[68Ga]Ga-DK223

[68Ga]Ga-DK223 is a **gallium-68-labeled cyclic peptide radiotracer** designed for PET imaging of **human PD-L1 (programmed death-ligand 1)** exposure in tumors[1][7]. DK223 is derived from DK221 and shows high specificity and affinity for human PD-L1, with a dissociation constant of approximately 1 nM[1]. The compound inhibits PD-1:PD-L1 interaction and accumulates in tumors expressing PD-L1, allowing noninvasive quantification of baseline and accessible PD-L1 levels in vivo by PET imaging. This is achieved significantly faster and with greater target-centric specificity than antibody-based radiotracers. The primary indication is for monitoring immune checkpoint therapies, patient screening, and quantifying drug-target engagement for immunotherapy in cancers such as triple-negative breast cancer (TNBC) and urothelial carcinoma (UC)[1][7]. [68Ga]Ga-DK223 is stable, efficiently cleared from non-target tissues, and is administered intravenously. Its imaging utility is based on radiolabeling with gallium-68 via chelation to DOTA.

Brand names

[68Ga]Ga-DK223

Other names

DK223 (parent peptide)Gallium-68–labeled DK223