Table 1.
Patient Characteristics.
Fig 1.
AMG 330-induced cytotoxicity without addition of healthy donor T-cells.
(A) 41 primary AML specimens were incubated with increasing concentrations of AMG 330. After 48 hours, cell counts were determined and cytotoxicity was assessed with DAPI staining to quantify drug-specific cytotoxicity. Results are shown as mean±SEM. (B) Relationship between percentage of autologous T-cells and AMG 330-induced cytotoxicity. (C) Relationship between CD33 expression on leukemic blasts (expressed as arbitrary fluorescence intensity) and AMG 330-induced cytotoxicity. (D) AMG 330-induced cytotoxicity, stratified by disease stage (newly diagnosed AML [n = 21] and relapsed/refractory AML [n = 20]). Results are shown as mean±SEM. (E) AMG 330-induced cytotoxicity, stratified by disease risk (favorable-risk [n = 5]; intermediate-risk [n = 26]); and adverse-risk [n = 10]). Results are shown as mean±SEM.
Fig 2.
AMG 330-induced cytotoxicity in the presence of healthy donor T-cells.
Forty-one primary AML specimens were incubated with increasing concentrations of AMG 330 and T-cells from a single healthy donor at various effector:target (E:T) cell ratios as indicated. After 48 hours, cell counts were determined and cytotoxicity was assessed with DAPI staining to quantify drug-specific cytotoxicity. Results are shown as mean±SEM.
Fig 3.
Relationship between CD33 expression and AMG 330-induced cytotoxicity.
Relationship between CD33 expression on leukemic blasts (expressed as arbitrary fluorescence intensity) and drug-induced cytotoxicity with AMG 330 at 250 pg/mL (open symbol) and 500 pg/mL (closed symbol) in the presence of T-cells from a single healthy donor at an E:T cell ratio of (A) 1:3, (B) 1:1, and (C) 3:1, determined after 48 hours.
Fig 4.
AMG 330-induced cytotoxicity in the presence of healthy donor T-cells, stratified by disease stage and risk.
AMG 330-induced cytotoxicity at 48 hours, stratified by (A, B) disease stage (newly diagnosed AML [n = 21] and relapsed/refractory AML [n = 20]), and (C, D) cytogenetic/molecular disease risk (favorable-risk [n = 5]; intermediate-risk [n = 26]); and adverse-risk [n = 10]) in the presence of T-cells from a single healthy donor at an E:T cell ratio of 1:3 and 1:1, as indicated.
Fig 5.
Effect of AMG 330 on colony-forming cells (CFC).
AML cells were incubated without AMG 330 or in the presence of 100 pg/mL or 500 pg/mL of AMG 330 together with healthy donor T-cells (labeled with CellVue Burgundy dye) at an E:T cell ratio of 3:1. After 48 hours, CellVue Burgundy dye-negative primary AML cells were separated by FACS and subsequently cultured for up to 4 weeks. After 2 and 4 weeks, aliquots of cultures cells were subjected to CFC assays. 10–14 days later, CFU-GMs were quantified and plating efficiency determined. Data (CFU-GMs/10,000 plated cells) from aliquots incubated with AMG 330 and healthy donor T-cells are expressed relative to aliquots incubated without AMG 330 (with no-AMG 330 controls set at 100%). Depicted are data from 16 AML specimens that yielded CFU-GM growth without AMG 330.