PD-L1-IN-2, a Naamidine J derivative, serves as a promising antineoplastic immunomodulator by hindering PD-L1 activity. In vivo studies indicate that it suppresses PD-L1 expression and amplifies tumor-infiltrating T-cell response, thus exerting anticancer effects. This compound is particularly utilized in the investigation of colorectal cancer [1].

PD-L1-IN-2 (compound 11c) has an IC50 value of 31.7 μM against RKO cells [1]. In concentrations of 0-10 μM and over 0-24 hours, PD-L1-IN-2 inhibits PD-L1 expression in RKO cells dose- and time-dependently [1]. PD-L1-IN-2 also enhances PD-L1 protein turnover, as shown by an accelerated PD-L1 turnover rate in treated cells compared to untreated cells in a CHX pulse-chase assay [1].

Administered intraperitoneally at 25/50 mg/kg once daily for 16 days, PD-L1-IN-2 (compound 11c) resulted in tumor size reduction, with the 50 mg/kg group showing a 45% inhibition rate and significantly lower average tumor weight compared to the PBS group [1].