Table 1.

Comparative in vitro characterization of SMCC-DM1 conjugates of five humanized anti-FRα monoclonal antibodies and a humanized nontargeting antibody

Anti-FRα antibodyKd, nmol/LaIC50, nmol/Lb
huFR1-480.19 ± 0.080.07 ± 0.02
huFR1-490.08 ± 0.070.07 ± 0.01
huFR1-570.18 ± 0.060.15 ± 0.02
huFR1-650.16 ± 0.070.08 ± 0.02
M9346A0.08 ± 0.020.10 ± 0.02
Nontargeting AbThere was no detectable binding at 10 nmol/LThere was no detectable cytotoxicity at 10 nmol/L

NOTE: Data represent the mean ± SD of three independent experiments.

  • aApparent affinity, flow-cytometric binding assay on Skov-3 cells; the affinities of the conjugates were similar to the affinities of the respective antibodies.

  • bThe cytotoxicities of anti-FRα-SMCC-DM1 conjugates for KB cells, five-day continuous exposure.