Information LDC4297 is a novelCDK7inhibitor (IC50=0.13±0.06 nM for CDK7 versus IC50s between 10 nM and 10,000 nM for all other analyzed CDKs). Targets CDK7 (Cell-free assay) 0.13 nM In vitro LDC4297 inhibits CDK7 in vitro in the nano-picomolar range. The affinity of LDC4297 for CDK7 proves to be extremely high. The replication of HCMV in cultured primary human fibroblasts (HFFs) is inhibited by LDC4297 in a concentration-dependent manner with a 50% effective concentration (EC50) value of 24.5 ± 1.3 nM. Notably, CDK7 inhibition by LDC4297 is not associated with general cytotoxicity at submicromolar concentrations. In contrast, LDC4297 induces cytotoxicity in a set of tumor cell lines, i.e., already at extremely low, nanomolar concentrations in specific cases. Anti-HCMV activity of LDC4297 is exerted through a multifaceted mode of action that involves an interference with virus-induced Rb phosphorylation. In vivo The PK analyses of LDC4297 performed thus far have also been highly promising. An analysis of the PK parameters in CD1 mice reveals positive characteristics after oral administration, as demonstrated for a single-dose treatment (100 mg/kg of LDC4297. The half-life (t 1/2z ) is determined to be 1.6 h, and a time (Tmax) to a mean peak plasma concentration of 1,297.6 ng/ml is reached 0.5 h after administration, with a continued presence of LDC4297 plasma levels for at least 8 h and a bioavailability of 97.7%. Cell Research(from reference) Cell lines：human fibroblasts Concentrations：0.1 to 50 μM Incubation Time：3 days