Treatment Trials in Young Patients with Chronic Obstructive Pulmonary Disease and Pre-Chronic Obstructive Pulmonary Disease Patients: Time to Move Forward.

Chronic obstructive pulmonary disease (COPD) is the end result of a series of dynamic and cumulative gene-environment interactions over a lifetime. The evolving understanding of COPD biology provides novel opportunities for prevention, early diagnosis, and intervention. To advance these concepts, we propose therapeutic trials in two major groups of subjects: "young" individuals with COPD and those with pre-COPD. Given that lungs grow to about 20 years of age and begin to age at approximately 50 years, we consider "young" patients with COPD those patients in the age range of 20-50 years. Pre-COPD relates to individuals of any age who have respiratory symptoms with or without structural and/or functional abnormalities, in the absence of airflow limitation, and who may develop persistent airflow limitation over time. We exclude from the current discussion infants and adolescents because of their unique physiological context and COPD in older adults given their representation in prior randomized controlled trials (RCTs). We highlight the need of RCTs focused on COPD in young patients or pre-COPD to reduce disease progression, providing innovative approaches to identifying and engaging potential study subjects. We detail approaches to RCT design, including potential outcomes such as lung function, patient-reported outcomes, exacerbations, lung imaging, mortality, and composite endpoints. We critically review study design components such as statistical powering and analysis, duration of study treatment, and formats to trial structure, including platform, basket, and umbrella trials. We provide a call to action for treatment RCTs in 1) young adults with COPD and 2) those with pre-COPD at any age.

A disease progression model of longitudinal lung function decline in idiopathic pulmonary fibrosis patients.

Pirfenidone and nintedanib are the first two FDA-approved therapies for treatment of idiopathic pulmonary fibrosis (IPF). The clinical programs for pirfenidone and nintedanib included 1132 patients in the placebo arms and 1691 patients in the treatment arms across 6 trials. We developed a disease progression model to characterize the observed variability in lung function decline, measured as percent predicted forced vital capacity (%p-FVC), and its decrease in decline after treatment. The non-linear longitudinal change in %p-FVC was best described by a Weibull function. The median decreased decline in %p-FVC after treatment was estimated to be 1.50% (95% CI [1.12, 1.79]) and 1.96% (95% CI [1.47, 2.36]) at week 26 and week 52, respectively. Smoking status, weight, %p-FVC, %p-DLco and oxygen use at baseline were identified as significant covariates affecting decline in %p-FVC. The decreased decline in %p-FVC were observed among all subgroups of interest, of which the effects were larger at 1 year compared to 6 months. Based on the disease progression model smoking status and oxygen use at baseline may affect the treatment effect size. At week 52, the decreased decline in %p-FVC for current smokers and patients with oxygen use at baseline were 1.56 (90% CI [1.02, 1.99]) and 2.32 (90% CI [1.74, 2.86]), respectively. These prognostic factors may be used to enrich studies with patients who are more likely to respond to treatment, by demonstrating a lesser decline in lung function, and therefore provide the potential to allow for IPF studies with smaller study populations or shorter durations.

Limitations of model based dose selection for indacaterol in patients with chronic obstructive pulmonary disease.

OBJECTIVE: Indacaterol is a long-acting ß-agonist (LABA) approved by FDA in 2011 at a dose of 75 µg once daily for the treatment of chronic obstructive pulmonary disease (COPD). During the review process for indacaterol approval, data were reanalyzed by FDA to evaluate the validity of the model based conclusions regarding dose selection. METHODS: The same dose response model applied by the sponsor was used to analyze a subset of the original data. Model predictions were compared with observed data to evaluate the model. Subgroups were created to visualize the relationship between key model parameters and covariates. The Emax model structure was evaluated for a meta-analysis. RESULTS: Patient-level analyses showed that the model based claim of additional benefit of 150 µg over 75 µg for more severe patients is not supported by the data. Mis-specified covariate model structures for key parameters contributed to this inconsistency. The assumed Emax model structure is not supported by the study-level data and the study-level analysis overestimates the incremental difference between two adjacent doses. CONCLUSIONS: Even though model based drug development is highly desirable, thorough model evaluation and justification is necessary to ensure the validity of related decisions.

Uniform definition of asthma severity, control, and exacerbations: document presented for the World Health Organization Consultation on Severe Asthma.

Asthma is a global health problem affecting around 300 million individuals of all ages, ethnic groups and countries. It is estimated that around 250,000 people die prematurely each year as a result of asthma. Concepts of asthma severity and control are important in evaluating patients and their response to treatment, as well as for public health, registries, and research (clinical trials, epidemiologic, genetic, and mechanistic studies), but the terminology applied is not standardized, and terms are often used interchangeably. A common international approach is favored to define severe asthma, uncontrolled asthma, and when the 2 coincide, although adaptation may be required in accordance with local conditions. A World Health Organization meeting was convened April 5-6, 2009, to propose a uniform definition of severe asthma. An article was written by a group of experts and reviewed by the Global Alliance against Chronic Respiratory Diseases review group. Severe asthma is defined by the level of current clinical control and risks as "Uncontrolled asthma which can result in risk of frequent severe exacerbations (or death) and/or adverse reactions to medications and/or chronic morbidity (including impaired lung function or reduced lung growth in children)." Severe asthma includes 3 groups, each carrying different public health messages and challenges: (1) untreated severe asthma, (2) difficult-to-treat severe asthma, and (3) treatment-resistant severe asthma. The last group includes asthma for which control is not achieved despite the highest level of recommended treatment and asthma for which control can be maintained only with the highest level of recommended treatment.

Scientific Considerations for the Review and Approval of First Generic Mometasone Furoate Nasal Suspension Spray in the United States from the Bioequivalence Perspective.

In 2016, the US Food and Drug Administration (FDA) approved the first Abbreviated New Drug Application for Mometasone Furoate Nasal Suspension Spray. To establish the bioequivalence of this generic nasal suspension spray with the reference listed drug product (RLD), Nasonex®, a "weight-of-evidence" approach was utilized by the applicant that included formulation and device similarities, equivalent in vitro performance, equivalent systemic exposure, and equivalent local delivery. In addition to these testing for comprehensive evaluation of the drug product, FDA also considered supportive data generated by a novel in vitro method, Morphologically-Directed Raman Spectroscopy (MDRS), to characterize the particle size distribution (PSD) of active pharmaceutical ingredient (API) in the drug product. In this case, MDRS data eliminated the need for a comparative clinical endpoint bioequivalence study. The approval of the first generic Mometasone Furoate Nasal Suspension Spray is precedent-setting and paves a new pathway to establish bioequivalence for generic nasal suspension sprays. This approval also exemplifies FDA's commitment to advance regulatory science for evaluation of generic drug products.

Delayed onset and protracted progression of anaphylaxis after omalizumab administration in patients with asthma.

BACKGROUND: Risk of anaphylaxis is included in the prescribing information for omalizumab, but the nature of these reactions merits further elaboration. OBJECTIVE: To describe cases of anaphylaxis associated with omalizumab administration in patients with asthma. METHODS: We reviewed spontaneous postmarketing adverse event reports submitted to the US Food and Drug Administration's Adverse Event Reporting System database and to the manufacturers of omalizumab and cases published in the literature through December 2006. Diagnostic criteria for anaphylaxis outlined by the National Institute of Allergy and Infectious Diseases and the Food Allergy and Anaphylaxis Network were used to screen cases. RESULTS: One-hundred twenty-four cases of anaphylaxis associated with omalizumab administration in patients with asthma were identified. Many cases had a delayed onset of symptoms beyond 2 hours after dose administration. Many cases were also characterized by a protracted progression, with individual signs and symptoms of anaphylaxis staggered over hours. Review of the case reports did not reveal any predictive risk factors for the delayed onset or protracted progression of anaphylaxis. CONCLUSION: Omalizumab-induced anaphylaxis may be characterized by a delayed onset and a protracted progression of symptoms. CLINICAL IMPLICATIONS: The unusual timing of anaphylaxis in these cases challenges our understanding of anaphylaxis. A delayed onset of symptoms and protracted progression of anaphylaxis should be taken into account when administering omalizumab.

The U.S. Food and Drug Administration's Experience with Ivacaftor in Cystic Fibrosis. Establishing Efficacy Using In Vitro Data in Lieu of a Clinical Trial.

On May 17, 2017, the U.S. Food and Drug Administration expanded the patient population for use of ivacaftor to include patients with cystic fibrosis with relatively rare mutations in the cystic fibrosis transmembrane conductance regulator gene. The label expansion is unique in that clinical efficacy was not based on clinical data but on in vitro assay data demonstrating increased chloride ion transport across cells in response to ivacaftor. Such an approach provides a pathway for adding difficult-to-study mutation-based cystic fibrosis subpopulations to the indication as well as defining mutations unresponsive to ivacaftor and has important implications for cystic fibrosis drug development and other rare genetic diseases whose genetics and disease pathophysiology are well understood.

Considerations for Developing Targeted Therapies in Low-Frequency Molecular Subsets of a Disease.

Advances in our understanding of the molecular underpinnings of disease have spurred the development of targeted therapies and the use of precision medicine approaches in patient care. While targeted therapies have improved our capability to provide effective treatments to patients, they also present additional challenges to drug development and benefit-risk assessment such as identifying the subset(s) of patients likely to respond to the drug, assessing heterogeneity in response across molecular subsets of a disease, and developing diagnostic tests to identify patients for treatment. These challenges are particularly difficult to address when targeted therapies are developed to treat diseases with multiple molecular subtypes that occur at low frequencies. To help address these challenges, the US Food and Drug Administration recently published a draft guidance entitled "Developing Targeted Therapies in Low-Frequency Molecular Subsets of a Disease." Here we provide additional information on specific aspects of targeted therapy development in diseases with low-frequency molecular subsets.

Pulmonary biomarkers in chronic obstructive pulmonary disease.

There has been increasing interest in using pulmonary biomarkers to understand and monitor the inflammation in the respiratory tract of patients with chronic obstructive pulmonary disease (COPD). In this Pulmonary Perspective we discuss the merits of the various approaches by reviewing the current literature on pulmonary biomarkers in COPD and underscore the need for more systematic studies in the future. Bronchial biopsies and bronchoalveolar lavage provide valuable information about inflammatory cells and mediators, but are invasive, so that repeated measurements have to be very limited in assessing any interventions. Induced sputum has provided considerable information about the inflammatory process, including mediators and proteinases in COPD, but selectively samples proximal airways and may not closely reflect distal inflammatory processes. Exhaled gases and breath condensate are noninvasive procedures, so repeated measurements are possible, but for some assays the variability is relatively high. There is relatively little information about how any of these biomarkers relate to other clinical outcomes, such as progression of the disease, severity of disease, clinical subtypes, or response to therapy. More information is also needed about the variability in these measurements. In the future, pulmonary biomarkers may be useful in predicting disease progression, indicating disease instability, and in predicting response to current therapies and novel therapies, many of which are now in development.

Valved Holding Chambers and In Vitro Metered Dose Inhaler Performance: Effects of Flow Rate and Inhalation Delay.

BACKGROUND: Multiple factors may influence the performance of a metered dose inhaler (MDI) when used with a valved holding chamber (VHC or "spacer"). METHODS: Andersen Cascade Impactor measurements were conducted for three MDI products and two different VHCs using a specially designed system that accommodated variable delay times between MDI actuation and introduction of the aerosol into the impactor, and allowed reduced flow through the VHC while the impactor was operated at 28.3 L/min. Deposited drug mass and aerodynamic particle size distribution were determined using validated high-performance liquid chromatography (HPLC) methods. A two-level, three-factor full-factorial design of experiments (DOE) design was applied to assess the influences of VHC type, flow rate, and inhalation delay on a total of seven performance characteristics for each MDI product. An experiment without a VHC was added to assess the influence of VHC presence. RESULTS: DOE study shows the presence and type of VHC are the major influences on emitted dose and respirable fraction. Following the VHC effect, the inhalation delay has the most significant influence on most MDI performance metrics-emitted dose, respirable particle dose and fraction (aerosols between 1.1 and 4.7 µm), and fine particle dose and fraction (aerosols under 4.7 µm). CONCLUSION: This study illustrates the use of DOE analysis to effectively assess the effects of patient handling parameters (flow rate and inhalation delay) on the performance of MDI drugs when used with a VHC. The results of this study will inform Food and Drug Administration reviewers, the pharmaceutical industry, and healthcare practitioners as to safe and effective use of MDI products when used in conjunction with spacer devices.

Acute Exacerbation and Decline in Forced Vital Capacity Are Associated with Increased Mortality in Idiopathic Pulmonary Fibrosis.

RATIONALE: Exploration of FVC as it relates to mortality in idiopathic pulmonary fibrosis (IPF), a chronic, progressive, and ultimately fatal parenchymal lung disease, is important both clinically and to the current drug development paradigm. We evaluated the association between FVC decline and mortality in what is to our knowledge the largest well-characterized placebo cohort to date. Additionally, we sought to explore the risk of death caused by acute exacerbations and to further validate previously identified baseline predictors of mortality. OBJECTIVES: To validate and further characterize FVC decline, acute exacerbations, and previously identified baseline predictors as they relate to risk of death. METHODS: A total of 1,132 placebo subjects from six studies used for the clinical development of nintedanib and pirfenidone for the treatment of IPF were included in the present analysis. Deaths were captured as all-cause mortality. A stratified Cox proportional hazards model was used to test the association between baseline predictors, decline in FVC % predicted from baseline, acute exacerbations, and death. Decline in FVC % predicted and exacerbations were treated as time-varying covariates. RESULTS: Subjects were followed for a mean of 60 weeks. At baseline, age, smoking status, lower FVC % predicted, and lower diffusing capacity of the lung for carbon monoxide % predicted were associated with an increased risk of death. The risk of death was also increased for subjects having one or more exacerbations with a hazard ratio (HR) of 10.3 (95% confidence interval [CI], 5.7-18.7). Compared with an FVC % predicted absolute decline from baseline at any time during the study of less than 5%, a decline greater than or equal to 10% to less than 15% was associated with an increased risk of death, with an HR of 2.2 (95% CI, 1.1-4.4), as was a decline greater than or equal to 15%, which was estimated with an HR of 6.1 (95% CI, 3.1-11.8). A decline ranging from greater than or equal to 5% to less than 10% was not associated with increased mortality. CONCLUSIONS: Our analyses validate the importance of baseline FVC, diffusing capacity of the lung for carbon monoxide, age, and smoking status as predictors of mortality and strengthen the association between decline in FVC and exacerbations with death, verifying a decline in FVC as an appropriate endpoint in IPF drug development. Clinical trial registered with www.clinicaltrials.gov (NCT00514683, NCT01335464, NCT01335477, NCT00287729, NCT00287716, and NCT01366209).

Exposure-Response Modeling and Power Analysis of Components of ACR Response Criteria in Rheumatoid Arthritis (Part 2: Continuous Model).

Population pharmacokinetic/pharmacodynamic (PK/PD) models were developed to quantitate the exposure-response relationships using continuous longitudinal data on American College of Rheumatology (ACR) subcomponents, that is, tender-joint count (TJC), swollen-joint count (SJC), C-reactive protein, patient's assessment of pain, patient's global assessment of disease activity, physician's global assessment of disease activity, and patient's assessment of physical function for 5 biologics approved for use in rheumatoid arthritis. The models were then used to simulate the time courses of clinical outcomes following different treatment regimens. The relative sensitivity of the 7 subcomponents was assessed using Monte Carlo simulation-based power analysis. The developed population PK/PD models adequately described the relationship between serum concentrations and changes in ACR subcomponents. The trial simulation and subsequent power analysis showed that SJC and TJC appeared to be more sensitive than the other 5 ACR subcomponents to detect treatment effect over placebo/methotrexate. These 7 ACR subcomponents had similar power in detecting the treatment difference between different doses. In addition, the continuous measures of ACR subcomponents did not appear to be more sensitive than binary measures.

Exposure-Response Modeling and Power Analysis of Components of ACR Response Criteria in Rheumatoid Arthritis (Part 1: Binary Model).

American College of Rheumatology (ACR) response criteria is used to assess improvement in tender and swollen joint counts and in 3 of the 5 core measures (acute-phase reactant, physician global assessment, patient global assessment, pain, and physical function). From the clinical trial data on 5 approved biological products for the treatment of rheumatoid arthritis, population pharmacokinetic/pharmacodynamic models were developed to quantitatively describe the relationship between exposure and response rates of 3 individual components of ACR response criteria. The models were then used to simulate the clinical outcomes at various time points following different treatment regimens. The relative sensitivity of these criteria components was assessed using power analysis. As compared to the composite endpoints (ACR20/ACR50/ACR70), the individual ACR criteria components had adequate power and higher sensitivity in distinguishing treatment effects over placebo/methotrexate control. The 3 individual ACR criteria components appeared to have similar powers at different dose levels after long-term treatment. This research provides a unique approach to assess the relative sensitivity of the 3 binary components of ACR response criteria which would be useful to support future dose selection and trial design in the treatment of rheumatoid arthritis.

Tiotropium Respimat Is Effective for the Treatment of Asthma at a Dose Lower Than That for Chronic Obstructive Pulmonary Disease.

Anticholinergic drug products are not part of the current treatment paradigm for asthma, despite their widespread availability for chronic obstructive pulmonary disease (COPD) and interest in their use for asthma. Published study results, mostly of short duration and primarily with ipratropium and tiotropium, have revealed inconsistent efficacy results. Consequently, the role of inhaled anticholinergic drugs in the treatment of asthma has been unclear. This commentary discusses and comments on data from five clinical trials in adults that were submitted by Boehringer Ingelheim to the U.S. Food and Drug Administration to support approval of tiotropium delivered by the Respimat device (Spiriva Respimat) for the treatment of asthma. These trials provided substantial evidence that supported the approval of Spiriva Respimat at a recommended dose of 2.5 µg once daily for asthma. Notably, in trials that evaluated two doses of tiotropium, 2.5 µg and 5 µg (the dose approved for COPD), pulmonary function measures for Spiriva Respimat 2.5 µg once daily were better overall than those obtained for the 5-µg once-daily dose, thus justifying selection of the lower dose for asthma. Spiriva Respimat represents the first new class of drug approved by the U.S. Food and Drug Administration for the treatment of asthma in more than a decade. The availability of Spiriva Respimat for asthma along with other novel therapies currently under development has the potential to impact asthma treatment guidelines.