Table 1.

CI and DRI for gefitinib and IFN-α combination

Cell linesp53 statusGefitinib ED50 (μmol/L)IFN-α ED50 (IU/mL)IC50 (r)DRI at IC50
GefitinibIFN-α
CAL 27Mutant1 ± 0.73,000 ± 8000.45 ± 0.1 (0.99 ± 0.001)4.01 ± 0.76.31 ± 1.9
KBNull/low wild-type5.4 ± 0.65,000 ± 1,0000.45 ± 0.09 (0.99 ± 0.001)5.24 ± 0.46.81 ± 0.9
HEP-2Wild-type30 ± 3.527,000 ± 8,0000.25 ± 0.08 (0.99 ± 0.001)18.30 ± 4.57.95 ± 0.4
  • NOTE: Mean ± SD of at least three different experiments done in quadruplicate. CIs were calculated for 50% cell survival (ED50) by isobologram analysis done on CalcuSyn software. DRI represents the order of magnitude (fold) of dose reduction obtained for ED50 effect in combination setting compared with each drug alone. r is the coefficient of correlation for the fitting between CIs and fractional effects.