Drug safety evaluation of roflumilast for the treatment of COPD: a meta-analysis

Treatment of recurrent aphthous stomatitis with oral roflumilast, a multicenter observational study

INTRODUCTION

Severe recurrent aphthous stomatitis (RAS) represents a therapeutic challenge because of its impact on the patient's quality of life. Additionally, no approved systemic therapies are available. Roflumilast, a phosphodiesterase-4 inhibitor, has shown promise in other inflammatory dermatological conditions. This study aimed to assess the characteristics, effectiveness, and safety of roflumilast in treating RAS in routine clinical practice.

METHODS

This is a single cohort ambispective observational study conducted in five Spanish centers. Twenty-two patients with RAS treated with roflumilast participated. Data collection included demographic, clinical, and outcome variables. Statistical analysis compared the outcomes of 12 weeks of roflumilast treatment with a similar prior period without treatment.

RESULTS

During treatment with roflumilast, a significant reduction in flare-ups (88%) and oral ulcers (94%) was observed compared to the untreated period. A reduction in pain (66%) and ulcer duration (63%) was observed. Adverse effects (AEs) occurred in 13 patients, predominantly headache and gastrointestinal disturbances. Most of these were self-limiting or manageable with dose adjustment. Treatment was withdrawn in three cases, mainly because of AEs.

CONCLUSIONS

This study suggests that roflumilast may effectively treat RAS by reducing the number of flare-ups and ulcers, their duration, and the symptomatology produced by the ulcers. In addition, roflumilast has a good safety profile, is well tolerated at low doses, and does not require close monitoring. These characteristics and its favorable economic profile make roflumilast a promising therapeutic option in this pathology.

The Dosing Strategy to Improve Adherence to Roflumilast in Treatment for Chronic Obstructive Lung Disease: A Systemic Review and Meta-Analysis

Background

The clinical efficacy of roflumilast, an oral phosphodiesterase-4 inhibitor, has been demonstrated in patients with severe chronic obstructive pulmonary disease (COPD). However, roflumilast has shown frequent adverse drug reactions (ADRs). This study was performed to investigate the dosing strategy that will improve adherence to roflumilast in COPD.

Methods

We conducted a systematic review and meta-analysis using PubMed, Embase, and Cochrane Central Register. The dosing strategy for roflumilast was classified into a dose-escalation group and a low-dose group. We investigated clinical outcomes according to dosing strategy.

Results

Five clinical trials involving 2424 patients were included. Both the dose-escalation and the low-dose groups showed a decrease in discontinuation rate compared to the standard dosing group for roflumilast (risk ratio [RR], 0.81; 95% confidence interval [CI], 0.67-0.97; P = 0.02 and RR, 0.62; 95% CI, 0.48-0.80; P < 0.01, respectively). In the two strategies, the pooled proportions of discontinuation were 27.9% and 11.7%, respectively. Although the pooled proportion of any ADR was not statistically decreased in the two strategies, diarrhea was significantly reduced in the low-dose group compared to the standard group (RR, 0.58; 95% CI, 0.42-0.82; P < 0.01). The pooled incidence of acute exacerbations was similar between the low-dose and the standard groups (22.9% and 20.1%, respectively; P = 0.27).

Conclusion

Our findings show that the two alternative dosing strategies might have the benefit of improving adherence to roflumilast in COPD. Further large-scale trials are required to support our findings.

Topical and Oral Roflumilast in Dermatology: A Narrative Review

Oral roflumilast is a phosphodiesterase-4 inhibitor approved for the prevention of exacerbations of chronic obstructive pulmonary disease and chronic bronchitis. In dermatology, topical roflumilast is authorized by the US Food and Drug Administration for the treatment of plaque psoriasis and mild to moderate seborrheic dermatitis. Several studies have described the off-label use of roflumilast in dermatology, including a randomized controlled trial showing its usefulness in the treatment of psoriasis; case reports and small series have also reported successful outcomes in hidradenitis suppurativa, recurrent oral aphthosis, nummular eczema, lichen planus, and Behçet disease. Roflumilast has a favorable safety profile, similar to that of apremilast, and it is considerably cheaper than new generation drugs and even some conventional immunosuppressants. We review the pharmacokinetics and pharmacodynamics of topical and oral roflumilast and discuss potential adverse effects and both approved and off-label uses in dermatology. Roflumilast is a promising agent to consider.

[Translated aticle] Topical and Oral Roflumilast in Dermatology: A Narrative Review

Oral roflumilast is a phosphodiesterase-4 inhibitor approved for the prevention of exacerbations of chronic obstructive pulmonary disease and chronic bronchitis. In dermatology, topical roflumilast is authorized by the US Food and Drug Administration for the treatment of plaque psoriasis and mild to moderate seborrheic dermatitis. Several studies have described the off-label use of roflumilast in dermatology, including a randomized controlled trial showing its usefulness in the treatment of psoriasis; case reports and small series have also reported successful outcomes in hidradenitis suppurativa, recurrent oral aphthosis, nummular eczema, lichen planus, and Behçet disease. Roflumilast has a favorable safety profile, similar to that of apremilast, and it is considerably cheaper than new generation drugs and even some conventional immunosuppressants. We review the pharmacokinetics and pharmacodynamics of topical and oral roflumilast and discuss potential adverse effects and both approved and off-label uses in dermatology. Roflumilast is a promising agent to consider.

Serum IL-8 as a Determinant of Response to Phosphodiesterase-4 Inhibition in Chronic Obstructive Pulmonary Disease

Rationale: Phosphodiesterase-4 (PDE4) inhibitors have demonstrated increased efficacy in patients with chronic obstructive pulmonary disease who had chronic bronchitis or higher blood eosinophil counts. Further characterization of patients who are most likely to benefit is warranted. Objective: To identify determinants of response to the PDE4 inhibitor tanimilast. Methods: A PDE4 gene expression signature in blood was developed by unsupervised clustering of the ECLIPSE study dataset (ClinicalTrials.gov ID: NCT00292552; Gene Expression Omnibus Series ID: GSE76705). The signature was further evaluated using blood and sputum transcriptome data from the BIOMARKER study (NCT03004417; GSE133513), enabling validation of the association between PDE4 signaling and target biomarkers. Predictivity of the associated biomarkers against clinical response was then tested in the phase-2b PIONEER tanimilast study (NCT02986321). Measurements and Main Results: The PDE4 gene expression signature developed in the ECLIPSE dataset classified subgroups of patients associated with different PDE4 signaling in the BIOMARKER cohort with an area under the receiver operator curve of 98%. In the BIOMARKER study, serum IL-8 was the only variable that was consistently associated with PDE4 signaling, with lower levels associated with higher PDE4 activity. In the PIONEER study, the exacerbation rate reduction mediated by tanimilast treatment increased up to twofold in patients with lower IL-8 levels; 36% versus 18%, reaching statistical significance at ⩽20 pg/ml (P = 0.035). The combination with blood eosinophils ⩾150 μl-1 or chronic bronchitis provided further additive exacerbation rate reduction: 45% (P = 0.013) and 47% (P = 0.027), respectively. Conclusions: Using selected heterogeneous datasets, this analysis identifies IL-8 as an independent predictor of PDE4 inhibition, as tanimilast had a greater effect on exacerbation prevention in patients with chronic obstructive pulmonary disease who had lower baseline serum IL-8 levels. Testing of this biomarker in other datasets is warranted. Clinical trial registered with www.clinicaltrials.gov (NCT00292552 [Gene Expression Omnibus Series ID: GSE76705], NCT03004417 [GSE133513], and NCT02986321).

Novel Anti-Inflammatory Approaches to COPD

Airway inflammation, driven by different types of inflammatory cells and mediators, plays a fundamental role in COPD and its progression. Neutrophils, eosinophils, macrophages, and CD4+ and CD8+ T lymphocytes are key players in this process, although the extent of their participation varies according to the patient's endotype. Anti-inflammatory medications may modify the natural history and progression of COPD. However, since airway inflammation in COPD is relatively resistant to corticosteroid therapy, innovative pharmacological anti-inflammatory approaches are required. The heterogeneity of inflammatory cells and mediators in annethe different COPD endo-phenotypes requires the development of specific pharmacologic agents. Indeed, over the past two decades, several mechanisms that influence the influx and/or activity of inflammatory cells in the airways and lung parenchyma have been identified. Several of these molecules have been tested in vitro models and in vivo in laboratory animals, but only a few have been studied in humans. Although early studies have not been encouraging, useful information emerged suggesting that some of these agents may need to be further tested in specific subgroups of patients, hopefully leading to a more personalized approach to treating COPD.

Structure-based optimization of Toddacoumalone as highly potent and selective PDE4 inhibitors with anti-inflammatory effects

Phosphodiesterase-4 (PDE4) is an important drug target for inflammatory diseases. Previously, we identified a series of novel PDE4 inhibitors derived from the natural Toddacoumalone, among which the hit compound 2 with a naphthyridine scaffold showed moderate potency with the IC₅₀ value of 400 nM. Based on the co-crystal structure of PDE4D-2, further structural optimizations and structure-activity relationship studies led to a highly potent PDE4 inhibitor 23a with the IC₅₀ value of 0.25 nM and excellent selectivity profiles over other PDEs (>4000-fold). The co-crystal structure of PDE4D-23a elucidated that 23a has strong interactions with the M and Q pocket of PDE4D. Importantly, compound 23a significantly inhibits the release of inflammatory cytokines TNF-α and IL-6 in lipopolysaccharide-stimulated RAW264.7 cells. Thus, compound 23a with a naphthyridine scaffold is a promising PDE4 inhibitor for the treatment of inflammatory diseases.

Effectiveness of Roflumilast in Treating Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Background

Chronic obstructive pulmonary disease (COPD) is a chronic airflow obstructive condition. The mainstay of treatment is to avoid exacerbation and manage the symptoms. Roflumilast is being used as a part of treatment to reduce the inflammatory process in this disease.

Method

This systematic review and meta-analysis were conducted following the provided guidelines. PubMed, Cochrane Library, and Cinahl were considered for searching the desired studies selected until 19 June 2021. The eligibility criteria for inclusion and exclusion were set before selecting studies.

Result

Five hundred eighty (580) studies were identified at the beginning. Removal of duplicates was done using Endnote software. The eligibility criteria, including the randomized controlled trial study design and others, were applied for screening the title and abstracts. Six studies were selected for the qualitative analysis. After assessing the data from these studies, it was found that roflumilast is an effective drug to treat COPD. Roflumilast plays an essential role in improving quality of life, inflammatory process, and clinical improvement. The drug's mild to moderate adverse effects were observed, but no significant severe adverse events were reported, and the drug was well tolerated.

Conclusion

Roflumilast is a valuable drug that can be used for its beneficial effects on COPD exacerbation. The benefits of the drug outweigh its adverse effects.

Discovery and Structural Optimization of Toddacoumalone Derivatives as Novel PDE4 Inhibitors for the Topical Treatment of Psoriasis

Psoriasis is a common immune-mediated skin disorder manifesting in abnormal skin plaques, and phosphodiesterase 4 (PDE4) is an effective target for the treatment of inflammatory diseases such as psoriasis. Toddacoumalone is a natural PDE4 inhibitor with moderate potency and imperfect drug-like properties. To discover novel and potent PDE4 inhibitors with considerable druggability, a series of toddacoumalone derivatives were designed and synthesized, leading to the compound (2R,4S)-6-ethyl-2-(2-hydroxyethyl)-2,8-dimethyl-4-(2-methylprop-1-en-1-yl)-2,3,4,6-tetrahydro-5H-pyrano[3,2-c][1,8]naphthyridin-5-one (33a) with high inhibitory potency (IC₅₀ = 3.1 nM), satisfactory selectivity, favorable skin permeability, and a well-characterized binding mechanism. Encouragingly, topical administration of 33a exhibited remarkable therapeutic effects in an imiquimod-induced psoriasis mouse model.

The PDE4 Inhibitor Tanimilast Blunts Proinflammatory Dendritic Cell Activation by SARS-CoV-2 ssRNAs

Phosphodiesterase 4 (PDE4) inhibitors are immunomodulatory drugs approved to treat diseases associated with chronic inflammatory conditions, such as COPD, psoriasis and atopic dermatitis. Tanimilast (international non-proprietary name of CHF6001) is a novel, potent and selective inhaled PDE4 inhibitor in advanced clinical development for the treatment of COPD. To begin testing its potential in limiting hyperinflammation and immune dysregulation associated to SARS-CoV-2 infection, we took advantage of an in vitro model of dendritic cell (DC) activation by SARS-CoV-2 genomic ssRNA (SCV2-RNA). In this context, Tanimilast decreased the release of pro-inflammatory cytokines (TNF-α and IL-6), chemokines (CCL3, CXCL9, and CXCL10) and of Th1-polarizing cytokines (IL-12, type I IFNs). In contrast to β-methasone, a reference steroid anti-inflammatory drug, Tanimilast did not impair the acquisition of the maturation markers CD83, CD86 and MHC-II, nor that of the lymph node homing receptor CCR7. Consistent with this, Tanimilast did not reduce the capability of SCV2-RNA-stimulated DCs to activate CD4⁺ T cells but skewed their polarization towards a Th2 phenotype. Both Tanimilast and β-methasone blocked the increase of MHC-I molecules in SCV2-RNA-activated DCs and restrained the proliferation and activation of cytotoxic CD8⁺ T cells. Our results indicate that Tanimilast can modulate the SCV2-RNA-induced pro-inflammatory and Th1-polarizing potential of DCs, crucial regulators of both the inflammatory and immune response. Given also the remarkable safety demonstrated by Tanimilast, up to now, in clinical studies, we propose this inhaled PDE4 inhibitor as a promising immunomodulatory drug in the scenario of COVID-19.

Tanimilast, A Novel Inhaled Pde4 Inhibitor for the Treatment of Asthma and Chronic Obstructive Pulmonary Disease

Chronic respiratory diseases are the third leading cause of death, behind cardiovascular diseases and cancer, affecting approximately 550 million of people all over the world. Most of the chronic respiratory diseases are attributable to asthma and chronic obstructive pulmonary disease (COPD) with this latter being the major cause of deaths. Despite differences in etiology and symptoms, a common feature of asthma and COPD is an underlying degree of airways inflammation. The nature and severity of this inflammation might differ between and within different respiratory conditions and pharmacological anti-inflammatory treatments are unlikely to be effective in all patients. A precision medicine approach is needed to selectively target patients to increase the chance of therapeutic success. Inhibitors of the phosphodiesterase 4 (PDE4) enzyme like the oral PDE4 inhibitor roflumilast have shown a potential to reduce inflammatory-mediated processes and the frequency of exacerbations in certain groups of COPD patients with a chronic bronchitis phenotype. However, roflumilast use is dampened by class related side effects as nausea, diarrhea, weight loss and abdominal pain, resulting in both substantial treatment discontinuation in clinical practice and withdrawal from clinical trials. This has prompted the search for PDE4 inhibitors to be given by inhalation to reduce the systemic exposure (and thus optimize the systemic safety) and maximize the therapeutic effect in the lung. Tanimilast (international non-proprietary name of CHF6001) is a novel highly potent and selective inhaled PDE4 inhibitor with proven anti-inflammatory properties in various inflammatory cells, including leukocytes derived from asthma and COPD patients, as well as in experimental rodent models of pulmonary inflammation. Inhaled tanimilast has reached phase III clinical development by showing promising pharmacodynamic results associated with a good tolerability and safety profile, with no evidence of PDE4 inhibitors class-related side effects. In this review we will discuss the main outcomes of preclinical and clinical studies conducted during tanimilast development, with particular emphasis on the characterization of the pharmacodynamic profile that led to the identification of target populations with increased therapeutic potential in inflammatory respiratory diseases.

The challenge of addressing obesity in people with poorly controlled asthma

Objective

There is a high prevalence of obesity in people with asthma, and obesity is associated with poorly controlled asthma. Significant weight loss might improve asthma control: the purpose of this study was to investigate patient characteristics and factors that might affect implementation of a weight loss and/or roflumilast intervention, to target both obesity and asthma.

Methods

A cross-sectional study of people with obesity and poorly controlled asthma performed at 13 sites across the United States.

Results

One hundred and two people participated in this study. Median BMI was 37 (IQR 35-42). The majority, 55%, were African American and 76% were female. Fifty two percent had very poorly controlled asthma. Most participants were quite sedentary (70% reported being inactive or participating only in light-intensity activities according to the Stanford Brief Activity Survey). Participants reported significant impairments related to physical function on the Impact of Weight on Quality of Life-Lite questionnaire (median score 67 [IQR 41-84]). Thirty-five percent of participants reported mild, and 2 % moderate, depressive symptoms as assessed by the Patient Health Questionnaire-9.

Conclusions

Poorly controlled asthma and obesity often affect minority populations and are associated with significant impairments in health related to physical function and low levels of physical activity that might complicate efforts to lose weight. Interventions targeted at poorly controlled asthma associated with obesity in the United States need to address factors complicating health in underserved communities, such as increasing opportunities for physical activity, while also managing activity limitations related to the combination of asthma and obesity.

Tiotropium Bromide Attenuates Mucus Hypersecretion in Patients with Stable Chronic Obstructive Pulmonary Disease

BACKGROUND

Patients with stable chronic obstructive pulmonary disease (COPD) have been observed to benefit from tiotropium bromide. However, there are few studies of tiotropium bromide on sputum and sputum viscosity. To evaluate the effect of tiotropium bromide on mucus hypersecretion, a randomized, double-blind controlled trial was performed.

METHODS

120 cases of patients with pulmonary function grade II were divided into two groups, which include the treatment group given tiotropium bromide powder inhalation (18 μg, inhalation, QD) and the control group given formoterol fumarate powder inhalation (12 μg, inhalation, BID) plus ambroxol hydrochloride tablets (60 mg, oral, TID). After 3 months of treatment, the pulmonary function and α 1-acid glycoprotein (α 1-AGP) in sputum were detected, and the changes of glycoprotein and Ca2+ content were evaluated by Miller classification.

RESULTS

Three patients (2 cases in the treatment group and 1 case in the control group) were dropped due to loss of follow-up, and 117 cases of patients were enrolled in this study. After 3 months of treatment, the sputum character score, α1-acid glycoprotein, Ca2+ content, and lung function of the two groups were significantly improved; group comparison analyses revealed that there was no significant difference in the content of α 1-AGP, Ca2+ in sputum, and lung function between the two groups (P > 0.05), but the improvement of sputum properties was significant (P < 0.05), and the treatment group was better than the control group (t = -2.77; P = 0.007).

CONCLUSIONS

Inhaled tiotropium bromide can effectively inhibit the mucus hypersecretion in stable COPD patients, improve the sputum properties and lung function of patients, and improve the quality of life of patients.

Which LABA/LAMA should be chosen in COPD patients in real life?

BACKGROUND

Given COPD heterogeneity, we do not know if some LABA/LAMAs are more suitable for some COPD phenotypes. This real-life database study aimed to evaluate retrospectively the 4 LABA/LAMA effectiveness and highlight possible specificities that could better guide us in choosing the right LABA/LAMA to be used.

METHODS

We searched for subjects (1,779) adherent to umeclidinium/vilanterol (UM/VI), indacaterol/glycopyrronium (IND/GLY), aclidinium/formoterol (ACLI/FOR) and tiotropium/olodaterol (TIO/OLO) treatments in our prescribing/dispensing database. Prescriptions for systemic corticosteroids (SC), antibiotics and salbutamol during one year of LABA/LAMA treatment were analyzed.

RESULTS

A better adherence was found in individuals taking IND/GLY (10.42 ± 1.86 packages/year) compared with UM/VI (10.09 ± 1.9; p = 0.008), ACLI/FOR (9.8 ± 1.8; p = 0.001) and TIO/OLO (10.1 ± 2.1; p = 0.047). The number of patients that were prescribed at least one package of SC/year and their package numbers/year were similar in males/females, across age groups and in "non-frequent exacerbators" with the 4 LABA/LAMAs. More SC were taken by frequent exacerbators, whereas fewer SC/antibiotic packages were prescribed to subjects aged >80 years with all treatments. In patients treated with ACLI/FOR or TIO/OLO, lower risks to having antibiotic prescriptions were observed when UM/VI (0.698[0.516-0.945] and 0.696[0.491-0.985; p = 0.020 and p = 0.041) and IND/GLY (0.597[0.445-0.802] and 0.595[0.423-0.836]; p = 0.001 and p = 0.003) were considered as landmarks. Lower risks for salbutamol prescriptions were detected with UM/VI (0.678[0.480-0.958]; p = 0.027) and TIO/OLO (0.585[0.365-0.937]; p = 0.026) when ACLI/FOR was used as a reference.

CONCLUSION

According to our retrospective database study, each LABA/LAMA could have a specific efficacy profile in COPD that might be considered for personalized therapy. However, head-to-head targeted trials aimed to assess the impact of different LABA/LAMAs on COPD are needed to confirm/disprove such results.

Medium-dose ICS-containing FDCs reduce all-cause mortality in COPD patients: an in-depth analysis of dual and triple therapies

OBJECTIVES

The recent publication of additional data retrieval for patients missing week 52 vital status in the original analyses of the ETHOS study provides the urgent need of updating previous network meta-analyses (NMA) to produce stronger evidence on mortality in patients receiving dual and triple FDCs according with the level of ICS dose.

METHODS

A NMA was performed to compare the effect of ICS/LABA/LAMA, ICS/LABA, and LABA/LAMA FDCs administered via the same inhaler device in COPD patients. The number need to treat (NNT) was also calculated.

RESULTS

When considering on-treatment all-cause of death (analyzed patients: 18,864), MD ICS/LABA/LAMA and MD ICS/LABA FDCs significantly reduced the risk of mortality vs. LABA/LAMA FDC (RR 0.59 95%CrI 0.35-0.97 and 0.61 95%CrI 0.38-0.99 respectively, P < 0.05); NNT ranged between 123 and 129. MD ICS/LABA/LAMA FDC also significantly reduced the risk of adjudicated cardiovascular mortality vs. LABA/LAMA FDC (RR 0.44 95%CI 0.19-0.97, P < 0.05). Low-dose (LD) ICS/LABA FDC did not significantly modulate mortality.

CONCLUSION

MD ICS/LABA/LAMA and MD ICS/LABA FDCs were effective in reducing on-treatment all-cause of death, with MD ICS/LABA/LAMA FDC being effective also against adjudicated cardiovascular mortality. The protection against mortality was related with the level of ICS dose in the FDCs.

Classes of drugs that target the cellular components of inflammation under clinical development for COPD

INTRODUCTION

The persistent inflammation that characterizes COPD and affects its natural course also impacting on symptoms has prompted research to find molecules that can regulate the inflammatory process but still available anti-inflammatory therapies provide little or no benefit in COPD patients. Consequently, numerous anti-inflammatory molecules that are effective in animal models of COPD have been or are being evaluated in humans.

AREAS COVERED

In this article we describe several classes of drugs that target the cellular components of inflammation under clinical development for COPD.

EXPERT OPINION

Although the results of many clinical trials with new molecules have often been disappointing, several studies are underway to investigate whether some of these molecules may be effective in treating specific subgroups of COPD patients. Indeed, the current perspective is to apply a more personalized treatment to the patient. This means being able to better define the patient's inflammatory state and treat it in a targeted manner. Unfortunately, the difficulty in translating encouraging experimental data into human clinical trials, the redundancy in the effects induced by signal-transmitting substances and the nonspecific effects of many classes that are undergoing clinical trials, do not yet allow specific inflammatory cell types to be targeted.

Neuroprotective effects of roflumilast against quinolinic acid-induced rat model of Huntington's disease through inhibition of NF-κB mediated neuroinflammatory markers and activation of cAMP/CREB/BDNF signaling pathway

Huntington's disease (HD) is a progressive neurodegenerative and hyperkinetic movement disorder. Decreased activity of cAMP-responsive element-binding protein (CREB) is thought to contribute to the death of striatal medium spiny neurons in HD. The present study has been designed to explore the possible role of roflumilast against qunilonic acid (QA) induced neurotoxicity in rats intending to investigate whether it inhibits the neuroinflammatory response through activation of the cAMP/CREB/BDNF signaling pathway. QA was microinjected (200 nmol/2 µl, bilaterally) through the intrastriatal route in the stereotaxic apparatus. Roflumilast (0.5, 1, and 2 mg/kg, orally) once-daily treatment for 21 days significantly improved locomotor activity in actophotometer, motor coordination in rotarod, and impaired gait performance in narrow beam walk test. Moreover, roflumilast treatment significantly attenuated oxidative and nitrosative stress (p < 0.05) through attenuating lipid peroxidation nitrite concentration and enhancing reduced glutathione, superoxide dismutase, and catalase levels. Furthermore, roflumilast also significantly decreased elevated pro-inflammatory cytokines like TNF-α (p < 0.01), IL-6 (p < 0.01), IFN-γ (p < 0.05), NF-κB (p < 0.05) and significantly increased BDNF(p < 0.05) in the striatum and cortex of rat brain. The results further demonstrated that roflumilast effectively increased the gene expression of cAMP(p < 0.05), CREB(p < 0.05) and decreased the gene expression of PDE4 (p < 0.05) in qRT-PCR. These results conclusively depicted that roflumilast could be a potential candidate as an effective therapeutic agent in the management of HD through the cAMP/CREB/BDNF signaling pathway.

Roflumilast Ameliorates Isoflurane-Induced Inflammation in Astrocytes via the CREB/BDNF Signaling Pathway

Background and purpose: Astrocyte-mediated neuroinflammation plays an important role in anesthetic isoflurane-induced cognitive impairment. Roflumilast, a selective inhibitor of phosphodiesterase-4 (PDE-4) used for the treatment of chronic obstructive pulmonary disease (COPD), has displayed a wide range of anti-inflammatory capacity in different types of cells and tissues. In the current study, we aimed to investigate whether roflumilast possesses a protective effect against isoflurane-induced insults in mouse primary astrocytes. Methods: Primary astrocytes were isolated from the cerebral cortices of immature rats. The production of NO was determined using DAF-FM DA staining assay. QRT-PCR and western blot were used to evaluate the expression levels of iNOS, COX-2, and BDNF in the astrocytes treated with different therapies. The gene expressions and concentrations of IL-6 and MCP-1 released by the astrocytes were detected using qRT-PCR and ELISA, respectively. The expression levels of phosphorylated CREB and PGE₂ were determined using western blot and ELISA, respectively. H89 was introduced to evaluate the function of CREB. Recombinant human BDNF and ANA-12 were used to verify the role of BDNF. Results: The upregulated iNOS, excessive production of NO, IL-6, and MCP-1, and activated COX-2/PGE₂ signaling pathways in the astrocytes induced by isoflurane were significantly reversed by the introduction of roflumilast, in a dose-dependent manner. Subsequently, we found that BDNF could be upregulated by roflumilast, which was verified to be related to the activation of CREB and blocked by H89 (a CREB inhibitor). In addition, the COX-2/PGE₂ signaling pathway activated by isoflurane can be inactivated by recombinant human BDNF. Finally, the regulatory effect of roflumilast against the isoflurane-activated COX-2/PGE₂ signaling pathway was significantly blocked by ANA-12, which is a BDNF inhibitor. Conclusion: Roflumilast might ameliorate isoflurane-induced inflammation in astrocytes via the CREB/BDNF signaling pathway.

New putative insights into neprilysin (NEP)-dependent pharmacotherapeutic role of roflumilast in treating COVID-19

Nowadays, coronavirus disease 2019 (COVID-19) represents the most serious inflammatory respiratory disease worldwide. Despite many proposed therapies, no effective medication has yet been approved. Neutrophils appear to be the key mediator for COVID-19-associated inflammatory immunopathologic, thromboembolic and fibrotic complications. Thus, for any therapeutic agent to be effective, it should greatly block the neutrophilic component of COVID-19. One of the effective therapeutic approaches investigated to reduce neutrophil-associated inflammatory lung diseases with few adverse effects was roflumilast. Being a highly selective phosphodiesterase-4 inhibitors (PDE4i), roflumilast acts by enhancing the level of cyclic adenosine monophosphate (cAMP), that probably potentiates its anti-inflammatory action via increasing neprilysin (NEP) activity. Because activating NEP was previously reported to mitigate several airway inflammatory ailments; this review thoroughly discusses the proposed NEP-based therapeutic properties of roflumilast, which may be of great importance in curing COVID-19. However, further clinical studies are required to confirm this strategy and to evaluate its in vivo preventive and therapeutic efficacy against COVID-19.

Improving the evaluation of COPD exacerbation treatment effects by accounting for early treatment discontinuations: a post-hoc analysis of randomized clinical trials

Background

Chronic obstructive pulmonary disease (COPD) clinical trials aimed at evaluating treatment effects on exacerbations often suffer from early discontinuations of randomized treatment. Treatment discontinuations imply a loss of information and should ideally be considered in the statistical analysis of trial results, particularly if the discontinuations are related to the disease or treatment itself. Here, we explore this issue by investigating (1) whether there exists an association between the risks of exacerbation and treatment discontinuation in COPD clinical trials and (2) whether disregarding this association can cause bias in exacerbation treatment effect estimates. We focus on the hypothetical estimand, i.e. the treatment effect that would have been observed had all subjects completed the trial as planned.

Methods

The association between exacerbation and discontinuation risks was analysed by applying a joint frailty (random effect) model – allowing for the simultaneous analysis of multiple types of correlated events – to data from five Phase III-IV COPD clinical trials. Specifically, the impact of the association on exacerbation treatment effect estimates was assessed by comparing the treatment hazard ratios of the joint frailty model to the rate/hazard ratios of two related statistical models (the negative binomial and shared frailty models), which both assume discontinuations to be unrelated to the trial outcome. The models were also compared using simulated data.

Results

A statistically significant (p < 0.0001), positive association between exacerbation and discontinuation risks was found in all trials. Importantly, simulations confirmed that – with such an association – models disregarding the association risk producing biased results (> 5 percentage point difference in hazard/rate ratio). For some treatment comparisons in the clinical trials, the difference in treatment effect estimates between the joint frailty and the other models was as high as 10–15 percentage points. The difference was affected by the strength of the exacerbation-discontinuation association, the population heterogeneity in exacerbation risk, and the difference in discontinuation rates between treatment arms.

Conclusions

We have identified an association between the risks of exacerbation and treatment discontinuation in five COPD clinical trials. We recommend using the joint frailty model to account for this association when estimating exacerbation treatment effects, particularly when targeting the hypothetical estimand.

Suppression of neutrophilic inflammation can be modulated by the droplet size of anti-inflammatory nanoemulsions

Aim: We aimed to develop nanoemulsions containing phosphodiesterase 4 inhibitor rolipram with different droplet sizes, to evaluate the anti-inflammatory effect against activated neutrophils and a related lung injury. Materials & methods: We prepared nanoemulsions of three different sizes, 68, 133 and 188 nm. Results: The nanoemulsion inhibited the superoxide anion but not elastase release in primary human neutrophils. The large-sized nanoemulsions were mostly internalized by neutrophils, resulting in the reduction of intracellular Ca²⁺ half-life. The peripheral organ distribution of near-infrared dye-tagged nanoemulsions increased, following the decrease in droplet diameter. Rolipram entrapment into intravenous nanoemulsions ameliorated pulmonary inflammation. The smallest droplet size showed improvement, compared with the largest size. Conclusion: We established a foundation for the development of nanoemulsions against inflamed lung disease.

Ensifentrine (RPL554): an investigational PDE3/4 inhibitor for the treatment of COPD

Introduction: A compound that simultaneously inhibits PDE3 and PDE4 should increase airway caliber by relaxing the smooth muscle and, simultaneously, suppress airway inflammatory responses. Ensifentrine (RPL554) is considered a PDE3/4 inhibitor, although its affinity for PDE3 is 3,440 times higher than that for PDE4, that is under clinical development for the treatment of asthma and COPD and, potentially, cystic fibrosis. Areas covered: We analyze the development of this molecule from its basic pharmacology to the present clinical Phase II studies. Expert opinion: Ensifentrine is an interesting drug but there is a lack of solid studies that still does not allow us to correctly allocate this molecule in the current COPD and even asthma therapeutic armamentarium. Furthermore, apparently ensifentrine has not yet entered Phase III clinical development and, in any case, there is no reliable evidence of its ability to elicit an anti-inflammatory activity in patients with COPD or asthma. Therefore, the real anti-inflammatory profile of ensifentrine must be clarified with new studies of basic pharmacology and adequate clinical studies specifically designed. However, at present the most intriguing perspective is linked to its possible use in the treatment of cystic fibrosis, also considering the lack of valid therapeutic options for this disease.

Pharmacological treatment and current controversies in COPD

Bronchodilators, corticosteroids, and antibiotics are still key elements for treating chronic obstructive pulmonary disease in the 2019 Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommendations and this is due in part to our current inability to discover new drugs capable of decisively influencing the course of the disease. However, in recent years, information has been produced that, if used correctly, can allow us to improve the use of the available therapies.

Efficacy and safety profile of roflumilast in a real-world experience

Background

Roflumilast is the only phosphodiesterase enzyme 4 inhibitor approved in the treatment of chronic obstructive pulmonary disease (COPD) patients with chronic cough and sputum and a history of exacerbations. Real-world studies about the use of roflumilast are limited. Our aim was to assess the efficacy, safety and tolerability of roflumilast in the treatment of stable COPD, in a real-world setting.

Methods

From August 2014 to August 2017, medical records of all COPD patients who were prescribed roflumilast therapy in Akdeniz University Hospital were analyzed retrospectively. COPD patients were studied in terms of efficacy, safety, and drug discontinuation rate. Efficacy was evaluated as the effect of roflumilast on exacerbation and hospitalization rates of COPD compared to the pre-treatment period.

Results

Eighty-three COPD patients treated with roflumilast were included (mean age 66.2±9.3 years, 88.0% male). All the patients were chronic bronchitis and frequent exacerbator clinical phenotype and were classified in the Global Initiative for Chronic Obstructive Lung Disease categories C (n=17; 20.5%) and D (n=66; 79.5%). Mean duration of roflumilast use was 18.9±10.4 months. There was a significant decrease in both COPD exacerbations (2.7 vs. 1.16; P<0.001) and hospitalizations (0.77 vs. 0.32; P<0.001) in roflumilast users compared to the pre-treatment period. Of the patients, 22 (26.5%) experienced adverse events (AE) during their treatment period. The most frequently reported AEs were weight loss (10.8%), loss of appetite (10.8%) and nausea (8.4%). Serious or life-threatening AEs were not detected. Sixteen (19.3%) patients discontinued roflumilast because of AEs.

Conclusions

Roflumilast reduced exacerbations and hospitalizations in our real-world population with severe COPD. AEs are common and frequently leading to discontinuation of roflumilast therapy.

Early effects of roflumilast on insulin sensitivity in adults with prediabetes and overweight/obesity involve age-associated fat mass loss - results of an exploratory study

PURPOSE

Roflumilast (Daliresp, Daxas) is a FDA-approved phosphodiesterase 4 (PDE4) inhibitor for the treatment of moderate-to-severe chronic obstructive pulmonary disease. In mice and in limited human studies, this oral medication can cause weight loss and improve insulin sensitivity. We set out to determine the mechanism of its effect on insulin sensitivity.

PATIENTS AND METHODS

Eight adults with overweight/obesity and prediabetes received roflumilast for 6 weeks. Before and after roflumilast, subjects underwent tests of insulin sensitivity, mixed meal test, body composition, markers of inflammation, and mitochondria function. Dietary intake and physical activity were also assessed. Our primary outcome was the change in peripheral insulin sensitivity, as assessed by the hyper-insulinemic euglycemic clamp.

RESULTS

This study was underpowered for the primary outcome. Pre- and post-roflumilast mean peripheral insulin sensitivity were 48.7 and 70.0 mg/g fat free mass/minute, respectively, (P-value=0.18), respectively. Among the mixed meal variables, roflumilast altered glucagon-like peptide 1 (GLP-1) hormone the most, although the average effect was not statistically significant (P=0.18). Roflumilast induced a trend toward significance in 1) decreased energy intake (from 11,095 KJ to 8,4555 KJ, P=0.07), 2) decreased fat mass (from 34.53 to 32.97 kg, P=0.06), 3) decreased total and LDL cholesterol (P=0.06 for both variables), and 4) increased plasma free fatty acids (from 0.40 to 0.50 mEq/L, P=0.09) The interval changes in adiposity and free fatty acid were significantly associated with the subject's age (P-value range= <0.001 to 0.02 for the correlations). Inflammatory and adhesion markers, though unchanged, significantly correlated with one another and with incretin hormones only after roflumilast.

CONCLUSION

We demonstrate, for the first time in humans, increasing percentage of fat mass loss from roflumilast with increasing age in adults with prediabetes and overweight/obesity. We also demonstrate novel associations among roflumilast-induced changes in incretin hormones, inflammatory markers, peripheral insulin sensitivity, and adiposity. We conclude that roflumilast's early effects on insulin sensitivity is indirect and likely mediated through roflumilast's prioritization of lipid over glucose handling.

CLINICAL TRIALS REGISTRATION

NCT01862029.

Phosphodiesterase-4 Inhibitors for the Treatment of Inflammatory Diseases

Phosphodiesterase-4 (PDE4), mainly present in immune cells, epithelial cells, and brain cells, manifests as an intracellular non-receptor enzyme that modulates inflammation and epithelial integrity. Inhibition of PDE4 is predicted to have diverse effects via the elevation of the level of cyclic adenosine monophosphate (cAMP) and the subsequent regulation of a wide array of genes and proteins. It has been identified that PDE4 is a promising therapeutic target for the treatment of diverse pulmonary, dermatological, and severe neurological diseases. Over the past decades, numerous PDE4 inhibitors have been designed and synthesized, among which roflumilast, apremilast, and crisaborole were approved for the treatment of inflammatory airway diseases, psoriatic arthritis, and atopic dermatitis, respectively. It is regrettable that the dramatic efficacies of a drug are often accompanied by adverse effects, such as nausea, emesis, and gastrointestinal reactions. However, substantial advances have been made to mitigate the adverse effects and obtain better benefit-to-risk ratio. This review highlights the dialectical role of PDE4 in drug discovery and the disquisitive details of certain PDE4 inhibitors to provide an overview of the topics that still need to be addressed in the future.

Incidence of Adverse Effects and Discontinuation Rate between Patients Receiving 250 Micrograms and 500 Micrograms of Roflumilast: A Comparative Study

BACKGROUND

Roflumilast is the only approved oral phosphodiesterase-4 inhibitor for the treatment of severe chronic obstructive pulmonary disease (COPD) in patients with chronic bronchitis and a history of frequent exacerbations. The purpose of this study was to examine the incidence of adverse effects associated with roflumilast treatment in a real-world setting. Further, we compared the incidence of adverse effects and the discontinuation rate among patients receiving different doses.

METHODS

We identified all outpatients diagnosed with COPD at Seoul St. Mary's Hospital between May 2011 and September 2016 and retrospectively reviewed their medical records. Roflumilast was prescribed to patients in doses of 500 μg and 250 μg.

RESULTS

A total of 269 COPD patients were prescribed roflumilast in our hospital during the study period. Among them, 178 patients were treated with 500 μg and 91 patients were treated with 250 μg. The incidence of adverse effects was 38.2% in the 500 μg group and 25.3% in the 250 μg group (p=0.034). The discontinuation rate of roflumilast was 41.6% (n=74) in the 500 μg group and 23.1% (n=21) in the 250 μg group (p=0.003). When adjusted by age, sex, smoking status, and lung function, 500 μg dose was significantly associated with the discontinuation of roflumilast (odds ratio, 2.87; p<0.001).

CONCLUSION

There was a lower incidence of adverse effects and discontinuation among patients treated with 250 μg compared with 500 μg dose. Further studies regarding the optimal dose of roflumilast are required.

Anti-inflammatory effects of the phosphodiesterase type 4 inhibitor CHF6001 on bronchoalveolar lavage lymphocytes from asthma patients

BACKGROUND

Lymphocytes play a key role in asthma pathophysiology, secreting various cytokines involved in chronic inflammation. CHF6001 is a highly potent and selective phosphodiesterase type 4 (PDE4) inhibitor designed for inhaled administration and has been shown to reduce the late asthmatic response. However, the effect of PDE4 inhibition on the different cytokines produced by lung lymphocytes from asthma patients has not been examined.

METHODS

This study investigated the anti-inflammatory effects of CHF6001 and the corticosteroid, 17-BMP, on T-cell receptor (TCR) stimulated Th1, Th2 and Th17 cytokine release from bronchoalveolar lavage (BAL) cells from mild (n = 12) and moderate asthma (n = 12) patients.

RESULTS

CHF6001 inhibited IFNγ, IL-2 and IL-17, but not IL-13, secretion from both mild and moderate asthma patient BAL cells; there was a greater effect on IFNγ and IL-2 than IL-17. The corticosteroid inhibited all four cytokines from both patient groups, but was less effective in cells from more severe patients. CHF6001 had a greater inhibitory effect on IFNγ and IL-2 than 17-BMP.

CONCLUSION

The PDE4 inhibitor CHF6001 had a greater effect on Th1 cytokines from TCR-stimulated BAL cells than corticosteroid. This pharmacological effect suggests the therapeutic potential for PDE4 inhibitors to be used in the subset of more severe asthma patients with increased airway levels of IFNγ.

Roflumilast Usage from 2010 to 2016: A Danish Nationwide Drug Utilization Study

Roflumilast, a phosphodiesterase-4-inhibitor, is marketed as add-on treatment to inhaled bronchodilators and corticosteroids in COPD patients with frequent exacerbations. Although marketed since 2010, usage pattern of roflumilast for an entire nation has not previously been explored. This study aimed to estimate the total utilization of roflumilast in Denmark during 2010 to 2016, using the Danish nationwide health registers. We identified 1573 individuals (47% males) who used roflumilast during the study period, of whom 705 (45%) redeemed only one prescription. Of all patients initiating roflumilast, 67% discontinued treatment within the first year. The rate of treatment initiation decreased 73% from 2011 (7.5/100,000 person-years) to 2016 (2.0/100,000 person-years) concurrent with a stable prevalence of 3.0-4.0/100,000 persons throughout the study period. The median duration of roflumilast use was 76 days. Patients with severe comorbidity tended to exhibit a lower degree of early discontinuation (Charlson Comorbidity Index 3+: odds ratio [OR]: 0.59; 95% confidence interval [CI] 0.33-1.04), as well as patients with a COPD-related admission within a year prior to roflumilast initiation (OR 0.62; 95% CI 0.49-0.80). The decreasing incidence and high level of early roflumilast discontinuation could be due to lack of benefit, a low awareness of romiflulast's indication among physicians, secondary to a challenging prescribing procedure or to adverse effects.

The Challenges of Precision Medicine in COPD

Pheno-/endotyping chronic obstructive pulmonary disease (COPD) is really important because it provides patients with precise and personalized medicine. The central concept of precision medicine is to take individual variability into account when making management decisions. Precision medicine should ensure that patients get the right treatment at the right dose at the right time, with minimum harmful consequences and maximum efficacy. Ideally, we should search for genetic and molecular biomarker-based profiles. Given the clinical complexity of COPD, it seems likely that a panel of several biomarkers will be required to characterize pathogenetic factors and their course over time. The need for biomarkers to guide the clinical care of individuals with COPD and to enhance the possibilities of success in drug development is clear and urgent, but biomarker development is tremendously challenging and expensive, and translation of research efforts to date has been largely ineffective. Furthermore, the development of personalized treatments will require a much more detailed understanding of the clinical and biological heterogeneity of COPD. Therefore, we are still far from being able to apply precision medicine in COPD and the treatable traits and FEV₁-free approaches are attempts to precision medicine in COPD that must be considered still quite unsophisticated.

Multidimensional approach for the proper management of a complex chronic patient with chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is frequently associated with comorbidities occurring either independently or as consequences of COPD. Areas covered: This review examines the interactions between the pathophysiology of COPD and the most frequent comorbidities, and highlights the need for multidimensional clinical strategies to manage COPD patients with comorbidities. Expert commentary: Most COPD patients need to be approached in a complex and multifactorial scenario. The diagnosis of COPD is necessarily based on the presence of chronic respiratory symptoms and poorly reversible airflow obstruction, but exacerbations and comorbidities need to be considered in the evaluation of disease severity and prognosis in individual patients. More importantly, defining the precise relationship between COPD and comorbidities for each patient is the basis for a correct therapeutic approach.

The impact of dual bronchodilation on cardiovascular serious adverse events and mortality in COPD: a quantitative synthesis

Objective

Long-acting β₂-agonists (LABAs) and long-acting muscarinic antagonists (LAMAs) are burdened by the potential risk of inducing cardiovascular serious adverse events (SAEs) in COPD patients. Since the risk of combining a LABA with a LAMA could be greater, we have carried out a quantitative synthesis to investigate the cardiovascular safety profile of LABA/LAMA fixed-dose combinations (FDCs).

Methods

A pair-wise and network meta-analysis was performed by using the data of the repository database ClinicalTrials.gov concerning the impact of approved LABA/LAMA FDCs versus monocomponents and/or placebo on cardiovascular SAEs in COPD.

Results

Overall, LABA/LAMA FDCs did not significantly (P>0.05) modulate the risk of cardiovascular SAEs versus monocomponents. However, the network meta-analysis indicated that aclidinium/formoterol 400/12 µg and tiotropium/olodaterol 5/5 µg were the safest FDCs, followed by umeclidinium/vilanterol 62.5/25 µg which was as safe as placebo, whereas glycopyrronium/formoterol 14.9/9.6, glycopyrronium/indacaterol 15.6/27.5 µg, and glycopyrronium/indacaterol 50/110 µg were the least safe FDCs. No impact on mortality was detected for each specific FDC.

Conclusion

This meta-analysis indicates that LABA/LAMA FDC therapy is characterized by an excellent cardiovascular safety profile in COPD patients. However, the findings of this quantitative synthesis have been obtained from populations that participated in randomized clinical trials, and were devoid of major cardiovascular diseases. Thus, post-marketing surveillance and observational studies may help to better define the real impact of specific FDCs with regard to the cardiovascular risk.

Roflumilast restores cAMP/PKA/CREB signaling axis for FtMt-mediated tumor inhibition of ovarian cancer

The abrogation of cAMP generation by overexpression of PDE isoforms promotes the inflammatory pathology, and the PDE inhibitors have showed the potential anti-inflammation effects in clinical. However, the function of PDE inhibitors in cancer treatment remains unclear. We here investigated the role of PDE4 inhibitor Roflumilast in the treatment of ovarian cancer. We found that Roflumilast could effectively inhibit the proliferation, and induce apoptosis and cell cycle arrest in two ovarian cancer cell lines OVCAR3 and SKOV3. Meanwhile, the cAMP/PKA/CREB signals was activated by Roflumilast, which was accompanied by the up-regulation of mitochondrial ferritin (FtMt) level. Interestingly, forced expression of FtMt in ovarian cancer enhanced the apoptosis and inhibited tumor growth and the PKA inhibitor H89 and knockdown of CREB significantly repressed the expression of FtMt to restore the tumor proliferation and inhibit apoptosis. In addition, we found that Roflumilast-induced phosphorylated CREB directly promoted transcription of FtMt, indicating that Roflumilast up-regulated the expression of FtMt in ovarian cancer via cAMP/PKA/CREB signals. The anti-tumor role of Roflumilast in vivo was also demonstrated, the treatment of roflumilast effectively inhibited tumor proliferation and elevated the FtMt expression to restrict the tumor growth via the activation of cAMP/PKA/CREB signals in ovarian cancer.

Pharmacological treatments in asthma-affected horses: A pair-wise and network meta-analysis

BACKGROUND

Equine asthma is a disease characterised by reversible airflow obstruction, bronchial hyper-responsiveness and airway inflammation following exposure of susceptible horses to specific airborne agents. Although clinical remission can be achieved in a low-airborne dust environment, repeated exacerbations may lead to irreversible airway remodelling. The available data on the pharmacotherapy of equine asthma result from several small studies, and no head-to-head clinical trials have been conducted among the available medications.

OBJECTIVES

To assess the impact of the pharmacological interventions in equine asthma and compare the effect of different classes of drugs on lung function.

STUDY DESIGN

Pair-wise and network meta-analysis.

METHODS

Literature searches for clinical trials on the pharmacotherapy of equine asthma were performed. The risk of publication bias was assessed by funnel plots and Egger's test. Changes in maximum transpulmonary or pleural pressure, pulmonary resistance and dynamic lung compliance vs. control were analysed via random-effects models and Bayesian networks.

RESULTS

The results obtained from 319 equine asthma-affected horses were extracted from 32 studies. Bronchodilators, corticosteroids and chromones improved maximum transpulmonary or pleural pressure (range: -8.0 to -21.4 cmH₂ O; P<0.001). Bronchodilators, corticosteroids and furosemide reduced pulmonary resistance (range: -1.2 to -1.9 cmH₂ O/L/s; P<0.001), and weakly increased dynamic lung compliance. Inhaled β₂ -adrenoreceptor (β₂ -AR) agonists and inhaled corticosteroids had the highest probability of being the best therapies. Long-term treatments were more effective than short-term treatments.

MAIN LIMITATIONS

Weak publication bias was detected.

CONCLUSIONS

This study demonstrates that long-term treatments with inhaled corticosteroids and long-acting β₂ -AR agonists may represent the first choice for treating equine asthma. Further high quality clinical trials are needed to clarify whether inhaled bronchodilators should be preferred to inhaled corticosteroids or vice versa, and to investigate the potential superiority of combination therapy in equine asthma.

LABA/LAMA combination in COPD: a meta-analysis on the duration of treatment

When there are no randomised clinical trials directly comparing all relevant treatment options, an indirect treatment comparison via meta-analysis of the available clinical evidence is an acceptable alternative. However, meta-analyses may be very misleading if not adequately performed. Here, we propose and validate a simple and effective approach to meta-analysis for exploring the effectiveness of long-acting β2-agonist (LABA)/long-acting muscarinic antagonist (LAMA) fixed-dose combinations in chronic obstructive pulmonary disease.

14 articles with 20 329 patients (combinations n=9292; monocomponents n=11 037) were included in this study. LABA/LAMA combinations were always more effective than the monocomponents in terms of the improvement in trough forced expiratory volume in 1 s, transition dyspnoea index and St George's Respiratory Questionnaire scores after 3, 6 and 12 months of treatment. No significant publication bias was identified. Significant discrepancies with previous network meta-analyses have been found, with overall differences ranging from 26.7% to 43.3%.

Results from previous network meta-analyses were misleading because no adequate attention was given to formulating the review question, specifying eligibility criteria, correctly identifying studies, collecting appropriate information and deciding what it would be pharmacologically relevant to analyse. The real gradient of effectiveness of LABA/LAMA fixed-dose combinations remains an unmet medical need; however, it can be investigated indirectly using a high-quality meta-analytic approach.

Tiotropium formulations and safety: a network meta-analysis

Tiotropium is now delivered via two different inhaler devices: the original Handihaler 18 μg once daily, which uses a powder formulation; and the newer Respimat Soft Mist Inhaler (SMI) 5 μg once daily. It has been questioned whether the two devices can be assumed to have the same safety profile, although the TIOSPIR trial showed that tiotropium when administered via Respimat SMI 5 μg is not less safe than Handihaler 18 μg. Therefore, we have carried out a safety evaluation of tiotropium Handihaler 18 µg versus tiotropium Respimat SMI 5 µg and 2.5 µg, via systematic review and network meta-analysis of the currently available clinical evidence. The results of our meta-analysis with an extremely large number of patients analysed demonstrate that the safety profile of tiotropium HandiHaler is generally superior to that of tiotropium Respimat SMI, although no statistical difference was detected between these two devices. However, the SUCRA analysis favoured tiotropium Respimat SMI with regards to serious adverse events (AEs). We do not believe that using Respimat SMI rather that HandiHaler exposes patients to higher risks of real AEs. Rather, we believe that there may be a different cardiovascular (CV) response to muscarinic receptors blockage in individual patients. Therefore, it will be essential to make all possible efforts to proactively identify patients at increased risk of CV AEs when treated with tiotropium or another antimuscarinic drug.