MSC2015103

MSC2015103 is an orally bioavailable, selective, and potent small molecule inhibitor of MEK1 and MEK2 (MEK1/2). Developed by EMD Serono (Merck KGaA) as a follow-up to pimasertib, it was designed to optimize brain pharmacokinetic properties. Preclinical studies in glioblastoma models demonstrated that MSC2015103 effectively crosses the blood-brain barrier and exhibits a higher brain tumor-to-normal brain exposure ratio compared to pimasertib. This profile suggests a potentially improved therapeutic index by maintaining target inhibition (phospho-ERK) in tumor tissue while minimizing modulation in normal brain tissue, which may also reduce ocular toxicities associated with other MEK inhibitors.