Benefit-harm analysis of azithromycin for the prevention of acute exacerbations of chronic obstructive pulmonary disease

Longitudinal lung function trajectories in response to azithromycin therapy for chronic lung disease in children with HIV infection: a secondary analysis of the BREATHE trial

BACKGROUND

Chronic lung disease (CLD) is common among children with HIV (CWH) including in those taking antiretroviral therapy (ART). Azithromycin has both antimicrobial and anti-inflammatory effects and has been effective in improving lung function in a variety of lung diseases. We investigated lung function trajectories among CWH with CLD on ART enrolled in a randomized controlled trial of adjuvant azithromycin. We also investigated factors that modified the effect of azithromycin on lung function.

METHODS

The study used data from a double-blinded placebo-controlled trial conducted in Malawi and Zimbabwe of 48 weeks on azithromycin (BREATHE: ClinicalTrials.gov NCT02426112) among CWH aged 6 to 19 years taking ART for at least six months who had a forced expiratory volume in one second (FEV1) z-score <-1.0. Participants had a further follow-up period of 24 weeks after intervention cessation. FEV1, forced vital capacity (FVC) and FEV1/FVC were measured at baseline, 24, 48 and 72-weeks and z-scores values calculated. Generalized estimating equations (GEE) models were used to determine the mean effect of azithromycin on lung-function z-scores at each follow-up time point.

RESULTS

Overall, 347 adolescents (51% male, median age 15 years) were randomized to azithromycin or placebo. The median duration on ART was 6.2 (interquartile range: 3.8-8.6) years and 56.2% had an HIV viral load < 1000copies/ml at baseline. At baseline, the mean FEV1 z-score was - 2.0 (0.7) with 44.7% (n = 155) having an FEV1 z-score <-2, and 10.1% had microbiological evidence of azithromycin resistance. In both trial arms, FEV1 and FVC z-scores improved by 24 weeks but appeared to decline thereafter. The adjusted overall mean difference in FEV1 z-score between the azithromycin and placebo arms was 0.004 [-0.08, 0.09] suggesting no azithromycin effect and this was similar for other lung function parameters. There was no evidence of interaction between azithromycin effect and baseline age, lung function, azithromycin resistance or HIV viral load.

CONCLUSION

There was no observed azithromycin effect on lung function z-scores at any time point suggesting no therapeutic effect on lung function.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02426112. First registered on 24/04/2015.

Delphi Consensus on Clinical Applications of GOLD 2023 Recommendations in COPD Management: How Aligned are Recommendations with Clinical Practice?

INTRODUCTION

The objective of this Delphi study was to understand and assess the level of consensus among respiratory experts on the clinical application of GOLD 2023 recommendations in management of patients with chronic obstructive pulmonary disease (COPD).

METHODS

The study comprised two online surveys and a participant meeting with 34 respiratory experts from 16 countries. Responses of 73 questions were recorded using a Likert scale ranging from 0 (disagreement) to 9 (agreement). The consensus threshold was 75%.

RESULTS

Survey 1 and survey 2 had 34 and 32 participants, respectively; and 25 attended the participant meeting. Consensus was reached on survey 1: 28/42; survey 2: 18/30 close-ended questions. A consensus was reached on the clinical relevance of most updates in definitions and diagnosis of COPD. Mixed results for the treatment recommendations by GOLD were noted: 74% agreed with the recommendation to initiate treatment with dual bronchodilators for group E patients; 63% agreed for including inhaled corticosteroids (ICS)/long-acting β2 agonist(LABA)/ Long-acting muscarinic receptor antagonists (LAMA) as a treatment option for GOLD B patients. Also, consensus lacked on removing ICS + LABA as an initial therapeutic option, in countries with challenges in access to other treatment option;. 88% agreed that they use GOLD recommendations in their daily clinical practice.

CONCLUSIONS

This Delphi study demonstrated a high level of consensus regarding key concepts of GOLD 2023 report, with most participants favoring recent updates in definitions, diagnosis, management, and prevention of COPD. More evidence on the etiotype based management and treatment options for group B and E are required which could further strengthen clinical application of the GOLD report.

A Cost-Effectiveness Analysis of Azithromycin for the Prevention of Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Rationale: Daily oral azithromycin therapy can reduce the risk of acute exacerbations of chronic obstructive pulmonary disease (COPD). However, given its adverse events and additional costs, it is not known whether adding long-term azithromycin as an adjunct therapy to inhaled pharmacotherapy is cost effective. Objectives: The objective of this study was to evaluate the cost-effectiveness of add-on azithromycin therapy in COPD as recommended by contemporary COPD management guidelines. Methods: We extended a previously validated Canadian COPD policy model to include azithromycin-related inputs and outcomes. The cost-effectiveness of azithromycin was evaluated over a 20-year time horizon in patients who continue to exacerbate despite receiving maximal inhaled therapies. The benefit of azithromycin was modeled as a reduction in exacerbation rates. Adverse events included cardiovascular death, hearing loss, gastrointestinal symptoms, and antimicrobial resistance. The incremental cost-effectiveness ratio (ICER) was calculated with costs in 2020 Canadian dollars ($) and quality-adjusted life-years (QALYs) discounted at 1.5% per year. The analysis was stratified among patient subgroups based on exacerbation histories. Results: In patients with a positive exacerbation history (one or more events in the previous 12 mo), azithromycin was associated with $49,732 costs, 7.65 QALYs, and 10.95 exacerbations per patient over 20 years. The corresponding values were $48,436, 7.62, and 11.86 for the reference group, resulting in an ICER of $43,200 per QALY gained. In patients defined as frequent exacerbators (two or more moderate or one or more severe events in the past 12 mo), the ICER was reduced to $8,862 per QALY gained. In patients with no history of exacerbation, azithromycin had lower QALYs and higher costs than the reference group. Conclusions: Add-on azithromycin is cost effective in patients with a recent history of exacerbations at commonly accepted willingness-to-pay thresholds of $50,000-$100,000/QALY. Guidelines should consider recommending add-on azithromycin for patients who had at least one moderate or severe exacerbation in the past year, albeit more information about treatment efficacy would strengthen this recommendation.

Current Perspectives of Pharmacotherapies for COPD

Pharmacotherapies and avoidance of environmental/inhaled toxins are core to managing COPD. Compared to the drugs available 50 years ago, there has been substantial progress with COPD pharmacotherapies, but gaps in adherence and inhaler use persist. Personalizing inhaled pharmacotherapies is now possible with digital technologies by objectively documenting adherence and guiding inhaler technique. Another means to improve existing pharmacotherapies is through phenotyping and biomarkers. This is especially important considering the heterogeneity of the disease COPD. Blood eosinophils are now a recommended biomarker to guide use of inhaled corticosteroids and biologics in COPD. On the near horizon, we will see new inhaled medications as dual phosphodiesterase inhibitors, drugs to treat basic protein abnormalities as in alpha-1 antitrypsin deficiency that could have remarkable benefits, and biologic drugs targeting specific cell/mediator types in the COPD population. Characterization of COPD phenotypes, as asthma/COPD overlap and comorbid heart disease are vital to understand how to optimize pharmacotherapies. Importantly, we must determine how to optimize current medications; otherwise, we will repeat the same mistakes with new medications. But as we know so well, as we peel one layer of complexity, we encounter many more questions, all the while dedicated to limiting the burden of COPD.