and TNF-α in MC. In vivo assays revealed that IMP can mitigate SP-induced mouse PCA and ASA. IMP could also mitigate lung inflammation in an OVA induced mice model by inhibiting MC activation in the lung tissue. Furthermore, IMP binds well to MRGPRX2 protein. The binding constant (KD) is 4.48 ± 0.49 × 10-7 M. The data suggeste that IMP is a novel inhibitor of MRGPRX2 to treat allergic asthma.

Precision Medicine in House Dust Mite-Driven Allergic Asthma

House dust mites (HDMs) are the allergenic sources most frequently involved in airway allergy. Nevertheless, not every sensitized patient develops respiratory symptoms upon exposure to HDM, and there is a clinical need to differentiate allergic asthmatics (AAs) from atopic non-allergic asthmatics with HDM sensitization. This differentiation sometimes requires in vivo provocations like the bronchial allergen challenge (BAC). Interestingly, recent data demonstrate that non-atopic patients with asthma can also develop positive BAC results. This novel phenotype has been termed local allergic asthma (LAA). The interest in identifying the allergic triggers of asthma resides in the possibility of administering allergen immunotherapy (AIT). AIT is a disease-modifying intervention, the clinical benefit of which persists after therapy discontinuation. Recently, new modalities of sublingual tablets of HDM immunotherapy registered as pharmaceutical products (HDM-SLIT tablets) have become commercially available. HDM-SLIT tablets have demonstrated a robust effect over critical asthma parameters (dose of inhaled corticosteroids, exacerbations, and safety), thus being recommended by international guidelines for patients with HDM-driven AA. In this review, we will summarize the current knowledge on the phenotype and endotype of HDM-driven AA, and LAA, address the difficulties for BAC implementation in the clinic, and discuss the effects of AIT in AA and LAA.