Safety and efficacy of an oral CCR3 antagonist in patients with asthma and eosinophilic bronchitis: a randomized, placebo-controlled clinical trial.

BACKGROUND: Several chemokines, notably eotaxin, mediate the recruitment of eosinophils into tissues via the CCR3 receptor. OBJECTIVE: In this study, we investigated the role of CCR3 agonists in asthma by observing the effect of a small molecule antagonist of the CCR3 receptor (GW766994) on sputum eosinophil counts in patients with eosinophilic asthma. METHODS: Clinical and physiological outcomes, the chemotactic activity of sputum supernatant for eosinophils and the presence of eosinophil progenitors in sputum and blood samples were also studied. RESULTS: In a double-blind parallel group study, 60 patients with asthma were randomized to 300 mg of GW766994 twice daily or matching placebo for 10 days followed by prednisone 30 mg for 5 days. Of these patients, 53 had a sputum eosinophil count > 4.9% at baseline. Despite plasma concentrations of drug consistent with > 90% receptor occupancy during the dosing period, the CCR3 antagonist did not significantly reduce eosinophils or eosinophil progenitor cells (CD34(+) 45(+) IL-5Rα(+)) in sputum or in blood. The ex vivo chemotactic effect of sputum supernatants on eosinophils was attenuated by GW766944 compared to placebo. There was no improvement in FEV1 ; however, there was a modest but statistically significant improvement in PC20 methacholine (0.66 doubling dose) and ACQ scores, (0.43). Whilst the improvement in PC20 is statistically significant, it is not of clinical significance. CONCLUSIONS AND CLINICAL RELEVANCE: In conclusion, this study calls into question the role of CCR3 in airway eosinophilia in asthma and suggests that other cellular mechanisms mediated by the CCR3 receptor may contribute to airway hyperresponsiveness.

Prolonged protection of the new inhaled corticosteroid fluticasone furoate against AMP hyperresponsiveness in patients with asthma.

INTRODUCTION: Single-dose inhaled corticosteroids (ICS) induce direct anti-inflammatory effects in asthma thereby improving airway hyperresponsiveness (AHR). A novel enhanced-affinity ICS, fluticasone furoate (FF), demonstrated a prolonged duration of action in vitro. The aim of this study was to evaluate the efficacy and duration of action of a single dose of FF by studying protection against AHR to adenosine 5'-monophosphate (AMP) and effects on exhaled nitric oxide (eNO). METHODS: A randomized, double-blind, placebo-controlled, 6-way crossover study (FFA10026) was performed in 24 patients with allergic asthma (mean age 32.8 years, FEV(1) ≥ 70% predicted and PC(20) AMP ≤ 50 mg/ml). Each subject received a single dose of FF 1000 µg, fluticasone proprionate (FP) 1000 µg, or placebo at 2 (FF only), 14 or 26 h prior to AMP challenge and eNO measurement. RESULTS: FF significantly improved PC(20) AMP compared to placebo, the difference in doubling concentrations being 2.18 (95% confidence interval: 1.13-3.23), 1.54 (0.48-2.59), and 1.30 (0.26-2.34) at 2, 14 and 26 h. FP improved PC(20) AMP significantly at 14 h compared to placebo, but not at the 26-hour time point, the difference in doubling concentrations being 1.72 (0.70-2.75) and 0.33 (-0.69-1.34). There was no significant effect on eNO after either FF or FP at all time points. FF was well tolerated and there were no serious adverse events. CONCLUSION: The new inhaled corticosteroid FF, but not FP, demonstrates prolonged protection up to 26 h against AHR to AMP in asthma patients.

GW420867X administered to HIV-1-infected patients alone and in combination with lamivudine and zidovudine.

PURPOSE: GW420867X is a nonnucleoside inhibitor of HIV-1 reverse transcriptase. The primary objective was to assess the safety of GW420867X in HIV-1-infected patients. The secondary objectives were to assess the effect of GW420867X on plasma HIV-1 RNA and viral genotype and phenotype and to examine the pharmacokinetics of GW420867X in HIV-1-infected patients. METHOD: HIV-1-infected patients were randomized to GW420867X 50 mg/day, 100 mg/day, or 200 mg/day from days 1-28 (n = 15 per group). Lamivudine (3TC) plus zidovudine (ZDV) was added from days 8-28. A control group (n = 15) received GW420867X, 3TC, and ZDV placebos. RESULTS: Plasma HIV-1 RNA and CD4+ counts improved in the GW420867X groups at days 8 and 28. No significant development of drug resistance was detected. Median observed peak GW420867X concentration (C(max)) generally occurred at 2 hours. The area under the curve over the dosing interval (AUCtau)on day 14 increased less than proportionally to dose, suggesting there was increased clearance and/or decreased absorption. Mean trough GW420867X concentrations were many fold above the in vitro IC(50) in the presence of human serum proteins. Seven of 15 patients on 50 mg GW420867X, 8/15 on 100 mg GW420867X, 12/15 on 200 mg GW420867X, and 8/15 on placebo reported drug-related adverse events. CONCLUSION: GW420867X was well tolerated and has potent antiretroviral activity alone and in combination with 3TC plus ZDV.

Pharmacokinetics and tolerability of GW420867X, a nonnucleoside reverse transcriptase inhibitor, following single escalating doses in healthy male volunteers.

The aim of the current study was to characterize the pharmacokinetics of GW420867X, a new nonnucleoside reverse transcriptase inhibitor, using a single escalating dose protocol in healthy volunteers. Four dose levels were investigated in sequential order: 300, 600, 900, and 1200 mg, with a ratio of 4:1 subjects receiving active or placebo treatment, respectively. Following single-dose administration, GW420867X was readily absorbed with a median time to peak concentration of 3 to 5 hours. GW420867X plasma exposure (AUC) was dose proportional but variable within the 300 to 1200 mg dose range. Less than dose-proportional increases were observed for Cmax. The terminal elimination t(1/2) was 50 hours, which supports once-daily dosing in future studies. Plasma trough concentrations of GW420867X at 24 hours after dosing were many fold greater than the in vitro IC50 HIV-1(HXB2) in MT4 cells. GW420867X was generally well tolerated following single-dose administration up to 900 mg; increased central nervous system-related adverse events were observed at higher doses. GW420867X had a favorable pharmacokinetic and safety profile that would enable this drug to be explored in future clinical studies with HIV-1 infected patients at doses that would provide appropriate safety and efficacy.

The bioavailability of the novel nonnucleoside reverse transcriptase inhibitor GW420867X is unaffected by food in healthy male volunteers.

The effect of food on the bioavailability of GW420867X, a novel nonnucleoside reverse transcriptase inhibitor, was investigated in 15 young, healthy, male volunteers. A single oral dose of GW420867X 100 mg was administered in the fasted state, after a high-fat meal, and after a meal of normal fat composition. Tolerability and pharmacokinetic sampling were assessed at baseline and up to 600 hours. The median concentration-time plots for each treatment group were essentially superimposable. Neither the rate nor the extent of absorption of GW420867X was significantly affected by food. The median time to peak plasma concentration was 3 to 4 hours, irrespective of treatment. Pairwise comparisons using the fasted treatment as the comparator showed no impact of food on GW420867X pharmacokinetics. GW420867X was well tolerated. There were no serious or treatment-limiting adverse events; all episodes reported were rated as mild to moderate. The bioavailability of GW420867X was unaffected by food. GW420867X may be administered independently of food and fat intake.

Plethysmography and impulse oscillometry assessment of tiotropium and ipratropium bromide; a randomized, double-blind, placebo-controlled, cross-over study in healthy subjects.

AIMS: Spirometry, plethysmography and impulse oscillometry (IOS) measure different aspects of lung function. These methods have not been compared for their ability to assess long- and short-acting anticholinergic agents. We therefore performed a double-blind, placebo-controlled, four-way cross-over study in 30 healthy subjects. METHODS: Single doses of tiotropium bromide (Tio) 54 and 18 mcg, ipratropium bromide (IB) 40 mcg and placebo were administered. Specific conductance (sGaw), total lung capacity (TLC), inspiratory capacity (IC) and residual volume (RV) were measured using plethysmography, while IOS measured resistance (R5-25) and reactance (RF and X5). Pulmonary function was measured for 26 h post dose. RESULTS: Tio caused significant improvements in sGaw, forced expiratory voume in 1 s (FEV(1)), maximum mid-expiratory flow (MMEF) and R5-R25 at time points up to 26 h, with no clear differences between doses. IB improved the same parameters, but only up to 8 h. The weighted mean change (0-24 h) caused by Tio 54 mcg compared with placebo for FEV(1) was 240 ml (95% confidence interval 180, 300), while for sGaw the ratio of geometric means (Tio compared with placebo) was 1.35 (1.28, 1.41). Neither drug caused consistent statistically significant changes in RF, forced vital capacity, TLC or IC over 26 h. RV was significantly improved from 8 to 24 h by Tio 54 mcg only. CONCLUSIONS: In addition to spirometry, IOS resistance measurements and sGaw can distinguish between the effects of long- and shortacting anticholinergic effects in healthy subjects.

Enantiomeric disposition of inhaled, intravenous and oral racemic-salbutamol in man--no evidence of enantioselective lung metabolism.

Aims To establish whether enantioselective metabolism of racemic (rac )-salbutamol occurs in the lungs by determining its enantiomeric disposition following inhalation, in the absence and presence of oral charcoal, compared with that following the oral and intravenous routes. Methods Fifteen healthy subjects (eight male) were randomized into an open design, crossover study. Plasma and urine salbutamol enantiomer concentrations were measured for 24 h following oral (2 mg) with or without oral charcoal (to block oral absorption), inhaled (MDI; 1200 microg) with or without oral charcoal and intravenous (500 microg) rac-salbutamol. Systemic exposure (plasma AUC(0,infinity) and urinary excretion (Au24h ) of both enantiomers were calculated, and relative exposure to (R)-salbutamol both in plasma (AUC(R)-/AUC(S)- ) and urine (Au(R)-/Au(S)- ) was derived for each route. Relative exposure after the inhaled with charcoal and oral routes were compared with the intravenous route. Results AUC(R)-/AUC(S)- [geometric mean (95% CI)] was similar following the intravenous [0.32 (0.28, 0.36)] and inhaled with charcoal rates [0.29 (0.24, 0.36); P=0.046], but was far lower following oral dosing [0.05 (0.03, 0.07); P<0.001]. Similar results were found when relative exposure was analysed using Au24h. Conclusions These results show no evidence of significant enantioselective presystemic metabolism in the lungs, whilst confirming it in the gut and systemic circulation, indicating that the (R)- and (S)-enantiomers are present in similar quantities in the airways following inhaled rac-salbutamol.

Beclomethasone dipropionate: absolute bioavailability, pharmacokinetics and metabolism following intravenous, oral, intranasal and inhaled administration in man.

AIMS: To assess the absolute bioavailability, pharmacokinetics and metabolism of beclomethasone dipropionate (BDP) in man following intravenous, oral, intranasal and inhaled administration. METHODS: Twelve healthy subjects participated in this seven-way cross-over study where BDP was administered via the following routes: intravenous infusion (1000 microg), oral (4000 microg, aqueous suspension), intranasal (1344 microg, aqueous nasal spray) and inhaled (1000 microg ex-valve, metered dose inhaler). The contribution of the lung, nose and gut to the systemic exposure was assessed by repeating the inhaled, intranasal and oral dosing arms together with activated charcoal, to block oral absorption. Blood samples were collected for 24 h postdose for the measurement of BDP, beclomethasone-17-monopropionate (B-17-MP) and beclomethasone (BOH) in plasma by liquid chromatography tandem mass spectrometry. RESULTS: Intravenous administration of BDP (mean CL 150 l h-1, Vss 20 l, t(1/2) 0.5 h) was associated with rapid conversion to B-17-MP which was eliminated more slowly (t1/2 2.7 h). In estimating the parameters for B-17-MP (mean CL 120 l h-1, Vss 424 l) complete conversion of BDP to B-17-MP was assumed. The resultant plasma concentrations of BOH were low and transient. BDP was not detected in plasma following oral or intranasal dosing. The mean absolute bioavailability (%F, 90% CI; nominal doses) of inhaled BDP was 2% (1-4%) and not reduced by coadministration of charcoal. The mean percentage F of the active metabolite B-17-MP was 41% (31-54%), 44% (34-58%) and 62% (47-82%) for oral, intranasal and inhaled dosing without charcoal, respectively. The corresponding estimates of nasal and lung absorption, based on the coadministration of charcoal, were < 1% and 36% (27-47%), respectively. CONCLUSIONS: Unchanged BDP has negligible oral and intranasal bioavailability with limited absorption following inhaled dosing due to extensive (95%) presystemic conversion of BDP to B-17-MP in the lung. The oral and intranasal bioavailabilities of the active metabolite B-17-MP were high and similar, but direct absorption in the nose was insignificant. The total inhaled bioavailability of B-17-MP (lung + oral) was also high (62%) and approximately 36% of this was due to pulmonary absorption. Estimates of oral bioavailability and pulmonary deposition based on total BOH were approximately half those found for B-17-MP.

Pharmacokinetics and safety of escalating single and repeat oral doses of GW420867X, a novel non-nucleoside reverse transcriptase inhibitor.

OBJECTIVE: To assess the pharmacokinetics, safety and tolerability of escalating oral doses of GW420867X, a non-nucleoside reverse transcriptase inhibitor, was investigated in healthy male volunteers in a randomized, double-blind placebo-controlled study. METHODS: Study subjects were divided into four groups of 12 subjects (10, 50, 100 and 200-mg dose groups) with eight subjects from each group receiving active treatment and the remaining four matched placebo. Subjects were initially administered a single dose of GW420867X or placebo, and following a 24- to 28-day washout period, re-exposed to the same treatment for 14 consecutive days. Safety measurements including clinical laboratory evaluations, ECG and vital signs were performed before, during and after dosing. RESULTS: Geometric mean GW420867X peak plasma concentrations (Cmax) following single oral doses of 10, 50, 100 and 200 mg were 160, 608, 1,000 and 1,662 ng/ml, respectively. Time to Cmax (tmax) increased from a median value of 1 h following the 10-mg dose, to 3 h after the 200-mg dose. Geometric mean plasma areas under the curves (AUC) were 4,325 (10 mg), 17,862 (50 mg), 35,295 (100 mg) and 62,338 ng/ml per hour (200 mg) and were proportionally less than the increase in the administered dose. Apparent terminal elimination half-life (t1/2) was approximately 50 h. Following repeat dosing, accumulation ratios based on plasma AUC were: 3.0+/-1.0 (10mg), 2.6+/-0.9 (50mg), 1.8+/-0.3 (100 mg) and 1.9+/-0.8 (200 mg) after 14 days of dosing compared to the corresponding single dose. In general, oral clearance (CL/F) was greater after 14 days and greater with higher doses except for the 10-mg dose group. Steady-state CL/F was 2.2, 3.4, 4.2, and 5.1 l/h for 10, 50, 100, and 200 mg, respectively. Steady-state was generally achieved within 7-10 days. Comparison of single and repeat dosing with GW420867X showed that Cmax increased by a factor of between 1.4 to 1.8, after 14 days of daily dosing to 288 (10 mg), 1,006 (50 mg), 1,401 (100 mg) and 2,613 (200 mg) ng/ml. These increases were proportionally less than the increase in the administered dose. GW420867X was well tolerated by subjects both after single and repeated dosing. Adverse effects reported by subjects on the active drug were similar to those receiving placebo. All episodes were rated as mild to moderate in severity and resolved spontaneously without further intervention. CONCLUSION: The pharmacokinetic findings of this study imply that systemic exposure to GW420867X decreases with increasing dose and displays time-variant pharmacokinetics, which suggests decreased absorption and/or increased clearance of GW420867X. The relatively long plasma half-life, of approximately 50 h, makes it suitable for once-daily dosing.

A dose ranging study of the pharmacokinetics, safety, and preliminary efficacy of lamivudine in children and adolescents with chronic hepatitis B.

Fifty-three patients with chronic hepatitis B and active viral replication were studied for 4 weeks while on treatment and for 12 weeks after treatment with the oral nucleoside analogue lamivudine. Children aged 2 to 12 years were randomized to receive twice-daily doses of 0.35, 1.5, or 4 mg of lamivudine solution per kg of body weight or once-daily doses of 3 mg of lamivudine solution per kg. Adolescents aged 13 to 17 years received lamivudine at 100 mg (as tablets). Blood samples for pharmacokinetic assay were taken on days 1 and 28. Lamivudine was rapidly absorbed following oral administration, with the maximum concentration in serum being reached 0.5 to 1 h postdosing. Apparent oral clearance (CL/F) was higher in younger children and decreased with age, with CL/F values for adolescents reaching those seen for adults by the age of 12. All doses produced a dramatic fall in serum hepatitis B virus (HBV) DNA levels, with a median reduction of >/=99.5% after 4 weeks of treatment and with the levels returning to the baseline levels posttreatment. The correlation of dose, area under the concentration-time curve (AUC), and changes in HBV DNA levels, as measured by the Chiron Quantiplex assay, showed maximal antiviral effects (99.9% inhibition and a reduction of the amount of HBV DNA of approximately 3 log(10)) at 3 mg/kg/day, with no discernible increase in effect seen whether the drug was given at 4 mg/kg twice daily or whether it was given once daily or twice daily. The limit of detection of the assay (2.5 pg/ml) was reached for some but not all patients across the dose ranges, with the smallest number (n = 2) of those having values negative by the Chiron Quantiplex assay being in the lowest-dose group. The 13- to 17-year-olds showed a similar overall response in terms of the HBV DNA level reduction compared to that for patients younger than age 13. Analysis of the same samples by PCR, which has a lower limit of sensitivity than the Chiron Quantiplex assay, also showed average drops in HBV DNA levels of about 3 log(10) at 4 weeks for patients for which the AUC was >/=4,000 ng. h/ml, confirming the conclusions given above. Lamivudine treatment was well tolerated at all doses, with no significant adverse events or laboratory data changes. On the basis of pharmacokinetic and pharmacodynamic data, a 3-mg/kg/day dose in children (ages 2 to 12 years) with chronic hepatitis B provides levels of exposure and trough concentrations similar to those seen in adults following the receipt of doses of 100 mg. The 100-mg dose is being evaluated in a large phase III study with HBV-infected pediatric patients.

Non-invasive assessment of selective 5-HT(1B/1D)-receptor agonist-induced peripheral vascular effects in humans: comparison of different techniques.

OBJECTIVE: To compare the sensitivity of three non-invasive techniques for detecting serotonin (5-HT)(1B/1D)-receptor agonist-induced peripheral vascular effects in humans: the measurement of (1) systolic (SBP) and diastolic (DBP) blood pressures, (2) dorsal hand vein (DHV) diameter and (3) toe-arm systolic blood pressure gradient (DeltaSBP(toe-arm)). METHODS: A double-blind, placebo-controlled, three-way, cross-over study was performed in 12 healthy male volunteers. According to a randomly assigned allocation schedule, subjects were administered sumatriptan 3 mg, sumatriptan 6 mg or placebo subcutaneously. Measurements were performed at baseline, every 5 min for 30 min and at 40 min and 60 min after drug administration. SBP and DBP were recorded using a semi-automated oscillometric device. DHV diameter was measured using a linear variable differential transformer. DeltaSBP(toe-arm) was calculated after measuring toe and arm SBP with a strain-gauge technique. Sensitivity was evaluated with responsiveness statistics. RESULTS: Based on weighted mean and compared with placebo, sumatriptan 3 mg and 6 mg increased SBP by 3.3 mmHg ( P=0.023) and 6.4 mmHg ( P<0.001) and DBP by 5.0 mmHg ( P=0.006) and 7.5 mmHg ( P<0.001), respectively. Sumatriptan 3 mg and 6 mg decreased DHV diameter by 36% ( P=0.015) and 40% ( P=0.005), respectively. DeltaSBP(toe-arm) did not change. Peak changes were observed within 10-15 min after drug administration. The rank order of responsiveness was: BP > DHV diameter > DeltaSBP(toe-arm.) CONCLUSIONS: Clinically relevant doses of subcutaneous sumatriptan increased blood pressure and decreased DHV diameter without affecting DeltaSBP(toe-arm). The increase in blood pressure appeared to be dose dependent. Compared with DHV diameter and DeltaSBP(toe-arm), blood pressure measurement appeared to be the most sensitive technique for detecting selective 5-HT(1B/1D)-receptor agonist-induced peripheral vascular effects in humans.