Pacmilimab

Pacmilimab (CX-072) is a Probody immune checkpoint inhibitor targeting programmed death-ligand 1 (PD-L1) that exhibits antitumor activity. Pacmilimab achieves tumor-selective activation by exposing the PD-L1 binding site through cleavage by tumor microenvironment-specific proteases. Upon activation, it binds to PD-L1 with high affinity, blocking the PD-1/PD-L1 pathway, lifting immune suppression, and restoring T-cell antitumor activity. Pacmilimab is indicated for the study of solid tumors.

Pacmilimab demonstrated anti-tumor effects in MC38 tumor model mice that matched the effects of the parental antibody at the same dose. [1]
Pacmilimab predominantly clustered in tumor tissues of PD-L1-expressing mice, with minimal uptake in peripheral non-tumorigenic lymphoid tissues. This distributional property suggests that its uptake in non-tumorigenic PD-L1-expressing tissues is limited and may contribute to the maintenance of immune self-tolerance. [1]
Methods: A tumor-bearing MDA-MB-231 BALB/c nude mouse model was established; ⁸⁹Zr-Pacmilimab and ⁸⁹Zr-PbCtrl were administered intravenously, followed by PET imaging and in vitro distribution studies on days 1, 3, and 6; a dose-escalation group was established to validate target specificity.
Results: ⁸⁹Zr-Pacmilimab specifically accumulated in the tumor; on day 6, the tumor-to-blood ratio was 2.1-fold higher than that of PbCtrl. Tumor uptake of CX-072 was PD-L1-dependent, while spleen uptake did not exhibit target-mediated characteristics.[2]

Human

Monoclonal

Unconjugated