Pharmacokinetic evaluation of roflumilast

Roflumilast and cognition enhancement: A translational perspective

Cognitive impairment affiliated with neurological disorders has a severe impact on daily life functioning and the quality of life of patients. This is associated with a significant and long-lasting health, social and financial burden, not only for the patients, but also for families and the wider society. However, treatment for cognitive impairment is only available for the indication Alzheimer's disease (AD) and its prodromal stage Mild Cognitive Impairment (MCI), although with major adverse effects, i.e. gastrointestinal effects (drugs) or hemorrhages (antibodies). Roflumilast (selective phosphodiesterase type 4 (PDE4) inhibitor) has been approved as an anti-inflammatory drug for the treatment of chronic obstructive pulmonary disease (COPD), although still 5 % of the patients experience nausea or even vomiting at the approved dose of 500 μg. Nonclinical studies demonstrated that roflumilast appears a promising drug the treat cognitive impairment in healthy rodents and a wide variety of animal models of CNS disorders. These effects are attributed to pro-neuroplasticity and anti-inflammatory effects, which appeared dose dependent. Roflumilast has also been tested in clinical studies and showed cognition enhancement at low dosing (100-250 µg) in healthy adults, healthy elderly, MCI and schizophrenia. Currently, clinical trials are underway for testing the pro-cognitive effects in early AD, post stroke cognitive impairment and Fragile X. Overall, the data showed that roflumilast has beneficial effects on cognitive performance. These cognition-enhancing effects are found at doses that were well-tolerated. Based on this favorable therapeutic window, the repurposing of roflumilast for treating cognitive impairments in CNS diseases may offer an affordable treatment option for patients.

A Single-center, Open-label, Parallel Control Study Comparing the Pharmacokinetics and Safety of a Single Oral Dose of Roflumilast and Its Active Metabolite Roflumilast N-oxide in Healthy Chinese and Caucasian Volunteers

Roflumilast is a phosphodiesterase-4 inhibitor which treats chronic obstructive pulmonary disease (COPD). Roflumilast N-oxide is the major metabolite of roflumilast with a similar mechanism of action to roflumilast. Although racial differences in roflumilast drug disposition have been observed, the necessity of dose adjustment is subject to debate. This study compares the pharmacokinetics of a single 500 μg dose of roflumilast in healthy Chinese and Caucasian subjects under uniform conditions. Chinese subjects were found to have longer t_1/2 and higher AUC_0-t and C_max than Caucasian subjects. The point estimates on the geometric mean of AUC_0-t in Chinese subjects were 22% higher for roflumilast and 46% higher for roflumilast N-oxide. Point estimates on the geometric mean of C_max were 9% and 24% higher for roflumilast and roflumilast N-oxide, respectively. Total phosphodiesterase-4 (PDE4) inhibitory (tPDE4i) activity, a theoretical parameter that describes the combined contribution to PDE4 inhibitory activity of roflumilast and roflumilast N-oxide, was 44% higher in Chinese subjects than in Caucasian subjects. With about a 10-fold higher plasma AUC compared to the parent roflumilast and a much longer observed half-life, roflumilast N-oxide has been estimated to contribute about 90% of tPDE4i, with 10% attributed to the parent compound roflumilast. Following body weight normalization, these figures were lower but remained significant. Safety analysis showed signs of reduced tolerance or different pharmacodynamic response to roflumilast in Chinese recipients than in Caucasians. Our results suggest that Chinese patients should receive a dose of roflumilast lower than 500 μg daily during future clinical trials.

Adherence to roflumilast under dose-escalation strategy in Korean patients with COPD

Background

Frequent development of adverse events and consequent low adherence are major barriers in the wide use of roflumilast. Asian patients may be more susceptible to adverse events due to low BMI. In this study, we aimed to determine if a dose-escalation strategy is useful to improve the drug adherence rate.

Methods

This was a randomized, prospective, open-label, single-blind study to compare the adherence rate to roflumilast according to a dose-escalation or conventional dose strategy in patients with COPD in South Korea. Patients were randomized into two groups (1:1), either roflumilast 500 μg once daily for 12 weeks or roflumilast 250 μg once daily for 4 weeks, and then 500 μg for 12 weeks. The primary outcome was the percentage of patients prematurely discontinuing roflumilast due to adverse events.

Results

A total of 55 patients were randomly assigned to either a conventional-dose group (n=28) or a dose-escalation group (n=27). Discontinuation rates of roflumilast due to adverse events were 46.4% for the conventional-dose group and 59.3% for the dose-escalation group. The median time to discontinuation was not different between groups (58 days for the conventional-dose group, 56 days for the dose-escalation group, p=0.629). In a multivariate analysis, older age was a significant risk factor for drug discontinuation.

Conclusion

High discontinuation rates of roflumilast were observed in both groups regardless of the dose-escalation strategy. The frequent discontinuation suggests that the dose-escalation strategy may not be useful in Asian patients.

Clinical trial

This study is registered at www.ClinicalTrials.gov with identifier number NCT02018432.

Pharmacokinetics of single- and multiple-dose roflumilast: an open-label, three-way crossover study in healthy Chinese volunteers

Purpose

To determine the pharmacokinetic properties of the common tablet of roflumilast administered in single and multiple oral doses in Chinese subjects.

Subjects and methods

Both the single- and multiple-dose studies included 12 adults (6 males and 6 females). In this single-center, open-label study, single doses of 0.25, 0.375, and 0.5 mg were administered using a randomized, three-way crossover design, and then, the 0.375 mg dose was continued for 11 days once daily. The pharmacokinetic parameters for roflumilast and roflumilast N-oxide were determined and the safety evaluation included adverse events assessed by monitoring, physical examination, vital sign tests, and clinical laboratory tests.

Results

After every single dose, the time to the maximum concentration (C_max) of roflumilast (T_max) was 0.25–2.0 hours; thereafter, the concentration declined, with a mean half-life (t_1/2) of 19.7–20.9 hours over the range of 0.25–0.50 mg. As for roflumilast N-oxide, the mean t_1/2 was 23.2–26.2 hours. The area under curve from the beginning to 24 hours (AUC_{0–24 h}), the AUC until infinity (AUC_inf), and the C_max of roflumilast and roflumilast N-oxide increased in a dose-proportional manner. After multiple doses, the accumulation index (R_ac) on the 11th day of the steady state was ~1.63 for roflumilast and 3.20 for roflumilast N-oxide. No significant sex differences were observed in the pharmacokinetic parameters of roflumilast and roflumilast N-oxide. In addition, there were no serious adverse events across the trial.

Conclusion

Roflumilast was safe and well-tolerated in healthy volunteers, and a linear increase in its C_max and AUC values was observed at doses ranging from 0.25 to 0.50 mg.

Pharmacokinetic and Pharmacodynamic Modelling to Characterize the Tolerability of Alternative Up-Titration Regimens of Roflumilast in Patients with Chronic Obstructive Pulmonary Disease

BACKGROUND

In the OPTIMIZE study, 4 weeks of roflumilast 250 µg once daily before escalation to the approved 500 µg once daily maintenance dose reduced treatment discontinuations and improved tolerability to roflumilast among patients with chronic obstructive pulmonary disease (COPD). In this study, we present the pharmacokinetic (PK) results and PK/pharmacodynamic (PD) modelling data from OPTIMIZE.

METHODS

OPTIMIZE was a multicentre, double-blind, phase III study in which patients with severe COPD were randomized 1:1:1 to receive oral roflumilast 250 μg once daily, 500 μg every other day, or 500 μg once daily for 4 weeks, followed by 500 μg once daily for 8 weeks. A population PK (popPK) model characterized roflumilast exposure levels (total phosphodiesterase-4 inhibition [tPDE4i]). Furthermore, models characterized the percentage of patients with adverse events (AEs) of interest (PK/AE model), and time to discontinuation due to such AEs (PK/time-to-event model).

RESULTS

The popPK model adequately described average plasma concentrations and variability from 1238 patients. The percentage of patients with AEs of interest increased with predicted tPDE4i exposure (logit scale slope 0.484; confidence interval 0.262-0.706; p = 2 × 10-5). PK/time-to-event model analysis predicted that patients receiving the 250 μg up-titration regimen had significantly lower discontinuation rates and longer time to discontinuation compared with roflumilast 500 μg every other day or 500 μg once daily (p = 0.0014).

CONCLUSIONS

In this PK/PD model, a 4-week up-titration regimen with roflumilast 250 µg once daily was found to reduce discontinuations and improve tolerability, confirming the main clinical findings of the OPTIMIZE study. However, use of this lower dose as long-term maintenance therapy may not induce sufficient phosphodiesterase-4 inhibition to exert clinical efficacy, supporting the approval of 500 µg as maintenance dose.

TRIAL REGISTRATION

OPTIMIZE: NCT02165826; REACT: NCT01329029.

Acute administration of roflumilast enhances sensory gating in healthy young humans in a randomized trial

INTRODUCTION

Sensory gating is a process involved in early information processing which prevents overstimulation of higher cortical areas by filtering sensory information. Research has shown that the process of sensory gating is disrupted in patients suffering from clinical disorders including attention deficit hyper activity disorder, schizophrenia, and Alzheimer's disease. Phosphodiesterase (PDE) inhibitors have received an increased interest as a tool to improve cognitive performance in both animals and man, including sensory gating.

METHODS

The current study investigated the effects of the PDE4 inhibitor roflumilast in a sensory gating paradigm in 20 healthy young human volunteers (age range 18-30 years). We applied a placebo-controlled randomized cross-over design and tested three doses (100, 300, 1000 μg).

RESULTS

Results show that roflumilast improves sensory gating in healthy young human volunteers only at the 100-μg dose. The effective dose of 100 μg is five times lower than the clinically approved dose for the treatment of acute exacerbations in chronic obstructive pulmonary disease (COPD). No side-effects, such as nausea and emesis, were observed at this dose. This means roflumilast shows a beneficial effect on gating at a dose that had no adverse effects reported following single-dose administration in the present study.

CONCLUSION

The PDE4 inhibitor roflumilast has a favorable side-effect profile at a cognitively effective dose and could be considered as a treatment in disorders affected by disrupted sensory gating.

Potential synergistic effect of phosphodiesterase inhibitors with chemotherapy in lung cancer

Purpose: Lung cancer remains the leading cause of cancer-related deaths worldwide and novel therapeutic approaches targeting crucial pathways are urgently needed to improve its treatment. Differentiation-based therapeutics (Methylxanthines) and phosphodiesterase inhibitors (type 4 and 5), have been implicated in cancer treatment. Our objectives were to capture any potential anti-tumor effect of these drug combinations with chemotherapeutic agents in vitro. Methods: Theophylline as Methylxanthines, Roflumilast as phosphodiesterase type 4 (PDE4) inhibitor and Sildenafil as phosphodiesterase type 5 (PDE5) inhibitor are the drugs that we combined with the chemotherapeutic agents (Docetaxel, Cisplatin and Carboplatin) in vitro. Lung cancer cell lines (NCI-H1048-Small cell lung cancer-SCLC, A549- Non-small cell lung cancer-NSCLC) were purchased from ATCC LGC Standards. At indicated time-point, following 24h and 48h incubation, cell viability and apoptosis were measured with Annexin V staining by flow cytometry. Statistical analysis was performed by GraphPad Prism. Results: In SCLC, following 48h incubation, platinum combinations of carboplatin with roflumilast and sildenafil (p<0.001) and carboplatin with theophylline and sildenafil showed increased apoptosis when compared to carboplatin alone. Concerning the combinations of cisplatin, when combined with roflumilast, theophylline and sildenafil appeared with increased apoptosis of that alone (p<0.001, 24h and 48h incubation). In NSCLC, the 24h incubation was not enough to induce satisfactory apoptosis, except for the combination of cisplatin with roflumilast and theophylline (p<0.05) when compared to cisplatin alone. However, following 48h incubation, carboplatin plus sildenafil, carboplatin plus sildenafil, theophylline and roflumilast showed more cytotoxicity when compared to carboplatin alone (p<0.001). Docetaxel combinations showed no statistically significant results. Conclusion: The synergistic effect of PDE inhibitors with platinum-based agents has been demonstrated in lung cancer. Our suggestion is that these combinations could be used as additive and maintenance treatment in combination to antineoplastic agents in lung cancer patients.

Roflumilast, a phosphodiesterase-4 inhibitor, induces phagocytic activity in Greek COPD patients

Background

A new approach to the treatment of COPD includes controlling inflammation because of its important role in exacerbation of the disease. Recently, roflumilast has been added as a therapeutic option for COPD. Roflumilast is an oral phosphodiesterase-4 inhibitor that targets inflammatory cells involved in triggering exacerbations of COPD. The objective of the current study was to evaluate roflumilast for its contribution to phagocytic activity in COPD patients.

Methods

Twenty-one patients diagnosed with COPD received roflumilast once daily for 6 months in combination with fluticasone (an inhaled corticosteroid), salmeterol (a long-acting β2-agonist), and tiotropium (a long-acting muscarinic antagonist) or combinations of these agents. The main inclusion criterion was stable disease for at least the previous 30 days. Neutrophils and spirometric changes, ie, forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC), were measured in the COPD patients at indicated time points. The first sample was taken before receiving roflumilast, the second 3 months later, and the third after 6 months. Examination of defective phagocytosis was done by flow cytometry using a FagoFlowEx^® kit. The statistical analysis was performed using Statistica software.

Results

Our results indicate that phagocytic activity was increased after 3 and 6 months of treatment when compared with baseline (P<0.001). Similarly, FVC and FEV₁ were also increased during the 6-month period, but only FVC differed significantly from baseline (P<0.001).

Conclusion

Although the number of patients in this study was limited, our results indicate that roflumilast induces phagocytic activity, which improves lung function.

Roflumilast combined with adenosine increases mucosal hydration in human airway epithelial cultures after cigarette smoke exposure

Chronic obstructive pulmonary disease (COPD) is a growing cause of morbidity and mortality worldwide. Recent studies have shown that cigarette smoke (CS) induces cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction, which leads to airway-surface liquid (ASL) dehydration. This in turn contributes to the mucus dehydration and impaired mucociliary clearance that are seen in the chronic bronchitis form of COPD. Roflumilast is a phosphodiesterase 4 inhibitor that may improve lung function and reduce the frequency of exacerbations in patients with COPD. Although roflumilast can affect cAMP metabolism, little is known about the downstream pharmacological effects in the airways. We hypothesized that roflumilast would increase ASL rehydration in human bronchial epithelial cultures (HBECs) after chronic CS exposure. cAMP production was measured by Förster resonance energy transfer in HEK293T cells and by ELISA in HBECs. ASL height was measured by xz-confocal microscopy after air exposure or following HBEC exposure to freshly produced CS. Roflumilast had little effect on cAMP or ASL height when applied on its own; however, roflumilast significantly potentiated adenosine-induced increases in cAMP and ASL height in CS-exposed HBECs. Roflumilast increased the rate of ASL height recovery in cultures after CS exposure compared with controls. In contrast, the β2-adrenergic receptor agonists isoproterenol and salmeterol failed to increase ASL height after CS exposure. Our data suggest that roflumilast can increase ASL hydration in CS-exposed HBECs, which is predicted to be beneficial for the treatment of mucus dehydration/mucus stasis in patients with COPD chronic bronchitis.

What is in the guidelines about the pharmacological treatment of chronic obstructive pulmonary disease?

With the publication of the new guidelines (The Global Initiative for Chronic Obstructive Lung Disease 2011 and Guía Española de la COPD) on chronic obstructive pulmonary disease (COPD), the pharmacological treatment of this disease has changed substantially. In this article, the evidence supporting the use of pharmacological groups in COPD is summarized and the place of each of these drugs among the new therapeutic strategies is established. Although short-acting bronchodilators have been used as maintenance therapy for COPD for many years, few clinical trials are available on the efficacy and safety of these agents, whose role was defined at the very early stages of treatment. The introduction of long-acting bronchodilators, administered every 12 or 24 h, led to an increase in therapeutic effects and an improvement in both treatment adherence and dosage; therefore, both guidelines consider these drugs as the standard therapy for all types of patients and clinical phenotypes. The combination of long-acting bronchodilators from different families has been established as a new therapeutic approach for patients with persistent symptoms despite an appropriate bronchodilator treatment. Anti-inflammatory therapy with inhaled corticosteroids has been discussed at length, and is considered in the current guidelines as the treatment of choice in patients with a high risk of exacerbations associated with an impaired lung function or previous exacerbations, or presenting with phenotypes that are susceptible to the effect of corticosteroids. Roflumilast is a novel drug with a clearly defined indication. Finally, further evidence about other therapies, such as antibiotics or mucolytics, is emerging that will help define their appropriate use in selected patients. At present, pharmacological management of COPD is being re-evaluated. As long as we are able to apply the new treatment approaches to the clinical reality of our patients we will achieve greater benefits in both the short and the long term with a reduction in potential complications.