rpl-554

Ensifentrine (Ensifentrinum) is a PDE3/4 inhibitor, although its affinity for PDE3(IC50: 0.4 nM) is 3,440 times higher than that for PDE4(IC50: 1479 nM), that is under clinical development for the treatment of asthma and COPD and, potentially, cystic fibrosis.

(E/Z)-Ensifentrine is a potent and selective PDE3/4 inhibitor that acts as a long-acting inhibitor of the phosphodiesterase enzymes PDE-3 and PDE-4, producing both bronchodilator and anti-inflammatory effects. It is being developed by Verona Pharma as a potential treatment for asthma and hay fever and is currently in clinical trials.

Ensifentrine (RPL-554) tosylate is an inhaled dual inhibitor of PDE3 and PDE4, with IC50 values of 0.4 nM and 1479 nM, respectively. By blocking these enzymes, it increases the levels of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) in lung cells, leading to bronchodilation and inhibition of inflammatory cell activation and migration. Ensifentrine tosylate is used in the study of chronic obstructive pulmonary disease (COPD).