CYM5442 is a potent, highly-selective and orally active sphingosine 1-phosphate (S1P1) receptor agonist with an EC₅₀ of 1.35 nM. CYM5442 is inactive against S1P2, S1P3, S1P4, and S1P5. CYM5442 activates S1P1-dependent p42/p44-MAPK phosphorylation. CYM5442 exerts retinal neuroprotection. CYM5442 can easily penetrate the central nervous system (CNS)^[1][2]. IC50 & Target: EC50: 1.35 nM (Sphingosine 1-phosphate (S1P1) receptor)^[1] In Vitro: CYM5442 (0.5 µM; 0-60 minutes; HEK293 cells) treatment stimulates S1P1 phosphorylation in a time-dependent manner in P32-orthophosphate labeled cells^[1].
CYM5442 activates S1P1-dependent p42/p44-MAPK phosphorylation in CHO-K1 cells transfected with S1P1 with an EC₅₀ of 46 nM. The R120 for alanine (R120A) mutant is still able to maintain p42/p44-MAPK activity when incubated with CYM5442 (EC₅₀ of 67 nM). Activation of p42/p44-MAPK by CYM5442 in E121A S1P1 cells is concentration dependent, with a mean EC₅₀ value of 134 nM^[1]. In Vivo: CYM5442 (1 mg/kg; intraperitoneal injection; daily; for 5 days; adult male albino Wistar rats) treatment shows preserved visual function of visual evoked potentials (VEP). Retinal nerve fiber layer (RNFL) is significantly thicker in the CYM treated-animals compared to the vehicle^[2].