An orally bioavailable inhibitor of the fibroblast growth factor receptor (FGFR) types 1, 2, and 3 (FGFR1/2/3) and colony stimulating factor 1 receptor (CSF1R; CSF-1R; CD115; M-CSFR), with potential immunomodulatory and antineoplastic activities. Upon administration, FGFR/CSF-1R inhibitor 3D185 binds to and inhibits FGFR1/2/3, which may result in the inhibition of FGFR1/2/3-mediated signal transduction pathways. This inhibits proliferation in FGFR1/2/3-overexpressing tumor cells. 3D185 also targets and binds to CSF1R, thereby blocking CSF1R activation and CSF1R-mediated signaling. This inhibits the activities of tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs), and prevents immune suppression in the tumor microenvironment (TME). This enhances antitumor T-cell immune responses and inhibits the proliferation of tumor cells. FGFR, a family of receptor tyrosine kinases (RTKs) upregulated in many tumor cell types, plays a key role in cellular proliferation, migration and survival. CSF1R, also known as macrophage colony-stimulating factor receptor (M-CSFR) and CD115 (cluster of differentiation 115), is a cell-surface receptor that plays major roles in tumor cell proliferation and metastasis.