NPH16 is an orally active PD-1/PD-L1 inhibitor with an IC50 of 2.24 nM. It promotes apoptosis in HepG2 cells and demonstrates outstanding antitumor efficacy and favorable pharmacokinetic properties in vivo. NPH16 is applicable for liver cancer research.

NPH16 exhibits dose-dependent cytotoxicity against HepG2 cells within a co-culture system at concentrations ranging from 0-2 μM over a 48-hour period. Additionally, NPH16 interacts with human PD-L1 (dissociation constant K D = 54.6 nM) and mouse PD-L1 (dissociation constant K D = 51.6 nM) in a concentration-dependent manner at concentrations between 0.02-20 μM over a duration of 0-700 seconds.

In a C57BL/6 mouse model bearing HEPA1-6 liver cancer tumors, NPH16 (50-100 mg/kg, p.o., 7 days) demonstrated significant dose-dependent antitumor activity throughout the treatment period.