Talmadge E. King

Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis is a devastating, age-related lung disease of unknown cause that has few treatment options. This disease was once thought to be a chronic inflammatory process, but current evidence indicates that the fibrotic response is driven by abnormally activated alveolar epithelial cells (AECs). These cells produce mediators that induce the formation of fibroblast and myofibroblast foci through the proliferation of resident mesenchymal cells, attraction of circulating fibrocytes, and stimulation of the epithelial to mesenchymal transition. The fibroblast and myofibroblast foci secrete excessive amounts of extracellular matrix, mainly collagens, resulting in scarring and destruction of the lung architecture. The mechanisms that link idiopathic pulmonary fibrosis with ageing and aberrant epithelial activation are unknown; evidence suggests that the abnormal recapitulation of developmental pathways and epigenetic changes have a role. In this Seminar, we review recent data on the clinical course, therapeutic options, and underlying mechanisms thought to be involved in the pathogenesis of idiopathic pulmonary fibrosis.

A phase 3 trial of pirfenidone in patients with idiopathic pulmonary fibrosis.

BACKGROUND In two of three phase 3 trials, pirfenidone, an oral antifibrotic therapy, reduced disease progression, as measured by the decline in forced vital capacity (FVC) or vital capacity, in patients with idiopathic pulmonary fibrosis; in the third trial, this end point was not achieved. We sought to confirm the beneficial effect of pirfenidone on disease progression in such patients. METHODS In this phase 3 study, we randomly assigned 555 patients with idiopathic pulmonary fibrosis to receive either oral pirfenidone (2403 mg per day) or placebo for 52 weeks. The primary end point was the change in FVC or death at week 52. Secondary end points were the 6-minute walk distance, progression-free survival, dyspnea, and death from any cause or from idiopathic pulmonary fibrosis. RESULTS In the pirfenidone group, as compared with the placebo group, there was a relative reduction of 47.9% in the proportion of patients who had an absolute decline of 10 percentage points or more in the percentage of the predicted FVC or who died; there was also a relative increase of 132.5% in the proportion of patients with no decline in FVC (P<0.001). Pirfenidone reduced the decline in the 6-minute walk distance (P=0.04) and improved progression-free survival (P<0.001). There was no significant between-group difference in dyspnea scores (P=0.16) or in rates of death from any cause (P=0.10) or from idiopathic pulmonary fibrosis (P=0.23). However, in a prespecified pooled analysis incorporating results from two previous phase 3 trials, the between-group difference favoring pirfenidone was significant for death from any cause (P=0.01) and from idiopathic pulmonary fibrosis (P=0.006). Gastrointestinal and skin-related adverse events were more common in the pirfenidone group than in the placebo group but rarely led to treatment discontinuation. CONCLUSIONS Pirfenidone, as compared with placebo, reduced disease progression, as reflected by lung function, exercise tolerance, and progression-free survival, in patients with idiopathic pulmonary fibrosis. Treatment was associated with an acceptable side-effect profile and fewer deaths. (Funded by InterMune; ASCEND ClinicalTrials.gov number, NCT01366209.).

Pirfenidone in patients with idiopathic pulmonary fibrosis (CAPACITY): two randomised trials.

BACKGROUND Idiopathic pulmonary fibrosis is a progressive and fatal lung disease with inevitable loss of lung function. The CAPACITY programme (studies 004 and 006) was designed to confirm the results of a phase 2 study that suggested that pirfenidone, a novel antifibrotic and anti-inflammatory drug, reduces deterioration in lung function in patients with idiopathic pulmonary fibrosis. METHODS In two concurrent trials (004 and 006), patients (aged 40-80 years) with idiopathic pulmonary fibrosis were randomly assigned to oral pirfenidone or placebo for a minimum of 72 weeks in 110 centres in Australia, Europe, and North America. In study 004, patients were assigned in a 2:1:2 ratio to pirfenidone 2403 mg/day, pirfenidone 1197 mg/day, or placebo; in study 006, patients were assigned in a 1:1 ratio to pirfenidone 2403 mg/day or placebo. The randomisation code (permuted block design) was computer generated and stratified by region. All study personnel were masked to treatment group assignment until after final database lock. Treatments were administered orally, 801 mg or 399 mg three times a day. The primary endpoint was change in percentage predicted forced vital capacity (FVC) at week 72. Analysis was by intention to treat. The studies are registered with ClinicalTrials.gov, numbers NCT00287729 and NCT00287716. FINDINGS In study 004, 174 of 435 patients were assigned to pirfenidone 2403 mg/day, 87 to pirfenidone 1197 mg/day, and 174 to placebo. In study 006, 171 of 344 patients were assigned to pirfenidone 2403 mg/day, and 173 to placebo. All patients in both studies were analysed. In study 004, pirfenidone reduced decline in FVC (p=0·001). Mean FVC change at week 72 was -8·0% (SD 16·5) in the pirfenidone 2403 mg/day group and -12·4% (18·5) in the placebo group (difference 4·4%, 95% CI 0·7 to 9·1); 35 (20%) of 174 versus 60 (35%) of 174 patients, respectively, had a decline of at least 10%. A significant treatment effect was noted at all timepoints from week 24 and in an analysis over all study timepoints (p=0·0007). Mean change in percentage FVC in the pirfenidone 1197 mg/day group was intermediate to that in the pirfenidone 2403 mg/day and placebo groups. In study 006, the difference between groups in FVC change at week 72 was not significant (p=0·501). Mean change in FVC at week 72 was -9·0% (SD 19·6) in the pirfenidone group and -9·6% (19·1) in the placebo group, and the difference between groups in predicted FVC change at week 72 was not significant (0·6%, -3·5 to 4·7); however, a consistent pirfenidone effect was apparent until week 48 (p=0·005) and in an analysis of all study timepoints (p=0·007). Patients in the pirfenidone 2403 mg/day group had higher incidences of nausea (125 [36%] of 345 vs 60 [17%] of 347), dyspepsia (66 [19%] vs 26 [7%]), vomiting (47 [14%] vs 15 [4%]), anorexia (37 [11%] vs 13 [4%]), photosensitivity (42 [12%] vs 6 [2%]), rash (111 [32%] vs 40 [12%]), and dizziness (63 [18%] vs 35 [10%]) than did those in the placebo group. Fewer overall deaths (19 [6%] vs 29 [8%]) and fewer deaths related to idiopathic pulmonary fibrosis (12 [3%] vs 25 [7%]) occurred in the pirfenidone 2403 mg/day groups than in the placebo groups. INTERPRETATION The data show pirfenidone has a favourable benefit risk profile and represents an appropriate treatment option for patients with idiopathic pulmonary fibrosis. FUNDING InterMune.

Prednisone, Azathioprine, and N-Acetylcysteine for Pulmonary Fibrosis

BACKGROUND A combination of prednisone, azathioprine, and N-acetylcysteine (NAC) has been widely used as a treatment for idiopathic pulmonary fibrosis. The safety and efficacy of this three-drug regimen is unknown. METHODS In this randomized, double-blind, placebo-controlled trial, we assigned patients with idiopathic pulmonary fibrosis who had mild-to-moderate lung-function impairment to one of three groups -- receiving a combination of prednisone, azathioprine, and NAC (combination therapy), NAC alone, or placebo -- in a 1:1:1 ratio. The primary outcome was the change in longitudinal measurements of forced vital capacity during a 60-week treatment period. RESULTS When approximately 50% of data had been collected (with 77 patients in the combination-therapy group and 78 in the placebo group), a planned interim analysis revealed that patients in the combination-therapy group, as compared with the placebo group, had an increased rate of death (8 vs. 1, P=0.01) and hospitalization (23 vs. 7, P<0.001). These observations, coupled with no evidence of physiological or clinical benefit for combination therapy, prompted the independent data and safety monitoring board to recommend termination of the combination-therapy group at a mean follow-up of 32 weeks. Data from the ongoing comparison of the NAC-only group and the placebo group are not reported here. CONCLUSIONS Increased risks of death and hospitalization were observed in patients with idiopathic pulmonary fibrosis who were treated with a combination of prednisone, azathioprine, and NAC, as compared with placebo. These findings provide evidence against the use of this combination in such patients. (Funded by the National Heart, Lung, and Blood Institute and the Cowlin Family Fund; ClinicalTrials.gov number, NCT00650091.).

Clinical course and prediction of survival in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive, life-threatening, interstitial lung disease of unknown etiology. The median survival of patients with IPF is only 2 to 3 years, yet some patients live much longer. Respiratory failure resulting from disease progression is the most frequent cause of death. To date we have limited information as to predictors of mortality in patients with IPF, and research in this area has failed to yield prediction models that can be reliably used in clinical practice to predict individual risk of mortality. The goal of this concise clinical review is to examine and summarize the current data on the clinical course, individual predictors of survival, and proposed clinical prediction models in IPF. Finally, we will discuss challenges and future directions related to predicting survival in IPF.

The Clinical Course of Patients with Idiopathic Pulmonary Fibrosis

Context The natural history of idiopathic pulmonary fibrosis (IPF) is unclear. Contribution A total of 168 participants with mild to moderate IPF assigned to placebo in a randomized trial were followed at 12-week intervals for about 76 weeks. For 32 of 36 patients who died, IPF was a related or main cause of death. Although physiologic variables such as FVC changed little, acute clinical deterioration preceded death in half of the patients who died of IPF. Implications Clinicians may need to rethink referral timing for lung transplantation because many patients with IPF may experience precipitous clinical declines rather than gradual progression of disease. The Editors Idiopathic pulmonary fibrosis (IPF), the most frequent of the idiopathic interstitial pneumonias, is associated with the worst prognosis (1, 2). However, data on the natural history of IPF are sparse. To clearly describe the pace of progression and the cause of death in a well-characterized cohort with mild to moderate IPF, we analyzed data from the placebo group of a randomized, double-blind, controlled clinical trial evaluating therapy with interferon-1b in patients with IPF (3). These data provide important insight into the natural history of IPF and events preceding death in patients with IPF. The data suggest that a gradual, progressive decline does not occur in many patients, thereby supporting the need for early referral for lung transplantation. Methods Overview Using data from a recently completed clinical trial (3), we performed a series of exploratory analyses of physiologic variables, dyspnea measures, hospitalizations, and characteristics of mortality in patients randomly assigned to receive placebo. The prespecified primary end point analysis for the phase III study was to occur after the 306th randomly assigned patient was scheduled to complete 48 weeks of therapy. Patients were enrolled over an approximately 1-year period. Thus, follow-up times for the patients varied, and the numbers of patients available for visits beyond 48 weeks diminished over time. In the published report of the primary analysis of the trial, the median length of observation was 58 weeks (3). In the current report, we summarize data from randomization through the completion of blinded study therapy (the observation period); the median for this period was 76 weeks. Study Participants Study participants were all patients randomly assigned to the placebo group (n= 168) in the trial (3). Criteria for enrollment included a diagnosis of IPF according to American Thoracic Society criteria (4), an FVC of 50% to 90%, diffusing capacity of carbon monoxide (DLco) of 25% or greater, definite or probable IPF on high-resolution computed tomography according to prespecified criteria, and worsening of disease during the preceding year despite a total corticosteroid dose of 1800 mg or greater within the preceding 2 years (3). Patients were permitted to continue taking prednisone (15 mg/d) if the dosage remained stable. Data Collection Data were collected at 12-week intervals and recorded on standardized case report forms by trained research associates at each institution. Information derived from interview and examination of the patient included demographic and clinical data, physiologic assessments, measures of dyspnea, vital status, number of all-cause hospitalizations, and number of hospitalizations for which the primary reason was specified as respiratory. Physiologic measures included FVC, plethysmography, Dlco, and arterial blood gas at room-air ambient temperatures. The transition dyspnea score is derived from an instrument in which the patient assesses the extent of dyspnea in reference to his or her baseline at study entry (5). The transitions or changes in the patients dyspnea in 3 categories (function impairment, magnitude of task needed to evoke dyspnea, and magnitude of effort needed to evoke dyspnea) are rated in 7 grades from 3 (major deterioration) to 0 (unchanged) to 3 (major improvement); the final score ranged from 9 to 9. The lower the total score, the more severe the dyspnea. The validated University of California, San Diego, Shortness of Breath Questionnaire (6) has 24 items: Patients are asked to rate severity of shortness of breath using a 6-point scale (0 = not at all; 5 = maximal severity) during 21 different activities of daily living associated with varying levels of exertion; they are also asked to rate how their daily lives are limited by shortness of breath, fear of harm from overexertion, and fear of shortness of breath. Scores range from 0 to 120, with increasing score indicating worsening quality of life. The physician responsible for any patient who died during the study period completed a retrospective supplemental questionnaire. The investigator-physician, who had full access to all measurements obtained as a part of the study, specified the primary cause of death, whether the cause was respiratory, and whether death was related to IPF. Investigator-physicians were to cite IPF as the primary cause of death only in the absence of a known alternative cause and only if the event was witnessed. For deaths considered to be IPF-related, 1 of 4 categories was assigned on the basis of the interval from the onset of new or worsening symptoms or signs until death: abrupt (occurring within minutes to hours), acute (4 weeks), subacute (progressing over weeks or months), or unknown. In the current report, we combine the abrupt- and acute-onset events within a single category. Statistical Analysis Physiologic variables and measures of dyspnea were compared between baseline and week 72. The frequency of hospitalizations (all-cause and respiratory-related), number of hospital days in patients hospitalized, and mortality were assessed over the entire observation period. Mean values are followed by SDs. The relationships between baseline percentage predicted FVC and the incidence and length of hospitalization were examined by using the Fisher exact test or independent-sample t-test, as appropriate. Missing values were not imputed. The reasons for missing values are as follows: 1) To optimize data integrity, data obtained at visits outside a window of 7 days were not included in the analysis, 2) because trial enrollment was staggered, fewer patients were available for analysis at the latter time points, and 3) the value for a particular variable for a particular patient may be missing, even though all other values for that time point and patient are available. On the basis of the nature of the variations leading to the differences in available data over time, no apparent evidence indicated that the variations are not random. Data analyses were conducted by using SAS software, version 8.02 (SAS Institute, Inc., Cary, North Carolina). Role of the Funding Source InterMune, Inc., funded this study. Authors from InterMune (Drs. Safrin, Starko, and Bradford) participated in the design and analysis of the study, as did the other authors. All authors had full access to the data. The funding source had no role in the decision to publish the results. Results Patients We analyzed 168 patients (mean age, 64 years, SD 9). Most patients were male (66%), white (86%), and nonsmokers (that is, never-smokers or ex-smokers) (91%). Mean time since the diagnosis of IPF was 378 days, SD, 295. The diagnosis of IPF was confirmed by surgical lung biopsy in 58% of patients; in 83%, findings on high-resolution computed tomography met prespecified criteria for definite IPF. At study entry, 31% of patients used supplemental oxygen and 82% were receiving systemic corticosteroids. During the observation period, 2 patients (1.2%) used azathioprine and 1 patient (0.6%) used cyclophosphamide. Physiologic Variables and Measures of Dyspnea For patients who survived to week 72, the mean percentage predicted FVC decreased from 64.5%, SD 11.1%, to 61.0%, SD 14.1%; the mean percentage predicted DLco decreased from 37.8%, SD 11.1%, to 37.0%, SD 19.9%; and the mean alveolararterial gradient increased from 23.2 mm Hg, SD 10.9, to 26.9 mm Hg, SD 13.0. The mean transition dyspnea index score was 1.29, SD 3.6, at week 72, indicating worsening dyspnea, whereas the mean University of California, San Diego, Shortness of Breath Questionnaire score changed minimally (from 45.1, SD 23.4, to 46.8, SD 25.1) (Figure 1). For patients who died during the trial, we observed a general trend toward increases in alveolararterial gradient and dyspnea and toward decreases in FVC and DLco (Figure 2). The spaghetti plots (Figure 2) highlight the finding that although dyspnea or alveolararterial gradient often increased sharply before a patients death, significant intrapatient variability occurs over time. Figure 1. Measures of physiology and dyspnea from study entry through week 72 for patients who survived throughout trial. Figure 2. Measures of physiology and dyspnea for each of the 36 patients who died during the trial; each line represents a single patient. Hospitalizations Fifty-seven (34%) patients had a total of 95 all-cause hospitalizations during the observation period. Among those hospitalized, the mean total number of hospital days was 14.3, SD 13.5. Thirty-eight (23%) patients had 57 hospitalizations for a respiratory disorder, with a mean total number of hospital days of 15.0, SD 14.6. The most commonly reported reason for respiratory hospitalization (33%) was presumed infection. When stratified by the baseline median percentage predicted FVC, patients with more severely impaired lung function (62%) were more likely to be hospitalized for any reason than patients with baseline percentage predicted FVC greater than 62%35 (42%) versus 22 (26%) patients (P= 0.05) and 58 versus 37 hospitalizations overall. Respiratory hospitalizations were similarly more frequent in the subset of patients with baseline FVC of 62% or less: 25 (30%) versus 13 (15%) patients (P= 0.04). In hospitalized patients, the total number

Effect of interferon gamma-1b on survival in patients with idiopathic pulmonary fibrosis (INSPIRE): a multicentre, randomised, placebo-controlled trial

BACKGROUND Idiopathic pulmonary fibrosis is a fatal disease for which no effective treatment exists. We assessed whether treatment with interferon gamma-1b improved survival compared with placebo in patients with idiopathic pulmonary fibrosis and mild-to-moderate impairment of pulmonary function. METHODS 826 patients with idiopathic pulmonary fibrosis were enrolled from 81 centres in seven European countries, the USA, and Canada. Patients were randomly assigned (double-blind) in a 2:1 ratio to receive 200 microg interferon gamma-1b (n=551) or equivalent placebo (n=275) subcutaneously, three times per week. Eligible patients were aged 40-79 years, had been diagnosed in the past 48 months, had a forced vital capacity of 55-90% of the predicted value, and a haemoglobin-corrected carbon monoxide diffusing capacity of 35-90% of the predicted value. The primary endpoint was overall survival time from randomisation measured at the second interim analysis, when the proportion of deaths had reached 75% of those expected by the study conclusion. This study is registered with ClinicalTrials.gov, number NCT00075998. FINDINGS At the second interim analysis, the hazard ratio for mortality in patients on interferon gamma-1b showed absence of minimum benefit compared with placebo (1.15, 95% CI 0.77-1.71, p=0.497), and indicated that the study should be stopped. After a median duration of 64 weeks (IQR 41-84) on treatment, 80 (15%) patients on interferon gamma-1b and 35 (13%) on placebo had died. Almost all patients reported at least one adverse event, and more patients on interferon gamma-1b group had constitutional signs and symptoms (influenza-like illness, fatigue, fever, and chills) than did those on placebo. Occurrence of serious adverse events (eg, pneumonia, respiratory failure) was similar for both treatment groups. Treatment adherence was good and few patients discontinued treatment prematurely in either group. INTERPRETATION We cannot recommend treatment with interferon gamma-1b since the drug did not improve survival for patients with idiopathic pulmonary fibrosis, which refutes previous findings from subgroup analyses of survival in studies of patients with mild-to-moderate physiological impairment of pulmonary function. FUNDING InterMune.

A Multidimensional Index and Staging System for Idiopathic Pulmonary Fibrosis

BACKGROUND Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with an overall poor prognosis. A simple-to-use staging system for IPF may improve prognostication, help guide management, and facilitate research. OBJECTIVE To develop a multidimensional prognostic staging system for IPF by using commonly measured clinical and physiologic variables. DESIGN A clinical prediction model was developed and validated by using retrospective data from 3 large, geographically distinct cohorts. SETTING Interstitial lung disease referral centers in California, Minnesota, and Italy. PATIENTS 228 patients with IPF at the University of California, San Francisco (derivation cohort), and 330 patients at the Mayo Clinic and Morgagni-Pierantoni Hospital (validation cohort). MEASUREMENTS The primary outcome was mortality, treating transplantation as a competing risk. Model discrimination was assessed by the c-index, and calibration was assessed by comparing predicted and observed cumulative mortality at 1, 2, and 3 years. RESULTS Four variables were included in the final model: gender (G), age (A), and 2 lung physiology variables (P) (FVC and Dlco). A model using continuous predictors (GAP calculator) and a simple point-scoring system (GAP index) performed similarly in derivation (c-index of 70.8 and 69.3, respectively) and validation (c-index of 69.1 and 68.7, respectively). Three stages (stages I, II, and III) were identified based on the GAP index with 1-year mortality of 6%, 16%, and 39%, respectively. The GAP models performed similarly in pooled follow-up visits (c-index ≥71.9). LIMITATION Patients were drawn from academic centers and analyzed retrospectively. CONCLUSION The GAP models use commonly measured clinical and physiologic variables to predict mortality in patients with IPF.

Gastroesophageal Reflux Therapy Is Associated with Longer Survival in Patients with Idiopathic Pulmonary Fibrosis

RATIONALE Gastroesophageal reflux (GER) is highly prevalent in patients with idiopathic pulmonary fibrosis (IPF). Chronic microaspiration secondary to GER may play a role in the pathogenesis and natural history of IPF. OBJECTIVES To investigate the relationship between GER-related variables and survival time in patients with IPF. METHODS Regression analysis was used to investigate the relationship between GER-related variables and survival time in a retrospectively identified cohort of patients with well-characterized IPF from two academic medical centers. MEASUREMENTS AND MAIN RESULTS Two hundred four patients were identified for inclusion. GER-related variables were common in this cohort: reported symptoms of GER (34%), a history of GER disease (45%), reported use of GER medications (47%), and Nissen fundoplication (5%). These GER-related variables were significantly associated with longer survival time on unadjusted analysis. After adjustment, the use of GER medications was an independent predictor of longer survival time. In addition, the use of gastroesophageal reflux medications was associated with a lower radiologic fibrosis score. These findings were present regardless of center. CONCLUSIONS The reported use of GER medications is associated with decreased radiologic fibrosis and is an independent predictor of longer survival time in patients with IPF. These findings further support the hypothesis that GER and chronic microaspiration may play important roles in the pathobiology of IPF.

Ascertainment of Individual Risk of Mortality for Patients with Idiopathic Pulmonary Fibrosis

RATIONALE Several predictors of mortality in patients with idiopathic pulmonary fibrosis have been described; however, there is a need for a practical and accurate method of quantifying the prognosis of individual patients. OBJECTIVES Develop a practical mortality risk scoring system for patients with idiopathic pulmonary fibrosis. METHODS We used a Cox proportional hazards model and data from two clinical trials (n = 1,099) to identify independent predictors of 1-year mortality among patients with idiopathic pulmonary fibrosis. From the comprehensive model, an abbreviated clinical model comprised of only those predictors that are readily and reliably ascertained by clinicians was derived. Beta coefficients for each predictor were then used to develop a practical mortality risk scoring system. MEASUREMENTS AND MAIN RESULTS Independent predictors of mortality included age, respiratory hospitalization, percent predicted FVC, 24-week change in FVC, percent predicted carbon monoxide diffusing capacity, 24-week change in percent predicted carbon monoxide diffusing capacity, and 24-week change in health-related quality of life. An abbreviated clinical model comprising only four predictors (age, respiratory hospitalization, percent predicted FVC, and 24-wk change in FVC), and the corresponding risk scoring system produced estimates of 1-year mortality risk consistent with observed data (9.9% vs. 9.7%; C statistic = 0.75; 95% confidence interval, 0.71–0.79). CONCLUSIONS The prognosis for patients with idiopathic pulmonary fibrosis may be accurately determined using four readily ascertainable predictors. Our simplified scoring system may be a valuable tool for determining prognosis and guiding clinical management. Additional research is needed to validate the applicability and accuracy of the scoring system.