ABE171, also known as NVP-ABE171, is a potent and novel phosphodiesterase 4 inhibitor with anti-inflammatory activities. NVP-ABE171 inhibited the activity of phosphodiesterase 4A, 4B, 4C, and 4D with respective IC(50) values of 602, 34, 1230, and 1.5 nM. In human cells, NVP-ABE171 inhibited the eosinophil and neutrophil oxidative burst, the release of cytokines by T cells, and the tumor necrosis factor-alpha release from monocytes, in the nanomolar range. NVP-ABE171 inhibited the airway neutrophil influx and activation with an ED(50) in the range of 3 mg/kg. NVP-ABE171 shows activity both in vitro on human inflammatory cells and in vivo in animal models of lung inflammation.