James Hilbert

Pharmacokinetics and Dose Proportionality of Loratadine

The dose proportionality and pharmacokinetics of loratadine, a new nonsedating antihistamine, were studied in 12 normal volunteers. In a three‐way cross‐over, each volunteer received a single 10‐, 20‐, or 40‐mg loratadine capsule. Blood was collected up to 96 hours after dosing. Plasma loratadine concentrations were determined by radioimmunoassay (RIA), and those of a minor, but active metabolite, descarboethoxyloratadine, by high performance liquid chromatography (HPLC). Concentrations in the disposition phase were fitted to a biexponential equation for pharmacokinetic analysis. For dose proportionality, AUC‐ and Cmax‐dose relationships were evaluated by linear regression. Also, pharmacokinetic parameters and dose‐adjusted AUCs were compared by analysis of variance. Loratadine was rapidly absorbed, reaching Cmax values (4.7, 10.8, and 26.1 ng/mL) at 1.5, 1.0 and 1.2 hours for the 10‐, 20‐, and 40‐mg doses, respectively. The loratadine t1/2β ranged from 7.8 to 11.0 hours. Descarboethoxyloratadine reached Cmax values (4.0, 9.9, and 16.0 ng/mL) at 3.7, 1.5, and 2.0 hours for the 10‐, 20‐, and 40‐mg doses, respectively. Its t1/2β ranged from 17 to 24 hours. For both compounds, AUC‐ and Cmax‐dose relationships were linear and there were no differences in the t1/2β, CL/F, or dose‐adjusted AUC values among the treatments. Loratadine and descarboethoxyloratadine plasma concentrations and pharmacokinetics were not dose dependent.

Efficacy of the oral chemoattractant receptor homologous molecule on TH2 cells antagonist BI 671800 in patients with seasonal allergic rhinitis

BACKGROUND The inflammatory response in patients with seasonal allergic rhinitis (SAR) is partly mediated by the prostaglandin D2 receptor chemoattractant receptor homologous molecule on T(H)2 cells (CRTH2). OBJECTIVE We sought to investigate the efficacy and safety of the oral CRTH2 antagonist BI 671800 (50, 200, and 400 mg twice daily), fluticasone propionate nasal spray (200 μg once daily), or oral montelukast (10 mg once daily) administered for 2 weeks in patients with SAR. METHODS In this randomized, double-blind, placebo-controlled, partial-crossover study, participants aged 18 to 65 years with a positive skin prick test to Dactylis glomerata pollen were exposed to out-of-season allergen in the environmental challenge chamber for 6 hours. The primary efficacy variable was the total nasal symptom score assessed as the area under the curve (AUC)(0-6h). RESULTS In total, 146 patients (63.7% male; mean age, 36.1 years) were randomized. The adjusted mean total nasal symptom score AUC(0-6h) was significantly reduced versus placebo with 200 mg of BI 671800 (absolute difference, -0.85; percentage difference, -17%; P = .0026), montelukast (absolute difference, -0.74; percentage difference, -15%; P = .0115), and fluticasone propionate (absolute difference, -1.64; percentage difference, -33%; P < .0001). Compared with placebo, BI 671800 significantly reduced nasal eosinophil values (P < .05 for all doses), significantly inhibited nasal inflammatory cytokine levels (IL-4 and eotaxin, P < .05; 200 mg twice daily), and induced a dose-related reduction in ex vivo prostaglandin D2-mediated eosinophil shape change. CONCLUSION Two hundred milligrams of BI 671800 twice daily demonstrated efficacy in treating SAR symptoms induced by environmental challenge chamber allergen exposure and had a favorable safety profile.

A randomized study of BI 671800, a CRTH2 antagonist, as add-on therapy in poorly controlled asthma

BACKGROUND Asthma is characterized by a complex interaction of inflammatory mediators. The prostaglandin D2 receptor, chemoattractant receptor-homologous molecule on Th2 cells (CRTH2), plays a pivotal role in the pathogenesis of allergic airway inflammation. OBJECTIVE To ealuate the efficacy, safety, and pharmacokinetics of BI 671800, a CRTH2 antagonist, when added to inhaled corticosteroid therapy in adult patients with symptomatic asthma. METHODS In this phase IIa, 12-week, randomized, double-blind, three-period, four-treatment, incomplete block crossover trial, BI 671800 was administered either as a single 400-mg dose in the morning (A.M.) or evening (P.M.), or 200 mg twice daily (A.M. and P.M.) versus placebo, together with fluticasone propionate (44 μg, two inhalations twice daily). The primary end point was the change from baseline in trough forced expiratory volume in 1 second percentage predicted after 4 weeks. The secondary end point was the change in Asthma Control Questionnaire score from baseline. RESULTS A total of 108 patients were randomized and treated. After 4 weeks, the adjusted mean (± SE) treatment differences for the primary end point versus placebo were 0.08 ± 0.62%, 0.28 ± 0.61%, and 0.67 ± 0.63% for BI 671800 at 200 mg twice daily, 400 mg A.M., and 400 mg P.M., respectively (not statistically significant). No statistically significant or clinically meaningful differences in the Asthma Control Questionnaire score were observed versus placebo. Each treatment was well tolerated. CONCLUSION BI 671800 at a dose of 400 mg administered for 4 weeks with fluticasone propionate did not provide clinical improvement in patients with asthma; reasons for this are unclear, but it may be due to insufficient inhibition of the CRTH2 receptor at the doses used.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of the Novel CRTH2 Antagonist BI 1021958 at Single Oral Doses in Healthy Men and Multiple Oral Doses in Men and Women With Well‐Controlled Asthma

BI 1021958, a novel antagonist of the chemoattractant‐receptor‐homologous molecule (CRTH2), targets airway inflammation in asthma by inhibiting prostaglandin binding to CRTH2 receptors. Two phase 1 studies assessed BI 1021958 safety/tolerability and pharmacokinetics (PK)/pharmacodynamics (PD) following single doses in healthy men and multiple doses in men/women with well‐controlled asthma. Studies 1 had 2 parts: a placebo‐controlled, fixed‐sequence, single‐blind, single‐rising‐dose part (n = 56) and a randomized, 2‐way crossover, open‐label, repeated‐dose part studying the food effect on PK/PD (n = 12). Study 2 was a placebo‐controlled, single‐center, double‐blind multiple‐rising‐dose study (n = 84). Primary end points were safety/tolerability and PK/PD (both studies); secondary end points were eosinophil shape change (ESC; study 1) and dose proportionality/linearity following first dose and at steady state (study 2). BI 1021958 was adequately tolerated in both studies; adverse events were infrequent, generally mild to moderate, and occurred similarly in treatment groups. Maximum measured concentration (Cmax) was achieved in ≤2.5 hours in study 1 and ≤2.0 hours in study 2. BI 1021958 exposure increased proportionally with dose. In study 1, following a single 60‐mg dose, AUC parameters and Cmax were 20% and 15% lower, respectively, after a high‐fat meal compared with the fasted state. After ≥60‐mg single doses (study 1) and >40‐mg multiple doses (study 2), >95% ESC inhibition was observed for ≥24 hours. PK/PD was similar in healthy subjects and subjects with well‐controlled asthma. Data support further investigation of CRTH2 antagonists for the treatment of asthma.

Safety, Pharmacokinetics, and Pharmacodynamics of Multiple Rising Doses of BI 655064, an Antagonistic Anti‐CD40 Antibody, in Healthy Subjects: A Potential Novel Treatment for Autoimmune Diseases

BI 655064 is a humanized antagonistic anti‐cluster of differentiation (CD) 40 monoclonal antibody that selectively blocks the CD40‐CD40L interaction. The CD40‐CD40L pathway is a promising treatment target for autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, and lupus nephritis. The safety, tolerability, pharmacokinetics, and pharmacodynamics of repeated once‐weekly BI 655064 subcutaneous dosing over 4 weeks were evaluated in a multiple‐dose study in healthy subjects. Subjects (N = 40) were randomized 4:1 to four sequential BI 655064 dose groups (80, 120, 180, 240 mg) or to placebo. Safety and tolerability, plasma exposure, CD40 receptor occupancy, and CD40L‐induced CD54 upregulation were assessed over 64 and 78 days for the 80‐ to 180‐mg and 240‐mg dose groups, respectively. BI 655064 exposure increased in a supraproportional manner, due to target‐mediated drug clearance, for doses between 80 mg and 120 mg, but was near proportional for doses greater than 120 mg. Terminal half‐life ranged between 6 and 8 days. Dose‐dependent accumulation of BI 655064 supports the use of a loading dose in future clinical studies. Following 4 weeks of dosing, >90% CD40 receptor occupancy and inhibition of CD54 upregulation were observed at all dose levels, lasting for 17 days after the last dose. BI 655064 was generally well tolerated. There were no serious adverse events and the frequency and intensity of adverse events were similar for BI 655064 and placebo; no dose relationship or relevant signs of an acute immune reaction were observed. These findings support further investigation of BI 655064 as a potential treatment for autoimmune diseases.

Influence of the Duffy genotype on pharmacokinetics and pharmacodynamics of recombinant monocyte chemoattractant protein (MCP-1) in vivo

Monocyte chemoattractant protein-1 (MCP-1) binds to the Duffy antigen (Fy) on erythrocytes, which may act as a sink for several chemokines including MCP-1. We hypothesized that infusion of MCP-1 could result in different pharmacokinetics of MCP and possibly altered pharmacodynamics between Duffy positive and negative individuals. The primary aim of this trial was to compare pharmacokinetics of MCP-1 between Duffy positive and Duffy negative individuals under infusion of recombinant human MCP-1. This was a randomized, double-blinded, placebo-controlled dose escalation trial in 36 healthy volunteers. Subjects received infusions of 0.02–2.0 μg/kg MCP-1 or placebo for one hour. MCP-1 displayed linear pharmacokinetics. Duffy negative individuals reached maximal plasma levels earlier, but plasma concentration profiles were not altered. MCP-1 markedly increased monocyte counts, and estimated EC50 values were 10-fold higher in Duffy positive than Duffy negative subjects. Increased monocyte counts were associated with decreased surface expression of intercellular adhesion molecule 1 (ICAM-1, CD54). In contrast, MCP-1 neither altered CCR-2 or CD11b surface expression nor markers of platelet or endothelial activation, inflammation and coagulation. MCP-1 acts as a highly selective chemoattractant for monocytes in humans. The Duffy antigen had minimal effects on pharmacokinetics of MCP-1, but may affect EC50 values. from 13th Scientific Symposium of the Austrian Pharmacological Society (APHAR). Joint Meeting with the Austrian Society of Toxicology (ASTOX) and the Hungarian Society for Experimental and Clinical Pharmacology (MFT) Vienna, Austria. 22–24 November 2007