Biologics in Asthma: Role of Biomarkers.

Our modern understanding of asthma mainly concerns identification of inflammatory endotype to guide management. The distinction mostly concerns identification of type-2 inflammation, for which different biomarkers have been well characterized. Blood eosinophils corroborate activity in the interleukin (IL)-5 axis while fraction of exhaled nitric oxide is indicative of the IL-4/IL-13 axis, giving us an indication of activity in these distinct but complementary pathways. These biomarkers predict disease activity, with increased risk of exacerbations when elevated, and a further, multiplicative increase when both are elevated. Serum immunoglobulin E is also implicated in this pathway, and can represent allergen-related stimulation.

Twice-Yearly Depemokimab in Severe Asthma with an Eosinophilic Phenotype.

BACKGROUND: Depemokimab is an ultra-long-acting biologic therapy with enhanced binding affinity for interleukin-5 that may enable effective 6-month dosing intervals. METHODS: In these phase 3A, randomized, placebo-controlled replicate trials, we evaluated the efficacy and safety of depemokimab in patients with severe asthma and an eosinophilic phenotype characterized by a high eosinophil count (≥300 cells per microliter in the previous 12 months or ≥150 cells per microliter at screening) and a history of exacerbations despite the receipt of medium- or high-dose inhaled glucocorticoids. Patients were randomly assigned in a 2:1 ratio to receive either depemokimab (at a dose of 100 mg subcutaneously) or placebo at weeks 0 and 26, plus standard care. The primary end point was the annualized rate of exacerbations at 52 weeks. Secondary end points, which were analyzed in a hierarchical manner to adjust for multiplicity, included the change from baseline in the score on the St. George's Respiratory Questionnaire (SGRQ), the forced expiratory volume in 1 second, and asthma symptom reports at 52 weeks. RESULTS: Across the two trials, 792 patients underwent randomization and 762 were included in the full analysis; 502 were assigned to receive depemokimab and 260 to receive placebo. The annualized rate of exacerbations was 0.46 (95% confidence interval [CI]), 0.36 to 0.58) with depemokimab and 1.11 (95% CI, 0.86 to 1.43) with placebo (rate ratio, 0.42; 95% CI, 0.30 to 0.59; P<0.001) in SWIFT-1 and 0.56 (95% CI, 0.44 to 0.70) with depemokimab and 1.08 (95% CI, 0.83 to 1.41) with placebo (rate ratio, 0.52; 95% CI, 0.36 to 0.73; P<0.001) in SWIFT-2. No significant between-group difference in the change from baseline in the SGRQ score was observed in either trial, so no statistical inference was drawn on subsequent secondary end points. The proportion of patients with any adverse event was similar in the two groups in both trials. CONCLUSIONS: Depemokimab reduced the annualized rate of exacerbations among patients with severe asthma with an eosinophilic phenotype. (Funded by GSK; SWIFT-1 and SWIFT-2 ClinicalTrials.gov numbers, NCT04719832 and NCT04718103.).

Choosing the Right Biologic for the Right Patient With Severe Asthma.

In this instalment of the How I Do It series on severe asthma, we tackle the clinical conundrum of choosing the right biologic for the right patient with severe asthma. With 6 biologics now approved for use in this area comprising 4 different targeting strategies (anti-Ig E: omalizumab; anti-IL-5 and anti-IL-5-receptor: mepolizumab, reslizumab, and benralizumab; anti-IL-4-receptor: dupilumab; anti-thymic stromal lymphopoietin: tezepelumab), this question is increasingly complex. Recognizing that no head-to-head trial has compared biologics, we based our review on the expected effects of inhibiting different aspects of type 2 airway inflammation, supported whenever possible by clinical trial and real-world data. We use 4 variations of a case of severe uncontrolled asthma to develop concepts and considerations introduced in the previous installment ("Workup of Severe Asthma") and discuss pregnancy-related, biomarker-related, comorbidity-related, and corticosteroid dependency-related considerations when choosing a biologic. The related questions of deciding when, why, and how to switch from one biologic to another also are discussed. Overall, we consider that the choice of biologics should be based on the available clinical trial data for the desired efficacy outcomes, the biomarker profile of the patient, safety profiles (eg, when pregnancy is considered), and opportunities to target 2 comorbidities with 1 biologic. Using systemic and airway biomarkers (blood eosinophils and exhaled nitric oxide) and other phenotypic characteristics, we suggest a framework to facilitate therapeutic decision-making. Post hoc studies and new comparative studies are needed urgently to test this framework and to determine whether it allows us to make other clinically useful predictions.

Clinical response and on-treatment clinical remission with tezepelumab in a broad population of patients with severe, uncontrolled asthma: results over 2 years from the NAVIGATOR and DESTINATION studies.

BACKGROUND: In asthma, clinical response is characterized by disease improvement with treatment, whereas clinical remission is characterized by long-term disease stabilization with or without ongoing treatment. The proportion of patients receiving tezepelumab who responded to treatment and those who achieved on-treatment clinical remission was assessed in the NAVIGATOR (NCT03347279) and DESTINATION (NCT03706079) studies of severe, uncontrolled asthma. METHODS: NAVIGATOR and DESTINATION were phase 3, randomized, double-blind, placebo-controlled studies; DESTINATION was an extension of NAVIGATOR. Complete clinical response was defined as achieving all of the following: ≥50% reduction in exacerbations versus the previous year, improvements in pre-bronchodilator (BD) forced expiratory volume in 1 s (FEV1) of ≥100 mL or ≥5%, improvements in Asthma Control Questionnaire (ACQ)-6 score of ≥0.5 and physicians' assessment of asthma improvement. On-treatment clinical remission was defined as an ACQ-6 total score ≤1.5, stable lung function (pre-BD FEV1 >95% of baseline) and no exacerbations or use of oral corticosteroids during the time periods assessed. RESULTS: Higher proportions of tezepelumab than placebo recipients achieved complete clinical response over weeks 0-52 (46% versus 24%; OR: 2.83 [95% CI: 2.10-3.82]), and on-treatment clinical remission over weeks 0-52 (28.5% versus 21.9%; OR: 1.44 [95% CI: 0.95-2.19]) and weeks >52-104 (33.5% versus 26.7%; OR: 1.44 [95% CI: 0.97-2.14]). Tezepelumab recipients who achieved on-treatment clinical remission versus complete clinical response at week 52 had better preserved lung function and lower inflammatory biomarkers at baseline, and fewer exacerbations in the 12 months before the study. CONCLUSIONS: Among patients with severe, uncontrolled asthma, tezepelumab treatment was associated with an increased likelihood of achieving complete clinical response and on-treatment clinical remission compared with placebo. Both are clinically important outcomes but may be driven by different patient characteristics.

Species-level, metagenomic and proteomic analysis of microbe-immune interactions in severe asthma.

BACKGROUND: The airway microbiome in severe asthma has not been characterised at species-level by metagenomic sequencing, nor have the relationships between specific species and mucosal immune responses in 'type-2 low', neutrophilic asthma been defined. We performed an integrated species-level metagenomic data with inflammatory mediators to characterise prevalence of dominant potentially pathogenic organisms and host immune responses. METHODS: Sputum and nasal lavage samples were analysed using long-read metagenomic sequencing with Nanopore and qPCR in two cross-sectional adult severe asthma cohorts, Wessex (n = 66) and Oxford (n = 30). We integrated species-level data with clinical parameters and 39 selected airway proteins measured by immunoassay and O-link. RESULTS: The sputum microbiome in health and mild asthma displayed comparable microbial diversity. By contrast, 23% (19/81) of severe asthma microbiomes were dominated by a single respiratory pathogen, namely H. influenzae (n = 10), M. catarrhalis (n = 4), S. pneumoniae (n = 4) and P. aeruginosa (n = 1). Neutrophilic asthma was associated with H. influenzae, M. catarrhalis, S. pneumoniae and T. whipplei with elevated type-1 cytokines and proteases; eosinophilic asthma with higher M. catarrhalis, but lower H. influenzae, and S. pneumoniae abundance. H. influenzae load correlated with Eosinophil Cationic Protein, elastase and IL-10. R. mucilaginosa associated positively with IL-6 and negatively with FGF. Bayesian network analysis also revealed close and distinct relationships of H. influenzae and M. catarrhalis with type-1 airway inflammation. The microbiomes and cytokine milieu were distinct between upper and lower airways. CONCLUSIONS: This species-level integrated analysis reveals central, but distinct associations between potentially pathogenic bacteria and airways inflammation in severe asthma.

Airway proteomics reveals broad residual anti-inflammatory effects of prednisolone in mepolizumab-treated asthma.

BACKGROUND: Mepolizumab is an anti-IL-5 mAb treatment for severe eosinophilic asthma that reduces asthma exacerbations. Residual airway inflammation with mepolizumab therapy may lead to persistent exacerbations. Oral corticosteroids remain the main treatment for these residual exacerbations. OBJECTIVE: Our study aimed to explore the corticosteroid responsiveness of airway inflammation after mepolizumab treatment to find potentially treatable inflammatory mechanisms beyond the IL-5 pathway. METHODS: The MAPLE trial was a multicenter, randomized, double-blind, placebo-controlled, crossover study of 2 weeks of high-dose oral prednisolone treatment at stable state in 27 patients treated with mepolizumab for severe eosinophilic asthma. We analyzed paired sputum (n = 16) and plasma (n = 25) samples from the MAPLE trial using high-throughput Olink proteomics. We analyzed additional sputum proteins using ELISA. RESULTS: In patients receiving mepolizumab, prednisolone significantly downregulated sputum proteins related to type 2 inflammation and chemotaxis including IL-4, IL-5, IL-13, CCL24, CCL26, EDN, CCL17, CCL22, OX40 receptor, FCER2, and the ST2 receptor. Prednisolone also downregulated cell adhesion molecules, prostaglandin synthases, mast cell tryptases, MMP1, MMP12, and neuroimmune mediators. Neutrophilic pathways were upregulated. Type 2 proteins were also downregulated in plasma, combined with IL-12, IFN-γ, and IP-10. IL-10 and amphiregulin were upregulated. CONCLUSIONS: At stable state, prednisolone has broad anti-inflammatory effects on top of mepolizumab. These effects are heterogeneous and may be clinically relevant in residual exacerbations.

Clinical characterisation of exacerbations of severe eosinophilic asthma occurring on mepolizumab and placebo.

Asthma exacerbations in people treated with mepolizumab result in less peak expiratory flow reduction than placebo but similar symptom scores. Symptoms recover slower, indicating these exacerbations may be less prednisolone responsive. https://bit.ly/3xQsFRB.

Type 2 severe asthma: pathophysiology and treatment with biologics.

INTRODUCTION: The hallmark of most patients with severe asthma is type 2 inflammation, driven by innate and adaptive immune responses leading to either allergic or non-allergic eosinophilic infiltration of airways. The cellular and molecular pathways underlying severe type 2 asthma can be successfully targeted by specific monoclonal antibodies. AREAS COVERED: This review article provides a concise overview of the pathophysiology of type 2 asthma, followed by an updated appraisal of the mechanisms of action and therapeutic efficacy of currently available biologic treatments used for management of severe type 2 asthma. Therefore, all reported information arises from a wide literature search performed on PubMed. EXPERT OPINION: The main result of the recent advances in the field of anti-asthma biologic therapies is the implementation of a personalized medicine approach, aimed to achieve clinical remission of severe asthma. Today this accomplishment is made possible by the right choice of the most beneficial biologic drug for the pathologic traits characterizing each patient, including type 2 severe asthma and its comorbidities.

Biomarkers and clinical outcomes after tezepelumab cessation: Extended follow-up from the 2-year DESTINATION study.

BACKGROUND: Long-term tezepelumab treatment in the DESTINATION study (NCT03706079) resulted in reduced asthma exacerbations, reduced biomarker levels, and improved lung function and symptom control in patients with severe, uncontrolled asthma. OBJECTIVE: To explore the time course of changes in biomarkers and clinical manifestations after treatment cessation after 2 years of tezepelumab treatment. METHODS: DESTINATION was a 2-year, phase 3, multicenter, randomized, placebo-controlled, double-blind study of tezepelumab treatment in patients (12-80 years old) with severe asthma. Patients received their last treatment doses at week 100 and could enroll in an extended follow-up period from weeks 104 to 140. Change over time in key biomarkers and clinical outcomes were assessed in tezepelumab vs placebo recipients for 40 weeks after stopping treatment. RESULTS: Of 569 patients enrolled in the extended follow-up period, 426 were included in the analysis (289 received tezepelumab and 137 placebo). In the 40-week period after the last tezepelumab dose, blood eosinophil counts, fractional exhaled nitric oxide levels, and Asthma Control Questionnaire-6 scores gradually increased from weeks 4 to 10, with a gradual reduction in pre-bronchodilator forced expiratory volume in 1 second such that blood eosinophil counts, fractional exhaled nitric oxide levels, and clinical outcomes returned to placebo levels; however, none of these outcomes returned to baseline levels. Total IgE levels increased later from week 28 and remained well below placebo and baseline levels during the 40-week period after the last tezepelumab dose. CONCLUSION: This analysis reveals the benefits of continued tezepelumab treatment in the management of patients with severe, uncontrolled asthma, compared with stopping treatment after 2 years. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03706079.

Characterization of Moderate and Severe Asthma Exacerbations in the CAPTAIN Study.

BACKGROUND: Limited data exist on the relative impact of moderate and severe exacerbations on asthma control and impairment. OBJECTIVE: To explore data from the CAPTAIN trial to evaluate the relationship between first moderate or severe exacerbation and changes in lung function, symptoms, physical activity limitation scores, and short-acting ß2-agonist (SABA) usage to determine the clinical relevance of moderate events. METHODS: CAPTAIN was a phase IIIA 24- to 52-week, multicenter, international, randomized controlled trial evaluating efficacy and safety of fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) versus FF/VI in patients with uncontrolled asthma on inhaled corticosteroid/long-acting ß2-agonist. Outcomes reported include first postrandomization exacerbation event by severity (wk 1-52), frequency and duration of moderate and severe exacerbations, and time course of changes over ± 14-day peri-exacerbation period for lung function, symptoms, limitations, and SABA use. RESULTS: Of the intent-to-treat population (n = 2,436), 550 patients (23%) continued to 52 weeks. There were 529 moderate and 546 severe exacerbations. Lung function changes were similar, but symptom, physical activity limitation scores, and SABA use were higher, for severe versus moderate exacerbations. Lung function decline preceded increases in symptom, physical activity limitation scores, and SABA use, irrespective of exacerbation severity. Lung function variables, limitation scores, and SABA use returned to pre-exacerbation baseline after approximately 8 to 12 days for both exacerbation severities. CONCLUSIONS: Whereas severe events were associated with greater impact on symptoms, physical activity limitations, and SABA use, onset and time to resolution were generally similar for moderate and severe events. Both exacerbation severities represent clinically important deteriorations comprising clinical and functional changes.

The carbon footprint of as-needed budesonide/formoterol in mild asthma: a post hoc analysis.

INTRODUCTION: The use of pressurised metered-dose inhalers (pMDIs) and asthma exacerbations necessitating healthcare reviews contribute substantially to the global carbon footprint of healthcare. It is possible that a reduction in carbon footprint could be achieved by switching patients with mild asthma from salbutamol pMDI reliever-based therapy to inhaled corticosteroid-formoterol dry powder inhaler (DPI) reliever therapy, as recommended by the Global Initiative for Asthma. METHODS: This post hoc analysis included all 668 adult participants in the Novel START trial, who were randomised 1:1:1 to treatment with as-needed budesonide/formoterol DPI, as-needed salbutamol pMDI or maintenance budesonide DPI plus as-needed salbutamol pMDI. The primary outcome was carbon footprint of asthma management, expressed as kilograms of carbon dioxide equivalent emissions (kgCO2e) per person-year. Secondary outcomes explored the effect of baseline symptom control and adherence (maintenance budesonide DPI arm only) on carbon footprint. RESULTS: As-needed budesonide/formoterol DPI was associated with 95.8% and 93.6% lower carbon footprint compared with as-needed salbutamol pMDI (least-squares mean 1.1 versus 26.2 kgCO2e; difference -25.0, 95% CI -29.7 to -20.4; p<0.001) and maintenance budesonide DPI plus as-needed salbutamol pMDI (least-squares mean 1.1 versus 17.3 kgCO2e; difference -16.2, 95% CI -20.9 to -11.6; p<0.001), respectively. There was no statistically significant evidence that treatment differences in carbon footprint depended on baseline symptom control or adherence in the maintenance budesonide DPI arm. CONCLUSIONS: The as-needed budesonide/formoterol DPI treatment option was associated with a markedly lower carbon footprint than as-needed salbutamol pMDI and maintenance budesonide DPI plus as-needed salbutamol pMDI.

IL-5 antagonism reverses priming and activation of eosinophils in severe eosinophilic asthma.

Eosinophils are key effector cells mediating airway inflammation and exacerbation in patients with severe eosinophilic asthma. They are present in increased numbers and activation states in the airway mucosa and lumen. Interleukin-5 (IL-5) is the key eosinophil growth factor that is thought to play a role in eosinophil priming and activation. However, the mechanism of these effects is still not fully understood. The anti-IL-5 antibody mepolizumab reduces eosinophil counts in the airway modestly but has a large beneficial effect on the frequency of exacerbations of severe eosinophilic asthma, suggesting that reduction in eosinophil priming and activation is of central mechanistic importance. In this study, we used the therapeutic effect of mepolizumab and single-cell ribonucleic acid sequencing to investigate the mechanism of eosinophil priming and activation by IL-5. We demonstrated that IL-5 is a dominant driver of eosinophil priming and plays multifaceted roles in eosinophil function. It enhances eosinophil responses to other stimulators of migration, survival, and activation by activating phosphatidylinositol-3-kinases, extracellular signal-regulated kinases, and p38 mitogen-activated protein kinases signaling pathways. It also enhances the pro-fibrotic roles of eosinophils in airway remodeling via transforming growth factor-ß pathway. These findings provide a mechanistic understanding of eosinophil priming in severe eosinophilic asthma and the therapeutic effect of anti-IL-5 approaches in the disease.

The airway epithelium: an orchestrator of inflammation, a key structural barrier and a therapeutic target in severe asthma.

Asthma is a disease of heterogeneous pathology, typically characterised by excessive inflammatory and bronchoconstrictor responses to the environment. The clinical expression of the disease is a consequence of the interaction between environmental factors and host factors over time, including genetic susceptibility, immune dysregulation and airway remodelling. As a critical interface between the host and the environment, the airway epithelium plays an important role in maintaining homeostasis in the face of environmental challenges. Disruption of epithelial integrity is a key factor contributing to multiple processes underlying asthma pathology. In this review, we first discuss the unmet need in asthma management and provide an overview of the structure and function of the airway epithelium. We then focus on key pathophysiological changes that occur in the airway epithelium, including epithelial barrier disruption, immune hyperreactivity, remodelling, mucus hypersecretion and mucus plugging, highlighting how these processes manifest clinically and how they might be targeted by current and novel therapeutics.

Dupilumab Reduces Exacerbations Independent of Changes in Biomarkers in Moderate-to-Severe Asthma.

BACKGROUND: Changes from baseline in fractional exhaled nitric oxide (FeNO) and blood eosinophil count (Eos) may be related to efficacy outcomes in dupilumab-treated patients with moderate-to-severe asthma. OBJECTIVE: This post hoc analysis investigated biomarker changes in placebo- and dupilumab-treated patients with uncontrolled moderate-to-severe asthma enrolled in QUEST (NCT02414854). METHODS: Spline analyses of annualized severe exacerbation rate (AER) and change from baseline in pre-bronchodilator (BD) forced expiratory volume in 1 second (FEV1) at week 52 were performed as a function of the fold change in FeNO at week 52 and the maximum fold change in Eos over weeks 0-12 (also change from baseline in pre-BD FEV1 at week 12). RESULTS: The combined placebo and dupilumab groups comprised 638 and 1264 patients, respectively. FeNO levels declined rapidly by week 2 and then gradually to week 52 in patients treated with dupilumab versus placebo; Eos, after initially increasing with dupilumab, declined slightly from baseline in both treatment groups. AER during QUEST showed no significant association with the change in biomarkers in either treatment group. The change from baseline in pre-BD FEV1 at week 52 was inversely associated with the fold change in FeNO in both groups, with a significant difference between the dupilumab and placebo curves (P = .014), and was positively associated with the fold change in Eos in both groups (P = .022). CONCLUSIONS: Relative changes in FeNO and Eos were not associated with AER, regardless of treatment arm. However, changes in both biomarkers showed a predictive value for lung function improvement; for FeNO, this was specific to the dupilumab treatment arm.

Baseline Characteristics and ICS/LAMA/LABA Response in Asthma: Analyses From the CAPTAIN Study.

BACKGROUND: Findings from CAPTAIN (NCT02924688) suggest that treatment response to fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) differs according to baseline type 2 inflammation markers in patients with moderate to severe asthma. Understanding how other patient physiologic and clinical characteristics affect response to inhaled therapies may guide physicians toward a personalized approach for asthma management. OBJECTIVE: To investigate, using CAPTAIN data, the predictive value of key demographic and baseline physiologic variables in patients with asthma (lung function, bronchodilator reversibility, age, age at asthma onset) on response to addition of the long-acting muscarinic antagonist UMEC to inhaled corticosteroid/long-acting ß2-agonist combination FF/VI, or doubling the FF dose. METHODS: Prespecified and post hoc analyses of CAPTAIN data were performed using categorical and continuous variables of key baseline characteristics to understand their influence on treatment outcomes (lung function [trough FEV1], annualized rate of moderate/severe exacerbations, and asthma control [Asthma Control Questionnaire]) following addition of UMEC to FF/VI or doubling the FF dose in FF/VI or FF/UMEC/VI. RESULTS: Adding UMEC to FF/VI led to greater improvements in trough FEV1 versus doubling the FF dose across all baseline characteristics assessed. Doubling the FF dose was generally associated with numerically greater reductions in the annualized rate of moderate/severe exacerbations compared with adding UMEC, independent of baseline characteristics. Adding UMEC and/or doubling the FF dose generally led to improvements in Asthma Control Questionnaire scores irrespective of baseline characteristics. CONCLUSIONS: Unlike previous findings with type 2 biomarkers, lung function, bronchodilator reversibility, age and age at asthma onset do not appear to predict response to inhaled therapy.