Table 1 Quality testing results for three sequential lots of kits for the preparation of ¹¹¹In[In]-BnDTPA-trastuzumab-NLS injection

Protein concentration

4.5–5.5 mg/mL

5.3

5.4

5.4

Volume

0.95–1.05 mL

1.0

1.0

1.0

pH

5.5–6.0

6.0

6.0

6.0

Appearance

Clear, pale yellow, particle-free

Passed

Passed

Passed

BnDTPA substitution

2.0–7.0 BnDTPA/trastuzuumab

3.9

3.8

5.1

NLS peptide substitution

(SDS-PAGE)

Upward shift in major band for BnDTPA-trastuzumab-NLS compared to BnDTPA-trastuzumab

Passed

Passed

Passed

Purity and homogeneity (SDS-PAGE)

Non-reducing conditions: 1 major band (170 kDa)

Reducing conditions:

2 major bands (50 kDa and 25 kDa)

Passed

Passed

Passed

Purity and homogeneity (SE-HPLC)

1 major peak at t_R = 11.7 ± 0.2 min

Passed

Passed

Passed

¹¹¹In Labeling efficiency (ITLC)

 ≥ 90%

99.0

98.4

98.6

HER2 binding (SK-BR-3 cells)

K_a = 1.0–8.0 × 10⁸ L/mole; B_max = 0.5–2.0 × 10⁶ sites/cell

6.2 ± 0.9 x 10⁸ L/mole;

0.9 ± 0.03 x 10⁶ sites/cell

4.6 ± 0.7 x 10⁸ L/mole;

0.9 ± 0.2 x 10⁶ sites/cell

5.6 ± 1.0 x 10⁸ L/mole; 

0.9 ± 0.05 x 10⁶ sites/cell

Sterility

USP Sterility Test

Passed

Passed

Passed

Endotoxins

USP Bacterial Endotoxins Test

Passed

Passed

Passed