Background:

Cilomilast, also known as SB-207499 or Ariflo, is a potent second generation inhibitor of type 4 phosphodiesterase (PDE4), an enzyme metabolizing cellular cyclic adenosine monophosphate (cAMP) which acts as a second messenger to disrupt the function of inflammatory cell and induce airway smooth muscle relaxation. Cilomilast is currently used for the treatment of chronic obstructive pulmonary disease (COPD) due to its strong anti-inflammatory activity as well as inhibitory effects against the release of neutrophil chemoattractants (such as tumor necrosis factor TNF-?α, interleukin IL-8 and granulocyte-macrophage colony stimulating factor GM-CSF) and suppression of the recruitment of neutrophils into tissues and the LTB4 production.

Reference

[1].M Profita, G Chiappara, F Mirabella, RCDi Giorgi, L Chimenti, G Costanzo, L Riccobono, V Bellia, J Bousquet, and A M Vignola. Effect of cilomilast (Ariflo) on TNF-α, IL-8, and GM-CSF release by airway cells of patients with COPD. Thorax 2003; 58: 573-579
[2].Barry D. Zussman, Lisa J. Benincosa, Dawn M Webber, David j. Clark, Hugh Cowley, John Kelly, Robert D. Murdoch, James Upward, Peter Wyld, Andreas Port and Hermann Fuder. An overview of the pharmacokinetics of cilomilast (Ariflo), a new, orally active phosphodiesterase 4 inhibitor, in healthy young and elderly volunteers. J Clin Pharmacol 2001; 41: 950-958