awd-12-281 and Disease-Models--Animal

elbion (formerly ASTA Medica) and GlaxoSmithKline are developing an inhaled formulation of AWD-12-281 for the potential treatment of chronic obstructive pulmonary disease (COPD). By May 2005, phase II trials of this 5-hydroxyindole PDE4 inhibitor for COPD were ongoing.

Topics: 3',5'-Cyclic-AMP Phosphodiesterases; Administration, Inhalation; Administration, Topical; Amides; Aminopyridines; Animals; Benzamides; Clinical Trials as Topic; Cyclic Nucleotide Phosphodiesterases, Type 4; Cyclopropanes; Dermatitis, Atopic; Disease Models, Animal; Drug Evaluation, Preclinical; Humans; Indoles; Inflammation; Lipopolysaccharides; Ovalbumin; Phosphodiesterase Inhibitors; Psoriasis; Pulmonary Disease, Chronic Obstructive; Respiratory Tract Diseases; Structure-Activity Relationship

The selective phosphodiesterase 4 (PDE4) inhibitor AWD 12-281 is structurally optimized for topical administration. It has potent effects in models of lung inflammation if administered as a dry powder inhalation. It has also demonstrated its anti-inflammatory property in a mouse model of cutaneous inflammation after topical administration. The aim of this study was to evaluate whether AWD 12-281 may be capable of penetrating human skin. Therefore a new guinea-pig model of allergic skin inflammation had to be developed. In ovalbumin-sensitized guinea-pigs, intracutaneous administration of ovalbumin results in a rapid development of allergic skin wheals. Topically administered AWD 12-281 was capable of reducing the development of wheals, indicating that this compound can penetrate the stratum corneum of guinea-pig skin as a predictor of human skin penetration. A secondary aim was the evaluation of a T cell subtype preference of AWD 12-281 since PDE4 inhibitors are said to preferentially inhibit Th2-type cytokines. Therefore, the effects of AWD 12-281 on a broad spectrum of Th1- and Th2-type cytokines were studied in tissue homogenates after allergen challenge in sensitized mice and in supernatants of anti CD3/anti-CD28-stimulated peripheral blood mononuclear cells (PBMCs). In both models, AWD 12-281 suppressed both T cell subtype cytokines indicating a broad spectrum activity of AWD 12-281. A further issue was to determine the duration of action and the concentration-response relationship of the topical activity of AWD 12-281 using a model of acute local inflammation--the arachidonic-acid-induced mouse ear oedema. The compound exhibited a dose-dependent effect with a minimally effective concentration of 0.3%; after repeated administration the minimally effective concentration was found to be 0.03%. A single administration of a 3% solution resulted in significant suppression of inflammation even 48 h after treatment. In conclusion, our results indicate that AWD 12-281 is a very promising drug candidate not only for the treatment of lung inflammation using inhalative administration but also for the treatment of atopic dermatitis.

Topics: Amides; Animals; Cytokines; Dermatitis, Allergic Contact; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Guinea Pigs; Humans; Indoles; Male; Mice; Permeability; Phosphodiesterase Inhibitors; Skin Absorption; Th1 Cells; Th2 Cells

AWD 12-281 (N-(3,5-dichloro-4-pyridinyl)-2-[1-(4-fluorobenzyl)-5-hydroxy-1H-indol-3-yl]-2-oxoacetamide), a phosphodiesterase 4 inhibitor, which is optimized for topical administration, was tested in a model of allergic dermatitis in mice. To obtain an allergic dermatitis, BALB/c mice were sensitized to toluene-2,4-diisocyanate (TDI). The allergic reaction was challenged by topical administration of TDI onto the mice ears. AWD 12-281 was tested for its anti-inflammatory potential by oral, intraperitoneal and topical administration. The phosphodiesterase 4 inhibitor, cilomilast (SB 207499), and/or the corticosteroid, diflorasone diacetate, were used as reference compounds. Given orally and intraperitoneally 2 h before as well as 5 and 24 h after TDI challenge, AWD 12-281 showed no, or only a transient inhibition of the allergen-induced ear swelling, whereas cilomilast significantly inhibited this ear swelling. Applied topically onto the ears before TDI challenge, AWD 12-281, cilomilast and diflorasone diacetate caused total inhibition of ear swelling 24 h after challenge, confirmed by a decrease of the pro-inflammatory cytokines interleukin-4, interleukin-6 and macrophage inhibitory protein-2. Administered topically after TDI challenge as therapeutic intervention, AWD 12-281 and diflorasone diacetate caused significant inhibition of ear swelling; cilomilast failed to do so. These results indicate that topically administered AWD 12-281 may be potent in the prevention and treatment of allergic/inflammatory skin diseases.

Topics: 3',5'-Cyclic-AMP Phosphodiesterases; Administration, Oral; Administration, Topical; Amides; Animals; Bronchodilator Agents; Carboxylic Acids; Cattle; Cyclic Nucleotide Phosphodiesterases, Type 4; Cyclohexanecarboxylic Acids; Cytokines; Dermatitis, Allergic Contact; Disease Models, Animal; Ear; Female; Indoles; Inflammation; Inflammation Mediators; Injections, Intraperitoneal; Mice; Mice, Inbred BALB C; Nitriles; Time Factors; Toluene