Placebo-controlled, comparative study of the efficacy and safety of triamcinolone acetonide inhalation aerosol with the non-CFC propellant HFA-134a in patients with asthma. Azmacort HFA Clinical Study Group

Safety of SABA Monotherapy in Asthma Management: a Systematic Review and Meta-analysis

INTRODUCTION

Short-acting β₂-agonist (SABA) reliever overuse is common in asthma, despite availability of inhaled corticosteroid (ICS)-based maintenance therapies, and may be associated with increased risk of adverse events (AEs). This systematic literature review (SLR) and meta-analysis aimed to investigate the safety and tolerability of SABA reliever monotherapy for adults and adolescents with asthma, through analysis of randomized controlled trials (RCTs) and real-world evidence.

METHODS

An SLR of English-language publications between January 1996 and December 2021 included RCTs and observational studies of patients aged ≥ 12 years treated with inhaled SABA reliever monotherapy (fixed dose or as needed) for ≥ 4 weeks. Studies of terbutaline and fenoterol were excluded. Meta-analysis feasibility was dependent on cross-trial data comparability. A random-effects model estimated rates of mortality, serious AEs (SAEs), and discontinuation due to AEs (DAEs) for as-needed and fixed-dose SABA treatment groups. ICS monotherapy and SABA therapy were compared using a fixed-effects model.

RESULTS

Forty-two studies were identified by the SLR for assessment of feasibility. Final meta-analysis included 24 RCTs. Too few observational studies (n = 2) were available for inclusion in the meta-analysis. One death unrelated to treatment was reported in each of the ICS, ICS + LABA, and fixed-dose SABA groups. No other treatment-related deaths were reported. SAE and DAE rates were < 4%. DAEs were reported more frequently in the SABA treatment groups than with ICS, potentially owing to worsening asthma symptoms being classified as an AE. SAE risk was comparable between SABA and ICS treatments.

CONCLUSIONS

Meta-analysis of data from RCTs showed that deaths were rare with SABA reliever monotherapy, and rates of SAEs and DAEs were comparable between SABA reliever and ICS treatment groups. When used appropriately within prescribed limits as reliever therapy, SABA does not contribute to excess rates of mortality, SAEs, or DAEs.

The systemic safety of inhaled corticosteroid therapy: a focus on ciclesonide

OBJECTIVE

To review the potential systemic activity of ciclesonide and its active metabolite, desisobutyryl-ciclesonide, by evaluation of the effects on hypothalamic-pituitary-adrenal (HPA) axis function.

DATA SOURCES

EMBASE and MEDLINE searches using the keyword ciclesonide, without date restrictions, were conducted to identify published articles that related to clinical trials that included ciclesonide.

STUDY SELECTION

The primary articles that reported systemic safety data for ciclesonide were reviewed.

RESULTS

Ciclesonide (320-1,280 microg/d) demonstrated no detectable, clinically relevant effect on HPA axis function as evaluated by basal cortisol excretion measurements and dynamic stimulation tests. Furthermore, ciclesonide had no effect on the normal diurnal rhythm of endogenous cortisol secretion while simultaneously improving pulmonary function and reducing bronchial hyperresponsiveness. These results suggest that ciclesonide has a low systemic activity that may be attributable to unique pharmacologic properties, including a high degree of serum protein binding, a low oral bioavailability, and rapid systemic elimination, that reduce the level of systemically available pharmacologically active drug.

CONCLUSIONS

Even at the higher doses used to treat more severe cases of asthma, ciclesonide was observed to have no effect on HPA axis function. These data, in conjunction with the observed clinical efficacy, suggest that ciclesonide may have an improved therapeutic margin compared with some other currently available inhaled corticosteroid treatments and, therefore, the potential to improve therapeutic outcomes.

Propellant-driven metered-dose inhalers for pulmonary drug delivery

The current market for pulmonary drug delivery is at a bottleneck. The therapeutic advantages of inhalation aerosols, and the potential for the lungs as a route for systemically acting drugs, vaccines and gene therapeutic agents, have resulted in a rapid growth of the industry. Alongside this, the environment of inhaler design and formulation has changed markedly in recent years. Environmental concerns over propellants, the commercial success of dry powder inhalers, and the apparent lack of advancement of propellant-driven metered-dose inhalers (pMDIs) has led to a less clear future for these devices. This review critically assesses these pressures and also potential opportunities for the pMDI. It is proposed that the future role of pMDIs will be determined by several important forces that can be classified under 'technology development' or 'market climate' categories. Technology development forces will be strengthened by the ability of the industry to have a systematic understanding of mechanisms of spray formation, perform subsequent and continued device and formulation advances, and a focus on all patient groups: particularly paediatric and geriatric populations. The ability to succeed in these areas will be largely determined by the willingness to invest in fundamental research of pMDI technologies.

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.

Hydrofluoroalkane formulations of inhaled corticosteroids for the treatment of asthma

Current international guidelines for the treatment of asthma advocate inhaled corticosteroids as first-line therapy for persistent symptoms. As chlorofluorocarbon (CFC)-based products are being phased out because of environmental concerns, new inhaler propellants, such as hydrofluoroalkane (HFA)-134a, have been developed. The reformulation of existing corticosteroid compounds into HFA propellants has resulted in two distinct classes of corticosteroid aerosols consisting of HFA suspensions and HFA solutions. The new HFA formulations of flunisolide and beclomethasone dipropionate exist as solutions, whereas HFA preparations of fluticasone propionate, triamcinolone acetonide, and mometasone furoate are formulated as suspensions. HFA suspensions retain the same particle size, deposition, and efficacy profiles as their CFC counterparts. HFA solutions, however, exist as extra-fine aerosols which have been shown to penetrate more effectively into the peripheral regions of the lung. Comparisons of HFA solutions with their CFC counterparts have demonstrated equivalent efficacy when given in smaller doses. The safety profiles of both HFA suspensions and solutions, given at equivalent doses, are comparable to CFC formulations. Increasing evidence suggests that inflammation of the small airways plays an important role in the pathogenesis of asthma. Currently, the clinical implications of long-term treatment of the peripheral lung using an extra-fine inhaled corticosteroid aerosol remain uncertain. Future studies, involving histopathologic and clinical endpoints, will be necessary to determine whether treatment with HFA solutions offers significant advantages over currently available therapies.

A meta-analysis of the dose-response relationship of inhaled corticosteroids in adolescents and adults with mild to moderate persistent asthma

BACKGROUND

Although inhaled corticosteroids (ICS) are commonly used in the treatment of persistent asthma, the relationship between dose and clinical response remains unclear.

OBJECTIVE

This study investigated whether ICS exhibit a dose-response relationship in the treatment of mild to moderate persistent asthma.

METHODS

This was a meta-analysis of published randomized clinical trials concerning the relationship between ICS dose and response in asthma. Relevant studies were identified through a search of PubMed and MEDLINE for articles on asthma and ICS published between January 1996 and January 2001. The search was limited to publications classified as clinical trials that included the text words asthma and corticosteroids, glucocorticoids, beclomethasone, budesonide, fluticasone, flunisolide, mometasone, or triamcinolone acetonide. Five clinical measures were considered: morning peak expiratory flow rate (AM PEFR), evening PEFR (PM PEFR), forced expiratory volume in 1 second (FEV(1)), beta-agonist use, and asthma symptom score (severity of symptoms on a given day, as evaluated by patients).

RESULTS

Forty-three studies were identified, of which 16 met the criteria for inclusion in the meta-analysis. These studies involved 4 agents: fluticasone propionate, triamcinolone acetonide, budesonide, and mometasone furoate. A statistically significant dose response in AM PEFR was observed with fluticasone propionate, triamcinolone acetonide, and budesonide (respective 95% CIs, 4.9 to 11.5, 4.7 to 18.0, and 5.8 to 24.9). A statistically significant dose response to fluticasone propionate and triamcinolone acetonide was also observed in PM PEFR (95% CIs, 2.0 to 8.7 and 2.4 to 13.7) and asthma symptom score (95% CI, -0.069 to -0.002 and -0.60 to -0.10). In terms of FEV(1), the dose response was statistically significant only with budesonide (95% CI, 0.025 to 0.17). Dose-response relationships were not disproportionately driven by the highest doses, and the greatest effects on response were seen at doses below or at the low end of the recommended range, suggesting that use of high doses of ICS may contribute only marginally to efficacy.

CONCLUSIONS

Dose-response relationships were not uniformly observed with all drugs or for all measures of response. Use of higher doses of ICS in patients with mild to moderate persistent asthma does not appear to increase the efficacy of these drugs.

Triamcinolone: new and old indications

Triamcinolone is a commonly used synthetic corticosteroid that has recently been tested in a large clinical trial for chronic obstructive pulmonary disease and shown to have some benefits. To our knowledge, there are no reviews of the pharmacotherapy of triamcinolone. This review has a brief overview of the pharmacology of triamcinolone, followed by a discussion of the clinical trials with triamcinolone. Triamcinolone is used in the treatment of respiratory inflammation, rheumatoid arthritis and a variety of other inflammatory conditions.

In vitro and in vivo techniques used in drug development for evaluation of dose delivery of inhaled corticosteroids

Oral inhaled corticosteroids are important in the treatment of asthma since their delivery is targeted directly to the lung, which is the site of action. Triamcinolone acetonide (TAA) is an effective and safe corticosteroid that is marketed as a metered-dose inhaler (MDI) with an integrated spacer (Azmacort) for the treatment of asthma. Due to the phasing out of chlorofluorocarbon (CFC) propellants, Azmacort has been reformulated with a non-CFC propellant. Due to the complexities of oral inhaled formulations and the topical nature of drug delivery to the lung for efficacy, the reformulation of oral inhaled MDIs requires careful consideration and support throughout their development, using a combination of in vitro and in vivo studies to ensure clinical comparability for both efficacy and safety. This paper describes a chronological series of studies designed to support the reformulation of Azmacort. These included in vitro studies to estimate respirable fraction, in vivo pulmonary deposition studies, in vivo pharmacokinetic-pharmacodynamic studies to estimate the systemic effects of each formulation, and final clinical studies in adult and pediatric patients to confirm the clinical comparability of the new formulation of Azmacort. The results of these studies, performed at various stages during the development of new formulations, were critical in guiding the reformulation efforts for Azmacort.

Long-term safety of a non-chlorofluorocarbon-containing triamcinolone acetonide inhalation aerosol in patients with asthma. Azmacort HFA Study Group

In response to environmental concerns regarding chlorofluorocarbon (CFC), two new triamcinolone acetonide (TAA) inhalation aerosol (Azmacort Inhalation Aerosol) formulations have been developed using a more environmentally favorable propellant, HFA-134a (1,1,1,2-tetrafluoroethane). This multicenter, open-label study evaluated the safety of switching asthma patients from TAA-CFC to one of two TAA-HFA formulations. After a 2- or 4-week baseline period during which patients received only CFC-containing TAA Inhaler, 552 patients were randomized to receive TAA-HFA 75 or 225 microg for 6 or 12 months. A total of 493 patients completed treatment. Seven patients discontinued because of adverse events and two because of ineffective asthma control. The incidence of adverse events was similar in the two treatment groups, and most events were mild to moderate in severity and were not considered related to study medication. No clinically relevant suppression of the hypophyseal-pituitary-adrenal (HPA) axis was observed. Pulmonary function tests were not adversely affected by use of either study medication, and improvements were noted in forced expiratory volume in 1 sec (FEV1) and forced expiratory flow between 25% and 75% of forced vital capacity (FEF25%-75%) throughout the course of treatment. This study confirms that TAA-HFA provides effective, long-term asthma control and can safely be substituted for the currently marketed CFC-containing TAA product.