Richard May

A phase II placebo-controlled study of tralokinumab in moderate-to-severe asthma

Pre-clinical data demonstrate a pivotal role for interleukin (IL)-13 in the development and maintenance of asthma. This study assessed the effects of tralokinumab, an investigational human IL-13-neutralising immunoglobulin G4 monoclonal antibody, in adults with moderate-to-severe uncontrolled asthma despite controller therapies. 194 subjects were randomised to receive tralokinumab (150, 300 or 600 mg) or placebo subcutaneously every 2 weeks. Primary end-point was change from baseline in mean Asthma Control Questionnaire score (ACQ-6; ACQ mean of six individual item scores) at week 13 comparing placebo and combined tralokinumab dose groups. Secondary end-points included pre-bronchodilator lung function, rescue &bgr;2-agonist use and safety. Numerical end-points are reported as mean±sd. At week 13, change from baseline in ACQ-6 was -0.76±1.04 for tralokinumab versus -0.61±0.90 for placebo (p=0.375). Increases from baseline in forced expiratory volume in 1 s (FEV1) were 0.21±0.38 L versus 0.06±0.48 L (p=0.072), with a dose-response observed across the tralokinumab doses tested. &bgr;2-agonist use (puffs per day) was decreased for tralokinumab -0.68±1.45 versus placebo -0.10±1.49 (p=0.020). The increase in FEV1 following tralokinumab treatment remained evident 12 weeks after the final dose. Safety profile was acceptable with no serious adverse events related to tralokinumab. No improvement in ACQ-6 was observed, although tralokinumab treatment was associated with improved lung function.

Expression of the T Helper 17-Associated Cytokines IL-17A and IL-17F in Asthma and COPD

Background: Asthma and COPD are characterized by airway dysfunction and inflammation. Neutrophilic airway inflammation is a common feature of COPD and is recognized in asthma, particularly in severe disease. The T helper (Th) 17 cytokines IL-17A and IL-17F have been implicated in the development of neutrophilic airway inflammation, but their expression in asthma and COPD is uncertain. Methods: We assessed IL-17A and IL-17F expression in the bronchial submucosa from 30 subjects with asthma, 10 ex-smokers with mild to moderate COPD, and 27 nonsmoking and 14 smoking control subjects. Sputum IL-17 concentration was measured in 165 subjects with asthma and 27 with COPD. Results: The median (interquartile range) IL-17A cells/mm2 submucosa was increased in mild to moderate asthma (2.1 [2.4]) compared with healthy control subjects (0.4 [2.8]) but not in severe asthma (P = .04). In COPD, IL-17A+ cells/mm2 submucosa were increased (0.5 [3.7]) compared with nonsmoking control subjects (0 [0]) but not compared with smoking control subjects (P = .046). IL-17F+ cells/mm2 submucosa were increased in severe asthma (2.7 [3.6]) and mild to moderate asthma (1.6 [1.0]) compared with healthy controls subjects (0.7 [1.4]) (P = .001) but was not increased in subjects with COPD. IL-17A and IL-17F were not associated with increased neutrophilic inflammation, but IL-17F was correlated with the submucosal eosinophil count (rs = 0.5, P = .005). The sputum IL-17 concentration in COPD was increased compared with asthma (2 [0-7] pg/mL vs 0 [0-2] pg/mL, P < .0001) and was correlated with post-bronchodilator FEV1% predicted (r = −0.5, P = .008) and FEV1/FVC (r = −0.4, P = .04). Conclusions: Our findings support a potential role for the Th17 cytokines IL-17A and IL-17F in asthma and COPD, but do not demonstrate a relationship with neutrophilic inflammation.

Increased sputum and bronchial biopsy IL-13 expression in severe asthma.

BACKGROUND The importance of IL-13 in the asthma paradigm is supported by increased expression in human subjects, particularly in patients with mild-to-moderate asthma. However, the role of IL-13 in severe asthma needs to be further defined. OBJECTIVE We sought to assess IL-13 expression in sputum and bronchial biopsy specimens from subjects with mild-to-severe asthma. METHODS Sputum IL-13 concentrations were measured in 32 control subjects, 34 subjects with mild asthma, 21 subjects with moderate asthma, and 26 subjects with severe asthma. Enumeration of mast cells, eosinophils, and IL-13+ cells in the bronchial submucosa and airway smooth muscle (ASM) bundle was performed in 7 control subjects, 14 subjects with mild asthma, 7 subjects with moderate asthma, and 7 subjects with severe asthma. RESULTS The proportion of subjects with measurable IL-13 in the sputum was increased in the mild asthma group (15/34) and severe asthma group (10/26) compared with that seen in the control group (4/32; P = .004). IL-13+ cells were increased within the submucosa in all asthma severity groups compared with control subjects (P = .006). The number of IL-13+ cells were increased within the ASM bundle in the severe asthma group compared with that seen in the other groups (P < .05). Asthma control questionnaire scores positively correlated with sputum IL-13 concentrations (R(s) = 0.35, P = .04) and mast cells in the ASM bundle (R(s) = 0.7, P = .007). IL-13+ cells within the submucosa and ASM correlated with sputum eosinophilia (R(s) = 0.4, P < or = .05). CONCLUSIONS IL-13 overexpression in sputum and bronchial biopsy specimens is a feature of severe asthma.

Efficacy and safety of tralokinumab in patients with severe uncontrolled asthma: a randomised, double-blind, placebo-controlled, phase 2b trial

BACKGROUND Interleukin 13 is a central mediator of asthma. Tralokinumab is a human interleukin-13 neutralising monoclonal antibody. We aimed to assess the efficacy and safety of two dosing regimens of tralokinumab in patients with severe uncontrolled asthma. METHODS We did a randomised, double-blind, placebo-controlled, parallel-group, multicentre, phase 2b study at 98 sites in North America, South America, Europe, and Asia. Patients aged 18-75 years with severe asthma and two to six exacerbations in the previous year were randomly assigned (1:1), via an interactive voice-response or web-response system, to one of two dosing regimen groups (every 2 weeks, or every 2 weeks for 12 weeks then every 4 weeks) and further randomised (2:1), via computer-generated permuted-block randomisation (block size of six), to receive tralokinumab 300 mg or placebo for 1 year. All participants received high-dose fluticasone and salmeterol and continued other pre-study controller drugs. Treatment was administered by an unmasked study investigator not involved in the management of patients; all other study site personnel, patients, the study funder, and data analysts were masked to treatment allocation. The primary endpoint was the annual asthma exacerbation rate at week 52 in the intention-to-treat population. Key secondary endpoints included prebronchodilator forced expiratory volume in 1 s (FEV1), Asthma Control Questionnaire-6 (ACQ-6), and Asthma Quality of Life Questionnaire-Standardised Version (AQLQ[S]). This trial is registered with ClinicalTrials.gov, number NCT01402986. FINDINGS Between Oct 4, 2011, and Feb 22, 2014, we randomly assigned 452 patients to receive placebo (n=151) or tralokinumab every 2 weeks (n=150) or every 4 weeks (n=151), of whom 383 (85%) completed the treatment period up to week 52. The annual asthma exacerbation rate at week 52 was similar between patients receiving tralokinumab every 2 weeks (0.91 per patient per year [95% CI 0.76-1.08]) and every 4 weeks (0.97 [0.81-1.14]), and those receiving placebo (0.90 [0.75-1.08]). At week 52, percentage changes in annual asthma exacerbation rate were not significant with tralokinumab every 2 weeks or every 4 weeks versus placebo (6% [95% CI -31 to 33; p=0.709] and -2% [-46 to 29; p=0.904], respectively), with positive changes showing a decrease in exacerbation rate and negative changes showing an increase. Prebronchodilator FEV1 was significantly increased compared with placebo for tralokinumab every 2 weeks (change from baseline 7.3% [95% CI 2.6-12.0]; p=0.003), but not every 4 weeks (1.8% [-2.9 to 6.6]; p=0.448); however, we did not identify significant changes in the other key secondary endpoints. In a post-hoc subgroup analysis of patients not on long-term oral corticosteroids and with baseline FEV1 reversibility of 12% or greater, we noted a non-significant improvement in asthma exacerbation rate (44% [95% CI -22 to 74]; p=0.147) and significant improvements in key secondary endpoints (FEV1 12.2% [1.7-22.7]; p=0.022; ACQ-6 -0.55 [-1.07 to -0.04]; p=0.036; and AQLQ[S] 0.70 [0.12-1.28]; p=0.019) in patients given tralokinumab every 2 weeks (n=33) compared with placebo (n=48). In patients in this subgroup who also had baseline serum dipeptidyl peptidase-4 (DPP-4) higher than the population baseline median, we noted additional improvements in prebronchodilator FEV1, ACQ-6, and AQLQ(S), and, in those with periostin concentrations higher than the median, we noted improvements in asthma exacerbation rate, prebronchodilator FEV1, and ACQ-6. The incidence of treatment-emergent adverse events was similar between the tralokinumab and placebo groups. Treatment-emergent serious adverse events regarded as related to the study drug were pneumonia (one [1%] patient in the placebo group), pneumococcal pneumonia (one [1%] in the tralokinumab every 2 weeks group), angioedema (one [1%] in the placebo group), and worsening asthma (one [1%] in the tralokinumab every 2 weeks group and two [1%] in the tralokinumab every 4 weeks group). INTERPRETATION In this phase 2b study, both tralokinumab regimens had an acceptable safety and tolerability profile but did not significantly reduce asthma exacerbation rates in patients with severe uncontrolled asthma. Improvement in FEV1 with tralokinumab given every 2 weeks and results of post-hoc subgroup analyses suggested a possible treatment effect in a defined population of patients with severe uncontrolled asthma. This effect is being further investigated in ongoing phase 3 trials, along with the potential utility of DPP-4 and periostin as biomarkers of interleukin-13 pathway activation. FUNDING MedImmune.

Myeloid cell function in MRP-14 (S100A9) null mice.

ABSTRACT Myeloid-related protein 14 (MRP-14) and its heterodimeric partner, MRP-8, are cytosolic calcium-binding proteins, highly expressed in neutrophils and monocytes. To understand the function of MRP-14, we performed targeted disruption of the MRP-14 gene in mice. MRP-14−/− mice showed no obvious phenotype and were fertile. MRP-8 mRNA but not protein is present in the myeloid cells of these mice, suggesting that the stability of MRP-8 protein is dependent on MRP-14 expression. A compensatory increase in other proteins was not detected in cells lacking MRP-8 and MRP-14. Although the morphology of MRP-14−/− myeloid cells was not altered, they were significantly less dense. When Ca2+ responses were investigated, there was no change in the maximal response to the chemokine MIP-2. At lower concentrations, however, there was reduced responsiveness in MRP-14−/− compared with MRP-14+/+ neutrophils. This alteration in the ability to flux Ca2+ did not impair the ability of the MRP-14−/− neutrophils to respond chemotactically to MIP-2. In addition, the myeloid cell functions of phagocytosis, superoxide burst, and apoptosis were unaffected in MRP-14−/− cells. In an in vivo model of peritonitis, MRP-14−/− mice showed no difference from wild-type mice in induced inflammatory response. The data indicate that MRP-14 and MRP-8 are dispensable for many myeloid cell functions.

Elevated Sputum Interleukin-5 and Submucosal Eosinophilia in Obese Individuals with Severe Asthma

RATIONALE The relationship between airway inflammation and obesity in severe asthma is poorly understood. OBJECTIVES We sought to determine the relationship between sputum mediator profiles and the distribution of eosinophilic inflammation and obesity in people with severe asthma. METHODS Clinical parameters and eight mediators in sputum were assessed in 131 subjects with severe asthma from a single center categorized into lean, overweight, and obese groups defined by their body mass index. In an independent group of people with severe asthma (n = 45) and healthy control subjects (n = 19) eosinophilic inflammation was enumerated in bronchial submucosa, blood, and sputum and related to their body mass index. MEASUREMENTS AND MAIN RESULTS Sputum IL-5 geometric mean (95% confidence interval) (pg/ml) was elevated in the obese (1.8 [1.2-2.6]) compared with overweight (1.1 [0.8-1.3]; P = 0.025) and lean (0.9 [0.6-1.2]; P = 0.018) subjects with asthma and was correlated with body mass index (r = 0.29; P < 0.001). There was no relationship among body mass index, the sputum cell count, or other sputum mediators. In the bronchoscopy group the submucosal eosinophil number in the subjects with asthma was correlated with body mass index (Spearman rank correlation, rs = 0.38; P = 0.013) and the median (interquartile range) number of submucosal eosinophils was increased in obese (19.4 [11.8-31.2]) (cells per square millimeter) versus lean subjects (8.2 [5.4-14.6]) (P = 0.006). There was no significant association between sputum or peripheral blood eosinophil counts and body mass index. CONCLUSIONS Sputum IL-5 and submucosal eosinophils, but not sputum eosinophils, are elevated in obese people with severe asthma. Whether specific antieosinophilic therapy is beneficial, or improved diet and lifestyle in obese asthma has antiinflammatory effects beyond weight reduction, requires further study.

Mast cells express IL-13Rα1: IL-13 promotes human lung mast cell proliferation and FcɛRI expression

Background:  The Th2 cytokine interleukin (IL)‐13 is implicated in the development of various allergic diseases including asthma. The IL‐13 receptor, IL‐13Rα1, is expressed on most leukocytes, except T‐cells. Evidence to support IL‐13Rα1 expression on mast cells is limited.

Biological clustering supports both “Dutch” and “British” hypotheses of asthma and chronic obstructive pulmonary disease

Background Asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous diseases. Objective We sought to determine, in terms of their sputum cellular and mediator profiles, the extent to which they represent distinct or overlapping conditions supporting either the “British” or “Dutch” hypotheses of airway disease pathogenesis. Methods We compared the clinical and physiological characteristics and sputum mediators between 86 subjects with severe asthma and 75 with moderate-to-severe COPD. Biological subgroups were determined using factor and cluster analyses on 18 sputum cytokines. The subgroups were validated on independent severe asthma (n = 166) and COPD (n = 58) cohorts. Two techniques were used to assign the validation subjects to subgroups: linear discriminant analysis, or the best identified discriminator (single cytokine) in combination with subject disease status (asthma or COPD). Results Discriminant analysis distinguished severe asthma from COPD completely using a combination of clinical and biological variables. Factor and cluster analyses of the sputum cytokine profiles revealed 3 biological clusters: cluster 1: asthma predominant, eosinophilic, high TH2 cytokines; cluster 2: asthma and COPD overlap, neutrophilic; cluster 3: COPD predominant, mixed eosinophilic and neutrophilic. Validation subjects were classified into 3 subgroups using discriminant analysis, or disease status with a binary assessment of sputum IL-1β expression. Sputum cellular and cytokine profiles of the validation subgroups were similar to the subgroups from the test study. Conclusions Sputum cytokine profiling can determine distinct and overlapping groups of subjects with asthma and COPD, supporting both the British and Dutch hypotheses. These findings may contribute to improved patient classification to enable stratified medicine.

IL-33 drives airway hyper-responsiveness through IL-13-mediated mast cell: airway smooth muscle crosstalk.

Mast cell localization within the airway smooth muscle (ASM)‐bundle plays an important role in the development of airway hyper‐responsiveness (AHR). Genomewide association studies implicate the ‘alarmin’ IL‐33 in asthma, but its role in mast cell–ASM interactions is unknown.

Research in progress: Medical Research Council United Kingdom Refractory Asthma Stratification Programme (RASP-UK)

The UK Refractory Asthma Stratification Programme (RASP-UK) will explore novel biomarker stratification strategies in severe asthma to improve clinical management and accelerate development of new therapies. Prior asthma mechanistic studies have not stratified on inflammatory phenotype and the understanding of pathophysiological mechanisms in asthma without Type 2 cytokine inflammation is limited. RASP-UK will objectively assess adherence to corticosteroids (CS) and examine a novel composite biomarker strategy to optimise CS dose; this will also address what proportion of patients with severe asthma have persistent symptoms without eosinophilic airways inflammation after progressive CS withdrawal. There will be interactive partnership with the pharmaceutical industry to facilitate access to stratified populations for novel therapeutic studies.