Apilimod dimesylate is a potent and selective PIKfyve inhibitor (IC50 = 14 nM). Exhibits no significant activity at other lipid kinases and protein kinases, including PIP4K, PIP5K, mTOR, PI3K and PI4K. Inhibits cellular entry by SARS-CoV-2, MERS-CoV and MHV S pseudovirions. Apilimod dimesylate reduces the number of SARS-CoV-2-infected hiPSC-derived pneumocyte-like cells by 85% and inhibits SARS-CoV-2 replication in donor lung tissue. Also exhibits selective cytotoxicity in B-cell non-Hodgkin lymphoma compared with normal cells. Inhibits production of IL-12 and IL-23. In motor neurons derived from patients with amyotrophic lateral sclerosis (ALS) Apilimod dimesylate promotes exocytosis of neurotoxic proteins and in mouse ALS models, the compound reduces pathology and prolongs survival. Anti-inflammatory. Water-soluble.