LY 2157299

Galunisertib (LY2157299 monohydrate) is a small-molecule inhibitor of TGFβR1 that binds antagonistically to TGFR1 to prevent the intracellular phosphorylation of SMAD2 and SMAD3.Phase I studies have demonstrated that galunisertib had an acceptable tolerability and safety profile in patients with advanced solid tumors.Recently the preclinical studies from Tran et al. demonstrated that galunisertib combined with anti-GD2 antibody Dinutuximab augmented the anti-tumor cytotoxicity of activated NK(aNK) cells which were activated ex vivo with K562.mbIL21 artificial antigen presenting cells.Galunisertib suppressed SMAD2 phosphorylation and restored the expression of DNAX Accessory Molecule-1,NKp30, NKG2D and TNF-related apoptosis-inducing ligand death ligand expression on aNK cells and also significantly enhanced the release of perforin and granzyme A from aNK cells and the direct cytotoxicity and ADCC of aNK cells against neuroblastoma cells in vitro.The combination of galunisertib, aNK cells plus dinutuximab reduced tumor growth and increased survival of mice xenografted with two neuroblastoma cell lines or a patient derived xenograft.In another study,galunisertib was shown to preserve the cytotoxic function of ex vivo expanded, highly activated NK cells and significantly improved eradication of liver metastases of colon cancer in mice treated with adoptive NK cells compared with mice receiving NK cells or TGF beta inhibition alone. Overall these studies demonstrate that the therapeutic efficacy of adoptive NK cell therapy clinically will be markedly enhanced by complementary approaches targeting TGF-beta signaling in vivo.

LY2157299 is a small molecule inhibitor of the TGF-β receptor type 1 kinase (IC50 = 56 nM). It has been used to study the role of TGF-β signaling in chemotherapy-induced expansion of cancer stem-like cells in triple negative breast cancer cell lines and xenografts. LY2157299 has also been shown to inhibit the migration and tumor growth of hepatocellular carcinoma cell lines by disrupting Smad-2 phosphorylation.[Cayman Chemical]