Tumor-Shed Antigen Affects Antibody Tumor Targeting: Comparison of Two ⁸⁹Zr-Labeled Antibodies Directed against Shed or Nonshed Antigens

Table 2

Effect of mAb dose on tumor-to-blood and tumor-to-organ uptake ratios of ⁸⁹Zr-amatuximab (2.96 MBq/10 or 60 µg) or ⁸⁹Zr-B3 (2.22 MBq/15 or 60 µg) in nude mice with A431/H9 tumor. The ratios were calculated by maximum uptake values from ROI analysis of PET images. Blood-H represents the blood activity in the heart. All values are reported as mean ± standard deviation ().

mAb	Time	Injection dose	Tumor/liver	Tumor/spleen	Tumor/muscle	Tumor/blood-H
Amatuximab	3 h	10 µg
Amatuximab	24 h	10 µg
Amatuximab	48 h	10 µg
Amatuximab	3 h	60 µg
Amatuximab	24 h	60 µg
Amatuximab	48 h	60 µg
B3	3 h	15 µg
B3	24 h	15 µg
B3	48 h	15 µg
B3	3 h	60 µg
B3	24 h	60 µg
B3	48 h	60 µg