For decades, the bleomycin model has served as the primary tool for evaluating antifibrotic candidates in pulmonary fibrosis research. Yet as the field has matured, it has become increasingly clear that reliance on a single preclinical model is insufficient to capture the biological complexity, chronic progression, and therapeutic responses observed in human disease.

Key Discussion Points:

• The strengths and limitations of traditional models, including bleomycin, and how they fit within a broader preclinical evaluation strategy
• How emerging platforms such as human lung tissue models, organoids, and PCLS are being used to complement in vivo studies and improve translational relevance
• Detecting safety signals and drug–drug interactions early in development to better inform clinical trial design and regulatory discussions