Table 1.

Comparison of ARX788 and T-DM1 in vitro activity in cell lines with variable HER2 expression.

ARX788T-DM1ARX788HER2 IHC/FISH reports
Cell lineTissueHER2 cell surface numberIC50 (nmol/L)Maximum efficacy (%)IC50 (nmol/L)Maximum efficacy (%)potency gain (fold)HER2 IHCa,b,cHER2 amplification (FISH)d,e
SK-BR-3Breast cancer1,132,0000.025770.057722.33+Positive
HCC1954Breast cancer911,0000.049710.075671.5NRNR
Calu-3Lung cancer900,0000.316491.22403.9NRNR
BT-474Breast cancer821,0000.250632.01468.03+NR
NCI-N87Gastric cancer750,0000.098680.130691.33+NR
SKOV-3Ovarian cancer645,0000.061520.059551.03+NR
MDA-MB-453Breast cancer117,0000.137334.1665302+Positive
JIMT-1Breast cancer106,0000.0976514.9811542+NR
MDA-MB-175Breast cancer62,0000.246402.15398.71+Negative
OVCAR-3Ovarian cancer46,000No activity (>30 nmol/L)19∼3052NANRNR
MCF-7Breast cancer21,000No activity (>30 nmol/L)0No activity (>30 nmol/L)0NA0NR
AC10Normal cardiomyocytes13,000No activity (>30 nmol/L)7No activity (>30 nmol/L)17NANRNR
MDA-MB-231Breast cancer12,000No activity (>30 nmol/L)0NDNDNA0Negative
MDA-MB-468Breast cancer0No activity (>100 nmol/L)22176NA0NR
  • Abbreviations: NA, not applicable; ND, not determined; NR, not reported.

  • aDako HercepTest IHC.

  • bVENTANA anti-HER2 (4B5) IHC.

  • cLi and colleagues (12).

  • dBartlett JMS, Ibrahim M, Jasani B, Morgan JM, Ellis I, Kay E, et al. External quality assurance of HER2 FISH and ISH testing: three years of the UK National External Quality Assurance Scheme. Am J Clin Pathol 2009;131:106–111.

  • ePathVysion HER-2 DNA Probe kit.