Thomas L. Croxton

The COPD Biomarker Qualification Consortium (CBQC)

Abstract Knowledge about the pathogenesis and pathophysiology of chronic obstructive pulmonary disease (COPD) has advanced dramatically over the last 30 years. Unfortunately, this has had little impact in terms of new treatments. Over the same time frame, only one new class of medication for COPD has been introduced. Even worse, the rate at which new treatments are being developed is slowing. The development of new tools for the assessment of new treatments has not kept pace with understanding of the disease. In part, this is because drug development tools require a regulatory review, and no interested party has been in a position to undertake such a process. In order to facilitate the development of novel tools to assess new treatments, the Food and Drug Administration, in collaboration with the COPD Foundation, the National Heart Lung and Blood Institute and scientists from the pharmaceutical industry and academia conducted a workshop to survey the available information that could contribute to new tools. Based on this, a collaborative project, the COPD Biomarkers Qualification Consortium, was initiated. The Consortium in now actively preparing integrated data sets from existing resources that can address the problem of drug development tools for COPD.

Chronic obstructive pulmonary disease: a view from the NHLBI.

The past decade has witnessed great progress in chronic obstructive pulmonary disease (COPD) research. New drugs have been developed and tested, indications for lung volume reduction surgery (LVRS) have been determined, and a growing base of scientific evidence now documents the efficacy of various therapies for symptoms and exacerbations. This advance in knowledge shatters the old conception of COPD as a hopelessly untreatable condition (1–4). It is clear that many patients with COPD can benefit from aggressive management, with a decrease in the frequency of hospitalizations and improvements in quality of life and survival. In addition, basic and clinical scientists have now identified cells, mechanisms, and molecules that appear to play key roles in disease pathogenesis. Additional novel treatments are on the horizon. The good news about COPD is getting out as many organizations are working effectively to increase awareness of the disease (5). Despite advances in care, the COPD epidemic persists, causing more than 120,000 deaths per year in the United States alone. COPDs position as the fourth leading cause of death in the United States is ominous and the probability of the number of cases rising even further is disturbing. Population-based surveys show that as many as 24 million people in the United States have airflow limitation consistent with COPD and that half or more of these cases have not yet been diagnosed (6). Despite the availability of effective treatments for COPD, no existing therapy halts or reverses the progressive and accelerated decline in lung function that is characteristic of this condition. We are far from having a cure for COPD, and in fact, the most basic questions about this disease remain unanswered: Why do only a minority of smokers develop clinically significant COPD? Why is there great heterogeneity in the presentation of COPD? Which pathogenetic pathways are critical, and how can they be modulated therapeutically? Why does the disease continue to progress even after smoking cessation? How can the lung injury that characterizes COPD be reversed? Better means of preventing and treating COPD are urgently needed, but it is not entirely clear what studies should be done. The strategic decisions in COPD research—which investigative approaches to use, which hypotheses to test, which pathways to explore in detail, which basic findings to translate into human studies, and which therapeutic targets to test—are perhaps more difficult to make now than ever before. As opportunities for investigation in COPD have expanded, the pulmonary communitys task of choosing the most effective directions and approaches for COPD research has become even more complex, and wise choices are critical to secure future success. In this essay, we encourage the pulmonary medical community to think about needs, opportunities, and the most productive approaches for research in COPD. We summarize new research directions and findings, how the disease itself is evolving, what research activities are currently underway, and how the infrastructure and organization of the research enterprise in the United States is adapting to new biological and technological challenges and advances that offer unprecedented opportunities for COPD research. We close with a call to action that presses the pulmonary community to widen its horizons and build interdisciplinary teams to better confront the problems of COPD.

Opportunities and Challenges in the Genetics of COPD 2010: An International COPD Genetics Conference Report

Chronic obstructive pulmonary disease (COPD) is defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) as a disease state characterized by airflow limitation that is not fully reversible (1). Cigarette smoking is the most important risk factor for the development of COPD. Although the dose-response relationship between cigarette smoking and pulmonary function is well-established, there is considerable variability in the reduction in FEV1 among smokers with similar smoking exposures (2, 3). The low percentage of variance in pulmonary function explained by smoking suggests that there could be genetic differences in susceptibility to the effects of cigarette smoking (4, 5). In addition to genetic factors, other environmental determinants such as indoor biomass smoke exposure can be important risk factors for COPD (6). A small percentage of COPD patients (estimated at 1-2%) inherit severe alpha-1 antitrypsin (AAT) deficiency, which proves that genetic factors can in-fluence COPD susceptibility. The discovery of AAT deficiency was a major factor in the development of the Protease-Antiprotease Hypothesis for COPD, which has been one of the prevailing models of disease pathogenesis for more than 40 years. With the substantial impact of AAT deficiency on our understanding of COPD pathogenesis, it was natural to hope that the identification of other COPD susceptibility genes would lead to similar novel insights into COPD. Until recently, however, progress in the identification of additional genetic risk factors for COPD has been slow. To facilitate the development of such research, a meeting of COPD genetics investigators was held on July 13-14,2010 in Boston. The goals of the meeting were: To review the current state of COPD genetics research; To discuss existing study populations for COPD genetics research throughout the world; To consider opportunities for collaborations between different COPD research groups through an International COPD Genetics Consortium; To recognize challenges in building COPD genetics collaborations and to discuss them openly; and, To develop a framework for future collaborative studies. Current status of COPD genetics research Many candidate gene association studies have been performed over the past 40 years, but the results have been largely inconsistent. These inconsistencies likely relate to a variety of methodological issues, including small sample sizes, variable definitions of case and control groups, failure to adjust for multiple statistical testing, and inadequate adjustments for population stratification and smoking exposure. Most of the studies describing COPD-associated polymorphisms were performed in White populations (7). A meta-analysis of 20 polymorphisms in 12 candidate genes involved in the protease-antiprotease balance and several an-tioxidant pathways showed that, after combining independent studies, many of these candidate genes had no association with COPD (8). Another factor likely impeding the progress of identifying COPD susceptibility genes is the lack of accurate phenotypic characterization of this complex and heterogeneous disease. Airflow limitation determined by spirometry has been the most common approach to classify and monitor the disease. Structural changes of the lung including emphysema and small airway obstruction are the primary processes that affect lung function (9), but they are not easily discernable with the simple spirometric measures commonly used for phe-notyping COPD. Recent advances in characterizing pathologic changes such as emphysema and remodeling of the small and large airways by quantitative analyses of image data from multidetector computed tomography (CT), together with physiological testing, have been helpful to differentiate COPD phenotypes (emphysema-predominant, airway-predominant, or mixed)(10). Study populations that have chest CT data may help to better identify COPD-associated genetic variations (11). Other potentially relevant COPD phenotypes, such as cachexia and low exercise capacity, have not been widely analyzed in COPD genetic studies. Perhaps the greatest problem in the candidate gene era of COPD genetic studies was improper candidate gene selection, which reflects our limited understanding of COPD pathogenesis. However, the application of genome-wide association studies (GWAS), which provide an unbiased and comprehensive search throughout the genome for common susceptibility loci, has changed the landscape of COPD genetics. Based on GWAS, three genetic loci have been unequivocally associated with COPD susceptibility, located on chromosome 4 near the HHIP gene, on chromosome 4 in the FAM13A gene, and on chromosome 15 in a block of genes which contains several components of the nicotinic acetyl-choline receptor as well as the IREB2 gene. In 2009, a series of studies provided convincing support for these three genetic loci in COPD susceptibility. Pillai and colleagues found genome-wide significant associations of the CHRNA3/CHRNA5/IREB2 region to COPD (12). DeMeo and colleagues performed gene expression studies of normal vs. COPD lung tissues followed by genetic association analysis of COPD (13), suggesting that at least one of the key COPD genetic determinants in the chromosome 15 GWAS region was IREB2. In the Framingham Heart Study (14), the HHIP region was associated with FEV1/FVC at genome-wide significance with replication of the effect on FEV1/FVC demonstrated in an independent sample drawn from the Family Heart Study, and this same region nearly reached genome-wide significance with COPD susceptibility in the Pillai paper (12). Recently, two papers published in Nature Genetics from large general population samples have provided strong support for the association of HHIP SNPs with FEV1/FVC (15, 16). One of these articles, from the CHARGE Consortium, also found evidence for association of FEV1/FVC with the FAM13A locus (15), which has been strongly associated with COPD susceptibility (17). Moreover, several case-control studies from other European populations have replicated these findings by confirming significant associations to the chromosome 15q25 locus (CHRNA3/CHRNA5/IREB2) (18, 19), chromosome 4q31 locus (HHIP) (20, 21), and chromosome 4q22 locus (FAM13 A) (22). Thus, the frustration of inconsistent genetic association results in COPD from the beginning of the last decade has been replaced by optimism regarding the likely importance of the IREB2/CHRNA3/CHRNA5, HHIP, and FAM13A loci in COPD susceptibility.

Challenges associated with estimating minimal clinically important differences in COPD-the NHLBI perspective.

Chronic Obstructive Pulmonary Disease (COPD) is a common lung disease that exemplifies the value, as well as the difficulties and challenges, of using minimal clinically important differences (MCID) in clinical research. Development and validation of better endpoints for clinical studies is critical to research progress in COPD. However, the clinical, genetic, and pharmacological heterogeneity of the COPD patient population complicates attempts to define and validate MCIDs for COPD. It is difficult to identify a single measurable outcome that reflects the many components of the COPD patients health state. Acute exacerbations of symptoms, which COPD patients often experience, present another challenge in the development of MCIDs for this disease. Consequently, the NHLBI does not require the use of MCIDs in clinical research. This allows research on the causes, prevention and diagnosis of COPD and use of endpoints for which an MCID is not yet known. It is important for the scientific community to reach agreement on what is a meaningful MCID in therapeutic trials for COPD. Further research into the concept of the MCID and its application should enable therapeutic trials in COPD to yield knowledge that is more effectively translated into improved public health.

Critical resources for gene therapy in Heart, Lung, and Blood Diseases Working Group.

Gene therapy has tremendous potential to provide highly specific, safe, and effective treatments for many different diseases, ranging from single gene defects to complex conditions that are primarily due to environmental causes. Despite the conceptual simplicity of treating a disease state by altering the expression of a particular protein, progress in this field has been slow. Although much progress has been made in basic science research, the major bottleneck appears to be at the transition between basic science and human studies. Relatively few clinical trials of gene therapy have been initiated for heart, lung, and blood disorders, and very few are currently ongoing. To understand better the issues that impede progress in gene therapy research, the National Heart, Lung, and Blood Institute (NHLBI) convened a Working Group (WG) of experts on June 1, 2005. This group was charged with evaluating the status of gene therapy research and identifying critical resources needed by investigators to speed the clinical translation of gene therapy for heart, lung, and blood diseases. While the discussion was focused on heart, lung, and blood disorders, it was soon recognized that the identified problems and recommended solutions are applicable to the entire field of gene therapy. WG members discussed a variety of factors that make the development and testing of gene therapeutics a particular challenge. These included basic science limitations such as inefficient gene transfer to target tissues in animals, scientific complexity (the need for a spectrum of studies and diverse expertise), the inappropriateness of existing mechanisms for allocating research funds, exquisite concerns of both patients and institutions regarding safety, and a burdensome regulatory system that requires many redundant levels of review and approval. In general, it was felt that gene therapy research is highly distinctive and is not well served by the usual systems that fund, conduct, and regulate studies related to new drugs and medical devices. To overcome these difficul-

Opportunities and challenges in the genetics of COPD 2010

Chronic obstructive pulmonary disease (COPD) is defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) as a disease state characterized by airflow limitation that is not fully reversible (1). Cigarette smoking is the most important risk factor for the development of COPD. Although the dose-response relationship between cigarette smoking and pulmonary function is well-established, there is considerable variability in the reduction in FEV1 among smokers with similar smoking exposures (2, 3). The low percentage of variance in pulmonary function explained by smoking suggests that there could be genetic differences in susceptibility to the effects of cigarette smoking (4, 5). In addition to genetic factors, other environmental determinants such as indoor biomass smoke exposure can be important risk factors for COPD (6). A small percentage of COPD patients (estimated at 1-2%) inherit severe alpha-1 antitrypsin (AAT) deficiency, which proves that genetic factors can in-fluence COPD susceptibility. The discovery of AAT deficiency was a major factor in the development of the Protease-Antiprotease Hypothesis for COPD, which has been one of the prevailing models of disease pathogenesis for more than 40 years. With the substantial impact of AAT deficiency on our understanding of COPD pathogenesis, it was natural to hope that the identification of other COPD susceptibility genes would lead to similar novel insights into COPD. Until recently, however, progress in the identification of additional genetic risk factors for COPD has been slow. To facilitate the development of such research, a meeting of COPD genetics investigators was held on July 13-14,2010 in Boston. The goals of the meeting were: To review the current state of COPD genetics research; To discuss existing study populations for COPD genetics research throughout the world; To consider opportunities for collaborations between different COPD research groups through an International COPD Genetics Consortium; To recognize challenges in building COPD genetics collaborations and to discuss them openly; and, To develop a framework for future collaborative studies. Current status of COPD genetics research Many candidate gene association studies have been performed over the past 40 years, but the results have been largely inconsistent. These inconsistencies likely relate to a variety of methodological issues, including small sample sizes, variable definitions of case and control groups, failure to adjust for multiple statistical testing, and inadequate adjustments for population stratification and smoking exposure. Most of the studies describing COPD-associated polymorphisms were performed in White populations (7). A meta-analysis of 20 polymorphisms in 12 candidate genes involved in the protease-antiprotease balance and several an-tioxidant pathways showed that, after combining independent studies, many of these candidate genes had no association with COPD (8). Another factor likely impeding the progress of identifying COPD susceptibility genes is the lack of accurate phenotypic characterization of this complex and heterogeneous disease. Airflow limitation determined by spirometry has been the most common approach to classify and monitor the disease. Structural changes of the lung including emphysema and small airway obstruction are the primary processes that affect lung function (9), but they are not easily discernable with the simple spirometric measures commonly used for phe-notyping COPD. Recent advances in characterizing pathologic changes such as emphysema and remodeling of the small and large airways by quantitative analyses of image data from multidetector computed tomography (CT), together with physiological testing, have been helpful to differentiate COPD phenotypes (emphysema-predominant, airway-predominant, or mixed)(10). Study populations that have chest CT data may help to better identify COPD-associated genetic variations (11). Other potentially relevant COPD phenotypes, such as cachexia and low exercise capacity, have not been widely analyzed in COPD genetic studies. Perhaps the greatest problem in the candidate gene era of COPD genetic studies was improper candidate gene selection, which reflects our limited understanding of COPD pathogenesis. However, the application of genome-wide association studies (GWAS), which provide an unbiased and comprehensive search throughout the genome for common susceptibility loci, has changed the landscape of COPD genetics. Based on GWAS, three genetic loci have been unequivocally associated with COPD susceptibility, located on chromosome 4 near the HHIP gene, on chromosome 4 in the FAM13A gene, and on chromosome 15 in a block of genes which contains several components of the nicotinic acetyl-choline receptor as well as the IREB2 gene. In 2009, a series of studies provided convincing support for these three genetic loci in COPD susceptibility. Pillai and colleagues found genome-wide significant associations of the CHRNA3/CHRNA5/IREB2 region to COPD (12). DeMeo and colleagues performed gene expression studies of normal vs. COPD lung tissues followed by genetic association analysis of COPD (13), suggesting that at least one of the key COPD genetic determinants in the chromosome 15 GWAS region was IREB2. In the Framingham Heart Study (14), the HHIP region was associated with FEV1/FVC at genome-wide significance with replication of the effect on FEV1/FVC demonstrated in an independent sample drawn from the Family Heart Study, and this same region nearly reached genome-wide significance with COPD susceptibility in the Pillai paper (12). Recently, two papers published in Nature Genetics from large general population samples have provided strong support for the association of HHIP SNPs with FEV1/FVC (15, 16). One of these articles, from the CHARGE Consortium, also found evidence for association of FEV1/FVC with the FAM13A locus (15), which has been strongly associated with COPD susceptibility (17). Moreover, several case-control studies from other European populations have replicated these findings by confirming significant associations to the chromosome 15q25 locus (CHRNA3/CHRNA5/IREB2) (18, 19), chromosome 4q31 locus (HHIP) (20, 21), and chromosome 4q22 locus (FAM13 A) (22). Thus, the frustration of inconsistent genetic association results in COPD from the beginning of the last decade has been replaced by optimism regarding the likely importance of the IREB2/CHRNA3/CHRNA5, HHIP, and FAM13A loci in COPD susceptibility.

A Decade of National Heart, Lung, and Blood Institute Programs Supporting COPD Research and Education

The past decade of research in chronic obstructive pulmonary disease (COPD) has seen a new age of understanding both pathogenic mechanisms and clinical manifestations of the disease. The National Heart, Lung, and Blood Institute (NHLBI) has helped guide this progress with a series of initiatives to stimulate COPD research in various ways. These initiatives were designed to promote a precision medicine approach to treating COPD, one that takes advantage of targeting particular molecular pathways and the individual pathobiologies of the diversity of COPD patients. This review describes the strategic objectives of these initiatives, as well as some of their observed and anticipated outcomes. In addition, we address parallel steps NHLBI has taken to promote COPD awareness among the public. As we look toward the immediate future of COPD research and education, we see a time of great progress in terms of understanding and treatment. Furthermore, while this remains a debilitating and disturbingly prevalent disease, as NHLBI looks even farther ahead, we envision emerging efforts toward COPD prevention.

Opportunities and challenges in the Genetics of COPD 2010: An international COPD Genetics conference report

Chronic obstructive pulmonary disease (COPD) is defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) as a disease state characterized by airflow limitation that is not fully reversible (1). Cigarette smoking is the most important risk factor for the development of COPD. Although the dose-response relationship between cigarette smoking and pulmonary function is well-established, there is considerable variability in the reduction in FEV1 among smokers with similar smoking exposures (2, 3). The low percentage of variance in pulmonary function explained by smoking suggests that there could be genetic differences in susceptibility to the effects of cigarette smoking (4, 5). In addition to genetic factors, other environmental determinants such as indoor biomass smoke exposure can be important risk factors for COPD (6). A small percentage of COPD patients (estimated at 1-2%) inherit severe alpha-1 antitrypsin (AAT) deficiency, which proves that genetic factors can in-fluence COPD susceptibility. The discovery of AAT deficiency was a major factor in the development of the Protease-Antiprotease Hypothesis for COPD, which has been one of the prevailing models of disease pathogenesis for more than 40 years. With the substantial impact of AAT deficiency on our understanding of COPD pathogenesis, it was natural to hope that the identification of other COPD susceptibility genes would lead to similar novel insights into COPD. Until recently, however, progress in the identification of additional genetic risk factors for COPD has been slow. To facilitate the development of such research, a meeting of COPD genetics investigators was held on July 13-14,2010 in Boston. The goals of the meeting were: To review the current state of COPD genetics research; To discuss existing study populations for COPD genetics research throughout the world; To consider opportunities for collaborations between different COPD research groups through an International COPD Genetics Consortium; To recognize challenges in building COPD genetics collaborations and to discuss them openly; and, To develop a framework for future collaborative studies. Current status of COPD genetics research Many candidate gene association studies have been performed over the past 40 years, but the results have been largely inconsistent. These inconsistencies likely relate to a variety of methodological issues, including small sample sizes, variable definitions of case and control groups, failure to adjust for multiple statistical testing, and inadequate adjustments for population stratification and smoking exposure. Most of the studies describing COPD-associated polymorphisms were performed in White populations (7). A meta-analysis of 20 polymorphisms in 12 candidate genes involved in the protease-antiprotease balance and several an-tioxidant pathways showed that, after combining independent studies, many of these candidate genes had no association with COPD (8). Another factor likely impeding the progress of identifying COPD susceptibility genes is the lack of accurate phenotypic characterization of this complex and heterogeneous disease. Airflow limitation determined by spirometry has been the most common approach to classify and monitor the disease. Structural changes of the lung including emphysema and small airway obstruction are the primary processes that affect lung function (9), but they are not easily discernable with the simple spirometric measures commonly used for phe-notyping COPD. Recent advances in characterizing pathologic changes such as emphysema and remodeling of the small and large airways by quantitative analyses of image data from multidetector computed tomography (CT), together with physiological testing, have been helpful to differentiate COPD phenotypes (emphysema-predominant, airway-predominant, or mixed)(10). Study populations that have chest CT data may help to better identify COPD-associated genetic variations (11). Other potentially relevant COPD phenotypes, such as cachexia and low exercise capacity, have not been widely analyzed in COPD genetic studies. Perhaps the greatest problem in the candidate gene era of COPD genetic studies was improper candidate gene selection, which reflects our limited understanding of COPD pathogenesis. However, the application of genome-wide association studies (GWAS), which provide an unbiased and comprehensive search throughout the genome for common susceptibility loci, has changed the landscape of COPD genetics. Based on GWAS, three genetic loci have been unequivocally associated with COPD susceptibility, located on chromosome 4 near the HHIP gene, on chromosome 4 in the FAM13A gene, and on chromosome 15 in a block of genes which contains several components of the nicotinic acetyl-choline receptor as well as the IREB2 gene. In 2009, a series of studies provided convincing support for these three genetic loci in COPD susceptibility. Pillai and colleagues found genome-wide significant associations of the CHRNA3/CHRNA5/IREB2 region to COPD (12). DeMeo and colleagues performed gene expression studies of normal vs. COPD lung tissues followed by genetic association analysis of COPD (13), suggesting that at least one of the key COPD genetic determinants in the chromosome 15 GWAS region was IREB2. In the Framingham Heart Study (14), the HHIP region was associated with FEV1/FVC at genome-wide significance with replication of the effect on FEV1/FVC demonstrated in an independent sample drawn from the Family Heart Study, and this same region nearly reached genome-wide significance with COPD susceptibility in the Pillai paper (12). Recently, two papers published in Nature Genetics from large general population samples have provided strong support for the association of HHIP SNPs with FEV1/FVC (15, 16). One of these articles, from the CHARGE Consortium, also found evidence for association of FEV1/FVC with the FAM13A locus (15), which has been strongly associated with COPD susceptibility (17). Moreover, several case-control studies from other European populations have replicated these findings by confirming significant associations to the chromosome 15q25 locus (CHRNA3/CHRNA5/IREB2) (18, 19), chromosome 4q31 locus (HHIP) (20, 21), and chromosome 4q22 locus (FAM13 A) (22). Thus, the frustration of inconsistent genetic association results in COPD from the beginning of the last decade has been replaced by optimism regarding the likely importance of the IREB2/CHRNA3/CHRNA5, HHIP, and FAM13A loci in COPD susceptibility.