Nerandomilast Shows Promise for IIM-ILD, Approved for IPF/PPF

Nerandomilast (also known as BI 1015550 or commercially as JASCAYD® in approved indications), an investigational oral drug developed by Boehringer Ingelheim International, is demonstrating promising therapeutic effects in preclinical models for Idiopathic Inflammatory Myopathy-Associated Interstitial Lung Disease (IIM-ILD), according to a recent article in the European Medical Journal. This development is particularly noteworthy as it follows the drug's recent approvals by the U.S. Food and Drug Administration (FDA) in late 2025 for other severe fibrotic lung conditions, namely Idiopathic Pulmonary Fibrosis (IPF) and Progressive Pulmonary Fibrosis (PPF). IIM-ILD is a debilitating autoimmune condition characterized by inflammation of the muscles (myopathy) and progressive scarring of the lung tissue (interstitial lung disease). It is a severe disorder with currently limited effective treatment options, often leading to significant pulmonary fibrosis and impaired respiratory function. The preclinical study, highlighted by the European Medical Journal on March 12, 2026, indicates that nerandomilast effectively reduced lung inflammation and fibrosis in experimental mouse models of IIM-ILD. Researchers observed improvements in disease indicators, including reductions in muscle inflammation and pulmonary fibrosis, and a decrease in immune cell activity within the lung tissue, specifically targeting B cells. The mechanism of action for nerandomilast centers on its role as a preferential inhibitor of phosphodiesterase 4B (PDE4B). PDE4B is an enzyme found in immune cells and lung fibroblasts that plays a crucial role in regulating inflammation and tissue remodeling by breaking down cyclic adenosine monophosphate (cAMP). By inhibiting PDE4B, nerandomilast increases intracellular cAMP levels, which in turn reactivates anti-inflammatory and anti-fibrotic signaling pathways. This dual action helps to alleviate excessive immune responses, suppress fibrosis progression, and promote epithelial regeneration in the lungs. The positive preclinical findings for IIM-ILD extend the therapeutic potential of nerandomilast beyond its already established role in IPF and PPF. Boehringer Ingelheim, the developer, successfully conducted global Phase III clinical trials, FIBRONEER-IPF and FIBRONEER-ILD, which demonstrated that nerandomilast significantly slowed the rate of decline in Forced Vital Capacity (FVC) over 52 weeks in patients with IPF and PPF, respectively. FVC is a key measure of lung function, and a reduced rate of decline signifies a slowing of disease progression. Based on these compelling results, the FDA granted approval for nerandomilast (JASCAYD®) for the treatment of adult patients with IPF on October 7, 2025, and subsequently for PPF on December 19, 2025, in the USA. Regulatory submissions are also actively under review in other major markets, including China, Japan, and the European Union, indicating a global reach for this innovative therapy. The safety profile of nerandomilast in the Phase III trials was generally favorable, with common side effects predominantly gastrointestinal, such as diarrhea, nausea, and loss of appetite, as well as headache and fatigue. These side effects were generally manageable, with discontinuation rates due to adverse events being comparable to placebo in some studies. The development of nerandomilast marks a significant advancement in the treatment landscape for fibrotic lung diseases, offering a novel mechanism of action compared to previously available treatments like nintedanib and pirfenidone. Its potential in IIM-ILD, as suggested by preclinical data, offers new hope for patients suffering from this challenging autoimmune-related lung condition.

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