The invention belongs to the field of medicines, discloses an application of a CSF1R inhibitor in preparation of a
medicine for treating or relieving
myelofibrosis, and also discloses a
medicine for treating or relieving
myelofibrosis. According to the application disclosed by the invention, a
delta (5q) MDS mouse model constructed based on Diaph1- / -miR-146a- / -(DKO) is treated by giving a CSF1R inhibitor PLX3397, and the following positive effects are observed: PLX3397 can relieve
anemia symptoms of a DKO mouse, remarkably reduce the number of
peripheral blood and fibrocytes in the
spleen of the DKO mouse, reduce deposition of reticular fibers and collagenous fibers in
bone marrow and effectively improve
myelofibrosis. In addition, PLX3397 can also reduce the clone formation ability of
peripheral blood and
spleen of the DKO mouse and prolong the lifetime of the DKO mouse.
Flow cytometry analysis shows that PLX3397 treatment can increase the number of early erythroid
progenitor cells and LSK cells in
bone marrow of a DKO mouse, so that hematopoietic function defects of the DKO mouse are partially improved. Generally speaking, the invention reveals the potential
curative effect of PLX3397 in treating MDS mouse
disease models, and provides a new direction for treating and relieving myelofibrosis caused by
clinical treatment of MDS.