Tirbanibulin (KX-01) is the first clinical Src inhibitor of the novel 
peptidomimetic class that targets the peptide substrate site of Src providing 
more specificity toward the Src kinase. This study assessed the impact of KX-01 
on cobalt chloride (CoCl2)-treated L929 cells and bleomycin (BLM)-induced 
pulmonary fibrosis in rats to evaluate the efficacy of this compound in vitro 
and in vivo, respectively. In CoCl2-treated L929 cells, KX-01 significantly 
reduced the expression of smooth muscle actin (α-SMA), collagen I, collagen III, 
hypoxia inducing factor (HIF-1α), signal transducers and transcriptional 
activators (p-STAT3), and p-Src. In BLM-induced pulmonary fibrosis rats, KX-01 
reduced pathological scores, collagen deposition, α-SMA, collagen I, collagen 
III, p-Src, HIF-1α, and p-STAT3. Overall, these findings revealed that KX-01 can 
alleviate experimental pulmonary fibrosis via suppressing the p-SRC/p-STAT3 
signaling pathways.