Lirimilast is reported to be 5-fold more effective than Cilomilast and equipotent with CDP-840, In PDE4 assays, using freshly prepared PDE4 from human PMNL[1].

When compared in a rat model of lung neutrophilic inflammation, Lirimilast is found to be 3-fold more potent than Cilomilast. Since Lirimilast is orally active in the guinea-pig at 3 mg/kg and in primates at 0.1 mg/kg/day it appears to have a good therapeutic ratio [2].