Safety, Tolerability, and Pharmacokinetics of a Novel Oral Phosphodiesterase 4 Inhibitor, ME3183: First-in-Human Phase 1 Study.

A novel, oral phosphodiesterase 4 (PDE4) inhibitor, ME3183, is under development for the treatment of psoriasis, atopic dermatitis, and other inflammatory diseases. To evaluate its safety, tolerability, and pharmacokinetics, double-blind, placebo-controlled, single ascending dose (SAD), and multiple ascending dose (MAD) phase 1 studies were conducted in 126 healthy adults. The food effect was evaluated in a randomized, open-label, crossover manner (n = 5). ME3183 was safe and tolerable up to 25 mg in the SAD part and up to 10 mg twice daily in the MAD part. Frequently observed treatment-emergent adverse events included diarrhea and headache, as commonly reported for approved PDE4 inhibitors, providing no novel safety concerns. Pharmacokinetic analysis showed dose-dependent increases in Cmax and AUC, with later tmax and longer t1/2 than apremilast, an approved PDE4 inhibitor. The food effect study showed slightly decreased systemic exposure. In the MAD part, plasma exposure levels of ME3183 were higher even at the minimal dose (2.5 mg twice daily) than the estimated therapeutically effective level. These results show the safe profile of ME3183 and support further studies to confirm the safety and efficacy of the drug in patients with psoriasis and other inflammatory diseases.