A dose-dependent effect of the novel inhaled corticosteroid ciclesonide on airway responsiveness to adenosine-5'-monophosphate in asthmatic patients

Cytokine-activated bronchial epithelial cell pro-inflammatory functions are effectively downregulated in vitro by ciclesonide

Ciclesonide, a new inhaled corticosteroid, is administered as a parent compound and converted in the airway mucosa into the active metabolite, desisobutyryl-(des-)ciclesonide. A study was designed to evaluate the ability of ciclesonide to modulate pro-inflammatory functions of human bronchial epithelial cell (HBEC) primary cultures being converted into des-ciclesonide. HBECs were stimulated with interleukin (IL)-4 and tumour necrosis factor (TNF)-alpha (20 ng/mL) in the presence of ciclesonide and intercellular adhesion molecule (ICAM)-1 expression, granulocyte-macrophage colony stimulating factor (GM-CSF) and IL-8 release evaluated respectively by FACS and ELISA. Ciclesonide (3 microM) significantly inhibited ICAM-1 expression by stimulated HBECs, already after 3h and still after 48 h culture (p < 0.01). At all the concentrations tested ciclesonide inhibited ICAM-1 expression (p < 0.05). GM-CSF and IL-8 release by stimulated HBECs was also downregulated by ciclesonide (p < 0.05). All the ciclesonide activities tested appeared to be mainly due to a partial inhibition of the 'IL-4 + TNF-alpha-induced' and little or no involvement of the 'constitutive' cell functions. Des-ciclesonide was detected in 24 h culture HBEC supernatants using high-performance liquid chromatography, while no parental compound ciclesonide was present. These results show at cellular level the fast and prolonged activity of ciclesonide on pro-inflammatory functions of HBECs, a selective target of asthma therapy, involved in the activation of this new inhaled corticosteroid.

Preclinical profile of ciclesonide, a novel corticosteroid for the treatment of asthma

Ciclesonide is a novel, inhaled corticosteroid under development for the treatment of asthma. Ciclesonide is activated to desisobutyryl-ciclesonide (des-CIC) in the lungs to provide potent anti-inflammatory activity. The investigations herein compared the activity of ciclesonide with fluticasone in animal models to assess efficacy/potency as an airway anti-inflammatory and the comparative side effect potential to consider the therapeutic ratio of each compound. In radioligand binding assays, des-CIC and fluticasone exhibited comparable high-affinity binding to the glucocorticoid receptor, whereas ciclesonide exhibited 100-fold less binding affinity. In the Brown Norway rat model of antigen-induced airway eosinophilia and in a model of Sephadex-induced lung edema, ciclesonide and fluticasone exhibited comparable efficacy. Interestingly, following 7-day intratracheal administration, ciclesonide elicited adrenal involution with a potency that was 44-fold less than fluticasone. Furthermore, ciclesonide was 22-fold less active than fluticasone in eliciting hypoplasia of the femoral growth plate. These data support the concept that ciclesonide acts as a parent compound that, when delivered to the airways, can be transformed into the active metabolite des-CIC, resulting in local high anti-inflammatory activity. Furthermore, ciclesonide possesses equivalent anti-inflammatory efficacy through pulmonary activation with a significantly improved safety profile in preclinical animal models compared with fluticasone.

Maintenance of asthma control by once-daily inhaled ciclesonide in adults with persistent asthma

BACKGROUND

Inhaled corticosteroids (ICS) are recommended therapy for persistent asthma, although side effects can limit appropriate use. Ciclesonide, a novel ICS, is activated in the lung, thereby reducing systemic activity and side effects. This 12-week, double-blind, randomized, parallel-group, placebo-controlled study evaluated the efficacy and safety of ciclesonide in adults with persistent asthma.

METHODS

After a 2-week baseline period in which current ICS treatment was continued, 329 patients were randomized to receive ciclesonide 160 microg (n = 107) or 640 microg (n = 112) (ex-actuator doses, equivalent to 200 and 800 microg ex-valve, respectively), or placebo (n = 110) once daily in the morning. Efficacy was monitored by asthma symptom scores, rescue medication use, morning and evening peak expiratory flow (PEF) measurements, spirometry, and probability of study completion without experiencing lack of efficacy.

RESULTS

Morning PEF remained stable with either ciclesonide dose but decreased with placebo; the differences were significant (P < 0.0001) for both ciclesonide doses vs placebo. The forced expiratory volume in 1 s and forced vital capacity decreased significantly with placebo (P < 0.005), but were unchanged with ciclesonide. Lack of efficacy was significantly greater for patients switched to placebo (63%) than it was for those treated with ciclesonide 160 microg (30%) (P < 0.0001 vs placebo) or ciclesonide 640 microg (31%) (P < 0.0001 vs placebo). There were no significant differences between the two tested doses of ciclesonide with respect to efficacy and safety. Serum and 24-h urine cortisol were unaffected by ciclesonide treatment. Both doses of ciclesonide were well tolerated with no cases of oral candidiasis.

CONCLUSION

Ciclesonide (160 or 640 microg) once daily in the morning effectively maintains asthma control, does not affect cortisol levels, and has an adverse event profile comparable with placebo in adults with primarily mild to moderate asthma.

Step-down compared to fixed-dose treatment with inhaled fluticasone propionate in asthma

BACKGROUND

Inhaled corticosteroids (ICSs) are an effective treatment of asthma even when administered at a low dose. Once asthma is controlled, current guidelines recommend that the dose of ICS be reduced to the lowest possible and effective dose. Although the most appropriate strategy for the stepping down has not yet been defined, quantification of sputum eosinophils and bronchial hyperresponsiveness (BHR) are indeed measures of asthma control.

OBJECTIVE

To compare the efficacy of step-down and fixed-dose strategies in the control of BHR to methacholine and eosinophilic inflammation patients with mild-to-moderate asthma.

METHODS

We performed a double-blind, randomized study to compare inhaled fluticasone propionate (FP), 1,000 microg/d, then reduced to 200 microg/d (group 1; n = 18) to a fixed dose of FP, 200 microg/d (group 2; n = 17) administered for 6 weeks and then 8 weeks in reducing the provocative dose of methacholine causing a 20% fall in FEV1 (PD20) and sputum eosinophils in 35 patients. The duration of the efficacy was also followed subsequently after 8 weeks of placebo treatment.

RESULTS

PD20 remarkably increased with both treatment strategies, but differences between groups were not significant. Sputum eosinophils (median values, percentage) at baseline and after each treatment period were not different (group 1, 16.4 to 1.0 to 2.7%; group 2, 16.7 to 2.8 to 2.8%, respectively). The percentages of patients in whom sputum eosinophilia was normalized (< or = 3%) were as follows: group 1, 69% and 60%; group 2, 50% and 57%. After placebo treatment, sputum eosinophils were still "normalized" in approximately one third of patients.

CONCLUSION

Step-down and fixed-dose strategies with FP improved PD20 and sputum eosinophilia to a similar degree. The effect on sputum eosinophils persisted longer than that on methacholine.

Ciclesonide

Ciclesonide is an inhaled corticosteroid (delivered via a hydrofluoroalkane metered-dose inhaler) that is converted to an active metabolite, desisobutyryl-ciclesonide, in the lung, thereby minimising effects on endogenous cortisol. In two 12-week, randomised studies in patients with asthma, ciclesonide 80 or 320 microg once daily was at least as effective as budesonide 400 microg/day at increasing forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) from baseline; ciclesonide 320 microg daily was significantly more effective than budesonide 400 microg once daily in one study. In a randomised, double-blind study in patients with asthma controlled with high-dosages of inhaled corticosteroids, FEV(1) and FVC decreased significantly from baseline at 12 weeks in patients receiving ciclesonide 320 microg daily or budesonide 400 microg daily; peak expiratory flow values decreased significantly only in patients receiving budesonide. Inhaled ciclesonide 80 or 320 microg daily improved asthma symptom scores and decreased the use of rescue medication by a similar, significant amount to budesonide 400 microg/day in two 12-week studies. Inhaled ciclesonide was generally well tolerated in patients with asthma. Ciclesonide did not suppress biochemical markers of adrenal function in 52-week studies. The long-term (>52 weeks) systemic effects of ciclesonide remain unknown.

New advances and potential therapies for the treatment of asthma

Asthma is a disease of the airways with an underlying inflammatory component. The prevalence and healthcare burden of asthma is still rising and is predicted to continue to rise in the current century. Inhaled beta(2)-adrenoceptor agonists and corticosteroids form the basis of the treatments available to alleviate the symptoms of asthma. There is a need for novel, safe treatments to tackle the underlying inflammation that characterizes asthma pathology. Furthermore, there is a requirement for new treatments to be developed as oral therapy in order to alleviate patient compliance issues, especially in children. A multitude of new approaches and new targets are being investigated, which may provide opportunities for novel therapeutic interventions in this debilitating disease. For simplicity, these approaches can be divided into two categories. The first comprises therapies directed against specific components or steps seen in allergic asthma. By 'components' we mean the key inflammatory cells (T cells [in particular T(h)2], B cells, eosinophils, mast cells, basophils and antigen presenting cells [APC]) and mediators (immunoglobulin E [IgE], cytokines, histamines, leukotrienes and prostanoids) believed to be involved in the chronic inflammation seen in asthma. By 'steps' we mean the allergic response, such as antigen processing and presentation, T(h)2-cell activation, B-cell isotype switching, mast cell involvement and airway remodeling. The other category of novel approaches to disease modification in asthma encompasses general anti-inflammatory therapies including phosphodiesterase 4 (PDE4) inhibitors, p38 mitogen-activated protein kinase (MAPK) inhibitors, peroxisome proliferator-activated receptor-gamma (PPARgamma) agonists, and lipoxins.

New drugs for asthma

Asthma is a major and increasing global health problem and, despite major advances in therapy, many patients' symptoms are not adequately controlled. Treatment with combination inhalers, which contain a corticosteroid and long-acting beta(2) adrenoceptor agonist, is the most effective current therapy. There is therefore a search for new therapies, particularly safe and effective oral treatments and those that are more efficacious in severe asthma. New therapies in development include mediator antagonists and inhibitors of cytokines, although these therapies might be too specific to be very effective. New anti-inflammatory therapies include corticosteroids and inhibitors of phosphodiesterase-4, p38 mitogen-activated protein kinase and nuclear factor-kappaB. The prospects for a curative treatment are on the horizon.

Add-on therapy options in asthma not adequately controlled by inhaled corticosteroids: a comprehensive review

Many patients with persistent asthma can be controlled with inhaled corticosteroids (ICS). However, a considerable proportion of patients remain symptomatic, despite the use of ICS. We present systematically evidence that supports the different treatment options. A literature search was made of Medline/PubMed to identify randomised and blinded trials. To demonstrate the benefit that can be obtained by increasing the dose of ICS, dose-response studies with at least three different ICS doses were identified. To demonstrate whether more benefit can be obtained by adding long-acting beta2-agonist (LABA), leukotriene antagonist (LTRA) or theophylline than by increasing the dose of ICS, studies comparing these options were identified. Thirdly, studies comparing the different "add-on" options were identified. The addition of a LABA is more effective than increasing the dose of ICS in improving asthma control. By increasing the dose of ICS, clinical improvement is likely to be of small magnitude. Addition of a LTRA or theophylline to the treatment regimen appears to be equivalent to doubling the dose of ICS. Addition of a LABA seems to be superior to an LTRA in improving lung function. However, addition of LABA and LTRA may be equal with respect to asthma exacerbations. However, more and longer studies are needed to better clarify the role of LTRAs and theophylline as add-on therapies.

Effects of hydrofluoroalkane formulations of ciclesonide 400 microg once daily vs fluticasone 250 microg twice daily on methacholine hyper-responsiveness in mild-to-moderate persistent asthma

AIMS

There are no data comparing the relative efficacy of hydrofluoroalkane (HFA) formulations of ciclesonide (CIC) and fluticasone propionate (FP) on airway hyper-responsiveness, in mild-to-moderate persistent asthma. We therefore elected to evaluate the comparative efficacy of HFA pressurized metered-dose inhaler formulations of CIC and FP, assessing methacholine challenge, in addition to exhaled nitric oxide, lung function, diary cards and quality of life.

METHODS

Nineteen mild-to-moderate asthmatic patients completed the study per protocol in randomized, double-blind, double-dummy, crossover fashion. Patients were required to stop their usual inhaled corticosteroid therapy for the duration of the study. Patients were commenced instead on salmeterol (SM) 50 microg one puff twice daily + montelukast (ML) 10 mg once daily for 2-week washout periods prior to each randomized treatment, in order to prevent dropouts. Patients received 4 weeks of either CIC 200 microg two puffs once daily (08.00 h) + CIC-placebo (PL) two puffs once daily (20.00 h) + FP-PL two puffs twice daily (08.00 h and 20.00 h), or FP 125 microg two puffs twice daily (08.00 h and 20.00 h) + CIC-PL two puffs twice daily (08.00 h and 20.00 h). SM + ML were withheld for 72 h prior to post-washout visits and CIC or FP was withheld for 24 h prior to study visits.

RESULTS

There was no significant difference between CIC vs. FP for the primary outcome of methacholine PC20 as doubling dilution (dd) shift from respective baseline; mean difference: 0.4 dd (95% CI -0.4, 1.2). Moreover, there was no difference between treatments for the sequence of CIC first vs FP second; mean difference: 0.2 dd (95% CI -1.3, 1.7) or FP first vs CIC second; mean difference: 0.9 dd (95% CI -0.1, 1.8). There were also no differences for other secondary outcomes between treatments, either respective or irrespective of sequence, as change from baseline.

CONCLUSIONS

There were no differences between 4 weeks of CIC 400 microg once daily and FP 250 microg twice daily on methacholine hyper-responsiveness in mild-to-moderate persistent asthma. Longer-term studies are indicated to evaluate their relative efficacy on asthma exacerbations.

How do we measure the effectiveness of inhaled corticosteroids in clinical studies?

Inhaled corticosteroids (ICSs) are the gold standard anti-inflammatory therapy for asthma and have been studied using a variety of different clinical trial designs. In long-term comparative studies ICSs are more effective in controlling asthma than beta-agonists or leukotriene antagonists (LTAs). Efficacy has also been shown retrospectively, as patients frequently experience an exacerbation of their asthma upon withdrawal of ICSs, whilst the regular use of low dose ICSs prevents death from asthma. The combination of ICSs with long-acting beta2-agonists (LABAs) is effective for patients with asthma non-responsive to low doses of ICSs, particularly in reducing exacerbations. In shorter term studies a modest dose-response effect of ICSs has been shown for lung function, symptom control and oral corticosteroid use in asthmatic patients. ICSs are also effective in reducing airway hyperresponsiveness (AHR) to various stimuli, as well as reducing exhaled nitric oxide (NO) concentrations and the number and activation state of a wide variety of inflammatory cells. Finally, using allergen challenge models even single doses of ICSs have profound inhibitory effects on the late asthmatic reaction. Since ICSs are the mainstay of asthma management guidelines, it is important that novel therapies should be judged against ICSs in future clinical trials. There are many potential designs for these comparative studies.

Pharmacokinetics of [14C]ciclesonide after oral and intravenous administration to healthy subjects

BACKGROUND

Ciclesonide is a novel inhaled corticosteroid developed for the treatment of asthma.

OBJECTIVE

To investigate the extent of oral absorption and bioavailability of ciclesonide referenced to an intravenous infusion. This information provides an estimate for the contribution of the swallowed fraction to systemic exposure to ciclesonide after oral inhalation.

METHODS

In a randomised crossover study, six healthy male subjects (age range 19-40 years) received single doses of 6.9 mg (oral administration) and 0.64 mg (intravenous administration) of [14C]ciclesonide, separated by a washout period of at least 14 days. Total radioactivity was determined in whole blood, plasma, urine and faeces. Serum concentrations of ciclesonide and its major metabolite, the pharmacologically active desisobutyryl-ciclesonide (des-CIC), were determined in serum by high-performance liquid chromatography with tandem mass spectrometry detection.

RESULTS

After a 10-minute intravenous infusion, the mean half-life for total radioactivity was 45.2 hours. Elimination of des-CIC was fast with a mean elimination half-life of 3.5 hours. After oral administration, the mean half-life for total radioactivity was 27.5 hours. On the basis of a comparison of dose-normalised areas under the curve of total plasma radioactivity versus time, 24.5% of orally administered [14C]ciclesonide was absorbed. The parent compound ciclesonide was not detected in any of the serum samples after oral administration; serum concentrations of des-CIC were mostly near or below the lower limit of quantification. Thus, systemic bioavailability for des-CIC is <1% and the absolute bioavailability of ciclesonide is even less than this. [14C]Ciclesonide showed no retention in red blood cells. The mean cumulative excretion of total radioactivity was almost complete by 120 hours after oral and intravenous administration. Faecal excretion was the predominant route of excretion for total radioactivity after both routes of administration. Single oral and intravenous administration of ciclesonide was well tolerated.

CONCLUSIONS

Because of an almost complete first-pass metabolism, ciclesonide is undetectable in serum after oral administration. Thus, any ciclesonide swallowed after oral inhalation does not contribute to systemically available ciclesonide or to its active metabolite. Drug-related metabolites are excreted mainly via the faeces, and overall recovery of administered radioactivity is virtually complete after an extended sample collection period.

Soft steroids: a new approach to the treatment of inflammatory airways diseases

Inhaled synthetic glucocorticosteroids are widely used in the treatment of bronchial asthma where they provide very effective first line treatment. However, a range of unwanted side effects and the often complex dosing schedules associated with these drugs frequently result in poor patient compliance. The soft drug approach has been utilised as a means of delivering these potent anti-inflammatory agents close to their site of action while reducing the degree of systemic exposure and thus limiting or eliminating the associated systemic and local side effects. A further target for pharmaceutical companies is to deliver these new treatments in a once daily formulation thus further enhancing patient compliance. While many soft steroids have failed to progress into the clinic two are meeting with some degree of success. Loteprednol etabonate, an inactive metabolite soft steroid, has been accepted for the treatment of ophthalmic disorders and is being examined in clinical trials for its effects on airway inflammation. Ciclesonide, a pro-drug soft steroid, has demonstrated efficacy without side effects in a once daily formulation in asthma patients and is being developed for the treatment of both asthma and chronic obstructive pulmonary disease with launches of a once daily inhaler formulation expected in 2003. These drugs may represent a significant step forward in the treatment of inflammatory diseases of the airways.

Risk-benefit value of inhaled glucocorticoids: a pharmacokinetic/pharmacodynamic perspective

Inhaled glucocorticoids induce therapeutic and adverse systemic effects via the same types of receptors. Analysis of the pharmacokinetic/pharmacodynamic parameters of inhaled glucocorticoids generates a risk-benefit value (RBV). Targeted efficacy with minimal adverse effects helps to quantify an appropriate RBV. High lung deposition/targeting, high receptor binding, longer pulmonary retention, and high lipid conjugation are among the pharmacokinetic parameters to be considered for improved efficacy of the compound. Low or negligible oral bioavailability, small particle size and inactive drug at the oropharynx, high plasma protein binding, rapid metabolism, high clearance, and lower systemic concentrations are associated with low risks for adverse effects. Inhaled glucocorticoid potency is enhanced by solution inhalers, which result in higher pulmonary deposition and minimize local adverse effects. These properties, among others, determine the efficacy and safety of inhaled glucocorticoids. Currently available inhaled glucocorticoids do not provide the complete pharmacokinetic/pharmacodynamic parameters to optimize RBV, leaving room for improvement in the development of future agents.

Use of sequential quadrupling dose regimens to study efficacy of inhaled corticosteroids in asthma

BACKGROUND

Inhaled corticosteroids are widely used to treat asthma. There is a need to be able to compare different inhaled corticosteroids and different doses of an inhaled corticosteroid to determine potency and dose equivalence, but measuring efficacy in a dose related manner is difficult because of their slow onset of action. There is uncertainty about the role of sequential dosing regimens and the best end point for such studies. We have explored the use of sequential quadrupling dose regimens and a range of end points to assess the response to budesonide in subjects with asthma.

METHODS

21 subjects with mild asthma, aged 18-65, took part in a randomised three way crossover study comparing two sequential and one non-sequential regimen, separated by at least 3 weeks. The sequential regimens consisted of increasing doses of inhaled budesonide (100, 400 1600 microg/day) with each dose being given for 1 or 2 weeks; the non-sequential regimen consisted of 1600 microg/day for 2 weeks with end points measured after 1 and 2 weeks. The end points studied included the provocative dose of adenosine monophosphate causing a 20% fall in forced expiratory volume in 1 second (PD20AMP), lung function, symptoms, and bronchodilator use.

RESULTS

There was a dose related increase in PD20AMP with both sequential dose regimens. The increase in PD20AMP ranged from 1.49 doubling doses (DD) following the lowest dose (100 microg/day) to 3.1 DD following the highest dose (1600 microg/day) in the 1 week sequential regimen and from 1.98 to 4.03 DD in the 2 week sequential regimen; standard deviations (SD) for the changes in PD20AMP ranged from 1.3 to 2.6 DD. Changes in forced expiratory volume in 1 second (FEV1) and morning peak expiratory flow rate (PEFR) were dose related but small and more variable (maximum change in FEV1=148 ml, SD 228 ml), while changes in evening PEFR, symptoms, and bronchodilator use were small and not dose related. Change in PD20AMP after budesonide 1600 microg did not differ significantly between regimens.

CONCLUSION

Combining PD20AMP measurements with a sequential regimen of three quadrupling doses of an inhaled corticosteroid given for 1 or 2 weeks provides clear dose-response curves for comparative studies. PD20AMP is a more sensitive end point for this purpose than FEV1, PEFR, symptoms, or relief inhaler use.

Airway responsiveness to adenosine 5'-monophosphate and exhaled nitric oxide measurements: predictive value as markers for reducing the dose of inhaled corticosteroids in asthmatic subjects

OBJECTIVES

To investigate the utility of the determination of airway responsiveness to inhaled adenosine 5'-monophosphate (AMP) and exhaled nitric oxide (ENO) levels as markers for safely reducing the dose of inhaled corticosteroids (ICS) in patients with asthma well controlled with a moderately high ICS dose.

METHODS

A total of 37 patients with asthma well controlled for at least 3 months by treatment with a moderately high ICS dose (beclomethasone dipropionate, 500 to 1,000 microg or equivalent daily) were included in the study. Patients were treated for a 2-week run-in (baseline) period with their usual dose of ICS. For the next 12 weeks, patients were treated with ICS at half the previous dose, maintaining the same inhalation device. At the end of the baseline period and after 2 weeks, 8 weeks, and 12 weeks of treatment with a reduced dose of ICS, measurements were made in the following order: ENO, spirometry, and AMP challenge. Furthermore, patients completed a diary twice daily recording peak expiratory flow, daytime and nighttime symptoms, and use of rescue albuterol.

RESULTS

Ten patients had an asthma exacerbation. Using a Kaplan-Meier survival analysis, the significant predictors of a failure of ICS reduction were having both bronchoconstriction in response to AMP and ENO levels > or = 15 parts per billion (ppb) at baseline (p = 0.006), as well as having both bronchoconstriction in response to AMP and ENO levels > or = 20 ppb at baseline (p = 0.033). Having a decrease in the provocative concentration of AMP causing a 20% fall in FEV(1) of at least one doubling concentration 2 weeks after the dose of ICS was halved was a borderline significant predictor for failure of ICS reduction (p = 0.062).

CONCLUSION

These observations suggest that in asthmatic patients well controlled with ICS, the determination of AMP responsiveness and ENO levels may be useful to identifying those subjects whose condition will or will not deteriorate when the dose of ICS is reduced.

Research applications and implications of adenosine in diseased airways

Adenosine, when given by inhalation, initiates the narrowing of airways in subjects with asthma or chronic obstructive pulmonary disease (COPD). The underlying mechanism of this narrowing appears to involve the stimulation of specific mast cell surface adenosine receptors with the subsequent release of mediators and contraction of airway smooth muscle. Although methacholine and histamine have become gold standards as bronchial provocants used to quantify bronchial hyperresponsiveness, the airways response to the indirect stimulus adenosine more closely reflects bronchial inflammation. This distinctive feature of adenosine could be exploited to enable superior diagnostic discrimination between asthma and COPD, allow better monitoring of disease activity and progression, and improve the individual adjustment of long-term asthma management with topical glucocorticosteroids. In this article, we review recent developments in this area of rapidly evolving clinical research, focusing on the putative role of adenosine as a mediator of airway inflammation and as a useful bronchoprovocant in several clinical and research applications.

Effect of ciclesonide on allergen challenge in subjects with bronchial asthma

BACKGROUND

The aim of this clinical trial was to investigate whether repeated inhalation of the new inhaled steroid ciclesonide reduces the early-phase (EAR) and late-phase (LAR) reactions after allergen challenge in patients with mild allergic asthma. Also, this study provides further data on safety and tolerance of ciclesonide.

METHODS

The study was designed as a double-blind placebo-controlled randomized crossover trial. Following a baseline period, patients were randomized to either of two treatment sequences (ciclesonide/placebo, placebo/ciclesonide) each of which lasted for one week and were separated by 3-5 weeks from the alternate treatment sequence. Patients received 800 micro g ciclesonide twice daily by means of a Cyclohaler. At the end of each treatment patients were subjected to an allergen challenge.

RESULTS

Thirteen asthmatic patients (mean FEV1 of 91% predicted) who experienced an EAR and LAR after allergen challenge participated in the study. The time-average FEV1 decreases 0-2 h (2-12 h) after allergen challenge as measure of the EAR (LAR) were significantly reduced (P < 0.05, one-sided) from 0.426 L to 0.233 L (EAR) and from 0.443 L to 0.213 L (LAR), respectively. Thus, the study results suggest that ciclesonide significantly lowered the extent of EAR and LAR compared to placebo. Ciclesonide was well tolerated and no drug-related adverse events were reported. Cortisol excretion in 24-h urine showed no significant difference between ciclesonide and placebo.

CONCLUSIONS

The study supports the efficacy and safety of ciclesonide.

The role of adenosine as a novel bronchoprovocant in asthma

PURPOSE OF REVIEW

There is evidence that bronchial hyperresponsiveness to inhaled adenosine may be a better marker of airway allergic inflammation than bronchial hyperresponsiveness to other spasmogens. Here the authors review the most recent development in this area of rapidly evolving clinical research, focusing on the putative role of adenosine as a useful bronchoprovocant in asthma.

RECENT FINDINGS

New studies have provided evidence that hyperresponsiveness to AMP strongly correlates with sputum, blood/bronchial tissue eosinophilia and exhaled nitric oxide, whereas hyperresponsiveness to methacholine is related to changes in forced expiratory volume in 1 s, thus reflecting changes in airway caliber and functional state. Other recent studies have emphasized that the state of atopy is critically important in the bronchial response to inhaled AMP. The early finding that in people with asthma treatment with inhaled glucocorticosteroids significantly reduces airway responsiveness to AMP, as compared with other spasmogens such as methacholine or bradykinin, has been confirmed by recent reports which have also outlined that this is an early phenomenon.

SUMMARY

Taken together these studies evidence that hyperresponsiveness to inhaled adenosine may be a better marker of airway allergic inflammation than hyperresponsiveness to other spasmogens. This peculiar property of adenosine suggests that bronchial provocation with inhaled adenosine could provide a reliable noninvasive tool for monitoring asthma activity/progression, and assessing the response to antiinflammatory treatments.

Dose response of inhaled corticosteroids on bronchial hyperresponsiveness: a meta-analysis

BACKGROUND

There is a relatively steep dose-response curve for effects of inhaled corticosteroids on conventional airway markers of asthmatic disease control.

OBJECTIVE

We sought to determine whether a dose-response effect exists for bronchial hyperresponsiveness.

METHODS

A meta-analysis of placebo-controlled trials in asthmatic patients was performed using a computerized systematic review of databases. Doubling dose/dilution protection of inhaled corticosteroid was compared with placebo. Studies which used direct (methacholine and histamine) and indirect (adenosine monophosphate) bronchial challenge stimuli were eligible for inclusion.

RESULTS

Twenty-five studies fulfilled eligibility criteria (963 patients). Values for doubling dose/dilution protection categorized by low/medium dose (< 1,000 microg) and high dose (> or = 1,000 microg) of inhaled corticosteroid amounted to a 1.25 (95% confidence interval 1.08 to 1.42) and 2.16 (95% confidence interval 1.88 to 2.44) shift, respectively.

CONCLUSIONS

High doses of inhaled corticosteroids conferred greater improvements in bronchial hyperresponsiveness than low doses.

Dose response and therapeutic index of inhaled corticosteroids in asthma

Inhaled glucocorticoids play an indispensable role in the therapy of asthma. Development of new compounds was initially directed to increase the potency of the individual corticosteroid; thereafter, pharmacokinetic characteristics were modified to reduce unwanted systemic effects. Target of the present development is to attain compounds with the most favorable risk-to-benefit ratios. Since then, there has been substantial discussion about how to rank and weigh the different glucocorticoids. This article provides an evaluation of the relevant clinical studies published between May 2001 and June 2002, identifying the main determinants of the therapeutic value of inhaled glucocorticoids.

Novel therapies for the treatment of inflammatory airway disease

Asthma and chronic obstructive pulmonary disease (COPD) are diseases of the airways with an underlying inflammatory component. The prevalence and healthcare burden of asthma and COPD is still rising and is predicted to continue to rise in the current century. The beta-agonists and corticosteroids form the basis of the treatments available to alleviate the symptoms of asthma, whereas the treatments available for COPD have been shown to have a limited effect on slowing the progression of the disease. Asthma and COPD are both in need of novel, safe treatments to tackle the underlying inflammation that characterises their pathology. The inflammatory processes inherent in asthma and COPD provide the opportunity for innovative drug research. This review will outline the new approaches and targets being investigated, which may provide opportunities for novel therapeutic interventions in these debilitating diseases.

Asthma remission: does it exist?

Subjects believed to have grown out of asthma often develop symptoms again later in life. Ongoing airway inflammation may determine the risk of relapse, although the mechanisms involved are still misunderstood. Additionally, patients with asthma during childhood may develop irreversible airflow obstruction ( airway remodeling) as a result of chronic airway inflammation. Recently, airway inflammation and remodeling could be demonstrated in bronchial biopsy specimens from young adults who considered themselves grown out of asthma. It is also shown that evidence of airway inflammation and remodeling can be obtained noninvasively, thereby providing the opportunity to monitor disease activity. If chronic airway inflammation and/or remodeling are consistent findings in asymptomatic subjects with a history of atopic asthma, the question arises whether natural history can be positively altered with prolonged antiinflammatory therapy. Benefits of long-term prognosis are, however, not yet shown. Since epidemiologic work has demonstrated that a certain percentage of subjects with apparently outgrown atopic asthma remains asymptomatic without needing therapy for the rest of their lives, it can be argued that "asthma remission does exist." The question is whether this percentage can be increased with prolonged antiinflammatory therapy and regular control.

Changes in sputum counts and airway hyperresponsiveness after budesonide: monitoring anti-inflammatory response on the basis of surrogate markers of airway inflammation

BACKGROUND

Airway hyperresponsiveness (AHR) to pharmacologic stimuli and sputum eosinophils might be useful in the individual adjustment of long-term asthma management. However, it is not clear whether inhaled glucocorticosteroids (GCSs) provide greater protection against specific surrogate markers of airways inflammation than other means. In addition, detailed longitudinal assessment of changes in airway response with inhaled GCSs has never been carried out.

OBJECTIVES

We compared changes in AHR to inhaled methacholine and adenosine 5'-monophosphate (AMP) after budesonide treatment in a randomized, double-blind, placebo-controlled, crossover study of patients with mild-to-moderate asthma. Subsequently, we undertook a separate study to examine the time course of the changes in AHR in more detail and the changes in sputum cell counts in relation to budesonide treatment.

METHODS

In the phase 1 of the study, patients undertook bronchial provocation studies with increasing doubling concentrations of methacholine (0.06 to 16 mg/mL) and AMP (3.125 to 800 mg/mL) before and after budesonide 0.8 mg/daily for 3 weeks. The bronchial responses to the inhaled agonists were expressed as the provocative concentration causing a 20% decline in FEV(1) (PC(20)). In phase 2 of the study, patients attended the laboratory on 12 separate occasions to investigate changes in PC(20) methacholine, PC(20) AMP, and sputum cell counts before, during, and after withdrawal of therapy with inhaled budesonide 0.8 mg/daily for 6 weeks.

RESULTS

Budesonide treatment for 3 weeks significantly attenuated the constrictor response by 0.8 +/- 0.3 doubling doses for methacholine and by 2.6 +/- 0.5 doubling doses for AMP. These changes were significantly different from each other (P =.003). Significant variation in PC(20) methacholine (P <.05) value, PC(20) AMP (P <.001) value, percentage of sputum eosinophils (P <.001), and percentage of sputum epithelial cells (P <.001) were observed throughout the longitudinal assessment of changes in airway response to budesonide. Compared with the other surrogate markers, PC(20) AMP appears to be useful in promptly detecting early inflammatory changes of the asthmatic airways; a significant change of 1.6 +/- 0.3, 2.2 +/- 0.3, and 2.8 +/- 0.3 doubling doses of PC(20) AMP was observed at 1, 4, and 6 weeks, respectively, in the course of budesonide treatment.

CONCLUSIONS

The present findings underline the exquisite selectivity of diverse surrogate markers of airway inflammation in response to inhaled budesonide. When compared with that to the other markers, AHR to inhaled AMP is an early and sensitive indicator of the beneficial anti-inflammatory effects of topical GCSs.

Use of aerosols for bronchial provocation testing in the laboratory: where we have been and where we are going

Bronchial provocation testing with pharmacological agents that act directly on airway smooth muscle has important limitations. These include the inability to identify exercise-induced asthma (EIA), to differentiate the airway hyperresponsiveness (AHR) of airway remodelling from the AHR of active inflammation and to differentiate between doses of steroids. Recent studies show that tests that act indirectly to narrow airways are more sensitive than pharmacological agents for identifying airway inflammation and response to treatment. Adenosine monophosphate (AMP) is an indirect challenge that acts on mast cells to cause release of mediators. Hypertonic saline is another and, since its development in the 1980s, has become widely used in Australia. Hypertonic (4.5%) saline is used to identify those with active asthma, those with EIA and those who wish to enter certain occupations or sports (e.g., diving). The recent development, again in Australia, of a test that uses dry powder mannitol has promise for use in the laboratory, the office, or for testing in the field. AHR to mannitol identifies people with EIA and is an estimate of its severity. The mannitol response is modified by drugs used to prevent EIA, implying that similar mediators are involved. A mannitol test can be used to monitor response to steroids and is more sensitive than histamine for identifying persistent airway hyperresponsiveness in asthmatics well controlled on steroids. These findings suggest that indirect challenges give more useful clinical information about currently active asthma and the response to treatment than direct challenge and they will become more widely used.

Rapid effect of inhaled fluticasone propionate on airway responsiveness to adenosine 5'-monophosphate in mild asthma

Inhaled adenosine 5'-monophosphate (AMP) has an "indirect" bronchoconstrictive effect through mast cell degranulation and mediator release, whereas inhaled histamine has a "direct" effect on smooth muscle. Prolonged treatment with inhaled glucocorticosteroids attenuates airway responsiveness (AR) to AMP and histamine. We investigated the early effects of inhaled fluticasone propionate (FP) therapy on AR in 3 consecutive double-blind, randomized, placebo-controlled crossover studies in steroid-naive subjects with mild asthma. In one study, each of 12 subjects received FP 1000 microg or matched placebo for 7 inhalations at 12 hourly intervals; AR to AMP and FEV(1) were measured 2 hours after the 3rd and 7th inhalations. In a second study, each of 12 subjects received FP 100, 250, or 1000 microg or matched placebo for 3 inhalations at 12 hourly intervals; AR to AMP and FEV(1) were measured 2 hours after the 1st and 3rd inhalations. In a third study, each of 8 subjects received a single inhalation of FP 1000 microg or matched placebo; AR to histamine was measured 2 hours later. In the first study, FP 1000 microg significantly attenuated AR to AMP by 2.7 and 2.5 doubling doses after 3 and 7 inhalations, respectively (P < or =.0001). In the second study, FP 100, 250, and 1000 microg significantly attenuated AR to AMP by 1.9, 2.2, and 2.7 doubling doses, respectively, after 1 inhalation and by 2.4, 2.2, and 3.2 doubling doses, respectively, after 3 inhalations (P < or =.0001); a small but significant increase in FEV(1) (>0.15 L) was observed after 3 inhalations but not after 1 inhalation of FP irrespective of dose (P < or =.05). In the third study, a single inhalation of FP 1000 microg had no effect on AR to histamine. We have demonstrated a reduction in AR to AMP but not AR to histamine within 2 hours of a single inhalation of FP. This reflects a rapid, topical anti-inflammatory action of inhaled FP by a mechanism of action that remains unknown.

Evolving concepts on the value of adenosine hyperresponsiveness in asthma and chronic obstructive pulmonary disease

Adenosine is a purine nucleoside which mediates a variety of cellular responses relevant to asthma and COPD through interaction with specific receptors. Administration of adenosine by inhalation to patients with asthma and COPD is known to cause concentration related bronchoconstriction. Responses elicited by this purine derivative in asthma and COPD should not be considered as a mere reflection of non-specific airways hyperresponsiveness. Evaluation of airways responsiveness by adenosine induced bronchoconstriction may be valuable in differentiating asthma from COPD, monitoring of anti-inflammatory treatment in asthma, surveying disease progression, and assessing disease activity in relation to allergic airways inflammation.

Bronchoprotective effects of leukotriene receptor antagonists in asthma: a meta-analysis

STUDY OBJECTIVE

Cysteinyl leukotrienes are important proinflammatory mediators in the pathogenesis of asthma. Since bronchial hyperresponsiveness is a noninvasive surrogate marker of asthmatic airway inflammation, we evaluated the bronchoprotection afforded by leukotriene receptor antagonists (LTRAs).

DESIGN

Systematic review of randomized, placebo-controlled trials in which LTRAs were administered for >or= 5 days. Studies in which active drug was administered as a first-line or second-line therapy were used.

SETTING

MEDLINE, BIDS, and Cochrane Library data registers.

MEASUREMENTS

The doubling dose/dilution difference that caused a 20% fall in the FEV(1) between LTRA and placebo.

RESULTS

Thirteen trials (353 subjects) fulfilled eligibility criteria. Combining the results the overall weighted estimated protection amounted to a 0.85 doubling dose shift (95% confidence interval, 0.69 to 1.02).

CONCLUSION

Since the estimated protection amounted to almost one doubling dose, this reinforces the role of LTRAs as anti-inflammatory therapy in asthma.

Effects of 4-week treatment with low-dose budesonide (100 micrograms BID) from a novel inhaler Airmax and from a conventional inhaler on bronchial hyper-responsiveness, lung function and symptoms in patients with mild asthma

This study investigated the effect of low dose of budesonide 100 micrograms b.d from a new multi-dose dry powder inhaler (Airmax) and from a conventional inhaler (Turbuhaler) on bronchial hyper-responsiveness, lung function and asthma symptoms in mild stable asthmatics. Twenty-five patients were enrolled into a double-blind double-dummy crossover study with two 4-week treatment periods separated by a 4-week washout. Patients had a mean forced expiratory volume in 1 s (FEV1) of 91 +/- 13% predicted, had previously received inhaled short-acting beta 2-agonists only and had a PC20 to adenosine 5' monophosphate (AMP) < 40 mg/ml. PC20 AMP was assessed at baseline, and at the start and end of each treatment period. Patients recorded peak expiratory flow and symptoms throughout the study. There was a mean increase in PC20AMP from start to end of 3.49 doubling dilutions (DD) in the Airmax group and 2.90 DD in the Turbuhaler group. The difference was 0.60 DD (95% CI--0.47, 1.69) favouring Airmax and the upper limit exceeded the equivalence limit of +/- 1 DD. There were similar improvements in FEV1, daily PEF and symptoms in both groups. The majority of patients preferred treatment with Airmax to Turbuhaler (64 vs. 23%). Both treatments were equally well tolerated. In conclusion, 100 micrograms budesonide bid during 4 weeks from Airmax effectively attenuates the response to AMP in mild asthmatics. Overall Airmax offers equal clinical benefit to Turbuhaler.

Circadian rhythm of serum cortisol after repeated inhalation of the new topical steroid ciclesonide

The new inhalative glucocorticoid ciclesonide which is activated in lung to a more potent metabolite was hypothesized to have low risk for systemic and local side-effects in man. Therefore, a placebo-controlled, randomized, double-blind, four-period, change-over equivalence study in 12 healthy male volunteers (age 21-28 yr, body weight 62-90 kg) was conducted to assess the influence of three dosage regimens (800 microg in the morning, 800 microg in the evening, 400 microg twice daily for 7 d, metered inhalers) on the circadian time serum cortisol rhythm.

RESULTS

Serum cortisol showed the typical circadian rhythm. The geometric mean of the 24-h mesor (AUC((0-24 h))/24 h) was 7.22 microg/dl for placebo, 6.75 microg/dl for the 800 microg ciclesonide morning dose, 7.08 microg/dl for the 800 microg evening dose, and 6.75 microg/dl for 400 microg ciclesonide inhaled twice daily. Because there was also no influence on cortisol amplitude and acrophase (time of maximum), the profiles after ciclesonide were equivalent to the placebo control. The small differences were considered not to be of clinical significance. In conclusion, inhaled ciclesonide in daily doses of 800 microg for 7 d is without clinically relevant effects on the hypothalamic-pituitary-adrenal axis independent of the time of administration.

Asthma stability after oral prednisone: a clinical model for comparing inhaled steroid potency

Clinical studies comparing the potency of inhaled corticosteroids require steep dose-response slopes (b) and minimal response variability (s), as statistical power is inversely related to the s/b ratio. To evaluate a new study model, we performed a randomized, crossover study of 12 adult asthmatics who required 800 to 2,000 microg of inhaled corticosteroids daily, and calculated s/b for 21 raw clinical outcomes and 36 mathematically derived variables based on these raw outcomes. Each of two 21-d treatment periods was preceded by 4 to 7 d of oral prednisone to maximize asthma control and minimize carry-over of previous inhaled treatment. Treatments were 100 and 800 micron/d of an HFA-134a beclomethasone dipropionate formulation. Assessments included daily home spirometry, histamine challenge, inhaled albuterol use, and asthma symptom scores. Efficacy variables with the greatest power (lowest s/b values) were A.M.FEF25-75, A.M.FEV1, and A.M.PEF, (s/b = 0.46, 0.48, and 0.59). Carry-over between treatment periods was not significant. Crossover study sample size calculations using these ratios yielded samples of 23, 25, and 37 patients, respectively. Otherwise identical parallel studies would require sample sizes of 657, 1,438, and 2,261 patients. These results support the use of a crossover asthma stability model after a short course of oral prednisone as a clinical study model for comparing topical potency of inhaled corticosteroids.

The use of sputum cell counts to evaluate asthma medications

Total and differential cell counts from hypertonic-induced, dithiothreitol-dispersed sputum provide reproducible measurements of airway inflammatory cell counts, which are responsive to treatment with anti-inflammatory drugs. They have helped to understand the kinetics of inflammatory cell changes in asthma after the reduction of corticosteroids and the subsequent re-introduction of treatment. They have identified that the presence of sputum eosinophilia in asthma, chronic cough and chronic airflow limitation is a predictor of steroid-responsiveness and of lack of 'asthma control'. They can be used to study the dose-response effect of inhaled corticosteroids and may be useful to establish the relative potency of different corticosteroid formulations and delivery devices. Sputum cell counts are also useful to study the potential anti-inflammatory effects of drugs like theophylline, long-acting beta-adrenoceptor agonists, leukotriene antagonists and newer drugs in development. They may be helpful to select add-on therapy to corticosteroids in 'difficult-to-control' asthma.

Effect of inhaled ciclesonide on airway responsiveness to inhaled AMP, the composition of induced sputum and exhaled nitric oxide in patients with mild asthma

To assess the efficacy of ciclesonide, a novel corticosteroid pro-drug, we compared its effect on lung function, airway responsiveness to inhaled AMP, the composition of induced sputum, and the level of exhaled nitric oxide (NO) with the effect of budesonide in patients with asthma. Fifteen non-smoking steroid-naive patients (mean FEV(1), 94%pred) inhaled either 400 microg ciclesonide or 400 microg budesonide as a single morning dose for two weeks each separated by a > or =3 week wash-out period. The study was performed in a double-observer, randomized, cross-over design. FEV(1)increased significantly during treatment with budesonide (3.38 vs. 3.64 l P=0,003), but not after ciclesonide (3.60 vs. 3.69 l). PC(20)FEV(1)of AMP increased (P<0,001, each) after both budesonide (4.59 vs. 32.48 mg/ml, 2.8 doubling doses) and ciclesonide (3.92 vs. 20.00 mg/ml, 2.4 doubling doses). The percentage of sputum eosinophils was significantly reduced after ciclesonide (7.9 vs. 3.4% P=0.01), but not budesonide (6.0 vs. 4.3%). After both budesonide and ciclesonide, a significant (P<0.001) reduction in the level of exhaled NO occurred. In none of the parameters studied, the changes differed significantly between treatment with budesonide or ciclesonide. These data suggest that ciclesonide is equi-effective to budesonide with regard to its potency to reduce the airway responsiveness to inhaled AMP as well as airway inflammation in patients with mild asthma.

Treatment of asthma by the inhaled corticosteroid ciclesonide given either in the morning or evening

The study addressed the question whether the novel inhaled prodrug corticosteroid ciclesonide is equally effective when inhaled in the morning compared to the evening. For this purpose a double-blind, randomized, parallel group study was initiated in which 209 asthmatic patients (forced expiratory volume in one second = 50-90% predicted) inhaled either 200 microg ciclesonide in the morning or in the evening, for 8 weeks. Efficacy was assessed by means of spirometry as well as daily recordings of morning and evening peak expiratory flow (PEF), symptoms and use of rescue medication. The 24-h urinary cortisol excretion was measured to evaluate any effect on hypothalamic-pituitary-adrenol axis. Ciclesonide significantly improved asthma control. Morning and evening administration was shown to be equally effective for the different spirometry variables, evening PEF, symptoms, use of rescue medication and number of asthma exacerbations. Regarding morning PEF, the improvements after evening dosing were more prominent and equivalence of morning and evening administration could not be demonstrated. No relevant influence on cortisol excretion was found. Overall, the study indicates that ciclesonide can be given either in the morning or in the evening to meet the patients' preference and individual medical needs, although evening administration may lead to a more pronounced improvement in morning peak expiratory flow.

Repeatability of bronchial hyperresponsiveness to adenosine-5'-monophosphate (AMP) by a short dosimeter protocol

BACKGROUND

To study bronchial responsiveness to adenosine 5'-monophosphate (AMP) in population surveys, repeatability of a rapid dosimetric method with quadrupling doses was evaluated.

METHODS

Volunteers with symptoms of airway respiratory allergy or asthma were invited for AMP challenges on two occasions. After each dose the fall in forced expiratory volume in one second (FEV(1)) compared with the post-saline value was determined. The cumulative doses of AMP needed to cause a fall in FEV(1) of 20% (PD(20)), 15% (PD(15)), and 10% (PD(10)) were calculated. Agreement was evaluated by means of kappa values. After excluding systematic differences in PD values on two occasions (t test), repeatability of a single estimation of the chosen PD values was calculated and expressed in doubling doses (DD).

RESULTS

In 28 of 76 subjects a PD(20) was estimated on the two visits, in 29 subjects a PD(15) was estimated, and in 32 a PD(10) was obtained. Kappa values for a positive threshold were 0.89 for a cut off level for a 20% fall in FEV(1), 0.78 for a 15% fall in FEV(1), and 0.76 for a fall in FEV(1) of 10%. The PD values did not differ between the two visits and 95% repeatability of a single estimation was +/-1.7 DD for PD(20), +/-2.2 DD for PD(15), and +/-2.4 DD for PD(10). The quadrupling dose method reduced time by 40% in non-hyperresponsive subjects and no adverse effects were observed.

CONCLUSION

The short dosimeter protocol with quadrupling doses for AMP challenges is a rapid, reproducible tool for estimating bronchial responsiveness in population surveys.

Dose-Response Relationship and Reproducibility of the Fall in Exhaled Nitric Oxide After Inhaled Beclomethasone Dipropionate Therapy in Asthma Patients

STUDY OBJECTIVES

The fractional concentration of exhaled nitric oxide (FENO) is a marker of asthmatic airway inflammation. We determined the dose response and the reproducibility of the FENO fall following inhaled beclomethasone dipropionate (iBDP) therapy in nonsteroid-treated asthmatic patients.

STUDY DESIGN

Study A: For four 1-week periods (period 1 to period 4), the following regimens were administered in sequential order to 15 nonsteroid-treated asthmatic patients: period 1, placebo; period 2, 100 microg/d of iBDP; period 3, 400 microg/D of iBDP; and period 4, 800 microg/d of iBDP. Spirometry, FENO, and provocative concentration of methacholine resulting in a 20% fall in FEV(1) (PC(20)) were measured at each of five visits (visit 1 to visit 5). Study B: During four periods, 12 nonsteroid-treated asthmatic patients received placebo treatment for 7 days (period 1), 200 microg/d of iBDP for 14 days (period 2), washout on placebo treatment until the FENO was within 15% of baseline (period 3), and 200 microg/d of iBDP for 14 days (period 4).

RESULTS

Study A: Mean FEV(1) rose progressively from 3.10 L (visit 1) to 3.41 L (visit 5; p = 0.001). All iBDP doses caused a significant FEV(1) rise compared to placebo treatment, but with no significant separation of doses using FEV(1). FENO geometric mean (95% confidence limits) fell progressively from 103.5 parts per billion (ppb) (78.5 to 136.7) to 37.4 ppb (29.1 to 48.0) from visit 1 to visit 5 (p = 0.001). All doses of iBDP resulted in a significant change in FENO from placebo treatment, but with significant separation of only the 100-microg and 800-microg doses by FENO. Geometric mean (95% confidence limits) PC(20) rose progressively from 0.01 mg/mL (0.00 to 0.19) to 0.48 mg/mL (0.01 to 8.1) from visit 1 to visit 5 (p = 0.002). All doses of iBDP resulted in a significant change in PC(20) from baseline or placebo treatment, but with no significant separation of active iBDP doses using PC(20). Study B: FENO fell from 111.56 ppb (80.3 to 155.1) to 66.3 ppb (49.2 to 89.5; p < 0.001) from period 1 to period 2, and from 110.2 ppb (79.3 to 153.1) to 61.7 ppb (42.9 to 88.8; p < 0.001) from period 3 to period 4. There were no significant differences between FENO in period 1 and period 3 (p = 0.83) or between period 2 and period 4 (p = 0.220).

CONCLUSIONS

FENO was superior to FEV(1) and PC(20) in separating doses of iBDP. The fall in FENO after two identical administrations of iBDP separated by placebo washout was highly reproducible.

Novel drugs for treating asthma

The health burden of asthma is increasing globally at an alarming rate, providing a strong impetus for the development of new therapeutics, particularly drugs that may prevent development of the disease. Currently available inhaled bronchodilators and anti-inflammatory drugs are effective in most asthmatic patients, but this palliative therapy requires long-term daily administration. Despite considerable efforts by the pharmaceutical industry, it has been difficult to develop novel therapeutic agents, the leukotriene antagonists being the only new class of asthma treatments to be licensed in the past 30 years. It is clearly important to understand more about the underlying mechanisms of asthma and about how currently used drugs work before rational improvements in therapy can be expected. There are numerous therapies in clinical development that combat the inflammation found in asthma, specifically targeting eosinophils, IgE, adhesion molecules, cytokines (interleukin-4, -5, -13) and chemokines, inflammatory mediators, and cell signaling (kinase inhibitors). In particular, there is the obvious need for new therapy for severe asthma that is poorly controlled by high-dose corticosteroids as well as agents to counter acute emergency asthma. A long-term goal is to develop disease-modifying immunotherapy that could be introduced in childhood to alter the natural history of asthma. Thanks to the extensive efforts of the pharmaceutical industry, we can expect the introduction of a range of novel therapies for asthma in the near future.

Antiasthmatic effects of mediator blockade versus topical corticosteroids in allergic rhinitis and asthma

To compare the antiasthmatic efficacy of inflammatory mediator blockade versus topical corticosteroid therapy in patients with seasonal allergic rhinitis (SAR) and asthma, 14 patients were enrolled into a single-blind, double-dummy, placebo-controlled crossover study comparing 2 wk therapy of (1) 400 microgram orally inhaled budesonide plus 200 microgram intranasal budesonide (BUD) or (2) 10 mg oral montelukast plus 10 mg oral cetirizine (ML + CZ). Before each treatment period, patients received 7 to 10 d placebo washout. All treatments were given once daily in the morning. Throughout the study, patients recorded the following domiciliary measures: peak expiratory flow (PEF), rescue inhaler requirement, asthma symptoms, and daily activity score. Laboratory measurements were made at trough of adenosine monophosphate (AMP) bronchial challenge and exhaled nitric oxide (NO). Compared with pooled placebo (PL), there were significant (p < 0.05) improvements in all domiciliary measures with both treatments (mean PEF [L/min] PL: 463; BUD: 478; ML + CZ: 483). For geometric mean AMP PC(20) (mg/ml), there was an improvement (p < 0.05), compared with PL (47), for ML + CZ (133) but not for BUD (51); whereas for NO (ppb) there was significant suppression with BUD (7.6) but not ML + CZ (11.5) compared with PL (13.6). In conclusion, both combined mediator blockade and combined topical corticosteroids are equally effective antiasthma therapy in patients with asthma and SAR.

Adolescents in clinical remission of atopic asthma have elevated exhaled nitric oxide levels and bronchial hyperresponsiveness

Symptoms of atopic asthma often decrease or even seem to disappear around puberty. The aim of this study was to investigate whether this so-called clinical remission is accompanied by remission of airway inflammation, since symptoms relapse in a substantial proportion of subjects later in life. To assess indicators of inflammation and/or structural damage of the airways, exhaled nitric oxide (eNO) and bronchial responsiveness to adenosine-5'-monophosphate (AMP) and methacholine (MCh) were determined in 21 subjects in clinical remission of atopic asthma. Clinical remission was defined as complete absence of symptoms of asthma without the use of any medication in the year preceding the study. Results were compared with those of 21 patients with current asthma and 18 healthy control subjects. We found significantly higher eNO values in the remission group than in healthy controls (geometric mean, 18.9 and 1.0 ppb, respectively; p < 0.001) whereas eNO values of the remission group and those of the subjects with current asthma (geometric mean, 21.9 ppb) were similar (p = 0.09). The responsiveness to both AMP and MCh of subjects in clinical remission was significantly higher as compared with responsiveness of healthy controls, and lower than responsiveness of subjects with current asthma. A significant correlation could be established between eNO and responsiveness to AMP, but not between eNO and responsiveness to MCh. The results of this study are suggestive of persistent airway inflammation during clinical remission of atopic asthma. We speculate that subclinical inflammation is a risk factor for asthma relapse later in life, and that eNO and responsiveness to both AMP and MCh can be used as different, noninvasive indices of the inflammatory process of the airways.

New directions in allergic diseases: mechanism-based anti-inflammatory therapies

Advances in our understanding of allergic inflammation have led to the development of several novel anti-inflammatory drugs that target specific aspects of the inflammatory process. These treatments are based on improvements in existing therapies or on a better understanding of the cellular and molecular mechanisms involved in atopic diseases. Although most attention has been focused on asthma, treatments that inhibit the atopic disease process would have application to all atopic diseases, which often coincide. Specific agents that are now in development for the treatment of allergic inflammation include inhibitors of eosinophilic inflammation (eg, anti-IL-5, CCR3 antagonists, and very late antigen 4 inhibitors), drugs that may inhibit allergen presentation, and inhibitors of T(H)2 cells. More general anti-inflammatory approaches include novel cortico-steroids, phosphodiesterase inhibitors, and mitogen-activated protein kinase inhibitors. Most of the new therapies in development are aimed at inhibiting or suppressing components of the allergic inflammatory response, but in the future, there are possibilities for development of preventive and curative treatments.

Novel therapy for asthma

The health burden of asthma is increasing globally at an alarming rate, providing a strong impetus for the development of new therapeutics. Currently available inhaled bronchodilators and anti-inflammatory drugs are effective in most asthmatics, but this palliative therapy requires long-term daily administration. Despite considerable efforts by the pharmaceutical industry, it has been difficult to develop novel therapeutic agents; the leukotriene antagonists and synthesis inhibitors being the only new class of asthma treatments to have been licensed in the last 30 years. It is clearly important to understand more about the underlying mechanisms of asthma and about how current drugs work before rational improvements in therapy can be expected. There are numerous therapies in clinical development that combat the inflammation found in asthma, specifically targeting eosinophils, IgE, adhesion molecules, cytokines and chemokines, inflammatory mediators and cell signalling. In particular, there is the obvious need for new therapy for severe asthma that is poorly controlled by high doses of corticosteroids, as well as agents to counter acute emergency asthma. A long-term goal is to develop disease-modifying immunotherapy, that could be introduced in childhood to alter the natural history of asthma. Thanks to the extensive efforts of the pharmaceutical industry, in the near future we can expect the introduction of a range of novel therapies for asthma.

Therapeutic strategies for allergic diseases

Many drugs are now in development for the treatment of atopic diseases, including asthma, allergic rhinitis and atopic dermatitis. These treatments are based on improvements in existing therapies or on a better understanding of the cellular and molecular mechanisms involved in atopic diseases. Although most attention has been focused on asthma, treatments that inhibit the atopic disease process would have application to all atopic diseases, as they often coincide. Most of the many new therapies in development are aimed at inhibiting components of the allergic inflammatory response, but in the future there are real possibilities for the development of preventative and even curative treatments.