Association between pre-biologic T2-biomarker combinations and response to biologics in patients with severe asthma

Background

To date, studies investigating the association between pre-biologic biomarker levels and post-biologic outcomes have been limited to single biomarkers and assessment of biologic efficacy from structured clinical trials.

Aim

To elucidate the associations of pre-biologic individual biomarker levels or their combinations with pre-to-post biologic changes in asthma outcomes in real-life.

Methods

This was a registry-based, cohort study using data from 23 countries, which shared data with the International Severe Asthma Registry (May 2017-February 2023). The investigated biomarkers (highest pre-biologic levels) were immunoglobulin E (IgE), blood eosinophil count (BEC) and fractional exhaled nitric oxide (FeNO). Pre- to approximately 12-month post-biologic change for each of three asthma outcome domains (i.e. exacerbation rate, symptom control and lung function), and the association of this change with pre-biologic biomarkers was investigated for individual and combined biomarkers.

Results

Overall, 3751 patients initiated biologics and were included in the analysis. No association was found between pre-biologic BEC and pre-to-post biologic change in exacerbation rate for any biologic class. However, higher pre-biologic BEC and FeNO were both associated with greater post-biologic improvement in FEV1 for both anti-IgE and anti-IL5/5R, with a trend for anti-IL4Rα. Mean FEV1 improved by 27-178 mL post-anti-IgE as pre-biologic BEC increased (250 to 1000 cells/µL), and by 43-216 mL and 129-250 mL post-anti-IL5/5R and -anti-IL4Rα, respectively along the same BEC gradient. Corresponding improvements along a FeNO gradient (25-100 ppb) were 41-274 mL, 69-207 mL and 148-224 mL for anti-IgE, anti-IL5/5R, and anti-IL4Rα, respectively. Higher baseline BEC was also associated with lower probability of uncontrolled asthma (OR 0.392; p=0.001) post-biologic for anti-IL5/5R. Pre-biologic IgE was a poor predictor of subsequent pre-to-post-biologic change for all outcomes assessed for all biologics. The combination of BEC + FeNO marginally improved the prediction of post-biologic FEV1 increase (adjusted R2: 0.751), compared to BEC (adjusted R2: 0.747) or FeNO alone (adjusted R2: 0.743) (p=0.005 and <0.001, respectively); however, this prediction was not improved by the addition of IgE.

Conclusions

The ability of higher baseline BEC, FeNO and their combination to predict biologic-associated lung function improvement may encourage earlier intervention in patients with impaired lung function or at risk of accelerated lung function decline.

Biologics (mepolizumab and omalizumab) induced remission in severe asthma patients

BACKGROUND

Asthma remission has emerged as a potential treatment goal. This study evaluated the effectiveness of two biologics (mepolizumab/omalizumab) in achieving asthma remission.

METHODS

This observational study included 453 severe asthma patients (41% male; mean age ± SD 55.7 ± 14.7 years) from two real-world drug registries: the Australian Mepolizumab Registry and the Australian Xolair Registry. The composite outcome clinical remission was defined as zero exacerbations and zero oral corticosteroids during the previous 6 months assessed at 12 months and 5-item Asthma Control Questionnaire (ACQ-5) ≤1 at 12 months. We also assessed clinical remission plus optimization (post-bronchodilator FEV1 ≥80%) or stabilization (post-bronchodilator FEV1 not greater than 5% decline from baseline) of lung function at 12 months. Sensitivity analyses explored various cut-offs of ACQ-5/FEV1 scores. The predictors of clinical remission were identified.

RESULTS

29.3% (73/249) of AMR and 22.8% (37/162) of AXR cohort met the criteria for clinical remission. When lung function criteria were added, the remission rates were reduced to 25.2% and 19.1%, respectively. Sensitivity analyses identified that the remission rate ranged between 18.1% and 34.9% in the AMR cohort and 10.6% and 27.2% in the AXR cohort. Better lung function, lower body mass index, mild disease and absence of comorbidities such as obesity, depression and osteoporosis predicted the odds of achieving clinical remission.

CONCLUSION

Biologic treatment with mepolizumab or omalizumab for severe asthma-induced asthma remission in a subgroup of patients. Remission on treatment may be an achievable treatment target and future studies should consider remission as an outcome measure.

Pulmonology for the rhinologist

PURPOSE OF REVIEW

The upper and lower airways are inter-related despite serving different functions and can no longer be considered separately. Rhinologists are becoming increasingly aware of the role the lower airway plays in optimizing outcomes for their patients. This review highlights recent developments in pulmonology that impact rhinologic conditions.

RECENT FINDINGS

The unified airway concept now supports the multidisciplinary management of respiratory and rhinologic pathologies. Biomarkers, biologics and the concept of treatable traits have permitted the development of personalized and precise treatment of the entire respiratory tract. The concept of corticosteroid stewardship, the introduction of steroid sparing agents for the treatment of respiratory diseases and the development of biomarkers, now forces us to be more considerate and precise with oral corticosteroid (OCS) prescribing and to consider reduction regimens. Finally, current research on climate change and vaping will allow us to better educate and prepare our patients to improve adherence and avoid exacerbations to maintain optimal global respiratory health.

SUMMARY

The inter-relatedness of the upper and lower airway has encouraged a multidisciplinary focus in respiratory medicine. More research is required to improve the precision respiratory medicine model, particularly in the realm of biomarkers and endotyping. These developments must also consider the impact of climate change, pollution and toxins for us to provide optimum care for our patients.

Impact of Landscape Fire Smoke Exposure on Patients With Asthma With or Without Laryngeal Hypersensitivity

BACKGROUND

Individuals with asthma experienced severe and prolonged symptoms after the Australian 2019 to 2020 landscape fire. Many of these symptoms, such as throat irritation, occur in the upper airway. This suggests that laryngeal hypersensitivity contributes to persistent symptoms after smoke exposure.

OBJECTIVE

This study examined the relationship between laryngeal hypersensitivity and symptoms, asthma control, and health impacts on individuals exposed to landscape fire smoke.

METHOD

The study was a cross-sectional survey of 240 participants in asthma registries who were exposed to smoke during the 2019 to 2020 Australian fire. The survey, completed between March and May 2020, included questions about symptoms, asthma control, and health care use, as well as the Laryngeal Hypersensitivity Questionnaire. Daily concentration levels of particulate matter less than or equal to 2.5 μm in diameter were measured over the 152-day study period.

RESULTS

The 49 participants with laryngeal hypersensitivity (20%) had significantly more asthma symptoms (96% vs 79%; P = .003), cough (78% vs 22%; P < .001), and throat irritation (71% vs 38%; P < .001) during the fire period compared with those without laryngeal hypersensitivity. Participants with laryngeal hypersensitivity had greater health care use (P ≤ .02), more time off work (P = .004), and a reduced capacity to participate in usual activities (P < .001) during the fire period, as well as poorer asthma control during the follow-up (P = .001).

CONCLUSIONS

Laryngeal hypersensitivity is associated with persistent symptoms, reports of lower asthma control, and increased health care use in adults with asthma who were exposed to landscape fire smoke. Management of laryngeal hypersensitivity before, during, or immediately after landscape fire smoke exposure might reduce the symptom burden and health impact.

Mepolizumab effectiveness and identification of super-responders in severe asthma

Severe asthma is a high-burden disease. Real-world data on mepolizumab in patients with severe eosinophilic asthma is needed to assess whether the data from randomised controlled trials are applicable in a broader population.The Australian Mepolizumab Registry (AMR) was established with an aim to assess the use, effectiveness and safety of mepolizumab for severe eosinophilic asthma in Australia.Patients (n=309) with severe eosinophilic asthma (median age 60 years, 58% female) commenced mepolizumab. They had poor symptom control (median Asthma Control Questionnaire (ACQ)-5 score of 3.4), frequent exacerbations (median three courses of oral corticosteroids (OCS) in the previous 12 months), and 47% required daily OCS. Median baseline peripheral blood eosinophil level was 590 cells·µL^-1 Comorbidities were common: allergic rhinitis 63%, gastro-oesophageal reflux disease 52%, obesity 46%, nasal polyps 34%.Mepolizumab treatment reduced exacerbations requiring OCS compared with the previous year (annualised rate ratio 0.34 (95% CI 0.29-0.41); p<0.001) and hospitalisations (rate ratio 0.46 (95% CI 0.33-0.63); p<0.001). Treatment improved symptom control (median ACQ-5 reduced by 2.0 at 6 months), quality of life and lung function. Higher blood eosinophil levels (p=0.003) and later age of asthma onset (p=0.028) predicted a better ACQ-5 response to mepolizumab, whilst being male (p=0.031) or having body mass index ≥30 (p=0.043) predicted a lesser response. Super-responders (upper 25% of ACQ-5 responders, n=61, 24%) had a higher T2 disease burden and fewer comorbidities at baseline.Mepolizumab therapy effectively reduces the significant and long-standing disease burden faced by patients with severe eosinophilic asthma in a real-world setting.

Effectiveness and response predictors of omalizumab in a severe allergic asthma population with a high prevalence of comorbidities: the Australian Xolair Registry

BACKGROUND

Severe asthma is a high impact disease. Omalizumab targets the allergic inflammatory pathway; however, effectiveness data in a population with significant comorbidities are limited.

AIMS

To describe severe allergic asthma, omalizumab treatment outcomes and predictors of response among the Australian Xolair Registry participants.

METHODS

A web-based post-marketing surveillance registry was established to characterise the use, effectiveness and adverse effects of omalizumab (Xolair) for severe allergic asthma.

RESULTS

Participants (n = 192) (mean age 51 years, 118 female) with severe allergic asthma from 21 clinics in Australia were assessed, and 180 received omalizumab therapy. They had poor asthma control (Asthma Control Questionnaire, ACQ-5, mean score 3.56) and significant quality of life impairment (Asthma-related Quality of Life Questionnaire score 3.57), and 52% were using daily oral corticosteroid (OCS). Overall, 95% had one or more comorbidities (rhinitis 48%, obesity 45%, cardiovascular disease 23%). The omalizumab responder rate, assessed by an improvement of at least 0.5 in ACQ-5, was high at 83%. OCS use was significantly reduced. The response in participants with comorbid obesity and cardiovascular disease was similar to those without these conditions. Baseline ACQ-5 ≥ 2.0 (P = 0.002) and older age (P = 0.05) predicted the magnitude of change in ACQ-5 in response to omalizumab. Drug-related adverse events included anaphylactoid reactions (n = 4), headache (n = 2) and chest pains (n = 1).

CONCLUSION

Australian patients with severe allergic asthma report a high disease burden and have extensive comorbidity. Symptomatic response to omalizumab was high despite significant comorbid disease. Omalizumab is an effective targeted therapy for severe allergic asthma with comorbidity in a real-life setting.

Real-life effectiveness of omalizumab in severe allergic asthma above the recommended dosing range criteria

BACKGROUND

Omalizumab (Xolair) dosing in severe allergic asthma is based on serum IgE and bodyweight. In Australia, patients eligible for omalizumab but exceeding recommended ranges for IgE (30-1500 IU/mL) and bodyweight (30-150 kg) may still receive a ceiling dose of 750 mg/4 weeks. About 62% of patients receiving government-subsidized omalizumab are enrolled in the Australian Xolair Registry (AXR).

OBJECTIVES

To determine whether AXR participants above the recommended dosing ranges benefit from omalizumab and to compare their response to within-range participants.

METHODS

Data were stratified according to dose range status (above-range or within-range). Further sub-analyses were conducted according to the reason for being above the dosing range (IgE only vs. IgE and weight).

RESULTS

Data for 179 participants were analysed. About 55 (31%) were above recommended dosing criteria; other characteristics were similar to within-range participants. Above-range participants had higher baseline IgE [812 (IQR 632, 1747) IU/mL vs. 209 (IQR 134, 306) IU/mL] and received higher doses of omalizumab [750 (IQR 650, 750) mg] compared to within-range participants [450 (IQR, 300, 600) mg]. At 6 months, improvements in Juniper 5-item Asthma Control Questionnaire (ACQ-5, 3.61 down to 2.01 for above-range, 3.47 down to 1.93 for within-range, P < 0.0001 for both) and Asthma Quality of Life Questionnaire (AQLQ mean score (3.22 up to 4.41 for above-range, 3.71 up to 4.88 for within-range, P < 0.0001) were observed in both groups. Forced expiratory volume in one second (FEV₁ ) improved among above-range participants. There was no difference in response between above-range and within-range participants. Above-range participants due to either IgE alone or IgE and weight had similar improvements in ACQ-5, AQLQ and FEV₁ .

CONCLUSIONS AND CLINICAL RELEVANCE

Patients with severe allergic asthma above recommended dosing criteria for omalizumab have significantly improved symptom control, quality of life and lung function to a similar degree to within-range participants, achieved without dose escalation above 750 mg.

The Diacylglycerol-dependent translocation of ras guanine nucleotide-releasing protein 4 inside a human mast cell line results in substantial phenotypic changes, including expression of interleukin 13 receptor alpha2

Ras guanine nucleotide-releasing protein 4 (RasGRP4) is a mast cell (MC)-restricted guanine nucleotide exchange factor and diacylglycerol (DAG)/phorbol ester receptor. An RasGRP4-defective variant of the human MC line HMC-1 was used to create stable clones expressing green fluorescent protein-labeled RasGRP4 for monitoring the movement of this protein inside MCs after exposure to phorbol 12-myristate 13-acetate (PMA), and for evaluating the protein's ability to control gene expression. RasGRP4 resided primarily in the cytosol. After exposure to PMA, RasGRP4 quickly translocated to the inner leaflet of the cell's plasma membrane. 15-30 min later, this signaling protein translocated from the plasma membrane to other intracellular sites. The translocation of RasGRP4 from the cytosol to its varied membrane compartments was found to be highly dependent on Phe(548) in the protein's C1 DAG/PMA-binding domain. Extracellular signal-regulated kinases 1 and 2 were activated during this translocation process, and c-kit/CD117 was lost from the cell's surface. Transcript-profiling approaches revealed that RasGRP4 profoundly regulated the expression of hundreds of genes in HMC-1 cells. For example, the expression of the transcript that encodes the interleukin (IL) 13 receptor IL-13Ralpha2 increased 61- to 860-fold in RasGRP4-expressing HMC-1 cells. A marked increase in IL-13Ralpha2 protein levels also was found. The accumulated data suggest RasGRP4 translocates to varied intracellular compartments via its DAG/PMA-binding domain to regulate signaling pathways that control gene and protein expression in MCs, including the cell's ability to respond to IL-13.