LC-MS/MS determination of HY072808, a novel candidate for treating atopic dermatitis, and its active metabolite: Application to a first-in-human pharmacokinetic study.

HY072808 is a novel phosphodiesterase 4 inhibitor currently under clinical development to treat atopic dermatitis. The first step is to address the pharmacokinetics and safety after topical administration of HY072808 ointments in healthy humans. In this study, we developed a highly sensitive liquid chromatography-tandem mass spectrometry method to determine plasma HY072808 and its active metabolite, ZZ24, in tiny amounts. The plasma samples were prepared using a simple liquid-liquid extraction method. Liquid chromatographic separation was achieved by gradient elution. The MS/MS quantification was performed in positive ion mode via multiple reaction monitoring. The method showed satisfactory linearity from 10 to 4,000 pg/ml for HY072808 and ZZ24. There was no significant interference from blank plasma. The method was validated for accuracy and precision, matrix effect and extraction recovery, dilution integrity, injection carryover and stability according to the related guidelines of the regulatory authorities. The HY072808 and ZZ24 concentrations in human plasma from a clinical trial were determined using this method. In conclusion, the validated method was robust and could be utilized to support the clinical development of HY072808.

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 t1/2 and higher AUC0-t and Cmax than Caucasian subjects. The point estimates on the geometric mean of AUC0-t in Chinese subjects were 22% higher for roflumilast and 46% higher for roflumilast N-oxide. Point estimates on the geometric mean of Cmax 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.

Pharmacokinetics and tolerability of apremilast in healthy Korean adult men.

We performed a two-part study to evaluate the pharmacokinetics, safety, and tolerability of oral apremilast, a phosphodiesterase 4 inhibitor indicated for the treatment of psoriasis, in healthy Korean adult men. In part 1, there were 12 subjects who randomly received a single oral dose of apremilast at 20, 30, or 40 mg in each of 3 periods in a crossover fashion. In part 2, there were 16 subjects who randomly received 30 mg of apremilast or its matching placebo in a ratio of 3:1 twice daily for 14 days. Apremilast was rapidly absorbed (maximum concentration: ~2-3 h postdose), and eliminated according to a monoexponential pattern with a terminal-phase elimination half-life of 8-9 h. The exposure to apremilast increased in a dose-proportional manner and accumulation was 1.6-fold at steady-state. Apremilast was well-tolerated after a single oral administration and multiple oral administrations in Korean adult men; all of the treatment-emergent adverse events were mild and recovered without sequelae. In conclusion, apremilast was safe and well-tolerated in healthy Korean adult men when administered single oral doses of 20, 30, or 40 mg or when administered multiple oral doses of 30 mg b.i.d. for 14 days. Overall exposures increased in an approximate dose proportional manner in healthy Korean adult men.

Development of Apremilast Solid Dispersion Using TPGS and PVPVA with Enhanced Solubility and Bioavailability.

Apremilast (APST) is an effective inhibitor of phosphodieasterase 4 (PDE4) which is the first oral drug for the treatment of adult patients with active psoriatic arthritis. However, Apremilast's low solubility restricts its dissolution and bioavailability. In this study, APST solid dispersion with D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and Poly(1-vinylpyrrolidone-co-vinyl acetate) (PVPVA) was developed to improve the dissolution and bioavailability of APST by spray drying. A series of TPGS were synthesized to elucidate the effect of the ratio of monoester to diester on solubilizing capacity. X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and Fourier transform infrared spectrophotometry (FT-IR) were used to characterize the solid dispersion, and the results showed that APST was amorphous in solid dispersion. In vitro dissolution study showed that the dissolution rate of solid dispersion in phosphate buffered saline (pH 6.8) was remarkably increased, reaching a release of 90% within 10 min. Moreover, in vivo pharmacokinetics study revealed that the bioavailability of solid dispersion in rats had significant improvement. In particular, its Cmax and AUClast were nearly 22- and 12.9-fold greater as compared to APST form B, respectively. In conclusion, APST solid dispersion with TPGS and PVPVA is an alternative drug delivery system to improve the solubility and oral bioavailability of APST.

Protective effect of a novel phosphodiesterase 4 selective inhibitor, compound A, in diabetic nephropathy model mice.

Phosphodiesterase subtype 4 (PDE4) hydrolyzes cyclic AMP (cAMP), a secondary messenger that mediates intracellular signaling, and plays key roles in inflammatory and profibrotic responses. Clinical benefits of pentoxifylline, a non-selective PDE inhibitor, have been reported in patients with kidney disease. Here, we identified compound A as a potent and selective PDE4 inhibitor and evaluated its potential as a novel therapeutic agent for diabetic nephropathy (DN). To determine its in vivo efficacy on DN, uninephrectomized (UNx-) db/db mice and KKAy mice were used as DN mice models. Eight-week repeated dosing with compound A (1-10 mg/kg, QD, p.o.) showed dose-dependent and significant suppressive effects on glycosylated hemoglobin (GHb) and urinary albumin/creatinine ratio (UACR) in UNx-db/db mice. These effects are more potent than irbesartan, a clinically approved angiotensin II receptor blocker of DN. Moreover, compound A suppressed pro-fibrotic and pro-inflammatory marker mRNAs and increased anti-reactive oxygen species marker mRNAs in the kidneys of UNx-db/db mice. The similar effect of compound A on UACR was also demonstrated by 8-week repeated dose in KKAy mice, another model for DN with intact leptin axis. Taken together, these data suggest that the PDE4-selective inhibitor compound A has potential as a new therapeutic agent for DN with multiple mechanisms of action including anti-diabetic, anti-fibrotic, and anti-reactive oxygen species effects.

New imidazopyridines with phosphodiesterase 4 and 7 inhibitory activity and their efficacy in animal models of inflammatory and autoimmune diseases.

Herein, we describe the rapid synthesis of a focused library of trisubstituted imidazo[4,5-b]pyridines and imidazo[4,5-c]pyridines from 2,4-dichloro-3-nitropyridine using the combination of solution-phase/solid-phase chemistry as new potential anti-inflammatory agents in the treatment of autoimmune diseases. Structure-activity relationship studies, followed by the structure optimization, provided hit compounds (17 and 28) which inhibited phosphodiesterase 4 (PDE4) with IC50 values comparable to rolipram and displayed different inhibitory potency against phosphodiesterase 7 (PDE7). Among them, compound 17 showed a beneficial effect in all the studied animal models of inflammatory and autoimmune diseases (concanavalin A-induced hepatitis, lipopolysaccharide-induced endotoxemia, collagen-induced arthritis, and MOG35-55-induced encephalomyelitis). In addition, compound 17 showed a favorable pharmacokinetic profile after intraperitoneal administration; it was characterized by a fast absorption from the peritoneal cavity and a relatively long terminal half-life in rats. It was found to penetrate brain barrier in mice. The performed experiments sheds light on the impact of PDE7A inhibition for the efficacy of PDE4 inhibitors in these disease conditions.

Evaluating Dermal Pharmacokinetics and Pharmacodymanic Effect of Soft Topical PDE4 Inhibitors: Open Flow Microperfusion and Skin Biopsies.

PURPOSE: To investigate the difference in clinical efficacy in AD patients between two topical PDE4 inhibitors using dermal open flow microperfusion and cAMP as a pharmacodynamic read-out in fresh human skin explants. METHODS: Clinical formulations were applied to intact or barrier disrupted human skin explants and both skin biopsy samples and dermal interstitial fluid was sampled for measuring drug concentration. Furthermore, cAMP levels were determined in the skin biopsies as a measure of target engagement. RESULTS: Elevated cAMP levels were observed with LEO 29102 while no evidence of target engagement was obtained with LEO 39652. In barrier impaired skin the dISF concentration of LEO 29102 was 2100 nM while only 33 nM for LEO 39652. For both compounds the concentrations measured in skin punch biopsies were 7-33-fold higher than the dISF concentrations. CONCLUSIONS: Low unbound drug concentration in dISF in combination with minimal target engagement of LEO 39652 in barrier impaired human skin explants supports that lack of clinical efficacy of LEO 39652 in AD patients is likely due to insufficient drug availability at the target. We conclude that dOFM together with a pharmacodynamic target engagement biomarker are strong techniques for establishing skin PK/PD relations and that skin biopsies should be used with caution.

Roflumilast Cream Improves Signs and Symptoms of Plaque Psoriasis: Results from a Phase 1/2a Randomized, Controlled Study.

Background: Roflumilast cream (ARQ-151) is a highly potent, selective phosphodiesterase-4 inhibitor in development for once-daily topical treatment of chronic plaque psoriasis. Objectives: To assess the safety and efficacy of once-daily roflumilast cream 0.5% and 0.15% in patients with chronic plaque psoriasis. Methods: This phase 1/2a study enrolled a single-dose, open-label cohort (Cohort 1: 0.5% cream applied to 25 cm² psoriatic plaques), and a 28-day, double-blinded cohort (Cohort 2: 1:1:1 randomization to roflumilast cream 0.5%, 0.15%, or vehicle). Patients had chronic plaque psoriasis of >6 months' duration with ≤5% body surface area involvement. Outcomes included safety (adverse events) and efficacy (percentage change in the Target Plaque Severity Score [TPSS] × Target Plaque Area [TPA]) at week 4. Results: For Cohorts 1 (n=8) and 2 (n=89), adverse events (all mild/moderate; none severe or serious) were similar between active arms and vehicle. Treatment-related events were confined to the application site, without differences between drug and vehicle. No patient discontinued treatment due to adverse events. The primary efficacy endpoint was met for both roflumilast cream doses: TPSS×TPA improvement at week 4 was statistically significant for roflumilast 0.5% (P=0.0007) and 0.15% (P=0.0011) versus vehicle; significance was reached as early as 2 weeks. For both roflumilast cream doses, 66%-67% improvement from baseline was observed at week 4, without reaching a plateau, versus 38% improvement for vehicle. Conclusion: Roflumilast cream was safe and highly effective at doses of 0.5% and 0.15% and represents a potential novel once-daily topical therapy for the treatment of chronic plaque psoriasis. ClinicalTrials.gov NCT03392168. J Drugs Dermatol. 2020;19(8): doi:10.36849/JDD.2020.5370.

Predictors of Systemic Exposure to Topical Crisaborole: A Nonlinear Regression Analysis.

Crisaborole ointment, 2%, is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild to moderate atopic dermatitis. Results from 2 randomized, double-blind, vehicle-controlled phase 3 studies showed that twice-daily crisaborole in children and adults with mild to moderate atopic dermatitis was efficacious and well tolerated. Initial pharmacokinetics (PK) studies of crisaborole indicated absorption with measurable systemic levels of crisaborole. The current analysis was conducted to correlate steady-state systemic exposure parameters with ointment dose and identify covariates impacting PK parameters in healthy participants and patients with atopic dermatitis or psoriasis. A nonlinear regression analysis was conducted using ointment dose and noncompartmental PK parameters at steady state (area under the curve [AUCss ] and maximum concentration [Cmax,ss ]). PK data were available from 244 participants across 6 clinical studies (AUCss , N = 239; Cmax,ss , N = 241). Disease condition had the greatest impact on slope in both models, corresponding to 2.5-fold higher AUCss and Cmax,ss values at a given ointment dose in patients with atopic dermatitis or psoriasis relative to healthy participants. Disease severity, race/ethnicity, and sex had marginal effects on AUCss and Cmax,ss . Systemic exposures were similar across age groups ≥2 years of age when the same percentage of body surface area (%BSA) was treated. Predictive performance plots for AUCss and Cmax,ss for different age groups demonstrated that the models adequately describe the observed data. Model predictions indicated that systemic exposure to crisaborole in pediatric patients (2-17 years) is unlikely to exceed systemic exposure in adults (≥18 years), even at the highest possible ointment dose corresponding to a %BSA of 90.

Safety, Effectiveness, and Pharmacokinetics of Crisaborole in Infants Aged 3 to < 24 Months with Mild-to-Moderate Atopic Dermatitis: A Phase IV Open-Label Study (CrisADe CARE 1).

BACKGROUND: Crisaborole ointment, 2%, is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild-to-moderate atopic dermatitis (AD). OBJECTIVES: The aim of this study was to evaluate the safety, effectiveness, and pharmacokinetics (PK) of crisaborole in infants aged 3 to < 24 months with mild-to-moderate AD in an open-label study. METHODS: Infants (3 to < 24 months) with Investigator's Static Global Assessment (ISGA) of mild (2) or moderate (3) and percentage of treatable body surface area (%BSA) ≥ 5 received crisaborole twice daily for 28 days; a cohort with moderate AD per ISGA and %BSA ≥ 35 were included in a PK analysis. Endpoints included safety (primary), efficacy, and PK (exploratory). RESULTS: Included were 137 infants total (mean age [SD], 13.6 months [6.42]), with 21 in the PK cohort (12.7 months [6.58]). Treatment-emergent adverse events (TEAEs) were reported for 88 (64.2%) patients (98.9% rated as mild/moderate). TEAEs were considered treatment-related for 22 patients (16.1%); most frequently reported were application site pain (3.6%), application site discomfort (2.9%), and erythema (2.9%). ISGA clear/almost clear with ≥ 2-grade improvement at day 29 was achieved by 30.2% of patients. From baseline to day 29, mean percentage change in Eczema Area and Severity Index score was - 57.5%, and mean change in Patient-Oriented Eczema Measure total score was - 8.5. Crisaborole systemic exposures in infants were characterized and, based on nonlinear regression analysis, were comparable with that in patients aged ≥ 2 years. CONCLUSIONS: In this open-label study, crisaborole was well tolerated and effective in infants (3 to < 24 months) with mild-to-moderate AD with systemic exposures similar to patients aged ≥ 2 years. CLINICAL TRIAL REGISTRATION: NCT03356977.

Atopic dermatitis (AD) is a skin disease that causes inflamed and itchy skin. Crisaborole is an ointment that is approved to treat patients aged 2 years and older with mild-to-moderate AD. This clinical trial studied crisaborole in infants with mild-to-moderate AD who were 3 to under 24 months old. These infants were treated with crisaborole twice a day for 28 days. The trial studied crisaborole's safety, effectiveness, and absorption into the bloodstream. In total, 137 infants were treated. Although side effects of some sort occurred in about two-thirds of patients, only 1 in 6 patients experienced side effects that were attributed to crisaborole. When these side effects did occur, these were mainly pain, discomfort, or redness where crisaborole was applied. Fewer than 1 in 25 patients experienced each side effect where crisaborole was applied. The doctors saw improvement in the AD symptoms of some patients at day 29 of the study compared to the beginning of the study. Crisaborole blood-level measurements in this age group were consistent with those seen in patients aged 2 years and older. Overall, crisaborole was considered well tolerated and effective in infants (3 to under 24 months old) with mild-to-moderate AD. Safety, Effectiveness, and Pharmacokinetics of Crisaborole in Infants Aged 3 to < 24 Months with Mild-to-Moderate Atopic Dermatitis: An Open-Label, Phase 4 Study (MP4 40891 MB).

Discovery and Optimization of α-Mangostin Derivatives as Novel PDE4 Inhibitors for the Treatment of Vascular Dementia.

To validate PDE4 inhibitors as novel therapeutic agents against vascular dementia (VaD), 25 derivatives were discovered from the natural inhibitor α-mangostin (IC50 = 1.31 µM). Hit-to-lead optimization identified a novel and selective PDE4 inhibitor 4e (IC50 = 17 nM), which adopted a different binding pattern from PDE4 inhibitors roflumilast and rolipram. Oral administration of 4e at a dose of 10 mg/kg exhibited remarkable therapeutic effects in a VaD model and did not cause emesis to beagle dogs, indicating its potential as a novel anti-VaD agent.

In Silico, Ex Vivo and In Vivo Studies of Roflumilast as a Potential Antidiarrheal and Antispasmodic agent: Inhibition of the PDE-4 Enzyme and Voltage-gated Ca++ ion Channels.

The aim of the present study was to evaluate the possible gut inhibitory role of the phosphodiesterase (PDE) inhibitor roflumilast. Increasing doses of roflumilast were tested against castor oil-induced diarrhea in mice, whereas the pharmacodynamics of the same effect was determined in isolated rabbit jejunum tissues. For in silico analysis, the identified PDE protein was docked with roflumilast and papaverine using the Autodock vina program from the PyRx virtual screening tool. Roflumilast protected against diarrhea significantly at 0.5 and 1.5 mg/kg doses, with 40% and 80% protection. Ex vivo findings from jejunum tissues show that roflumilast possesses an antispasmodic effect by inhibiting spontaneous contractions in a concentration-dependent manner. Roflumilast reversed carbachol (CCh, 1 µM)-mediated and potassium (K+, 80 mM)-mediated contractile responses with comparable efficacies but different potencies. The observed potency against K+ was significantly higher in comparison to CCh, similar to verapamil. Experiments were extended to further confirm the inhibitory effect on Ca++ channels. Interestingly, roflumilast deflected Ca++ concentration-response curves (CRCs) to the right with suppression of the maximum peak at both tested doses (0.001-0.003 mg/mL), similar to verapamil. The PDE-inhibitory effect was authenticated when pre-incubation of jejunum tissues with roflumilast (0.03-0.1 mg/mL) produced a leftward deflection of isoprenaline-mediated inhibitory CRCs and increased the tissue level of cAMP, similar to papaverine. This idea was further strengthened by molecular docking studies, where roflumilast exhibited a better binding affinity (-9.4 kcal/mol) with the PDE protein than the standard papaverine (-8.3 kcal/mol). In conclusion, inhibition of Ca++ channels and the PDE-4 enzyme explains the pharmacodynamics of the gut inhibitory effect of roflumilast.

Pharmacokinetics and safety of apremilast in pediatric patients with moderate to severe plaque psoriasis: Results from a phase 2 open-label study.

BACKGROUND: No oral systemic treatments are approved for pediatric patients with psoriasis. OBJECTIVE: To evaluate the pharmacokinetics and safety of apremilast, an oral phosphodiesterase 4 inhibitor, in pediatric patients with psoriasis. METHODS: This phase 2, multicenter, open-label study enrolled pediatric patients with moderate to severe plaque psoriasis. Patients received apremilast twice daily without titration for 2 weeks (group 1 [age, 12-17 years; weight, ≥35 kg]: apremilast 20 or 30 mg; group 2 [age, 6-11 years; weight, ≥15 kg]: apremilast 20 mg), followed by a 48-week extension. Primary endpoints were pharmacokinetics and safety. Other endpoints were taste/acceptability and change from baseline in score on the Psoriasis Area and Severity Index. RESULTS: A total of 42 enrolled patients (21 adolescents [age, 12-17 years] and 21 children [age, 6-11 years]) received apremilast. Pharmacokinetics modeling and noncompartmental analyses showed that weight-based dosing with apremilast 20 mg twice daily in children or apremilast 20 or 30 mg twice daily in adolescents provides exposure (area under the concentration-time curve from time 0 to 12 hours after the dose) that is comparable to that achieved with apremilast 30 mg twice daily in adults. The safety profile was generally similar to that in adults. Most study participants liked the taste of the tablet. Improvements from baseline in mean Psoriasis Area and Severity Index score were 68% for adolescents (overall) and 79% for children. LIMITATIONS: No children weighing less than 20 kg were enrolled. CONCLUSIONS: This first-time-in-children phase 2 study supports weight-based apremilast dosing for future phase 3 studies of pediatric plaque psoriasis.

Phase 1 study of crisaborole in Japanese healthy volunteers and patients with atopic dermatitis.

Crisaborole ointment, 2%, is a non-steroidal phosphodiesterase 4 inhibitor for the treatment of mild to moderate atopic dermatitis (AD). This parallel-cohort, phase 1 study was conducted to investigate skin irritation potential and safety of crisaborole in healthy Japanese adults (cohort 1) and the safety and pharmacokinetic profile of crisaborole and metabolites AN7602 and AN8323 in Japanese adults with mild to moderate AD (cohort 2). In cohort 1, 20 healthy volunteers received single applications of crisaborole and vehicle simultaneously on separate locations under 48-h occlusion. In cohort 2, 12 patients with mild to moderate AD received crisaborole (n = 10) or vehicle (n = 2) twice daily for 8 days. Skin irritation and safety were assessed in cohort 1. Pharmacokinetics and safety were assessed in cohort 2. Skin irritation index (scale 0-400) was 40.0 for crisaborole and 5.0 for vehicle. No treatment-emergent adverse events (TEAE) were reported in cohort 1. The most common TEAE in the crisaborole group in cohort 2 were application site irritation (n = 7) and application site pain (n = 4). Crisaborole was rapidly absorbed, with limited systemic exposure between days 1 and 8 that was comparable with that seen in US-based participants in previous trials. Crisaborole had higher skin irritation than vehicle under occlusion in healthy Japanese adults and had an acceptable safety profile in Japanese adults with mild to moderate AD.

Crystal structures, dissolution and pharmacokinetic study on a novel phosphodiesterase-4 inhibitor chlorbipram cocrystals.

Cocrystallization of chlorbipram (ChBP), a novel phosphodiesterase-4 (PDE) inhibitor with water insoluble property developed in our lab, was performed to improve the physicochemical properties and bioavailability in the present study. Three new cocrystals with fumaric aicd (FA), gentisic acid (GA) and salicylic acid (SA) as coformers were synthesized and fully characterized by using the combination of multi-techniques. The cocrystals are phase stable even under high humidity conditions. In vitro study indicates that the solubility of ChBP-GA and ChBP-SA cocrystals increase to 3724.4 ±â€¯58.7, 2897.4 ±â€¯81.9 µg/mL in comparison with ChBP (2561.3 ±â€¯150.4 µg/mL), the intrinsic dissolution rates (IDRs) of ChBP-GA and ChBP-SA cocrystals (721.3 ±â€¯8.0, 614.4 ±â€¯13.2 µg/min/cm2) are both higher than ChBP (537.9 ±â€¯12.0 µg/min/cm2). The blood concentration peak values of ChBP-GA and ChBP-SA cocrystals (165.8 ±â€¯50.9, 105.3 ±â€¯35.6 ng/mL) are both higher than ChBP (51.3 ±â€¯15.1 ng/mL) in in vivo evaluation. It presents the same order in in vitro/vivo study: ChBP-GA > ChBP-SA > ChBP > ChBP-FA. ChBP-FA cocrystal presents a longer elimination half life (t1/2 = 10.0 ±â€¯2.6 h), which makes it a potential candidate for prolonged controlled release formulation. ChBP-GA and ChBP-SA cocrystals both present enhanced solubility and bioavailability in comparison with ChBP, making them a better candidate for the solid dosage formulation development.

WBQ5187, a Multitarget Directed Agent, Ameliorates Cognitive Impairment in a Transgenic Mouse Model of Alzheimer's Disease and Modulates Cerebral ß-Amyloid, Gliosis, cAMP Levels, and Neurodegeneration.

Previously, we designed, synthesized, and evaluated a series of quinolone-benzofuran derivatives as multitargeted anti-Alzheimer's disease (anti-AD) compounds, and we discovered that WBQ5187 possesses superior anti-AD bioactivity. In this work, we investigated the pharmacokinetics of this new molecule, as well as its therapeutic efficacy in restoring cognition and neuropathology, in the APP/PS1 mouse model of AD. Pharmacokinetic analyses demonstrated that WBQ5187 possessed rational oral bioavailability, metabolic stability, and excellent blood-brain barrier (BBB) permeability. Pharmacodynamics studies indicated that a 12-week treatment with the lead compound at doses of 40 mg/kg or higher significantly enhanced the learning and memory performance of the APP/PS1 transgenic mice, and the effect was more potent than that of clioquinol (CQ). Furthermore, WBQ5187 notably reduced cerebral ß-amyloid pathology, gliosis, and neuronal cell loss and increased the levels of cAMP in the hippocampus of these mice. The surrogate measures of emesis indicated that WBQ5187 had no effect at its cognitive effective doses. Overall, our results demonstrated that this compound markedly improves cognitive and spatial memory functions in AD mice and represents a promising pharmaceutical agent with potential for the treatment of AD.

Structure-Aided Identification and Optimization of Tetrahydro-isoquinolines as Novel PDE4 Inhibitors Leading to Discovery of an Effective Antipsoriasis Agent.

Psoriasis is a common, chronic inflammatory disease characterized by abnormal skin plaques, and the effectiveness of phosphodiesterase 4 (PDE4) inhibitor to lessen the symptoms of psoriasis has been proved. Aiming to find a novel PDE4 inhibitor acting as an effective, safe, and convenient therapeutic agent, we constructed a library consisting of berberine analogues, and compound 2 with a tetrahydroisoquinoline scaffold was identified as a novel and potent hit. The structure-aided and cell-based structure-activity relationship studies on a series of tetrahydro-isoquinolines lead to efficient discovery of a qualified lead compound (16) with the high potency and selectivity, well-characterized binding mechanism, high cell permeability, good safety and pharmacokinetic profile, and impressive in vivo efficacy on antipsoriasis, in particular with a topical application. Thus, our study presents a prime example for efficient discovery of novel, potent lead compounds derived from natural products using a combination of medicinal chemistry, biochemical, biophysical, and pharmacological approaches.

Oleic acid as the active agent and lipid matrix in cilomilast-loaded nanocarriers to assist PDE4 inhibition of activated neutrophils for mitigating psoriasis-like lesions.

Both phosphodiesterase (PDE4) inhibitors and omega-9 fatty acids show anti-inflammatory activity for treating inflamed skin diseases, but their efficacy remains low. Combinatorial agents are anticipated to offer an advanced strategy for efficient therapy. We prepared cilomilast-loaded oleic acid (OA) nanocarriers to test the inhibitory capability against human neutrophil stimulation and a murine psoriasis model. OA played dual roles in the nanocarriers as both the active ingredient and lipid matrix in the nanoparticulate core. OA nanoparticles but not free OA could restrain calcium mobilization in activated neutrophils. The inhibition level of superoxide anion and elastase by cilomilast-loaded OA nanocarriers approximated that of free forms. In the mouse model, the intradermal nanosystems reduced imiquimod-induced epidermal thickening from 230.4 to 63.1 µm. Transepidermal water loss was decreased from 30.2 to 11.3 g/m2/h by integrated nanocarriers. The nanosystems mitigated neutrophil infiltration and hyperproliferation in the psoriasiform lesion via decreased expression of cytokines and chemokines. STATEMENT OF SIGNIFICANCE: The long-term therapy for psoriasis is unsatisfactory due to the possible adverse effects and inefficiency after prolonged use. Both phosphodiesterase (PDE4) inhibitors and omega-9 fatty acids such as oleic acid (OA) show anti-inflammatory activity for treating inflamed skin diseases. Combinatorial agents are anticipated to offer an advanced strategy for efficient therapy. OA is also ideal for incorporation into nanoparticles to enhance particulate emulsification, drug entrapment, and biocompatibility. We prepared cilomilast-loaded oleic acid (OA) nanocarriers to test the inhibitory capability against human neutrophil stimulation and a murine psoriasis lesion. OA nanocarriers are indigenous to prevent neutrophil activation and the deterioration of psoriatic lesion. Cilomilast incorporation in OA nanocarriers could further mitigate the clinical score and suppressing proinflammatory mediators.

Pharmacokinetic disposition of topical phosphodiesterase-4 inhibitor E6005 in patients with atopic dermatitis.

Background: A novel topical phosphodiesterase-4 inhibitor E6005 shows potential as effective treatment option for atopic dermatitis (AD); however, systemic exposure may cause potentially undesirable adverse reactions. In this study, we evaluated the relationship between the systemic exposure of E6005 and clinical parameters including skin condition and the incidence of AEs in patients with AD. Methods: The association analysis used the clinical data obtained in a previously conducted clinical study with topical E6005 in adult patients with AD. To estimate associations with drug exposure, generalized estimating equation logistic regression models were used, along with clinical data and plasma concentrations of M11, the major metabolite of E6005 (as an indicator for E6005 exposure). Results: The metabolite M11 was detected in 62 of 221 plasma samples from 72 subjects. From association analysis, SCORAD-A obtained prior to E6005 treatment was identified as the clinical parameter influenced to M11 detection with statistical significance (p = .003). M11 detection was not clearly associated with the incidence of adverse events occurred. Conclusion: Exposure to topical E6005 is associated with the eczema-associated area, however, that is not distinctly associated with its adverse drug reactions occurred after drug applications possibly due to E6005's characteristics of tissue distribution.

Safety, tolerability, and pharmacokinetics of single and repeat ascending doses of CHF6001, a novel inhaled phosphodiesterase-4 inhibitor: two randomized trials in healthy volunteers.

PURPOSE: The purpose of this study was to evaluate safety, tolerability, and pharmacokinetics (PK) of CHF6001, an inhaled phosphodiesterase-4 inhibitor. MATERIALS AND METHODS: Two healthy volunteer, randomized, double-blind, placebo-controlled studies were conducted. In each, Part 1 evaluated single ascending doses, with PK sampling up to 48 hours post-dose; Part 2 evaluated multiple ascending doses (Study 1, 7 days; Study 2, 14 days), with PK sampling up to 24 hours post-dose on first and last day of each period. In Study 1, treatments were administered via single-dose dry-powder inhaler (SDDPI; Aerolizer): Part 1, 20, 100, 200, 400, 800, 1,600, and 2,000 µg or placebo; Part 2, 100, 300, 600, 1,200, and 1,600 µg or placebo once daily (OD). In Study 2, treatments were administered via multi-dose dry-powder inhaler (MDDPI; NEXThaler): Part 1, 2,400, 4,000, and 4,800 µg or placebo; Part 2, 1,200, 2,000, or 2,400 µg twice daily (BID) or placebo. Modeling and simulation then compared OD and BID dosing via MDDPI. RESULTS: There was a clear correlation between CHF6001 dose and plasma concentration, following single and multiple doses and using SDDPI and MDDPI. CHF6001 plasma concentration area under the curve (AUC) was dose proportional, with steady state slopes of the fitted line of 0.95 (90% CI: 0.86, 1.04) for AUC0-24 h in Study 1, and 0.85 (90% CI: 0.38, 1.32) for AUC0-12 h in Study 2. Bioavailability was30% higher with MDDPI than SDDPI. The PK simulation confirmed dose proportionality; the same total daily dose OD or BID via MDDPI resulted in similar 24 hours exposure, with BID dosing providing smaller fluctuation and lower maximum concentration. CHF6001 was well tolerated with no relationship between dose and adverse events. CONCLUSION: CHF6001 demonstrated a good safety profile. There was a clear dose proportionality for systemic exposure, with higher bioavailability via MDDPI, suggesting that the MDDPI provides better pulmonary drug deposition. BID dosing was associated with a better exposure profile.