Optimizing the Development Strategy of Combination Therapy in Respiratory Medicine: From Isolated Airways to Patients

Co-targeting the kappa opioid receptor and dopamine transporter reduces motivation to self-administer cocaine and partially reverses dopamine system dysregulation

Cocaine disrupts dopamine (DA) and kappa opioid receptor (KOR) system activity, with long-term exposure reducing inhibiton of DA uptake by cocaine and increasing KOR system function. Single treatment therapies have not been successful for cocaine use disorder; therefore, this study focuses on a combination therapy targeting the dopamine transporter (DAT) and KOR. Sprague Dawley rats self-administered 5 days of cocaine (1.5 mg/kg/inf, max 40 inf/day, FR1), followed by 14 days on a progressive ratio (PR) schedule (0.19 mg/kg/infusion). Behavioral effects of individual and combined administration of phenmetrazine and nBNI were then examined using PR. Additionally, ex vivo fast scan cyclic voltammetry was then used to assess alterations in DA and KOR system activity in the nucleus accumbens before and after treatments. Chronic administration of phenmetrazine as well as the combination of phenmetrazine and nBNI-but not nBNI alone-significantly reduced PR breakpoints. In addition, the combination of phenmetrazine and nBNI partially reversed cocaine-induced neurodysregulations of the KOR and DA systems, indicating therapeutic benefits of targeting the DA and KOR systems in tandem. These data highlight the potential benefits of the DAT and KOR as dual-cellular targets to reduce motivation to administer cocaine and reverse cocaine-induced alterations of the DA system.

Use of human airway smooth muscle in vitro and ex vivo to investigate drugs for the treatment of chronic obstructive respiratory disorders

Isolated airway smooth muscle has been extensively investigated since 1840 to understand the pharmacology of airway diseases. There has often been poor predictability from murine experiments to drugs evaluated in patients with asthma or chronic obstructive pulmonary disease (COPD). However, the use of isolated human airways represents a sensible strategy to optimise the development of innovative molecules for the treatment of respiratory diseases. This review aims to provide updated evidence on the current uses of isolated human airways in validated in vitro methods to investigate drugs in development for the treatment of chronic obstructive respiratory disorders. This review also provides historical notes on the pioneering pharmacological research on isolated human airway tissues, the key differences between human and animal airways, as well as the pivotal differences between human medium bronchi and small airways. Experiments carried out with isolated human bronchial tissues in vitro and ex vivo replicate many of the main anatomical, pathophysiological, mechanical and immunological characteristics of patients with asthma or COPD. In vitro models of asthma and COPD using isolated human airways can provide information that is directly translatable into humans with obstructive lung diseases. Regardless of the technique used to investigate drugs for the treatment of chronic obstructive respiratory disorders (i.e., isolated organ bath systems, videomicroscopy and wire myography), the most limiting factors to produce high-quality and repeatable data remain closely tied to the manual skills of the researcher conducting experiments and the availability of suitable tissue.

Evolving to a single inhaler extrafine LABA/LAMA/ICS - Inhalation technique and adherence at the heart of COPD patient care (TRIVOLVE)

OBJECTIVE

Incorrect inhaler use and poor treatment adherence have a negative impact on COPD outcomes. This multi-centre, single arm, non-interventional, phase IV study investigated whether inhalation technique, treatment adherence and patient outcomes change in patients who evolve from dual therapy or multiple inhaler triple therapy to single inhaler extrafine triple therapy (beclomethasone dipropionate (BDP, 87 μg), formoterol fumarate (FF, 5 μg) and glycopyrronium (G, 9 μg)) in combination with inhalation technique training.

METHODS

A total of 126 COPD patients were included in the per protocol set. Inhalation technique and treatment adherence were assessed at baseline and at two visits at approximately 3 and 6 months of treatment with extrafine BDP/FF/G. In addition, lung function, symptom score, patient satisfaction and exacerbations (exploratory) were followed up.

RESULTS

Before switching to single inhaler extrafine BDP/FF/G (baseline), any device errors and critical errors were detected for 28.8% and 9.6% of patients, respectively. After switching to BDP/FF/G, the percentage of patients with any device errors decreased to 14.0% (visit 2) and 16.3% (visit 3), without critical errors at the two follow-up visits. Treatment adherence increased from 67.5% at baseline to 75.8% (visit 2) and 80% (visit 3). In addition, lung function, symptom and patient satisfaction scores improved, whilst exacerbation rates substantially decreased.

CONCLUSIONS

This observational study demonstrates that in eligible COPD patients in a real-life setting, the switch from dual therapy or multiple inhaler triple therapy to single inhaler extrafine BDP/FF/G in combination with inhalation technique training is associated with improved inhalation technique and adherence.

When is LABA/LAMA Better than LAMA in GOLD Group B or D Patients for Reducing Acute Exacerbations of COPD?

Long-acting β2-agonist (LABA)/long-acting muscarinic-antagonist (LAMA) dual therapy has been found to be more effective than LAMA monotherapy in the treatment of chronic obstructive pulmonary disease (COPD). However, among patients with group B or D COPD, the characteristics of patients for whom LABA/LAMA dual therapy is superior to LAMA monotherapy in minimizing acute exacerbations remain unknown. With data from a prospective COPD cohort, subgroup analyses were conducted to determine whether LABA/LAMA dual therapy was superior to LAMA monotherapy in reducing the rate of acute exacerbations in group B and D COPD patients. Group B and D COPD patients taking LAMA or LABA/LAMA were enrolled according to the 2022 Global initiative for Chronic Obstructive Pulmonary Disease guidelines. A total of 737 patients were included in this study: 600 with group B COPD and 137 with group D COPD. Compared with patients taking LAMA monotherapy, those taking LABA/LAMA had a significantly lower incidence of acute exacerbations over 1 year. In the subgroup of patients ≥70 years old, there was a significantly lower risk of severe COPD exacerbations among group B patients taking LABA/LAMA than among those taking LAMA monotherapy (odds ratio [OR], 0.258; 95% confidence interval [CI], 0.095-0.703). In contrast, in the subgroup of group D patients with COPD Assessment Test scores ≥25, compared with LAMA monotherapy, LABA/LAMA treatment was associated with lower risk of severe COPD exacerbations (OR, 0.115; 95% CI, 0.018-0.749). The combination of LABA and LAMA was found to be superior to LAMA monotherapy, especially for treating older adults with group B COPD, as well as for group D patients with severe symptoms.

Experimental drugs in clinical trials for COPD: Artificial Intelligence via Machine Learning approach to predict the successful advance from early-stage development to approval

INTRODUCTION

Therapeutic advances in drug therapy of chronic obstructive pulmonary disease (COPD) really effective in suppressing the pathological processes underlying the disease deterioration are still needed. Artificial Intelligence (AI) via Machine Learning (ML) may represent an effective tool to predict clinical development of investigational agents.

AREAL COVERED

Experimental drugs in Phase I and II development for COPD from early 2014 to late 2022 were identified in the ClinicalTrials.gov database. Different ML models, trained from prior knowledge on clinical trial success, were used to predict the probability that experimental drugs will successfully advance toward approval in COPD, according to Bayesian inference as follows: ≤25% low probability, >25% and ≤ 50% moderate probability, >50% and ≤ 75% high probability, and > 75% very high probability.

EXPERT OPINION

The Artificial Neural Network and Random Forest ML models indicated that, among the current experimental drugs in clinical trials for COPD, only the bifunctional muscarinic antagonist - β₂-adrenoceptor agonists (MABA) navafenterol and batefenterol, the inhaled corticosteroid (ICS)/MABA fluticasone furoate/batefenterol, and the bifunctional phosphodiesterase (PDE) 3/4 inhibitor ensifentrine resulted to have a moderate to very high probability of being approved in the next future, however not before 2025.

Might It Be Appropriate to Anticipate the Use of Long-Acting Muscarinic Antagonists in Asthma?

A growing number of clinical trials are documenting that adding a long-acting muscarinic antagonist (LAMA) to established asthma treatment with an inhaled corticosteroid (ICS) and a long-acting β₂-agonist (LABA) is a treatment option that improves the health of patients with uncontrolled severe asthma even when therapy is optimized. These favorable results are the reason why the leading guidelines recommend triple therapy with ICS + LABA + LAMA in patients with asthma uncontrolled by medium- to high-dose ICS-LABA. However, we suggest adding LAMAs to ICS-LABAs at an earlier clinical stage. Such action could positively influence airflow limitation, exacerbations, and eosinophilic inflammation, conditions that are associated with acetylcholine (ACh) activity. It could also interrupt the vicious cycle related to a continuous release of ACh leading to the progressive expansion of neuronal plasticity resulting in small airway dysfunction. The utility of an earlier use of triple therapy in asthma should, in any case, be confirmed by statistically powered trials.

Optimization of Long-Acting Bronchodilator Dose Ratios Using Isolated Guinea Pig Tracheal Rings for Synergistic Combination Therapy in Asthma and COPD

The co-administration of a long-acting β2-agonist (LABA), and a long-acting muscarinic antagonist (LAMA), has been shown to be beneficial in the management of non-communicable chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease (COPD). The resulting relaxation of the airways can be synergistically enhanced, reducing symptoms and optimizing lung function. This provides an insight into more effective treatments. In this study, the LABAs formoterol fumarate dihydrate (FOR) and indacaterol maleate (IND) were each associated with tiotropium bromide monohydrate (TIO) to assess their synergistic potential. This was done using an appropriate ex vivo model of isolated perfused guinea pig tracheal rings, and pharmacological models of drug interaction. Among the dose ratios studied for both types of combination, a higher synergistic potential was highlighted for FOR/TIO 2:1 (w/w). This was done through three steps by using multiple additions of drugs to the organ baths based on a non-constant dose ratio and then on a constant dose ratio, and by a single addition to the organ baths of specific amounts of drugs. In this way, the synergistic improvement of the relaxant effect on the airways was confirmed, providing a basis for improving therapeutic approaches in asthma and COPD. The synergy found at this dose ratio should now be confirmed on a preclinical model of asthma and COPD by assessing lung function.

Drug interaction and chronic obstructive respiratory disorders

Chronic obstructive respiratory disorders uncontrolled by monotherapy should be given combinations of drugs that act by distinct mechanisms of action. The rationale for combining different classes of drugs should be to elicit a synergistic interaction, lower the dose of the single components in the combinations and, thus, reduce the risk of adverse events.

The aim of this systematic review was to investigate the combined effect of drugs acting on human airways, by including studies that used a validated method for assessing the nature of drug interaction.

Current evidence indicates that drug combinations modulating the bronchial contractility induce a synergistic relaxant effect when the individual components are combined at isoeffective concentrations. There are several mechanisms of action underlying drug interactions. Pharmacological research has been directed to elucidate what causes the synergism between long-acting β₂-adrenoceptor (β₂-AR) agonists (LABAs), long-acting muscarinic antagonist (LAMAs), and inhaled corticosteroids (ICS) administered as dual or triple combination. Conversely, the mechanisms behind the additive interaction between phosphodiesterase 3 and 4 inhibitors and LAMAs, and the synergistic interaction between proliferator-activated receptor gamma ligands and β₂ agonists have been only hypothesized. Overall, the synergism elicited by combined drugs for the treatment of chronic respiratory disorders is an effect of class, rather than specific for drug combinations. Optimal synergy can be achieved only when the single agents are combined at isoeffective concentrations, and when monocomponents are given concurrently to reach together the same levels of the bronchial tree.

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Drug interaction should be identified with validated pharmacological models.

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Synergistic efficacy is the rationale for combining drugs for respiratory diseases.

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Synergy is favored when combined agents act by distinct mechanisms of action.

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Optimal synergy is achieved when drugs are combined at isoeffective concentrations.

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Synergy is a class effect and is not specific for single drug combinations.

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.

Comparative studies of dual bronchodilation in COPD

Dual bronchodilation therapy is becoming the cornerstone for the treatment of COPD because the clinical benefits of LABA/LAMA fixed-dose combinations (FDCs) are now extensively established. Therefore, it not surprising that a number of LAMA/LABA combinations in a single inhaler have now been approved for clinical use as treatments for patients with COPD. Regrettably, very few head-to-head studies between all of the available LABA/LAMA FDCs have been carried out. This makes choosing the most appropriate FDC difficult. Comparative effectiveness research that also uses conventional meta-analyses to compare different care strategies can help generate useful information. A bidimensional comparative analysis across LAMA/LABA FDCs has suggested constant superiority for tiotropium/olodaterol. However, considering that there is not an equivalent amount of evidence on efficacy outcomes for all LAMA/LABA FDCs, a proper comparison between the different LAMA/LABA FDCs cannot be made yet, and the information available is still rather inconsistent.

Synergy across the drugs approved for the treatment of asthma

INTRODUCTION

Inhaled corticosteroids are the cornerstone for the treatment of stable asthma, however, when disease severity increases, escalating therapy to combinations of drugs acting on distinct signalling pathways is required. It is advantageous to providing evidence of a synergistic interaction across drug combinations, as it allows optimizing bronchodilation while lowering the dose of single agents. In the respiratory pharmacology field, two statistical models are accepted as gold standard to characterize drug interactions, namely the Bliss Independence criterion and the Unified Theory. In this review, pharmacological interactions across drugs approved for the treatment of asthma have been systematically assessed.

EVIDENCE ACQUISITION

A comprehensive literature search was performed in MEDLINE for studies that used a validated pharmacological method for assessing drug interaction. The results were extracted and reported via qualitative synthesis.

EVIDENCE SYNTHESIS

Overall, 45 studies were identified from literature search and 5 met the inclusion criteria. Current evidence coming from ex vivo models of asthma indicates that drug combinations modulating bronchial contractility induce a synergistic bronchorelaxant effect. In murine models of lung inflammation, the combination between inhaled corticosteroids and β2- adrenoceptor agonists synergistically improve lung function and the inflammatory profile.

CONCLUSIONS

There is still limited knowledge regarding the mechanistic basis underlying pharmacological interactions across drugs approved for asthma. The synergism elicited by combined agents is an effect of class. Specifically designed clinical trials are needed to confirm the results coming from preclinical evidence, but also to establish the minimal dose for combined agents to induce a synergistic interaction and maximize bronchodilation.

Pharmacokinetic/pharmacodynamic approaches to drug delivery design for inhalation drugs

Introduction: Inhaled drugs are important in the treatment of many lung pathologies, but to be therapeutically effective they must reach unbound concentrations at their effect site in the lung that are adequate to interact with their pharmacodynamic properties (PD) and exert the pharmacological action over an appropriate dosing interval. Therefore, the evaluation of pharmacokinetic (PK)/PD relationship is critical to predict their possible therapeutic effect.Areas covered: We review the approaches used to assess the PK/PD relationship of the major classes of inhaled drugs that are prescribed to treat pulmonary pathologies.Expert opinion: There are still great difficulties in producing data on lung concentrations of inhaled drugs and interpreting them as to their ability to induce the desired therapeutic action. The structural complexity of the lungs, the multiplicity of processes involved simultaneously and the physical interactions between the lungs and drug make any PK/PD approach to drug delivery design for inhalation medications extremely challenging. New approaches/methods are increasing our understanding about what happens to inhaled drugs, but they are still not ready for regulatory purposes. Therefore, we must still rely on plasma concentrations based on the axiom that they reflect both the extent and the pattern of deposition within the lungs.

Investigational treatments in phase I and II clinical trials: a systematic review in chronic obstructive pulmonary disease (COPD)

Introduction. The current pharmacological treatments for the management of stable COPD permit the reduction of symptoms and frequency and severity of exacerbations, and the improvement of exercise tolerance and health status. However, they do not modify the long-term decline in lung function and patient health. Consequently, there is the strong need for 'highly innovative' medications that are focused on new targets and/or mechanisms for the treatment of COPD. Areas covered. This systematic review assesses investigational agents in Phase I and II clinical trials over the last six years. It offers insights on whether drugs and/or formulations in clinical development offer future effective treatments of COPD. Expert opinion. There is no evidence to suggest that current investigational agents can reduce lung function decline and cure COPD. However, looking forward, investigational, innovative treatments in combination with the therapies already recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) may provide future suitable tools to counteract the progression of COPD.

A long-term clinical trial on the efficacy and safety profile of doxofylline in Asthma: The LESDA study

Doxofylline, an oral methylxanthine with bronchodilator and anti-inflammatory activities, offers a promising alternative to theophylline due to its superior efficacy/safety profile. No long-term studies on the efficacy and safety of doxofylline are currently available in asthma. The aim of the Long-term clinical trial on the Efficacy and Safety profile of Doxofylline in Asthma (LESDA) study was to investigate the safety and efficacy profile of doxofylline administered for one year in asthmatic patients. LESDA was a multicenter, open-label, Phase III, clinical trial in which adult asthmatic patients received the same treatment (oral doxofylline 400 mg t.i.d.) for one year. Efficacy was assessed through periodic pulmonary function tests and by having the subjects keep monthly records of asthma events rates and use of salbutamol as rescue medication. The rate of adverse events (AEs) was recorded during the study. Three-hundred nine patients were screened and allocated in the study. Doxofylline significantly improved the change from baseline in forced expiratory volume in 1 s (FEV₁) (+16.90 ± 1.81%, P < 0.001 vs. baseline). Doxofylline also significantly improved the rate of asthma events (events/day: -0.57 ± 0.18, P < 0.05 vs. baseline) and the use of salbutamol as rescue medication (puffs/day: -1.48 ± 0.25, P < 0.01 vs. baseline). The most common AEs were nausea (14.56%), headache (14.24%), insomnia (10.68%), and dyspepsia (10.03%). There were neither serious AEs nor deaths during or shortly after the study. Concluding, doxofylline is effective and well tolerated when administered chronically in asthmatic patients.