Masitinib

Masitinib is an inhibitor of the receptor tyrosine kinase c-Kit (IC₅₀ = 200 nM for the recombinant human enzyme).¹ It is also an inhibitor of PDGFRα, PDGFRβ, and Lyn B (IC₅₀s = 540, 800, and 510 nM, respectively). Masitinib inhibits stem cell factor-induced proliferation of Ba/F3 cells expressing wild-type KIT (IC₅₀ = 150 nM), as well as those expressing the KIT mutants KIT^V559D and KITΔ27 (IC₅₀s = 3 and 5 nM, respectively). It reduces tumor growth in a KITΔ27-expressing Ba/F3 murine model of cancer. Masitinib is also an inhibitor of the severe acute respiratory coronavirus 2 (SARS-CoV-2) main protease (M^pro; K_i = 2.6 µM), also known as 3C-like protease (3CL^pro), and inhibits replication of SARS-CoV-2 in infected A549 cells (EC₅₀ = 3.2 µM).² It decreases lung and nose viral titers, as well as reduces lung inflammation and increases survival, in ACE2-humanized mice infected with SARS-CoV-2 when administered at a dose of 25 mg/kg.

WARNING This product is not for human or veterinary use.

1. Dubreuil, P., Letard, S., Ciufolini, M., et al. Masitinib (AB1010), a potent and selective tyrosine kinase inhibitor targeting KIT. PLoS One 4(9), e7258 (2009).

2. Drayman, N., DeMarco, J.K., Jones, K.A., et al. Masitinib is a broad coronavirus 3CL inhibitor that blocks replication of SARS-CoV-2. Science 373(6557), 931-936 (2021).