In this article, we will discuss Cobimetinib (Mechanism of Action). So, let’s get started.
Mechanism of Action
Cobimetinib is a reversible inhibitor of mitogen-activated protein kinase (MAPK)/extracellular signal regulated kinase 1 (MEK1) and MEK2. MEK proteins are upstream regulators of the extracellular signal-related kinase (ERK) pathway, which promotes cellular proliferation. BRAF V600E and K mutations result in constitutive activation of the BRAF pathway which includes MEK1 and MEK2. In mice implanted with tumor cell lines expressing BRAF V600E, cobimetinib inhibited tumor cell growth. Cobimetinib and vemurafenib target two different kinases in the RAS/RAF/MEK/ERK pathway. Compared to either drug alone, coadministration of cobimetinib and vemurafenib resulted in increased apoptosis in vitro and reduced tumor growth in mouse implantation models of tumor cell lines harboring BRAF V600E mutations. Cobimetinib also prevented vemurafenib-mediated growth enhancement of a wild-type BRAF tumor cell line in an in vivo mouse implantation model.
Pharmacodynamics
Cardiac Electrophysiology
Clinically relevant QT prolongation has been reported with vemurafenib, further QTc prolongation was not observed when cobimetinib 60 mg daily was co-administered with vemurafenib. Monitor ECG and electrolytes before initiating treatment and routinely during treatment with cobimetinib, when administered with vemurafenib.