PD-1 and PD-L1 have been very successful for the treatment of various tumors, including NSCLC, urothelial cancer, melanoma, head and neck squamous cell cancer, and lymphoma. Researchers identified compound L7 as a potent PD-L1 inhibitor that blocked PD-1/PD-L1 interaction. Pharmacokinetic (PK) studies demonstrated that L7 was orally bioavailable. PK studies were conducted by Medicilon.

Reference:

Liu Liu, et al. Syntheses, Biological Evaluations, and Mechanistic Studies of Benzo[ c][1,2,5]oxadiazole Derivatives as Potent PD-L1 Inhibitors with In Vivo Antitumor Activity. J Med Chem. 2021 Jun 24;64(12):8391-8409. doi: 10.1021/acs.jmedchem.1c00392.