Table 1.

Toxicity of pretargeted RIT in athymic mice

	0 μCi	1200 μCi (44.4 MBq)				200 μCi (7.4 MBq)
Day	Untreated Control	CC49 (scFv)4-SA	1F5 Ab-SA	1F5 (scFv)4-SA	B9E9 (scFv)4-SA	DOTA-1F5 Ab, conventional	P*
WBCs, × 109/L
0	8.4 ± 1.3	5.2 ± 0.9	4.6 ± 1.7	6.2 ± 1.4	6.0 ± 1.9	3.3 ± 1.5	—
7	6.8 ± 2.7	3.1 ± 1.4	3.5 ± 1.3	3.3 ± 1.2	3.4 ± 1.2	0.8 ± 0.6	<.001
14	6.0 ± 1.7	5.6 ± 2.3	3.8 ± 1.9	5.4 ± 1.8	5.6 ± 2.6	1.4 ± 0.5	.009
21	6.1 ± 1.1	7.2 ± 2.5	5.0 ± 1.1	7.0 ± 1.2	6.5 ± 2.6	3.8 ± 1.4	.005
Hgb, g/dL†
0	15.2 ± 1.6	15.5 ± 0.4	15.2 ± 0.7	14.6 ± 1.2	16.2 ± 1.5	15.1 ± 1.5	—
7	14.6 ± 1.7	15.3 ± 0.3	15.0 ± 0.7	13.4 ± 1.8	14.6 ± 0.6	11.2 ± 2.0	—
14	14.7 ± 1.5	15.3 ± 1.0	13.9 ± 2.1	14.2 ± 1.5	15.3 ± 1.3	7.8 ± 2.6	<.001
21	15.0 ± 0.4	15.3 ± 1.2	15.2 ± 1.7	14.8 ± 0.9	15.4 ± 0.3	13.0 ± 1.5	—
Platelets, × 109/L
0	1411 ± 303	1522 ± 96	1270 ± 344	1198 ± 199	1414 ± 164	1288 ± 102	—
7	1165 ± 282	1561 ± 327	1157 ± 145	1054 ± 172	1398 ± 557	733 ± 113	.005
14	1561 ± 356	1707 ± 448	1239 ± 250	948 ± 192	1285 ± 463	880 ± 275	—
21	1173 ± 187	1650 ± 621	1298 ± 267	1092 ± 145	1278 ± 413	1153 ± 185	—

Serial measurements of leukocyte counts (WBC), hemoglobin (Hgb), and platelets were made in untreated control mice or in mice treated with either 200 μCi of directly radiolabeled ⁹⁰Y-DOTA-1F5 Ab or 1200 μCi ⁹⁰Y-DOTA-biotin following pretargeting with 1F5 (scFv)₄-SA, B9E9 (scFv)₄-SA, control CC49 (scFv)₄-SA, or 1F5 Ab-SA chemical conjugate. Data represent mean (n = 10) plus or minus the standard deviation (SD).

—indicates not significant.

^*P values are representative of significant differences between the 1F5 (scFv)₄-SA fusion protein and directly labeled DOTA-1F5 Ab.

^†For Hgb conversion to Sl units (g/L), multiply the given values by a factor of 10.