PD-1/PD-L1-IN-69

C57BL/6 mice (male, 6−8 weeks old, 18−22 g)^[1]

30; 60 mg/kg

i.g.; daily; 14 days

Sustained intragastric administration of QA9 was well tolerated, with no significant alterations in body weight or observable adverse effects.
QA9 exhibited pronounced dose-dependent antitumor activity.
At the higher dose (60 mg/kg), QA9 administration resulted in substantial reductions in tumor volume (75%) and tumor weight (79%), demonstrating superior efficacy compared to NP19 (65 and 70%, respectively) at an equivalent dosage.
The lower dose (30 mg/kg) also elicited significant antitumor effects, with reductions of 57% in tumor volume and 66% in tumor weight relative to vehicle-treated controls.
Histopathological assessment via H&E staining revealed intact cellular architecture and absence of necrosis across multiple organ systems in both treatment groups.
Flow cytometric analysis of tumor-infiltrating lymphocytes showed that QA9 treatment elevated activated helper T cells (CD3⁺ CD4⁺: 2.5%) and cytotoxic T cells (CD3⁺ CD8⁺: 7.8%) compared to the vehicle control (1.2 and 3.5%, respectively).