The brain-penetrant drug ibudilast, which prevents the binding of MIF to CD74, decreased brain metastasis in experimental models in vivo and in patient-derived organotypic cultures ex vivo in a primary tumor-agnostic manner. These findings suggest that MIF/CD74-induced reprogramming of myeloid cells in brain disorders is a vulnerability that could be exploited therapeutically against brain metastases, and possibly other brain disorders.