In the trial involving 1,176 patients, those receiving nerandomilast experienced a mean FVC decline of -98.6 mL for the 18 mg dose and -84.6 mL for the 9 mg dose, compared to -165.8 mL for the placebo group.

Diarrhea was the most common adverse event reported, affecting 36.6% of patients on the 18 mg dose, leading to more discontinuations compared to the placebo group.

Editorial comments have highlighted the need for future considerations regarding therapy choices and the role of immunosuppression in treating non-IPF interstitial lung disease (ILD).

The phase 3 FIBRONEER-ILD trial results indicate that the investigational oral agent nerandomilast significantly slows the decline in forced vital capacity (FVC) in patients with progressive pulmonary fibrosis (PF).

The adjusted differences in FVC decline between the nerandomilast and placebo groups were statistically significant, with a p-value of less than 0.001.

The study also reported mortality rates, with 24 deaths (6.1%) in the 18 mg group, 33 (8.4%) in the 9 mg group, and 50 (12.8%) in the placebo group, suggesting lower mortality in the nerandomilast groups.

While secondary endpoints related to acute exacerbations, hospitalizations, or deaths did not reach statistical significance, trends indicated potential benefits for nerandomilast.

Nerandomilast is a PDE-4B inhibitor, which has shown antifibrotic and immunomodulatory effects in preclinical studies.

Conducted at 403 sites across 44 countries, the trial randomized patients to receive either nerandomilast or placebo, with approximately 44% also on background therapy with nintedanib.

These findings were published in The New England Journal of Medicine and presented at the American Thoracic Society's 2025 International Conference.

Dr. Marlies S. Wijsenbeek from Erasmus Medical Center noted that these results mark a significant advancement in treating idiopathic pulmonary fibrosis (IPF), especially after a decade of unsuccessful trials.

Dr. Wijsenbeek emphasized that the FVC decline is the best available endpoint for this trial, despite ongoing debates about the appropriateness of trial endpoints.