TABLE 1

In vitro activity of JNJ-28871063 and comparators

Inhibition of kinase activity was determined in vitro with human recombinant enzymes. Each measurement was performed at least in duplicate and IC50 values were calculated in 2 - 8 separate experiments

ErbB family kinase
IC50
JNJ-28871063
Lapatinib
Gefitinib
Erlotinib
nM
Inhibition of ErbB kinase activity
ErbB1 (EGFR) 22 ± 10 11 ± 0.5a 11 ± 5 16 ± 1
ErbB2 (HER2) 38 ± 28 9 ± 0.75a 85 ± 3 281 ± 18
ErbB4 (HER4) 21 ± 4 367 ± 4a 210 ± 8 472 ± 32
Inhibition of ErbB receptor phosphorylation in cells
SKBR3b 223 ± 34 32 ± 1 4311 ± 6 >100,000
A431c
107 ± 46
63 ± 13
9 ± 2
5 ± 2

  • ↵ a Rusnak et al. (2001).

  • ↵ b Inhibition of unstimulated HER2 receptor phosphorylation.

  • ↵ c Inhibition of EGF-stimulated EGFR receptor phosphorylation.