Jascayd (nerandomilast): a novel PDE4B inhibitor for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial pneumonia with poor prognosis and limited therapeutic options. Despite the introduction of pirfenidone and nintedanib, treatment discontinuation due to adverse effects remains common, highlighting the need for better-tolerated, mechanistically distinct agents. Jascayd (nerandomilast), a first-in-class selective phosphodiesterase-4B inhibitor developed by Boehringer Ingelheim, was approved by the FDA in October 2025 for adults with IPF. By elevating intracellular cyclic adenosine monophosphate (cAMP) in inflammatory and structural lung cells, nerandomilast suppresses pro-inflammatory cytokines and fibroblast activation, producing anti-inflammatory and antifibrotic effects with improved tolerability over nonselective PDE4 inhibitors. In phase 3 FIBRONEER-IPF and FIBRONEER-ILD trials, nerandomilast significantly reduced the annual rate of forced vital capacity decline versus placebo, regardless of concomitant antifibrotic use. Common adverse effects included mild diarrhea, nausea, and fatigue, with low discontinuation rates. Long-term extension data demonstrate sustained safety and lung function preservation. Offering both monotherapy and combination potential, Jascayd establishes a new therapeutic class that targets inflammation and fibrosis concurrently, representing a pivotal advancement toward personalized, multi-pathway treatment in IPF.