Serum galectin-3 as a biomarker of progression of idiopathic pulmonary fibrosis treated with nintedanib.

Both serum and bronchoalveolar lavage fluid levels of galectin-3 (Gal-3) are elevated in patients with idiopathic pulmonary fibrosis (IPF). Phase II study on inhaler with Gal-3 inhibitor for IPF has been ongoing. In this study, 30 treatment-naive patients of IPF were prospectively enrolled and their sera were stored before and after nintedanib treatment. Though Gal-3 levels tended to increase after nintedanib treatment, in some patients, Gal-3 levels decreased immediately after the treatment. Patients whose serum Gal-3 levels decreased 1 month after nintedanib treatment tended to experience a smaller annual decline in forced vital capacity (FVC) than patients with increased Gal-3 levels. Furthermore, the rate of change in Gal-3 levels 1 month after nintedanib treatment positively correlated with the rate of annual FVC decline, whereas that of other fibrotic markers did not correlate with the rate of annual FVC decline. This study suggested that a decline in serum Gal-3 levels immediately after nintedanib treatment may predict less progression of IPF treated with nintedanib.