|Pharmacotherapeutic group: Drugs for obstructive airway diseases, Other systemic drugs for obstructive airway diseases, ATC code: R03DX07|
Mechanism of actionRoflumilast is a PDE4 inhibitor, a non-steroid, anti-inflammatory agent designed to target both the systemic and pulmonary inflammation associated with COPD. The mechanism of action is the inhibition of PDE4, a major cyclic adenosine monophosphate (cAMP)-metabolizing enzyme found in structural and inflammatory cells important to the pathogenesis of COPD. Roflumilast targets the PDE4A, 4B and 4D splicing variants with similar potency in the nanomolar range. The affinity to the PDE4C splicing variants is 5 to 10-fold lower. This mechanism of action and the selectivity also apply to roflumilast N-oxide, which is the major active metabolite of roflumilast.
Pharmacodynamic effectsInhibition of PDE4 leads to elevated intracellular cAMP levels and mitigates COPD-related malfunctions of leukocytes, airway and pulmonary vascular smooth muscle cells, endothelial and airway epithelial cells and fibroblasts in experimental models. Upon in vitro stimulation of human neutrophils, monocytes, macrophages or lymphocytes, roflumilast and roflumilast N-oxide suppress the release of inflammatory mediators e.g. leukotriene B4, reactive oxygen species, tumor necrosis factor α, interferon γ and granzyme B. In patients with COPD, roflumilast reduced sputum neutrophils. Furthermore, roflumilast attenuated influx of neutrophils and eosinophils into the airways of endotoxin challenged healthy volunteers.
Clinical efficacy and safetyIn two confirmative replicate one-year studies (M2-124 and M2-125) and two supplementary six-month studies (M2-127 and M2-128), a total number of 4,768 patients were randomized and treated of whom 2,374 were treated with Daxas. The design of the studies was parallel-group, double-blind and placebo-controlled. The one-year studies included patients with a history of severe to very severe COPD [FEV1 (forced expiratory volume in one second) ≤50% of predicted] associated with chronic bronchitis, with at least one documented exacerbation in the previous year and with symptoms at baseline as determined by cough and sputum score. Long-acting beta-agonists (LABAs) were allowed in the studies and were used in approximately 50% of the study population. Short-acting anticholinergics (SAMAs) were allowed for those patients not taking LABAs. Rescue medicinal products (salbutamol or albuterol) were allowed on an as-needed basis. The use of inhaled corticosteroids and theophylline was prohibited during the studies. Patients with no history of exacerbations were excluded.In a pooled analysis of the one-year studies M2-124 and M2-125, Daxas 500 micrograms once daily significantly improved lung function compared to placebo, on average by 48 ml (pre-bronchodilator FEV1, primary endpoint, p<0.0001), and by 55 ml (post-bronchodilator FEV1, p<0.0001). The improvement in lung function was apparent at the first visit after 4 weeks and was maintained up to one year (end of treatment period). The rate (per patient per year) of moderate exacerbations (requiring intervention with systemic glucocorticosteroids) or severe exacerbations (resulting in hospitalisation and/or leading to death) after 1 year was 1.142 with roflumilast and 1.374 with placebo corresponding to a relative risk reduction of 16.9% (95%CI: 8.2% to 24.8%) (primary endpoint, p=0.0003). Effects were similar, independent of previous treatment with inhaled corticosteroids or underlying treatment with LABAs. In the subgroup of patients with history of frequent exacerbations (at least 2 exacerbations during the last year), the rate of exacerbations was 1.526 with roflumilast and 1.941 with placebo corresponding to a relative risk reduction of 21.3% (95%CI: 7.5% to 33.1%). Roflumilast did not significantly reduce the rate of exacerbations compared with placebo in the subgroup of patients with moderate COPD.The reduction of moderate or severe exacerbations with Daxas and LABA compared to placebo and LABA was on average 21% (p=0.0011). The respective reduction in exacerbations seen in patients without concomitant LABAs was on average 15% (p=0.0387). The numbers of patients who died due to any reason were equal for those treated with placebo or roflumilast (42 deaths each group; 2.7% each group; pooled analysis). A total of 2,690 patients were included and randomized in two supportive 1-year studies (M2-111 and M2-112). In contrast to the two confirmative studies, a history of chronic bronchitis and of COPD exacerbations was not requested for patients' inclusion. Inhaled corticosteroids were used in 809 (61%) of the roflumilast treated patients, whereas the use of LABAs and theophylline was prohibited. Daxas 500 micrograms once daily significantly improved lung function compared to placebo, on average by 51 ml (pre-bronchodilator FEV1, p<0.0001), and by 53 ml (post-bronchodilator FEV1, p<0.0001). The rate of exacerbations (as defined in the protocols) were not significantly reduced by roflumilast in the individual studies (relative risk reduction: 13.5% in study M2-111 and 6.6% in study M2-112; p= not significant). Adverse events rates were independent of concomitant treatment with inhaled corticosteroids.Two six-month supportive studies (M2-127 and M2-128) included patients with a history of COPD for at least 12 months prior to baseline. Both studies included moderate to severe patients with a non-reversible airway obstruction and a FEV1 of 40% to 70% of predicted. Roflumilast or placebo treatment was added to continuous treatment with a long-acting bronchodilator, in particular salmeterol in study M2-127 or tiotropium in study M2-128. In the two six-month studies, pre-bronchodilator FEV1 was significantly improved by 49 ml (primary endpoint, p<0.0001) beyond the bronchodilator effect of concomitant treatment with salmeterol in study M2-127 and by 80 ml (primary endpoint, p<0.0001) incremental to concomitant treatment with tiotropium in study M2-128. No study has been conducted to compare Daxas to the combination of LABA plus inhaled corticosteroids or on top of the combination of LABA plus inhaled corticosteroids.
Paediatric populationThe European Medicines Agency has waived the obligation to submit the results of studies with Daxas in all subsets of the paediatric population in chronic obstructive pulmonary disease (see section 4.2 for information on paediatric use).