Real-world retrospective observational study exploring the effectiveness and safety of antifibrotics in idiopathic pulmonary fibrosis

Antifibrotics and mortality in idiopathic pulmonary fibrosis: external validity and avoidance of immortal time bias

BACKGROUND AND OBJECTIVE

Pooled analyses of previous randomized controlled trials reported that antifibrotics improved survival in patients with idiopathic pulmonary fibrosis (IPF), but the results were only based on short-term outcome data from selected patients who met strict criteria. Observational studies/meta-analyses also suggested that antifibrotics improve survival, but these studies failed to control for immortal time bias that considerably exaggerates drug effects. Therefore, whether antifibrotics truly improve long-term survival in patients with IPF in the real world remains undetermined and requires external validity.

METHODS

We used data from the Japanese National Claims Database to estimate the intention-to-treat effect of antifibrotics on mortality. To address immortal time bias, we employed models treating antifibrotic initiation as a time-dependent covariate and target trial emulation (TTE), both incorporating new-user designs for antifibrotics and treating lung transplantation as a competing event.

RESULTS

Of 30,154 patients with IPF, 14,525 received antifibrotics. Multivariate Fine-Gray models with antifibrotic initiation as a time-dependent covariate revealed that compared with no treatment, nintedanib (adjusted hazard ratio [aHR], 0.85; 95% confidence interval [CI], 0.81-0.89) and pirfenidone (aHR, 0.89; 95% CI, 0.86-0.93) were associated with reduced mortality. The TTE model also replicated the associations of nintedanib (aHR, 0.69; 95% CI, 0.65-0.74) and pirfenidone (aHR, 0.81; 95% CI, 0.78-0.85) with reduced mortality. Subgroup analyses confirmed this association regardless of age, sex, and comorbidities, excluding certain subpopulations.

CONCLUSIONS

The results of this large-scale real-world analysis support the generalizability of the association between antifibrotics and improved survival in various IPF populations.

Body mass index is associated with clinical outcomes in idiopathic pulmonary fibrosis

Association between body mass index (BMI) and prognosis in patients with idiopathic pulmonary fibrosis (IPF) remains uncertain. We investigated the association between BMI and clinical outcomes in patients with IPF using national health claims data. The study included 11,826 patients with IPF and rare incurable disease exemption codes (mean age: 68.9 years, male: 73.8%) and available BMI data who visited medical institutions between January 2002 and December 2018. Multivariable Cox proportional hazard models were used to evaluate the association of BMI with all-cause mortality and hospitalization. Based on BMI, 3.1%, 32.8%, 27.8%, and 36.4% were classified as underweight, normal, overweight, and obese, respectively. Multivariable analysis showed independent associations of overweight (hazard ratio [HR] 0.856, 95% confidence interval [CI] 0.801-0.916) and underweight (HR 1.538, 95% CI 1.347-1.757) with mortality in patients with IPF. Similarly, overweight (HR 0.887, 95% CI 0.834-0.943) and underweight (HR 1.265, 95% CI 1.104-1.449) were also associated with hospitalization in patients with IPF in the multivariable analysis. Spline HR curve analysis adjusted for all covariates revealed a non-linear relationship between BMI and mortality in patients with IPF. Our data suggest that BMI is associated with clinical outcomes in patients with IPF.

Understanding Patterns of Adherence to Antifibrotic Treatment in Idiopathic Pulmonary Fibrosis: Insights from an Italian Prospective Cohort Study

Background: Pirfenidone and Nintedanib have significantly improved the prognosis of patients with idiopathic pulmonary fibrosis (IPF), reducing mortality risk and exacerbations. This study aimed to analyze antifibrotic treatment utilization and its association with clinical outcomes (i.e., acute exacerbation or death) during 2014-2021 in newly diagnosed IPF patients, using Healthcare Utilization Databases of the Marche Region, Italy. Methods: The first 12-month adherence to antifibrotic was estimated using the Proportion of Days Covered (PDC), defining adherence as PDC ≥ 75%. State Sequence Analysis over the initial 52 weeks of treatment was used to identify adherence patterns. The role of adherence patterns on acute exacerbations/death, adjusted by demographic, clinical features, and monthly adherence after the 52-week period (time-dependent variable), was assessed with Cox regression. Results: Among 667 new IPF cases, 296 received antifibrotic prescriptions, with 62.8% being adherent in the first year. Three antifibrotic utilization patterns emerged-high adherence (37.2%), medium adherence (42.5%), and low adherence (20.3%)-with median PDCs of 95.3%, 79.5%, and 18.6%, respectively. These patterns did not directly influence three-year mortality/exacerbation probability, but sustained adherence reduced risk over time. Conclusions: Good adherence was observed in in this population-based study, emphasizing the importance of continuous antifibrotics therapy over time to mitigate adverse outcomes.

Toll-Like Receptor 9 Aggravates Pulmonary Fibrosis by Promoting NLRP3-Mediated Pyroptosis of Alveolar Epithelial Cells

The apoptosis-prone property of alveolar epithelial cells plays a crucial role in pulmonary fibrosis(PF), but the role of pyroptosis in it is still unclear. Toll-like receptor 9(TLR9) has been reported to play a vital role in the pathogenesis of many diseases. However, the effect of TLR9 on alveolar epithelial cells in PF has not been fully elucidated. Gene expression microarray related to Idiopathic pulmonary fibrosis(IPF) was obtained from the Gene Expression Omnibus(GEO) database. In the mouse model of bleomycin-induced PF, adeno-associated virus(AAV6) was used to interfere with TLR9 to construct TLR9 knockdown mice to study the role of TLR9 in PF, and the specific mechanism was studied by intratracheal instillation of NLR family pyrin domain containing 3(NLRP3) activator. In vitro experiments were performed using A549 cells. Bleomycin-induced pyroptosis in the lung tissue of PF mice increased, and TLR9 protein levels also increased, especially in alveolar epithelial cells. The levels of fibrosis and pyroptosis in lung tissue of TLR9 knockdown mice were improved. We found that TLR9 can bind to the NLRP3, thereby increasing the activation of the NLRP3/caspase-1 inflammasome pathway. When we use the NLRP3 activator, the levels of fibrosis and pyroptosis in lung tissue of TLR9 knockout mice can be counteracted. Pyroptosis of alveolar epithelial cells plays a vital role in PF, and TLR9 can promote NLRP3-mediated pyroptosis of alveolar epithelial cells to aggravate the progression of PF and may become a feasible target for the prevention and treatment of PF.

Baseline Blood Levels of Mucin-1 Are Associated with Crucial On-Treatment Adverse Outcomes in Patients with Idiopathic Pulmonary Fibrosis Receiving Antifibrotic Pirfenidone

Mucin-1 is a multi-functional glycoprotein expressed by type II alveolocytes and may be detectable in the circulation following pulmonary fibrosis. The prognostic utility of baseline pre-treatment blood levels of mucin-1 in patients with idiopathic pulmonary fibrosis (IPF) receiving antifibrotics has not yet been fully established. We retrospectively studied a cohort of patients (from two hospitals) with IPF who were receiving pirfenidone for >12 weeks. Baseline blood mucin-1 levels were measured via sandwich enzyme-linked immunosorbent assays. We investigated the performance of mucin-1 levels in longitudinally predicting the risks of acute exacerbation of IPF (AE-IPF) and severe adverse outcomes (SAO), including lung transplantation and death. Seventy patients were included; 20 developed AE-IPF; and 31 had SAO during the follow-up period. Patients with baseline mucin-1 levels ≥2.5 ng/mL had enhanced risks of AE-IPF (adjusted hazard ratio [aHR], 14.07; 95% confidence interval [CI], 4.26-46.49) and SAO within 2 years (aHR, 7.87; 95% CI, 2.86-21.70) and anytime during the follow-up (aHR, 4.68; 95% CI, 2.11-10.39). The risks increased across subgroups with increasing mucin-1 levels. Patients in the "mucin-1 ≥ 2.5" group also exhibited an accelerated decline in DLCO. This study supports baseline blood mucin-1 levels as a biomarker for IPF that predicts adverse outcomes during pirfenidone treatment.

Heterogenous Intrapulmonary Distribution of Aerosolized Model Compounds in Mice with Bleomycin-Induced Pulmonary Fibrosis

Background: A distinctive pathological feature of idiopathic pulmonary fibrosis (IPF) is the aberrant accumulation of extracellular matrix components in the alveoli in abnormal remodeling and reconstruction following scarring of the alveolar structure. The current antifibrotic agents used for IPF therapy frequently result in systemic side effects because these agents are distributed, through the blood, to many different tissues after oral administration. In contrast to oral administration, the intrapulmonary administration of aerosolized drugs is believed to be an efficient method for their direct delivery to the focus sites in the lungs. However, how fibrotic lesions alter the distribution of aerosolized drugs following intrapulmonary administration remains largely unknown. In this study, we evaluate the intrapulmonary distribution characteristics of aerosolized model compounds in mice with bleomycin-induced pulmonary fibrosis through imaging the organs and alveoli. Methods: Aerosolized model compounds were administered to mice with bleomycin-induced pulmonary fibrosis using a Liquid MicroSprayer®. The intrapulmonary distribution characteristics of aerosolized model compounds were evaluated through several imaging techniques, including noninvasive lung imaging using X-ray computed tomography, ex vivo imaging using zoom fluorescence microscopy, frozen tissue section observation, and three-dimensional imaging with tissue-clearing treatment using confocal laser microscopy. Results: In fibrotic lungs, the aerosolized model compounds were heterogeneously distributed. In observations of frozen tissue sections, model compounds were observed only in the fibrotic foci near airless spaces called honeycombs. In three-dimensional imaging of cleared tissue from fibrotic lungs, the area of the model compound in the alveolar space was smaller than in healthy lungs. Conclusion: The intrapulmonary deposition of extracellular matrix associated with pulmonary fibrosis limits the intrapulmonary distribution of aerosolized drugs. The development of delivery systems for antifibrotic agents to improve the distribution characteristics in fibrotic foci is necessary for effective IPF therapy.

Overall drug treatment of idiopathic pulmonary fibrosis patients from national registries - a real-world study from Finland

BACKGROUND

Currently, two disease-modifying antifibrotic drugs are indicated for the treatment of idiopathic pulmonary fibrosis. The objective of this study was to analyse antifibrotic and overall prescription medication use of IPF patients in the real world.

METHODS

Data was collected from the FinnishIPF registry and the Registry of the Social Insurance Institution of Finland (SII). Purchases of all prescription medicines were assessed. The frequency, the initiation interval, the duration, and the breaks of the antifibrotic treatments were defined. The association between the prescription of antifibrotic therapy and different patient-related clinical parameters was studied. Accordingly, the relationships between the delay in starting therapy and patient-related variables were analysed.

RESULTS

Of the 263 IPF patients, 132 (50.2%) had started antifibrotic treatment during the study period 2011-2018. The mean interval from the diagnosis to the first purchase was 367 (SD 429) days. The antifibrotic drug was switched in 14% of patients. Discontinuation of therapy occurred most commonly during the first year of the treatment. The one-year persistence was 77.1% for pirfenidone and 78.9% for nintedanib. A tendency of treating patients under 75 years was noticed. Low forced vital capacity predicted earlier initiation of medication.

CONCLUSIONS

The initiation of antifibrotics after diagnosis was slow, probably due to reimbursement limitations. Younger age at diagnosis affected treatment initiation although it is unknown which patients benefit most from these medications. The reasons for discontinuation of the antifibrotic therapy during the first year should be a focus in clinical work and further studies.

Design of a phase III, double-blind, randomised, placebo-controlled trial of BI 1015550 in patients with idiopathic pulmonary fibrosis (FIBRONEER-IPF)

IntroductionThere is an unmet need for new treatments for idiopathic pulmonary fibrosis (IPF). The oral preferential phosphodiesterase 4B inhibitor, BI 1015550, prevented a decline in forced vital capacity (FVC) in a phase II study in patients with IPF. This study design describes the subsequent pivotal phase III study of BI 1015550 in patients with IPF (FIBRONEER-IPF).

METHODS AND ANALYSIS

In this placebo-controlled, double-blind, phase III trial, patients are being randomised in a 1:1:1 ratio to receive 9 mg or 18 mg of BI 1015550 or placebo two times per day over at least 52 weeks, stratified by use of background antifibrotics (nintedanib/pirfenidone vs neither). The primary endpoint is the absolute change in FVC at week 52. The key secondary endpoint is a composite of time to first acute IPF exacerbation, hospitalisation due to respiratory cause or death over the duration of the trial.

ETHICS AND DISSEMINATION

The trial is being carried out in compliance with the ethical principles of the Declaration of Helsinki, in accordance with the International Council on Harmonisation Guideline for Good Clinical Practice and other local ethics committees. The results of the study will be disseminated at scientific congresses and in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT05321069.

Improved Survival of IPF patients Treated With Antifibrotic Drugs Compared With Untreated Patients

PURPOSE

Pirfenidone and nintedanib unequivocally inhibit FVC decline, but have been inconsistently linked to reduced mortality in phase III studies. On the contrary, real-world data show a survival benefit of antifibrotic drugs. However, it is unknown what this benefit is across different Gender, Age, and Physiology (GAP) stages.

RESEARCH QUESTIONS

Is there a difference in transplant-free (TPF) survival of IPF patients receiving antifibrotic drugs (IPFAF) compared with an untreated cohort (IPFnon-AF)? Is this different for patients with GAP stage I, II, or III.

METHODS

This is a single-center observational cohort study using prospectively included patients diagnosed with IPF between 2008-2018. Primary outcomes were TPF survival difference and 1-, 2-, and 3-year cumulative mortality for IPFAF and IPFnon-AF. This was repeated after stratification for GAP stage.

RESULTS

In total, 457 patients were included. The median transplant-free survival was 3.4 years in IPFAF (n = 313) and 2.2 years in IPFnon-AF (n = 144, p = 0.005). For GAP stage II, a median survival of 3.1 and 1.7 years was noted for IPFAF (n = 143) and IPFnon-AF (n = 59, p < 0.001), respectively. A significantly lower 1-, 2-, and 3- year cumulative mortality was found for IPFAF with GAP stage II (1 yr: 7.0% vs 35.6%, 2 yr: 26.6% vs 55.9%, and 3 yr: 46.9% vs 69.5%). The 1-year cumulative mortality of IPFAF with GAP III was also significantly lower (19.0% vs 65.0%).

CONCLUSION

This large real-world study showed a survival benefit in IPFAF compared with IPFnon-AF. This especially holds true for patients with GAP stage II and III.

A Narrative Review of Real-World Data on the Safety of Nintedanib in Patients with Idiopathic Pulmonary Fibrosis

Nintedanib is a tyrosine kinase inhibitor approved for the treatment of idiopathic pulmonary fibrosis (IPF) and other progressive fibrosing interstitial lung diseases. Placebo-controlled trials showed that the adverse event profile of nintedanib was characterised mainly by gastrointestinal events, particularly diarrhoea. We review the data from all published real-world studies of the safety of nintedanib in patients with IPF. These real-world data were consistent with the safety profile observed in clinical trials and described in the product label. The most common adverse events were diarrhoea, nausea and vomiting, but these infrequently led to permanent treatment discontinuation. Liver enzyme elevations were observed, supporting the recommendation for regular monitoring of liver enzymes, particularly in the first few months of treatment. Bleeding and cardiovascular adverse events were rarely reported. As in clinical trials, in real-world studies, reductions of the nintedanib dose, treatment interruptions and use of anti-diarrhoeal medications were frequently employed to manage adverse events. Few data are available on the use of nintedanib in patients who are elderly or have advanced disease, but there are some data to suggest a greater rate of treatment discontinuation in these patients. Effective management of adverse events associated with nintedanib is important to minimise their impact.

Nintedanib for non-IPF progressive pulmonary fibrosis: 12-month outcome data from a real-world multicentre observational study

Background

Nintedanib slows lung function decline for patients with non-idiopathic pulmonary fibrosis progressive pulmonary fibrosis (PPF) in clinical trials, but the real-world safety and efficacy are not known.

Methods

In this retrospective cohort study, standardised data were collected from patients in whom nintedanib was initiated for PPF between 2019 and 2020 through an early-access programme across eight centres in the United Kingdom. Rate of lung function change in the 12 months pre- and post-nintedanib initiation was the primary analysis. Symptoms, drug safety, tolerability and stratification by interstitial lung disease subtype and computed tomography pattern were secondary analyses.

Results

126 patients were included; 67 (53%) females; mean±sd age 60±13 years. At initiation of nintedanib, mean forced vital capacity (FVC) was 1.87 L (58% predicted) and diffusing capacity of the lung for carbon monoxide (D _LCO) was 32.7% predicted. 68% of patients were prescribed prednisolone (median dose 10 mg) and 69% were prescribed a steroid-sparing agent. In the 12 months after nintedanib initiation, lung function decline was significantly lower than in the preceding 12 months: FVC -88.8 mL versus -239.9 mL (p=0.004), and absolute decline in D _LCO -2.1% versus -6.1% (p=0.004). Response to nintedanib was consistent in sensitivity and secondary analyses. 89 (71%) out of 126 patients reported side-effects, but 86 (80%) of the surviving 108 patients were still taking nintedanib at 12 months with patients reporting a reduced perception of symptom decline. There were no serious adverse events.

Conclusion

In PPF, the real-world efficacy of nintedanib replicated that of clinical trials, significantly attenuating lung function decline. Despite the severity of disease, nintedanib was safe and well tolerated in this real-world multicentre study.

Caveolin-1-Related Intervention for Fibrotic Lung Diseases

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal interstitial lung disease (ILD) for which there are no effective treatments. Lung transplantation is the only viable option for patients with end-stage PF but is only available to a minority of patients. Lung lesions in ILDs, including IPF, are characterized by alveolar epithelial cell (AEC) senescence and apoptosis and accumulation of activated myofibroblasts and/or fibrotic lung (fL) fibroblasts (fLfs). These composite populations of fLfs show a high rate of basal proliferation, resist apoptosis and senescence, and have increased migration and invasiveness. They also more readily deposit ECM proteins. These features eventuate in progressive destruction of alveolar architecture and loss of lung function in patients with PF. The identification of new, safer, and more effective therapy is therefore mandatory for patients with IPF or related ILDs. We found that increased caveolin-1 and tumor suppressor protein, p53 expression, and apoptosis in AECs occur prior to and then with the proliferation of fLfs in fibrotic lungs. AECs with elevated p53 typically undergo apoptosis. fLfs alternatively demonstrate strikingly low basal levels of caveolin-1 and p53, while mouse double minute 2 homolog (mdm2) levels and mdm2-mediated degradation of p53 protein are markedly increased. The disparities in the expression of p53 in injured AECs and fLfs appear to be due to increased basal expression of caveolin-1 in apoptotic AECs with a relative paucity of caveolin-1 and increased mdm2 in fLfs. Therefore, targeting caveolin-1 using a caveolin 1 scaffolding domain peptide, CSP7, represents a new and promising approach for patients with IPF, perhaps other forms of progressive ILD or even other forms of organ injury characterized by fibrotic repair. The mechanisms of action differ in the injured AECs and in fLfs, in which differential signaling enables the preservation of AEC viability with concurrent limitation of fLf expansion and collagen secretion. The findings in three models of PF indicate that lung scarring can be nearly abrogated by airway delivery of the peptide. Phase 1 clinical trial testing of this approach in healthy volunteers has been successfully completed; Phase 1b in IPF patients is soon to be initiated and, if successful, will be followed by phase 2 testing in short order. Apart from the treatment of IPF, this intervention may be applicable to other forms of tissue injury characterized by fibrotic repair.

Real-world impact of antifibrotics on prognosis in patients with progressive fibrosing interstitial lung disease

OBJECTIVE

No studies have demonstrated the real-world efficacy of antifibrotics for progressive fibrosing interstitial lung disease (PF-ILD). Therefore, we evaluated the efficacy of antifibrotics in patients with PF-ILD.

METHODS

We retrospectively reviewed the medical records of patients with ILD from January 2012 to July 2021. Patients were diagnosed with PF-ILD if they had ≥10% fibrosis on high-resolution CT (HRCT) and a relative forced vital capacity (FVC) decline of either ≥10% or >5% to <10% with clinical deterioration or progression of fibrosis on HRCT during overlapping windows of 2 years and with a %FVC of ≥45%. We compared FVC changes and overall survival (OS) between patients with and without antifibrotics. FVC changes were analysed using generalised estimating equations. We used inverse probability weighting (IPW) and statistical matching to adjust for covariates.

RESULTS

Of the 574 patients, 167 were diagnosed with PF-ILD (idiopathic pulmonary fibrosis (IPF), n=64; non-IPF, n=103). Antifibrotics improved the FVC decline in both IPF (p=0.002) and non-IPF (p=0.05) (IPW: IPF, p=0.015; non-IPF, p=0.031). Among patients with IPF, OS was longer in the antifibrotic group (log-rank p=0.001). However, among patients with non-IPF, OS was not longer in the antifibrotic group (p=0.3263) (IPW and statistical matching: IPF, p=0.0534 and p=0.0018; non-IPF, p=0.5663 and p=0.5618).

CONCLUSION

This is the first real-world study to show that antifibrotics improve the FVC decline in PF-ILD. However, among patients with non-IPF, we found no significant difference in mortality between those with and without antifibrotics. Future studies must clarify whether antifibrotics improve the prognosis of non-IPF.

A Systematic Review of the Prognostic Significance of the Body Mass Index in Idiopathic Pulmonary Fibrosis

The identification of novel prognostic biomarkers might enhance individualized management strategies in patients with idiopathic pulmonary fibrosis (IPF). Although several patient characteristics are currently used to predict outcomes, the prognostic significance of the body mass index (BMI), a surrogate measure of excess fat mass, has not been specifically investigated until recently. We systematically searched PubMed, Web of Science, and Scopus, from inception to July 2022, for studies investigating associations between the BMI and clinical endpoints in IPF. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the risk of bias. The PRISMA 2020 statement on the reporting of systematic reviews was followed. Thirty-six studies were identified (9958 IPF patients, low risk of bias in 20), of which 26 were published over the last five years. Significant associations between lower BMI values and adverse outcomes were reported in 10 out of 21 studies on mortality, four out of six studies on disease progression or hospitalization, and two out of three studies on nintedanib tolerability. In contrast, 10 out of 11 studies did not report any significant association between the BMI and disease exacerbation. Our systematic review suggests that the BMI might be useful to predict mortality, disease progression, hospitalization, and treatment-related toxicity in IPF (PROSPERO registration number: CRD42022353363).

Nintedanib and pirfenidone for idiopathic pulmonary fibrosis in King Abdulaziz Medical City, Riyadh: Real-life data

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive age-related lung disease causing relentless fibrosis of the lung parenchyma. Currently, pirfenidone and nintedanib are the two antifibrotic drugs, approved for the treatment of IPF. Both are shown to slow progression by preserving lung functions from rapid decline compared to a placebo. We are reporting a real-life patient experience using these two antifibrotic medications (AFMs) in our tertiary care hospital.

METHODS

A retrospective cohort study was conducted for all IPF cases diagnosed in multidisciplinary meetings between 2015 and 2020 at KAMC, Riyadh (Saudi Arabia). We are reporting patients' demographics, lung function, survival, tolerance, side effects, or death in patients taking AFMs.

RESULTS

A total of 81 cases were identified. The majority of patients aged 67 years (68%) were men with a median age of 68 years. Late presentation, severe disease, and definite usual interstitial pneumonia patterns were reported in 60% of our patients. The average number of hospital admissions before starting treatment was 1 (range: 0-3) in the nintedanib group and 1.4 (range: 1.2-5) in the pirfenidone group. There was an increase in the number of hospital admissions in the group started on pirfenidone 1.7 (range: 1.9-8) compared to nintedanib 0.5 (range: 0-3), P = 0.001. The observed mortality outcome in this cohort was 4 (11%) and 12 (27%) for nintedanib and pirfenidone, respectively. The predominant side effects were gastrointestinal symptoms for both the groups 18 (22%).

CONCLUSIONS

Pirfenidone and nintedanib are the available approved antifibrotic agents used for many years to treat IPF patients. Real-life data showed better tolerability than reported in the West, good compliance, and a manageable side effect profile in this group of elderly and severe IPF patients.

The influence of immortal time bias in observational studies examining associations of antifibrotic therapy with survival in idiopathic pulmonary fibrosis: A simulation study

Background

Immortal time bias (ITB) has been overlooked in idiopathic pulmonary fibrosis (IPF). We aimed to identify the presence of ITB in observational studies examining associations between antifibrotic therapy and survival in patients with IPF and illustrate how ITB may affect effect size estimates of those associations.

Methods

Immortal time bias was identified in observational studies using the ITB Study Assessment Checklist. We used a simulation study to illustrate how ITB may affect effect size estimates of antifibrotic therapy on survival in patients with IPF based on four statistical techniques including time-fixed, exclusion, time-dependent and landmark methods.

Results

Of the 16 included IPF studies, ITB was detected in 14 studies, while there were insufficient data for assessment in two others. Our simulation study showed that use of time-fixed [hazard ratio (HR) 0.55, 95% confidence interval (CI) 0.47-0.64] and exclusion methods (HR 0.79, 95% CI 0.67-0.92) overestimated the effectiveness of antifibrotic therapy on survival in simulated subjects with IPF, in comparison of the time-dependent method (HR 0.93, 95% CI 0.79-1.09). The influence of ITB was mitigated using the 1 year landmark method (HR 0.69, 95% CI 0.58-0.81), compared to the time-fixed method.

Conclusion

The effectiveness of antifibrotic therapy on survival in IPF can be overestimated in observational studies, if ITB is mishandled. This study adds to the evidence for addressing the influence of ITB in IPF and provides several recommendations to minimize ITB. Identifying the presence of ITB should be routinely considered in future IPF studies, with the time-dependent method being an optimal approach to minimize ITB.

Extracting patient-level data from the electronic health record: Expanding opportunities for health system research

BACKGROUND

Epidemiological studies of interstitial lung disease (ILD) are limited by small numbers and tertiary care bias. Investigators have leveraged the widespread use of electronic health records (EHRs) to overcome these limitations, but struggle to extract patient-level, longitudinal clinical data needed to address many important research questions. We hypothesized that we could automate longitudinal ILD cohort development using the EHR of a large, community-based healthcare system.

STUDY DESIGN AND METHODS

We applied a previously validated algorithm to the EHR of a community-based healthcare system to identify ILD cases between 2012-2020. We then extracted disease-specific characteristics and outcomes using fully automated data-extraction algorithms and natural language processing of selected free-text.

RESULTS

We identified a community cohort of 5,399 ILD patients (prevalence = 118 per 100,000). Pulmonary function tests (71%) and serologies (54%) were commonly used in the diagnostic evaluation, whereas lung biopsy was rare (5%). IPF was the most common ILD diagnosis (n = 972, 18%). Prednisone was the most commonly prescribed medication (911, 17%). Nintedanib and pirfenidone were rarely prescribed (n = 305, 5%). ILD patients were high-utilizers of inpatient (40%/year hospitalized) and outpatient care (80%/year with pulmonary visit), with sustained utilization throughout the post-diagnosis study period.

DISCUSSION

We demonstrated the feasibility of robustly characterizing a variety of patient-level utilization and health services outcomes in a community-based EHR cohort. This represents a substantial methodological improvement by alleviating traditional constraints on the accuracy and clinical resolution of such ILD cohorts; we believe this approach will make community-based ILD research more efficient, effective, and scalable.

Long-Term Safety of Antifibrotic Drugs in IPF: A Real-World Experience

Pirfenidone and nintedanib are the only two drugs approved for the treatment of idiopathic pulmonary fibrosis (IPF). Both proved to be safe and well-tolerated in clinical trials, but real-world data and direct comparisons are scarce. This real-life study explored the safety profile of pirfenidone and nintedanib with a prolonged follow-up. We retrospectively collected clinical status, adverse events (AEs), and treatment changes from IPF patients who had started an antifibrotic treatment at our centre from December 2011 to December 2020, including 192 patients treated with pirfenidone and 89 with nintedanib. The majority of patients in both groups experienced one or more AEs during the follow-up. A higher proportion of AEs in the nintedanib group were effectively treated with behavioural modifications or additional medications compared with the pirfenidone group (52.5% vs. 40.6%, p = 0.04). Overall, a difference in the impact of AEs due to nintedanib versus pirfenidone resulted in a lower permanent discontinuation of therapy (8.3% vs. 18.3%, p = 0.02), with the latter being associated with a higher risk of drug discontinuation at 48 months after initiation (OR = 2.52, p = 0.03). Our study confirms the safety profile of antifibrotic drugs in IPF but highlights that AEs due to nintedanib are usually easier to manage and lead to fewer cases of permanent discontinuation of therapy.

Safety and tolerability of nintedanib in patients with interstitial lung diseases in subgroups by sex: a post-hoc analysis of pooled data from four randomised controlled trials

BACKGROUND

Nintedanib is a tyrosine kinase inhibitor used in the treatment of progressive fibrosing interstitial lung diseases (ILDs). We assessed the safety and tolerability of nintedanib in patients with autoimmune disease-related ILDs and with other ILDs in subgroups by sex.

METHODS

In this post-hoc analysis, we pooled data from the two INPULSIS trials in patients with idiopathic pulmonary fibrosis (IPF), the SENSCIS trial in patients with fibrosing ILDs associated with systemic sclerosis, and the INBUILD trial in patients with progressive fibrosing ILDs other than IPF. In each trial, patients were randomly assigned to receive oral nintedanib 150 mg twice daily or matched placebo. We assessed adverse events reported over 52 weeks in patients with autoimmune disease-related ILDs and other ILDs in subgroups by sex.

FINDINGS

In these analyses, we included 746 patients with autoimmune disease-related ILDs (523 [70%] were female, 223 [30%] were male; 615 [82%] had systemic sclerosis), of whom 370 (50%) received nintedanib (268 [72%] female and 102 [28%] male patients) and 376 (50%) received placebo (255 [68%] female and 121 [32%] male patients); and 1554 patients with other ILDs (437 [28%] female, 1117 [72%] male; 1061 [68%] with IPF), of whom 888 (57%) received nintedanib (237 [27%] female and 651 [73%] male patients) and 666 (43%) received placebo (200 [30%] female and 466 [70%] male patients). Of 102 male and 268 female patients with autoimmune disease-related ILDs treated with nintedanib, nausea was reported in 21 (21%) male and 92 (34%) female patients, vomiting in 12 (12%) male and 73 (27%) female patients, alanine aminotransferase increase in four (4%) male and 31 (12%) female patients, aspartate aminotransferase increase in three (3%) male and 23 (9%) female patients, and adverse events leading to dose reduction in 18 (18%) male and 101 (38%) female patients; 28 (27%) male and 107 (40%) female patients had at least one treatment interruption. Of 651 male and 237 female nintedanib-treated patients with other ILDs, nausea was reported in 135 (21%) male and 95 (40%) female patients, vomiting in 51 (8%) male and 70 (30%) female patients, alanine aminotransferase increase in 19 (3%) male and 31 (13%) female patients, aspartate aminotransferase increase in 17 (3%) male and 26 (11%) female patients, and adverse events leading to dose reduction in 106 (16%) male and 84 (35%) female patients; 155 (24%) male and 82 (35%) female patients had at least one treatment interruption. The proportions of patients with adverse events leading to discontinuation of nintedanib were similar between female and male patients with autoimmune disease-related ILDs (44 [16%] of 268 vs 17 [17%] of 102), but were greater among female than male patients with other ILDs (62 [26%] of 237 vs 112 [17%] of 651). Across subgroups by diagnosis and sex, diarrhoea was the most frequent adverse event associated with nintedanib (autoimmune-related ILDs: 198 [74%] of 268 female and 73 [72%] of 102 male patients; other ILDs: 155 [65%] of 237 female and 408 [63%] of 651 male patients), and was the event that most frequently led to treatment discontinuation (autoimmune-related ILDs: 20 [7%] female and five [5%] male patients; other ILDs: 16 [7%] female and 27 [4%] male patients).

INTERPRETATION

The adverse event profile of nintedanib was generally similar between male and female patients with autoimmune disease-related ILDs, and between male and female patients with other ILDs, but nausea, vomiting, liver enzyme elevations, dose reductions, and treatment interruptions were more frequent in female patients than in male patients. Sex should be considered in the monitoring and management of adverse events that might be associated with nintedanib.

FUNDING

Boehringer Ingelheim.

Clinical management and acute exacerbations in patients with idiopathic pulmonary fibrosis in Spain: results from the OASIS study

Background

Idiopathic pulmonary fibrosis (IPF) is a progressive disease associated with decline in lung function and poor prognosis entailing significant impairment in quality of life and high socioeconomic burden. The aim of this study was to characterize clinical management and resources utilization of patients with IPF in Spain, according to predicted forced vital capacity (FVC) % at baseline.

Methods

Prospective, non-interventional, multicentric real-world data study in patients with IPF in Spain with 12-months follow-up. Clinical management and resources utilization during study period were recorded and compared between groups. FVC decline and acute exacerbations occurrence and associated healthcare resource use were also analysed. FVC decline after 12 months was estimated as relative change.

Results

204 consecutive patients with IPF were included and divided according to baseline FVC % predicted value. At baseline, patients with FVC < 50% received significantly more pharmacological and non-pharmacological treatments, and more help from caregiver. During the 12-months follow-up, patients with FVC < 50% required more specialized care visits, emergency visits, hospitalizations, pulmonary functions tests, non-health resource use (special transportation), and pharmacological treatments (p < 0.05 for all comparisons). Moreover, patients with FVC < 50% at baseline experienced more AE-IPF (p < 0.05), requiring more health-related resources use (primary care visits, p < 0.05). FVC decline was observed in all groups over the 12 months. FVC decreased on average by 2.50% (95% CI: − 5.98 to 0.98) along the year. More patients experienced an FVC decline > 10% in the more preserved lung function groups than in the FVC < 50% group, because of their already deteriorated condition.

Conclusions

We observed a significantly higher annual IPF-related resource use in patients with more impaired lung function at baseline. Since FVC decreases irrespective of FVC% predicted at baseline, slowing IPF progression to maintain patients at early disease stages is relevant to improve IPF management and to optimize resource use.

Trial registration: EU PAS register number EUPAS19387 [June 01, 2017].

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02154-y.

Radiomics for the Prediction of Response to Antifibrotic Treatment in Patients with Idiopathic Pulmonary Fibrosis: A Pilot Study

Antifibrotic therapy has changed the treatment paradigm for idiopathic pulmonary fibrosis (IPF); however, a subset of patients still experienced rapid disease progression despite treatment. This study aimed to determine whether CT-based radiomic features can predict therapeutic response to antifibrotic agents. In this retrospective study, 35 patients with IPF on antifibrotic treatment enrolled from two centers were divided into training (n = 26) and external validation (n = 9) sets. Clinical and pulmonary function data were collected. The patients were categorized into stable disease (SD) and progressive disease (PD) groups based on functional or radiologic criteria. From pretreatment non-enhanced high-resolution CT (HRCT) images, twenty-six radiomic features were extracted through whole-lung texture analysis, and six parenchymal patterns were quantified using dedicated imaging platforms. The predictive factors for PD were determined via univariate and multivariate logistic regression analyses. In the training set (SD/PD: 12/14), univariate analysis identified eight radiomic features and ground-glass opacity percentage (GGO%) as potential predicators of PD. However, multivariate analysis found that the single independent predictor was the sum entropy (accuracy, 80.77%; AUC, 0.75). The combined sum entropy-GGO% model improved the predictive performance in the training set (accuracy, 88.46%; AUC, 0.77). The overall accuracy of the combined model in the validation set (SD/PD: 7/2) was 66.67%. Our preliminary results demonstrated that radiomic features based on pretreatment HRCT could predict the response of patients with IPF to antifibrotic treatment.

Idiopathic pulmonary fibrosis: Current and future treatment

Objectives

Idiopathic pulmonary fibrosis (IPF) is a chronic fibrotic lung disease characterized by dry cough, fatigue, and progressive exertional dyspnea. Lung parenchyma and architecture is destroyed, compliance is lost, and gas exchange is compromised in this debilitating condition that leads inexorably to respiratory failure and death within 3–5 years of diagnosis. This review discusses treatment approaches to IPF in current use and those that appear promising for future development.

Data Source

The data were obtained from the Randomized Controlled Trials and scientific studies published in English literature. We used search terms related to IPF, antifibrotic treatment, lung transplant, and management.

Results

Etiopathogenesis of IPF is not fully understood, and treatment options are limited. Pathological features of IPF include extracellular matrix remodeling, fibroblast activation and proliferation, immune dysregulation, cell senescence, and presence of aberrant basaloid cells. The mainstay therapies are the oral antifibrotic drugs pirfenidone and nintedanib, which can improve quality of life, attenuate symptoms, and slow disease progression. Unilateral or bilateral lung transplantation is the only treatment for IPF shown to increase life expectancy.

Conclusion

Clearly, there is an unmet need for accelerated research into IPF mechanisms so that progress can be made in therapeutics toward the goals of increasing life expectancy, alleviating symptoms, and improving well‐being.

The effect of additional antimicrobial therapy on the outcomes of patients with idiopathic pulmonary fibrosis: a systematic review and meta-analysis

Background

The effect of additional antimicrobial agents on the clinical outcomes of patients with idiopathic pulmonary fibrosis (IPF) is unclear.

Methods

We performed comprehensive searches of randomized control trials (RCTs) that compared the clinical efficacy of additional antimicrobial agents to those of placebo or usual care in the treatment of IPF patients. The primary outcome was all-cause mortality, and the secondary outcomes were changes in forced vital capacity (FVC), diffusing capacity of the lung for carbon monoxide (DLCO), and the risk of adverse events (AEs).

Results

Four RCTs including a total of 1055 patients (528 receiving additional antibiotics and 527 receiving placebo or usual care) were included in this meta-analysis. Among the study group, 402 and 126 patients received co-trimoxazole and doxycycline, respectively. The all-cause mortality rates were 15.0% (79/528) and 14.0% (74/527) in the patients who did and did not receive additional antibiotics, respectively (odds ratio [OR] 1.07; 95% confidence interval [CI] 0.76 to 1.51; p = 0.71). No significant difference was observed in the changes in FVC (mean difference [MD], 0.01; 95% CI − 0.03 to 0.05; p = 0.56) and DLCO (MD, 0.05; 95% CI − 0.17 to 0.28; p = 0.65). Additional use of antimicrobial agents was also associated with an increased risk of AEs (OR 1.65; 95% CI 1.19 to 2.27; p = 0.002), especially gastrointestinal disorders (OR 1.54; 95% CI 1.10 to 2.15; p = 0.001).

Conclusions

In patients with IPF, adding antimicrobial therapy to usual care did not improve mortality or lung function decline but increased gastrointestinal toxicity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01839-0.