MLN518 (formerly known as CT53518) is a novel, oral, small molecule drug specifically designed to inhibit type III receptor tyrosine kinases, including FLT3, PDGFR, and KIT. It is being developed by Millennium Pharmaceuticals.
MLN518 is being used in clinical trials against leukemias. It has not been tried against GIST to date. However, it has been mentioned as potentially being useful against GISTs with PDGFRA mutations of type D842V, for which imatinib does not work (Corless, Schroeder, Griffith et al, 2005). Because D842V is a mutation involving the intracellular kinase domain of PDGFRA, there may be potential for MLN518 to be active against the parallel KIT exon 17 mutations (involving the second kinase domain) that are resistant to imatinib.
For manufacturer information about this drug, link here.
For medical papers related to MLN518, link to this search in PubMed. See especially the paper by Corbin et al, 2004.