Background CHF6001 is a novel inhaled phosphodiesterase-4 inhibitor. This Phase IIa study assessed the effects of CHF6001 on markers of inflammation in induced sputum and blood in patients with chronic obstructive pulmonary disease (COPD). Methods This was a multicentre, three-period (each 32 days), three-way, placebo-controlled, double-blind, complete-block crossover study. Eligible patients had COPD, chronic bronchitis, and were receiving inhaled triple therapy for ≥2 months. Patients received CHF6001 800 or 1600 μg, or matching placebo twice daily via multi-dose dry-powder inhaler (NEXThaler). Induced sputum was collected pre-dose on Day 1, and post-dose on Days 20, 26 and 32. Blood was sampled pre-dose on Day 1, and pre- and post-dose on Day 32. Results Of 61 randomised patients, 54 (88.5%) completed the study. There were no significant differences between groups for overall sputum cell count, or absolute numbers of neutrophils, eosinophils or lymphocytes. CHF6001 800 μg significantly decreased the absolute number and percentage of macrophages vs placebo. In sputum, compared with placebo both CHF6001 doses significantly decreased leukotriene B4, C-X-C motif chemokine ligand 8, macrophage inflammatory protein 1β, matrix metalloproteinase 9, and tumour necrosis factor α (TNFα). In blood, both CHF6001 doses significantly decreased serum surfactant protein D vs placebo. CHF6001 1600 μg significantly decreased TNFα ex-vivo (after incubation with lipopolysaccharide). Conclusion The data from this study show that CHF6001 inhaled twice daily has anti-inflammatory effects in the lungs of patients with COPD already treated with triple inhaled therapy. Trial registration The study is registered on ClinicalTrials.gov ( NCT03004417 ). Electronic supplementary material The online version of this article (10.1186/s12931-019-1142-7) contains supplementary material, which is available to authorized users.

Background: Although phosphodiesterase-4 (PDE4) inhibitors have been shown to reduce COPD exacerbation rate, their biological mechanism of action is not completely elucidated at the molecular level. We aimed to characterise the whole genome gene expression profile of the inhaled PDE4-inhibitor CHF6001 on top of triple therapy in sputum cells and whole blood of patients with COPD and chronic bronchitis. Methods: Whole genome gene expression analysis was carried out by microarray in 54 patients before and after 32 days treatment with CHF6001 800 and 1600 μg and placebo twice daily (BID) in a randomised crossover study.Results: CHF6001 had a strong effect in sputum, with 1471 and 2598 significantly differentially-expressed probesets relative to placebo (p-adjusted for False Discovery Rate < 0.05) with 800 and 1600 μg BID, respectively. Functional enrichment analysis showed significant modulation of key inflammatory pathways involved in cytokine activity, pathogen-associated-pattern-recognition activity, oxidative stress and vitamin D with associated inhibition of downstream inflammatory effectors. A large number of pro-inflammatory genes coding for cytokines and matrixmetalloproteinases were significantly differentially expressed for both doses; the majority (> 87%) were downregulated, including macrophage inflammatory protein-1-alpha and 1-beta, interleukin-27-beta, interleukin-12beta, interleukin-32, tumour necrosis factor-alpha-induced-protein-8, ligand-superfamily-member-15, and matrixmetalloproteinases-7,12 and 14. The effect in blood was not significant. Conclusions: Inhaled PDE4 inhibition by CHF6001 on top of triple therapy in patients with COPD and chronic bronchitis significantly modulated key inflammatory targets and pathways in the lung but not in blood. Mechanistically these findings support a targeted effect in the lung while minimising unwanted systemic classeffects.

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.

Background This study evaluated the efficacy, safety and tolerability of the novel inhaled phosphodiesterase-4 inhibitor CHF6001 added-on to formoterol in patients with chronic obstructive pulmonary disease (COPD). Methods Randomised, double-blind, placebo- and active-controlled, parallel-group study. Eligible patients had symptomatic COPD, post-bronchodilator forced expiratory volume in 1 s (FEV1) 30–70% predicted, and history of ≥1 moderate/severe exacerbation. Patients were randomised to extrafine CHF6001 400, 800, 1200 or 1600 μg twice daily (BID), budesonide, or placebo for 24 weeks. Primary objectives: To investigate CHF6001 dose-response for pre-dose FEV1 after 12 weeks, and to identify the optimal dose. Moderate-to-severe exacerbations were a secondary endpoint. Results Of 1130 patients randomised, 91.9% completed. Changes from baseline in pre-dose FEV1 at Week 12 were small in all groups (including budesonide), with no CHF6001 dose-response, and no significant treatment–placebo differences. For moderate-to-severe exacerbations, CHF6001 rate reductions versus placebo were 13–28% (non-significant). In post-hoc analyses, CHF6001 effects were larger in patients with a chronic bronchitis phenotype (rate reductions versus placebo 24–37%; non-significant), and were further increased in patients with chronic bronchitis and eosinophil count ≥150 cells/μL (49–73%, statistically significant for CHF6001 800 and 1600 μg BID). CHF6001 was well tolerated with no safety signal (including in terms of gastrointestinal adverse events). Conclusions CHF6001 had no effect in the primary lung function analysis, although was well-tolerated with no gastrointestinal adverse event signal. Post-hoc analyses focused on exacerbation risk indicate specific patient subgroups who may receive particular benefit from CHF6001. Trial registration ClinicalTrials.gov (NCT02986321). Registered 8 Dec 2016.

Patients with COPD who have higher eosinophil numbers in the airways and peripheral blood demonstrate a greater clinical response to inhaled corticosteroids (ICS) [1–3]. Furthermore, the effect of the oral phosphodiesterase-4 (PDE4) inhibitor roflumilast on exacerbations in severe COPD patients with chronic bronchitis, who are treated with ICS and long-acting bronchodilators, also appears to be greater at higher blood eosinophil counts [4]. The mechanisms responsible for these differential drug effects remain to be defined, but may relate to increased type-2 inflammation and/or decreased presence of colonising airway bacteria in COPD patients with more eosinophils [5, 6], leading to different responses to anti-inflammatory drugs. An association between blood and sputum eosinophils has been observed in some, but not all studies [7–12]. Accurate sputum eosinophil count measurement requires good quality samples to make cytospins where eosinophils can be clearly counted; variable quality of sputum samples, particularly in multicentre studies, will affect the ability to show a relationship with blood eosinophil counts.