In this article we will discuss Midostaurin (Mechanism of Action). So, let’s get started.
Mechanism of Action
Midostaurin is a small molecule that inhibits multiple receptor tyrosine kinases. In vitro biochemical or cellular assays have shown that midostaurin or its major human active metabolites CGP62221 and CGP52421 inhibit the activity of wild type FLT3, FLT3 mutant kinases (ITD and TKD), KIT (wild type and D816V mutant), PDGFRα/β, VEGFR2, as well as members of the serine/threonine kinase PKC (protein kinase C) family.
Midostaurin demonstrated the ability to inhibit FLT3 receptor signaling and cell proliferation, and it induced apoptosis in leukemic cells expressing ITD and TKD mutant FLT3 receptors or overexpressing wild type FLT3 and PDGF receptors. Midostaurin also demonstrated the ability to inhibit KIT signaling, cell proliferation and histamine release and induce apoptosis in mast cells.
The effect of Midostaurin (75 mg twice daily for 3 days) on the QTc interval was evaluated in a randomized, placebo and moxifloxacin controlled, multiple-dose, blinded, parallel study. There was no clinically significant prolongation of QTc interval or relationship between changes in QTc and concentrations for midostaurin and its active metabolites (CGP62221 and CGP52421). The study duration was not long enough to estimate the effects of the metabolite CGP52421 on the
QT/QTc interval. In pooled clinical studies in patients with advanced SM, 4.7% patients had a post-baseline QTcF > 480 ms, no patients had a QTcF > 500 ms, and 6.3% patients had a QTcF > 60 ms compared to baseline.
In a randomized placebo-controlled study in patients with AML, the proportion of patients with QTc prolongation was higher in patients randomized to midostaurin as compared to placebo (QTcF > 480 ms: 10.1% vs 5.7%; QTcF > 500 ms: 6.2% vs 2.6%; QTcF > 60 ms: 18.4% vs 10.7%)