Table 4

Cytotoxic activity (IC50) in ng/ml of mutant immunotoxins on patient cells

Patient 1Patient 2Patient 3Patient 4Patient 5
GSSY (WT) vs. GTHW>1000490 ± 7034 ± 56.7 ± 2.3>1000
P < 0.01P < 0.01P < 0.01P < 0.01P < 0.01
GTHW vs. GSSY (WT)29 ± 1022 ± 21.5 ± 0.4<128 ± 6
P < 0.01P < 0.01P < 0.01P < 0.01P < 0.01
GYNW vs. GSSY (WT) vs. GTHW105 ± 4840 ± 53.4 ± 0.7N.D.a41 ± 2
P < 0.01P < 0.01P < 0.01
P < 0.01P < 0.05P < 0.05
GTTW vs. GSSY (WT) vs. GTHW>100095 ± 98.5 ± 31.5 ± 0.676 ± 9
P < 0.01P < 0.01P < 0.01P < 0.05P < 0.01
P < 0.01P < 0.01P < 0.01P < 0.01
GSTY vs. GSSY (WT) vs. GTHWN.D.N.D.15 ± 22.1 ± 0.7129 ± 50
P < 0.01P < 0.01P < 0.05P < 0.01
P < 0.01P < 0.05
  • Ficoll-purified mononuclear cells from patients were obtained by an approved protocol at the NIH. Cells were incubated with immunotoxins for 3 days at 37°C and pulsed with [3H]leucine for 6–8 h; protein synthesis was measured. IC50s are expressed in ng/ml; SDs are shown. Each assay was done in triplicate. Diagnosis for patients 1, 2, 3, and 5 was CLL; diagnosis for patient 4 was HCL variant.

  • a N.D., not determined.

  • Significance in difference between IC50s as in Table 3<$REFLINK> .