LEO 39652, a dual-soft PDE4 inhibitor, demonstrates potent inhibition of PDE4 subtypes A, B, C, and D with respective IC50 values of 1.2 nM, 1.2 nM, 3.0 nM, and 3.8 nM. Additionally, it inhibits TNF-α with an IC50 of 6.0 nM, indicating its potential for topical Atopic dermatitis (AD) research [1].

PDE4C2:3.0 nM (IC50), PDE4A:1.2 nM (IC50), PDE4D:3.8 nM (IC50), PDE4B:1.2 nM (IC50), TNF-α:6.0 nM (IC50)

LEO 39652 shows unbound in vitro potency when measured as LPS induced TNF-α release in human peripheral blood mononuclear cells (PBMC), incubated in serum free medium. LEO 39652 shows a relatively high binding to human serum albumin[2].

LEO 39652 is inactivated both in blood and liver (dual-soft) while stabled in the skin[1].Pharmacokinetic AnalysisLEO 39652 exhibits total clearance (rats 930, minipigs 200 and monkey 300 mL/min/kg) and ratio to total AUC (rats 4, minipigs 6 and monkey 6 %) following intravenous administration (rats 0.075, minipigs 0.5 and monkeys 2.0 mg/kg)[1].