Design and rationale of a multi-center, pragmatic, open-label randomized trial of antimicrobial therapy - the study of clinical efficacy of antimicrobial therapy strategy using pragmatic design in Idiopathic Pulmonary Fibrosis (CleanUP-IPF) clinical trial

Comparison of Pirfenidone and Nintedanib: Post Hoc Analysis of the CleanUP-IPF Study

BACKGROUND

Antifibrotics are effective in slowing FVC decline in idiopathic pulmonary fibrosis (IPF). However, whether antifibrotic type is differentially associated with FVC decline remains inconclusive.

RESEARCH QUESTION

Are there significant differences in 12-month FVC decline between pirfenidone and nintedanib?

STUDY DESIGN AND METHODS

A post hoc analysis was performed using the Clinical Efficacy of Antimicrobial Therapy Strategy Using Pragmatic Design in IPF (CleanUP-IPF) trial (No. NCT02759120). Participants who reported using pirfenidone or nintedanib on enrollment into the trial were in the primary analysis. Spirometry was scheduled at baseline and the 12- and 24-month study visits. Linear mixed-effects models with random intercept and slope were used to examine changes in FVC over time. Models were adjusted for age, sex, smoking history, coronary artery disease history, baseline FVC, and 12-month spline term. Survival and nonelective respiratory hospitalization by antifibrotic type were determined using Cox regression models with adjustment for age, sex, smoking history, coronary artery disease history, and baseline FVC and diffusing capacity for carbon monoxide.

RESULTS

Out of the 513 participants with IPF randomized in the CleanUP-IPF trial, 407 reported using pirfenidone (n = 264, 65%) or nintedanib (n = 143, 35%). The pirfenidone group had more participants with a history of coronary artery disease than the nintedanib group (34.1% vs 20.3%, respectively). Patients treated with nintedanib had a higher 12-month visit FVC than patients treated with pirfenidone (mean difference, 106 mL; 95% CI, 34-178). This difference was attenuated at the 24-month study visit. There were no significant differences in overall survival and nonelective respiratory hospitalization between the pirfenidone- and nintedanib-treated groups.

INTERPRETATION

Patients with IPF who used nintedanib had a slower 12-month FVC decline than pirfenidone in a post hoc analysis of a clinical trial.

Microbiota and IPF: hidden and detected relationships

Lung microbiota (LM) is an interesting new way to consider and redesign pathogenesis and possible therapeutic approach to many lung diseases, such as idiopathic pulmonary fibrosis (IPF), which is an interstitial pneumonia with bad prognosis. Chronic inflammation is the basis but probably not the only cause of lung fibrosis and although the risk factors are not completely clear, endogenous factors (e.g. gastroesophageal reflux) and environmental factors like cigarette smoking, industrial dusts, and precisely microbial agents could contribute to the IPF development. It is well demonstrated that many bacteria can cause epithelial cell injuries in the airways through induction of a host immune response or by activating flogosis mediators following a chronic, low-level antigenic stimulus. This persistent host response could influence fibroblast responsiveness suggesting that LM may play a role in repetitive alveolar injury in IPF. We reviewed literature regarding not only bacteria but also the role of virome and mycobiome in IPF. In fact, some viruses such as hepatitis C virus or certain fungi could be etiological agents or co-factors in the IPF progress. We aim to illustrate how the cross-talk between different local microbiotas throughout specific axis and immune modulation governed by microorganisms could be at the basis of lung dysfunctions and IPF development. Finally, since the future direction of medicine will be personalized, we suggest that the analysis of LM could be a goal to research new therapies also in IPF.

Clinical Trials for Idiopathic Pulmonary Fibrosis and the Role of Health Systems

We are in the midst of transformative innovation in health care delivery and clinical trials in idiopathic pulmonary fibrosis (IPF). Health systems are uniquely positioned at the crossroad of these shifting paradigms, equipped with the resources to expand the research pipeline in IPF through visionary leadership and targeted investments. The authors hope that by prioritizing development of health information technology, supporting a broader range of clinical trial designs, and cultivating broad stakeholder engagement, health systems will generate data to address knowledge-evidence-practice gaps in IPF. This will continue to improve the ability to deliver high-quality, safe, and effective care.

Management of Fibrotic Hypersensitivity Pneumonitis

Fibrotic hypersensitivity pneumonitis (fHP) is a chronic, often progressive fibrosing form of interstitial lung disease caused by inhaled antigenic exposures. fHP can lead to impaired respiratory function, reduced disease-related quality of life, and early mortality. Management of fHP should start with exposure remediation where possible, with systemic immunosuppression and antifibrotic therapy considered in patients with symptomatic or progressive disease. Nonpharmacologic and supportive management should be offered and, in cases of treatment-resistant, progressive illness, lung transplant should be considered.

Rethinking Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a devastating disease for patients and their loved ones. Since initial efforts to characterize this disease in the 1960s, understanding of IPF has evolved considerably. Such evolution has continually challenged prior diagnostic and treatment paradigms, ushering in an era of higher confidence diagnoses with less invasive procedures and more effective treatments. This review details how research and clinical experience over the past half century have led to a rethinking of IPF. Here, the evolution in understanding of IPF pathogenesis, diagnostic evaluation and treatment approach is discussed.

Validation and minimum important difference of the UCSD Shortness of Breath Questionnaire in fibrotic interstitial lung disease

RATIONALE

The University of California, San Diego Shortness of Breath Questionnaire (UCSDSOBQ) is a frequently used domain-specific dyspnea questionnaire; however, there is little information available regarding its use and minimum important difference (MID) in fibrotic interstitial lung disease (ILD). We aimed to describe the key performance characteristics of the UCSDSOBQ in this population.

METHODS

UCSDSOBQ scores and selected anchors were measured in 1933 patients from the prospective multi-center Canadian Registry for Pulmonary Fibrosis. Anchors included the St. George's Respiratory Questionnaire (SGRQ), European Quality of Life 5 Dimensions 5 Levels questionnaire (EQ-5D-5L) and EQ visual analogue scale (EQ-VAS), percent-predicted forced vital capacity (FVC%), diffusing capacity of the lung for carbon monoxide (DLCO%), and 6-min walk distance (6MWD). Concurrent validity, internal consistency, ceiling and floor effects, and responsiveness were assessed, followed by estimation of the MID by anchor-based (linear regression) and distribution-based methods (standard error of measurement).

RESULTS

The UCSDSOBQ had a high level of internal consistency (Cronbach's alpha = 0.97), no obvious floor or ceiling effect, strong correlations with SGRQ, EQ-5D-5L, and EQ-VAS (|r| > 0.5), and moderate correlations with FVC%, DLCO%, and 6MWD (0.3 < |r| < 0.5). The MID estimate for UCSDSOBQ was 5 points (1-8) for the anchor-based method, and 4.5 points for the distribution-based method.

CONCLUSION

This study demonstrates the validity of UCSDSOBQ in a large and heterogeneous population of patients with fibrotic ILD, and provides a robust MID estimate of 5-8 points.

Effect of Antimicrobial Therapy on Respiratory Hospitalization or Death in Adults With Idiopathic Pulmonary Fibrosis: The CleanUP-IPF Randomized Clinical Trial

IMPORTANCE

Alteration in lung microbes is associated with disease progression in idiopathic pulmonary fibrosis.

OBJECTIVE

To assess the effect of antimicrobial therapy on clinical outcomes.

DESIGN, SETTING, AND PARTICIPANTS

Pragmatic, randomized, unblinded clinical trial conducted across 35 US sites. A total of 513 patients older than 40 years were randomized from August 2017 to June 2019 (final follow-up was January 2020).

INTERVENTIONS

Patients were randomized in a 1:1 allocation ratio to receive antimicrobials (n = 254) or usual care alone (n = 259). Antimicrobials included co-trimoxazole (trimethoprim 160 mg/sulfamethoxazole 800 mg twice daily plus folic acid 5 mg daily, n = 128) or doxycycline (100 mg once daily if body weight <50 kg or 100 mg twice daily if ≥50 kg, n = 126). No placebo was administered in the usual care alone group.

MAIN OUTCOMES AND MEASURES

The primary end point was time to first nonelective respiratory hospitalization or all-cause mortality.

RESULTS

Among the 513 patients who were randomized (mean age, 71 years; 23.6% women), all (100%) were included in the analysis. The study was terminated for futility on December 18, 2019. After a mean follow-up time of 13.1 months (median, 12.7 months), a total of 108 primary end point events occurred: 52 events (20.4 events per 100 patient-years [95% CI, 14.8-25.9]) in the usual care plus antimicrobial therapy group and 56 events (18.4 events per 100 patient-years [95% CI, 13.2-23.6]) in the usual care group, with no significant difference between groups (adjusted HR, 1.04 [95% CI, 0.71-1.53; P = .83]. There was no statistically significant interaction between the effect of the prespecified antimicrobial agent (co-trimoxazole vs doxycycline) on the primary end point (adjusted HR, 1.15 [95% CI 0.68-1.95] in the co-trimoxazole group vs 0.82 [95% CI, 0.46-1.47] in the doxycycline group; P = .66). Serious adverse events occurring at 5% or greater among those treated with usual care plus antimicrobials vs usual care alone included respiratory events (16.5% vs 10.0%) and infections (2.8% vs 6.6%); adverse events of special interest included diarrhea (10.2% vs 3.1%) and rash (6.7% vs 0%).

CONCLUSIONS AND RELEVANCE

Among adults with idiopathic pulmonary fibrosis, the addition of co-trimoxazole or doxycycline to usual care, compared with usual care alone, did not significantly improve time to nonelective respiratory hospitalization or death. These findings do not support treatment with these antibiotics for the underlying disease.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02759120.

Regulatory Immune Cells in Idiopathic Pulmonary Fibrosis: Friends or Foes?

The immune system is receiving increasing attention for interstitial lung diseases, as knowledge on its role in fibrosis development and response to therapies is expanding. Uncontrolled immune responses and unbalanced injury-inflammation-repair processes drive the initiation and progression of idiopathic pulmonary fibrosis. The regulatory immune system plays important roles in controlling pathogenic immune responses, regulating inflammation and modulating the transition of inflammation to fibrosis. This review aims to summarize and critically discuss the current knowledge on the potential role of regulatory immune cells, including mesenchymal stromal/stem cells, regulatory T cells, regulatory B cells, macrophages, dendritic cells and myeloid-derived suppressor cells in idiopathic pulmonary fibrosis. Furthermore, we review the emerging role of regulatory immune cells in anti-fibrotic therapy and lung transplantation. A comprehensive understanding of immune regulation could pave the way towards new therapeutic or preventive approaches in idiopathic pulmonary fibrosis.

The Role of Microbiome and Virome in Idiopathic Pulmonary Fibrosis

The interest in the lung microbiome and virome and their contribution to the pathogenesis, perpetuation and progression of idiopathic pulmonary fibrosis (IPF) has been increasing during the last decade. The utilization of high-throughput sequencing to detect microbial and/or viral genetic material in bronchoalveolar lavage fluid or lung tissue samples has amplified the ability to identify and quantify specific microbial and viral populations. In stable IPF, higher microbial burden is associated with worse prognosis but no specific microbe has been identified to contribute to this. Additionally, no causative relation has been established. Regarding viral infections, although in the past they have been associated with IPF, causation has not been proved. Although in the past the diagnosis of acute exacerbation of IPF (AE-IPF) was not considered in patients with overt infection, this was amended in the last few years and infection is considered a cause for exacerbation. Besides this, a higher microbial burden has been found in the lungs of patients with AE-IPF and an association with higher morbidity and mortality has been confirmed. In contrast, an association of AE-IPF with viral infection has not been established. Despite the progress during the last decade, a comprehensive knowledge of the microbiome and virome in IPF and their role in disease pathogenesis are yet elusive. Although association with disease severity, risk for progression and mortality has been established, causation has not been proven and the potential use as a biomarker or the benefits of antimicrobial therapeutic strategies are yet to be determined.

Effect of Co-trimoxazole (Trimethoprim-Sulfamethoxazole) vs Placebo on Death, Lung Transplant, or Hospital Admission in Patients With Moderate and Severe Idiopathic Pulmonary Fibrosis: The EME-TIPAC Randomized Clinical Trial

IMPORTANCE

Idiopathic pulmonary fibrosis (IPF) has a poor prognosis and limited treatment options. Patients with IPF have altered lung microbiota, with bacterial burden within the lungs associated with mortality; previous studies have suggested benefit with co-trimoxazole (trimethoprim-sulfamethoxazole).

OBJECTIVE

To determine the efficacy of co-trimoxazole in patients with moderate and severe IPF.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind, placebo-controlled, parallel randomized trial of 342 patients with IPF, breathlessness (Medical Research Council dyspnea scale score >1), and impaired lung function (forced vital capacity ≤75% predicted) conducted in 39 UK specialist interstitial lung disease centers between April 2015 (first patient visit) and April 2019 (last patient follow-up).

INTERVENTIONS

Study participants were randomized to receive 960 mg of oral co-trimoxazole twice daily (n = 170) or matched placebo (n = 172) for between 12 and 42 months. All patients received 5 mg of folic acid orally once daily.

MAIN OUTCOMES AND MEASURES

The primary outcome was time to death (all causes), lung transplant, or first nonelective hospital admission. There were 15 secondary outcomes, including the individual components of the primary end point respiratory-related events, lung function (forced vital capacity and gas transfer), and patient-reported outcomes (Medical Research Council dyspnea scale, 5-level EuroQol 5-dimension questionnaire, cough severity, Leicester Cough Questionnaire, and King's Brief Interstitial Lung Disease questionnaire scores).

RESULTS

Among 342 individuals who were randomized (mean age, 71.3 years; 46 [13%] women), 283 (83%) completed the trial. The median (interquartile range) duration of follow-up was 1.02 (0.35-1.73) years. Events per person-year of follow-up among participants randomized to the co-trimoxazole and placebo groups were 0.45 (84/186) and 0.38 (80/209), respectively, with a hazard ratio of 1.2 ([95% CI, 0.9-1.6]; P = .32). There were no statistically significant differences in other event outcomes, lung function, or patient-reported outcomes. Patients in the co-trimoxazole group had 696 adverse events (nausea [n = 89], diarrhea [n = 52], vomiting [n = 28], and rash [n = 31]) and patients in the placebo group had 640 adverse events (nausea [n = 67], diarrhea [n = 84], vomiting [n = 20], and rash [n = 20]).

CONCLUSIONS AND RELEVANCE

Among patients with moderate or severe IPF, treatment with oral co-trimoxazole did not reduce a composite outcome of time to death, transplant, or nonelective hospitalization compared with placebo.

TRIAL REGISTRATION

ISRCTN Identifier: ISRCTN17464641.

Idiopathic pulmonary fibrosis: Molecular mechanisms and potential treatment approaches

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disease with high mortality that commonly occurs in middle-aged and older adults. IPF, characterized by a decline in lung function, often manifests as exertional dyspnea and cough. Symptoms result from a fibrotic process driven by alveolar epithelial cells that leads to increased migration, proliferation, and differentiation of lung fibroblasts. Ultimately, the differentiation of fibroblasts into myofibroblasts, which synthesize excessive amounts of extracellular matrix proteins, destroys the lung architecture. However, the factors that induce the fibrotic process are unclear. Diagnosis can be a difficult process; the gold standard for diagnosis is the multidisciplinary conference. Practical biomarkers are needed to improve diagnostic and prognostic accuracy. High-resolution computed tomography typically shows interstitial pneumonia with basal and peripheral honeycombing. Gas exchange and diffusion capacity are impaired. Treatments are limited, although the anti-fibrotic drugs pirfenidone and nintedanib can slow the progression of the disease. Lung transplantation is often contraindicated because of age and comorbidities, but it improves survival when successful. The incidence and prevalence of IPF has been increasing and there is an urgent need for improved therapies. This review covers the detailed cellular and molecular mechanisms underlying IPF progression as well as current treatments and cutting-edge research into new therapeutic targets.

Insights into the Role of Bioactive Food Ingredients and the Microbiome in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic disease mainly associated with aging and, to date, its causes are still largely unknown. It has been shown that dietary habits can accelerate or delay the occurrence of aging-related diseases; however, their potential role in IPF development has been underestimated so far. The present review summarizes the evidence regarding the relationship between diet and IPF in humans, and in animal models of pulmonary fibrosis, in which we discuss the bioactivity of specific dietary food ingredients, including fatty acids, peptides, amino acids, carbohydrates, vitamins, minerals and phytochemicals. Interestingly, many animal studies reveal preventive and therapeutic effects of particular compounds. Furthermore, it has been recently suggested that the lung and gut microbiota could be involved in IPF, a relationship which may be linked to changes in immunological and inflammatory factors. Thus, all the evidence so far puts forward the idea that the gut-lung axis could be modulated by dietary factors, which in turn have an influence on IPF development. Overall, the data reviewed here support the notion of identifying food ingredients with potential benefits in IPF, with the ultimate aim of designing nutritional approaches as an adjuvant therapeutic strategy.

Towards the Essence of Progressiveness: Bringing Progressive Fibrosing Interstitial Lung Disease (PF-ILD) to the Next Stage

Although only recently introduced in the ILD community, the concept of progressive fibrosing interstitial lung disease (PF-ILD) has rapidly acquired an important place in the management of non-idiopathic pulmonary fibrosis fibrosing ILD (nonIPF fILD) patients. It confirms a clinical gut feeling that an important subgroup of nonIPF fILD portends a dismal prognosis despite therapeutically addressing the alleged triggering event. Due to several recently published landmark papers showing a treatment benefit with currently available antifibrotic drugs in PF-ILD patients, endorsing a PF-ILD phenotype has vital therapeutic consequences. Importantly, defining progressiveness is based on former progression, which has proven to be a rather moderate predictor of future progression. As fibrosis extent >20% and the presence of honeycombing have superior predictive properties regarding future progression, we advocate immediate initiation of antifibrotic treatment in the presence of these risk factors. In this perspective, we describe the historical context wherein PF-ILD has emerged, determine the currently employed PF-ILD criteria and their inherent limitations and propose new directions to mature its definition. Finally, while ascertaining progression in a nonIPF fILD patient clearly demonstrates the need for (additional) therapy, in the future, therapeutic decisions should be taken after assessing which pathway is ultimately driving the progression. Although not readily available, pathophysiological insight and diagnostic means are emergent to go full steam ahead in this novel direction.