Table 1.

Synergistic indices of combination treatment with gefitinib and AG1024

Treatment A
Treatment B
Combination treatment
Index*
DrugConcentration (μmol/L)MGIP valueDrugConcentration (μmol/L)MGIP valueExpectedObserved§P value
Gefitinib10.855.3E−05AG102410.870.02990.730.690.0001241.05
50.707.5E−070.590.571.3E−091.03
50.651.9E−0910.870.02990.560.508.3E−081.12
50.707.5E−070.450.441.9E−101.022
100.594.3E−1010.870.02990.510.321.2E−121.59
50.707.5E−070.410.289.9E−141.46
  • NOTE: H460 cell proliferation treated with indicated concentrations of gefitinib, AG1024, or their combinations was calculated by the MTT assay.

    Abbreviation: MGI, mean growth inhibition rate = growth rate of treated group/growth rate of untreated group.

  • * Calculated by dividing the expected growth inhibition rate by the observed growth inhibition rate. An index more than 1 indicates synergistic effect and <1 indicates less than additive effect.

  • P value (two-sided) was calculated by t test compared with no treatment.

  • Growth inhibition rate of treatment A × growth inhibition rate of treatment B.

  • § Growth inhibition rate of combined treatment on treatments A and B.