Recent Advances in Medicinal Chemistry of Phosphodiesterase 7 Inhibitors and their Potential Therapeutic Applications

Phosphodiesterase 7 (PDE7) is a key enzyme in the PDE superfamily responsible for degrading cyclic adenosine monophosphate (cAMP) in pro-inflammatory and immunomodulatory cells. Elevated PDE7 activity is associated with inflammatory processes and various diseases. Suppression of PDE7 raises cAMP levels, reducing mucous secretion, cellular inflammation, and airway obstruction. This review provides an overview of the role of PDE7 in inflammatory disorders and highlights recent advances in the development of selective PDE7 inhibitors for therapeutic applications.

The review consolidates findings on the structure-activity relationships of PDE7 inhibitors. Key structural classes of small molecule inhibitors, including quinazolinone derivatives, thiadiazines, pyrimidines, and others, are discussed alongside preclinical and clinical data on selective inhibitors such as BRL50481 and OMS527.

Selective PDE7 inhibitors have shown exposed potential in animal models to reduce cAMP degradation, leading to decreased inflammation and airway obstruction. BRL50481 remains the only commercially available selective PDE7 inhibitor, while OMS527 has progressed to clinical trials, demonstrating promise in treating inflammatory, neurological disorders, and leukemias.

Selective PDE7 inhibitors represent a novel therapeutic class for inflammatory and neurodegenerative diseases. Further research is characterised by immune dysregulation.