Discovery of Small-Molecule TIM‑3 Inhibitors for Acute Myeloid Leukemia Using Pharmacophore-Based Virtual Screening

T-cell immunoglobulin and mucin domain 3 (TIM-3) is a
negative
immune checkpoint that represents a promising target for cancer immunotherapy.
Although encouraging results have been observed for TIM-3 inhibition
in the context of acute myeloid leukemia (AML), targeting TIM-3 is
currently restricted to monoclonal antibodies (mAbs). To fill this
gap, we implemented a pharmacophore-based screening approach to identify
small-molecule TIM-3 inhibitors. Our approach resulted in the identification
of hit compounds with TIM-3 binding affinity. Subsequently, we used
the structure–activity relationship (SAR) by a catalog approach
to identify compound A-41 with submicromolar TIM-3 binding
affinity. Remarkably, A-41 demonstrated the ability to
block TIM-3 interactions with key ligands and inhibited the immunosuppressive
function of TIM-3 using an in vitro coculture assay.
This work will pave the way for future drug discovery efforts aiming
at the development of small-molecule inhibitors TIM-3 for AML.