Rohit K. Katial

Safety profile, pharmacokinetics, and biologic activity of MEDI-563, an anti–IL-5 receptor α antibody, in a phase I study of subjects with mild asthma

BACKGROUND Increased eosinophil levels have been linked to airway inflammation and asthma exacerbations. IL-5 is responsible for eosinophil differentiation, proliferation, and activation; IL-5 receptors are expressed on eosinophils and their progenitors, and targeting such receptors induces eosinophil apoptosis. OBJECTIVE To evaluate the safety profile, pharmacokinetics, and pharmacodynamics of MEDI-563, a humanized mAb targeting the IL-5 receptor alpha chain. METHODS Single, escalating, intravenous doses (0.0003-3 mg/kg) of MEDI-563 were administered to subjects with mild atopic asthma (n = 44) over approximately 3 to 30 minutes in this open-label study. Pulmonary function, symptom scores, adverse events, MEDI-563 pharmacokinetics, and levels of C-reactive protein (CRP), IL-6, eosinophil cationic protein (ECP), and eosinophils were evaluated. RESULTS Mean peripheral blood (PB) eosinophil levels decreased in a dose-dependent fashion (baseline +/- SD, 0.27 +/- 0.2 x 10(3)/microL; 24 hours postdose, 0.01 +/- 0.0 x 10(3)/microL); 94.0% of subjects receiving >or=0.03 mg/kg exhibited levels between 0.00 x 10(3)/microL and 0.01 x 10(3)/microL. Eosinopenia lasted at least 8 or 12 weeks with doses of 0.03 to 0.1 and 0.3 to 3 mg/kg, respectively. ECP levels were reduced from 21.4 +/- 17.2 microg/L (baseline) to 10.3 +/- 7.0 microg/L (24 hours postdose). The most frequently reported adverse events were reduced white blood cell counts (34.1%), nasopharyngitis (27.3%), and increased blood creatine phosphokinase (25.0%). Mean C-reactive protein levels increased approximately 5.5-fold at 24 hours postdose but returned to baseline by study end; mean IL-6 levels increased approximately 3.9-fold to 4.7-fold at 6 to 12 hours postdose, respectively. Pharmacokinetic activity was dose proportional at doses of 0.03 to 3 mg/kg. CONCLUSION Single escalating doses of MEDI-563 had an acceptable safety profile and resulted in marked reduction of PB eosinophil counts within 24 hours after dosing.

Use and interpretation of diagnostic vaccination in primary immunodeficiency: a working group report of the Basic and Clinical Immunology Interest Section of the American Academy of Allergy, Asthma & Immunology.

A major diagnostic intervention in the consideration of many patients suspected to have primary immunodeficiency diseases (PIDDs) is the application and interpretation of vaccination. Specifically, the antibody response to antigenic challenge with vaccines can provide substantive insight into the status of human immune function. There are numerous vaccines that are commonly used in healthy individuals, as well as others that are available for specialized applications. Both can potentially be used to facilitate consideration of PIDD. However, the application of vaccines and interpretation of antibody responses in this context are complex. These rely on consideration of numerous existing specific studies, interpolation of data from healthy populations, current diagnostic guidelines, and expert subspecialist practice. This document represents an attempt of a working group of the American Academy of Allergy, Asthma & Immunology to provide further guidance and synthesis in this use of vaccination for diagnostic purposes in consideration of PIDD, as well as to identify key areas for further research.

The effect of aspirin desensitization on novel biomarkers in aspirin-exacerbated respiratory diseases

BACKGROUND Patients with aspirin-exacerbated respiratory disease have been shown to benefit clinically from aspirin desensitization followed by chronic high-dose aspirin therapy. However, the mechanism of this phenomenon is still unclear. OBJECTIVE The aim of this study was to characterize the airway inflammatory response to aspirin desensitization and after treatment with high-dose aspirin for 6 months. METHODS Twenty-one adult patients with asthma, chronic polypoid sinusitis, and a convincing history of acute respiratory reaction to the ingestion of aspirin or nonsteroidal anti-inflammatory drugs were selected. These patients underwent an oral desensitization to aspirin over a 2-day period, followed by daily ingestion of aspirin 650 mg twice daily. Induced sputum samples and exhaled nitric oxide measurements were taken before the procedure, during the second day of the procedure, and after 6 months of treatment. RESULTS There was a significant elevation in both the exhaled nitric oxide level (P = .03) and sputum tryptase level (P = .05) during the desensitization process. After 6 months of aspirin treatment, sputum IL-4 (P = .0007) and matrix metalloproteinase 9 (MMP-9; P = .05) decreased significantly compared with baseline. Predesensitization to postdesensitization changes in MMP-9 and tissue inhibitors of metalloproteinases 1 were highly correlated (r = 0.79; P = .0003). Immediately after the desensitization, MMP-9 and tryptase were correlated (r = 0.82; P = .001), whereas IL-4 was inversely related with FMS-like tyrosine kinase 3 ligand (FLT3-L) (r = -0.79; P = .0008). There was a significant decrease in the average symptom score at 6 months. CONCLUSION Consistent with previous reports, acute aspirin desensitization in patients with aspirin-exacerbated respiratory disease involves mast cell degranulation. In contrast, long-term treatment with aspirin involves suppression of IL-4 as well as downregulation of proinflammatory MMP-9 while T(H)1 marker FLT3-L increases.

Antihistamine Therapy in Allergic Rhinitis

Antihistamines have long been a mainstay in the therapy for allergic rhinitis. Many different oral antihistamines are available for use, and they are classified as first generation or second generation based on their pharmacologic properties and side-effect profiles. The recent introduction of intranasal antihistamines has further expanded the role of antihistamines in the treatment of allergic rhinitis. Certain patient populations, such as children and pregnant or lactating women, require special consideration regarding antihistamine choice and dosing as part of rhinitis therapy.

Characterization of aerosol output from various nebulizer/compressor combinations

OBJECTIVES Different commercially available nebulizers and compressors are available. However, the optimal combination for drug delivery is unknown. METHODS Flow rates of five different compressors (n = 3/compressor) tested alone and in combination with five different commercial nebulizers (n = 9 of each brand of nebulizer) were evaluated. Thereafter, the performances of the different nebulizers were evaluated using 2.5 mg albuterol solution (0.5 mL) added to 2.5 mL saline at flow rates of 2, 3, 4, and 5 L/minute using a laser particle analyzer. Volume median diameter and percentage of particles in the respirable range (1-5 microm) were calculated from this data. Time for nebulization (in seconds) and residual volume (in milliliters) were also recorded. RESULTS The mean flow rates for the compressors evaluated without a nebulizer attached ranged from 6.6 L/minute (LifeCare Freedom-neb; LifeCare International, Lafayette, CO) to 12.2 L/minute (DeVilbiss Pulmo-Aide; DeVilbiss Health Care, Somerset, PA). Flow rates for the nebulizer/compressor combinations ranged from 2.08 L/minute (Pari LC Jet Proneb; Pari Respiratory Equipment, Richmond, VA) to 5.42 L/minute (Puritan Bennett Raindrop; Puritan Bennett, Lenexa, KS/Omron Compare; Omron, Health Care,Vernon Hills, IL). Using the repeated measure ANOVA model, the interaction between flow rate and device was significant (P < 0.001) for both percentage of particles in the respirable range and log volume median diameter. It was observed that the percentage of particles in the respirable range for the Pari LC Jet did not increase across flow rates in contrast to the other 4 nebulizers. All comparisons to the Pari LC Jet at 2 L/minute were significant. CONCLUSIONS Marked variability exists in the flow rates among different commercially available compressors used for home nebulization of inhaled pulmonary medications. Different nebulizer/compressor combinations have markedly different performance characteristics which could result in different efficacy and safety profiles of the medications being administered via these devices. We recommend that this type of information be used as a starting point for selecting different nebulizer/compressor combinations. Further clinical evaluation is warranted.

Changing Paradigms in the Treatment of Severe Asthma: The Role of Biologic Therapies

Cytokine antagonists are monoclonal antibodies that offer new treatment options for refractory asthma but will also increase complexity because they are effective only for patients with certain asthma subtypes that remain to be more clearly defined. The clinical and inflammatory heterogeneity within refractory asthma makes it difficult to manage the disease and to determine which, if any, biologic therapy is suitable for a specific patient. The purpose of this article is to provide a data-driven discussion to clarify the use of biologic therapies in patients with refractory asthma. We first discuss the epidemiology and pathophysiology of refractory asthma. We then interpret current evidence for biomarkers of eosinophilic or type 2-high asthma so that clinicians can determine potential treatments for patients based on knowledge of their effectiveness in specific asthma phenotypes. We then assess clinical data on the efficacy, safety, and mechanisms of action of approved and pipeline biologic therapies. We conclude by discussing the potential of phenotyping or endotyping refractory asthma and how biologic therapies can play a role in treating patients with refractory asthma.

Characterization and treatment of patients with chronic rhinosinusitis and nasal polyps.

BACKGROUND Patients with chronic rhinosinusitis (CRS) and nasal polyps (NPs) may be subdivided into aspirin-sensitive (AS) and aspirin-tolerant (AT) populations. These cohorts are not well characterized. OBJECTIVE To examine phenotypic characteristics and determine the extent of medical/surgical interventions in patients with CRS+NP and to compare the AS with the AT subset in the CRS+NP sample. METHODS Retrospective chart review was performed at a tertiary academic respiratory hospital. Data included patient demographics, asthma severity, peripheral eosinophilia, Lund-Mackay computed tomographic score, symptomatic dysosmia, and therapeutic interventions. RESULTS Of the 182 patients included, 81 had aspirin sensitivity (45%) and 101 had aspirin tolerance (55%). Asthma was present in 94% of patients with CRS+NP (100% in AS subgroup vs 89% in AT subgroup, P = .001). Eighty-eight percent of the CRS+NP sample had moderate to severe persistent asthma. In the AS and AT subgroups, asthma severity was similar (P > .6). The CRS+NP sample showed a mean computed tomographic score of 14.0 (44% with eosinophilia and 46% with dysosmia). More severe sinus disease was noted in the AS group (Lund-Mackay computed tomographic scores, P = .002; olfactory symptoms, P = .001). Serum eosinophil levels were not statistically different between groups (51% in AS group, 39% in AT group, P > .1). CONCLUSION This study is one of the broadest reviews of patients with CRS+NP, with unique findings in the high prevalence of asthma in AS and AT patients, greater olfactory dysfunction in AS patients, and a minority of patients with CRS+NP and circulating eosinophils. Most AS patients do not have increased circulating eosinophils, as is often believed. These results shed further light on the association between asthma and upper respiratory tract disease in those with nasal polyposis.

Vocal cord dysfunction: a review

Vocal cord dysfunction (VCD) is a term that refers to inappropriate adduction of the vocal cords during inhalation and sometimes exhalation. It is a functional disorder that serves as an important mimicker of asthma. Vocal cord dysfunction can be difficult to treat as the condition is often underappreciated and misdiagnosed in clinical practice. Recognition of vocal cord dysfunction in patients with asthma-type symptoms is essential since missing this diagnosis can be a barrier to adequately treating patients with uncontrolled respiratory symptoms. Although symptoms often mimic asthma, the two conditions have certain distinct clinical features and demonstrate specific findings on diagnostic studies, which can serve to differentiate the two conditions. Moreover, management of vocal cord dysfunction should be directed at minimizing known triggers and initiating speech therapy, thereby minimizing use of unnecessary asthma medications. This review article describes key clinical features, important physical exam findings and commonly reported triggers in patients with vocal cord dysfunction. Additionally, this article discusses useful diagnostic studies to identify patients with vocal cord dysfunction and current management options for such patients.

Variations in expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in nasal mucosa of aspirin-sensitive versus aspirin-tolerant patients with nasal polyposis

BACKGROUND Matrix metalloproteinases (MMPs) are key enzymes responsible for extracellular matrix degradation contributing to the progressive histological changes seen in lower airway disease, including asthma. MMP-9 and TIMP-1 have also shown some role in the pathogenesis of chronic rhinosinusitis (CRS) and nasal polyposis (NP). OBJECTIVE We aim to determine variability in expression of MMP-9 and its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), in sinus tissue from distinct patient populations presenting with nasal polyposis. METHODS The expression of MMP-9 and TIMP-1 was investigated in nasal polyp tissue from 6 aspirin-sensitive (AS) and 6 aspirin-tolerant (AT) patients undergoing endoscopic sinus surgery for chronic rhinosinusitis with nasal polyposis (CRSwNP). Sinus mucosa from 6 patients with chronic rhinosinusitis without nasal polyposis (CRSsNP) was used as control. The MMP-9 and TIMP-1 expression was measured using immunofluorescence technique and graded using manual and computerized methods. RESULTS Expression of TIMP-1 was significantly reduced in the AS group when compared with both the AT and CRSsNP (control) groups (P < .001). The MMP-9/TIMP-1 ratio was significantly increased in the AS group when compared with other patient groups (P < .001). The MMP- 9 expression was similar between study and control groups. CONCLUSION These results support the importance of MMP-9 and TIMP-1 expression in nasal polyp formation. The decreased expression of TIMP-1 in AS patients may promote the effects of MMP-9 expression and thus contribute to tissue remodeling and inflammatory changes. This finding may lead to further understanding of disease severity and resistance to treatment in this group of patients, as well as the pathogenesis of nasal polyps.

Safety of Binodenoson, a Selective Adenosine A2A Receptor Agonist Vasodilator Pharmacological Stress Agent, in Healthy Subjects With Mild Intermittent Asthma

Background—The pharmacological stress agents adenosine and dipyridamole are contraindicated in asthma patients because of the risk of adenosine receptor-mediated bronchospasm. Binodenoson, a selective adenosine A2A receptor agonist, produces maximal coronary hyperemia during pharmacological stress testing yet has a low affinity for the adenosine A1, A2B, and A3 receptors that are probably responsible for bronchospasm. This study was conducted to assess the safety of binodenoson in 87 healthy young adult volunteers with documented mild, intermittent asthma. Methods and Results—This study consisted of a dose-escalating, single-blinded phase and a placebo-controlled, double-blinded phase conducted in healthy, young adults with documented mild, intermittent, asthma. In the single-blinded phase, 3 sequential cohorts of 8 subjects received intravenous binodenoson (0.5, 1.0, and 1.5 &mgr;g/kg). In the double-blinded phase, commenced after medical review of results from the single-blinded phase, subjects were randomly assigned 2:1 to either binodenoson 1.5 &mgr;g/kg (n=41) or placebo (n=22). The primary end point was clinically significant bronchoconstriction, defined as a decrease in forced expiratory volume in 1 second of ≥20% from the preinjection measure. Secondary safety end points were changes from preinjection measure in forced expiratory volume in 1 second, forced vital capacity, and forced expiratory flow during the middle 50% of the forced vital capacity; vital signs; pulse oximetry; and adverse events. Binodenoson caused no clinically significant bronchoconstriction or alterations in pulmonary function parameters and transiently increased heart rate and systolic blood pressure. The most common treatment-emergent adverse events were tachycardia, dizziness, and flushing. Conclusions—Binodenoson was safe, well tolerated, and caused no clinically significant bronchoconstriction or pulmonary responses in a small population of healthy subjects with mild, intermittent asthma.