|
|
Blood, Vol. 109, Issue 5, 2112-2120, March 1, 2007
Beneficial effects of combining nilotinib and imatinib in preclinical models of BCR-ABL+ leukemias
Blood Weisberg et al.
109: 2112
Supplemental materials for: Weisberg et al, Vol 109, Issue 5, 2112-2120
Files in this Data Supplement:
- Figure S1. Effects of nilotinib and imatinib, alone and combined, on the proliferation of the imatinib-resistant Bcr-Abl point mutant T315I (PDF, 31.1 KB) -
(A) Effects of nilotinib alone, imatinib alone, or a combination of nilotinib and imatinib on Ba/F3.p210-T315I following 3 days of treatment. (B) Comparison of treatment of Ba/F3.p210-T315I and Ba/F3.p210-F317L with nilotinib alone versus a combination of nilotinib and imatinib.
- Figure S2. Effects of nilotinib and imatinib, alone and combined, on induction of apoptosis of wild-type Bcr-Abl–expressing cells (K562) following 2 days of treatment (PDF, 144 KB)
- Figure S3. Tumor burden in 32D.p210-luc+–injected NCR nude mice plotted as raw bioluminescence values (PDF, 20.6 KB)
- Figure S4. Effects of nilotinib (15 mg/kg) and imatinib (75 mg/kg), alone and combined, on growth of 32D.p210-luc+ cells in NCR nude mice (PDF, 14.9 KB) -
Mice were sublethally irradiated with a single fraction of 300 rads, and approximately 3 hours later, a total of 800,000 cells was injected by tail vein. Images were taken on day 3, day 6, and day 8 after intravenous injection of cells. By day 8 after intravenous injection, mice had received a total of 5 days of treatment with vehicle or drug. Mice were killed and preserved for histopathological analysis on day 11 after intravenous injection. Bioluminescence values are plotted as percent of baseline. Vehicle (n = 2), nilotinib only (n = 4), imatinib only (n = 4), nilotinib + imatinib (n = 4). The Student t test was used for statistical evaluation of this experiment and yielded P ≤ .065 (vehicle versus drug combination on day 8 after intravenous injection).
- Figure S5. Hematology profile data for 2 vehicle control–treated male NCR nude mice and 3 imatinib (75 mg/kg) + nilotinib (20 mg/kg)–treated male NCR nude mice (PDF, 11.9 KB) -
All mice were treated for a total of one week, after which time tail bleeds were performed and peripheral blood was analyzed between the 2 treatment groups.
- Figure S6. Proliferation study showing a 2-day treatment of Y253H-Ba/F3 cells (D) with nilotinib, imatinib, or a combination of nilotinib and imatinib (PDF, 13.1 KB) -
The IC25 combination index calculated for this experiment was determined to be 1.22. The IC50, IC75, and IC90 values needed for calculation of the combination index could not be calculated because the percent inhibition for imatinib alone in this study was maximally 29% (at 10 mM).
- Figure S7. Normal murine bone marrow colony assay (PDF, 11.4 KB) -
Colony count following 7 days of treatment.
- Figure S8. Comparison of effects of imatinib alone versus imatinib plus nilotinib on growth of Ba/F3.p210 cells versus K562 cells (PDF, 12.3 KB) -
We compared imatinib at 0.15 µM versus imatinib (0.075 µM) + nilotinib (3.75 nM), and show substantially more cell killing by the combination of nilotinib + imatinib compared with imatinib alone for the Ba/F3.p210 cell line than what is observed for K562. These results are consistent with the full dose-response curves corresponding to the synergy experiments performed in Weisberg et al1 and studies shown in the present article using the traditional Chou and Talalay2 approach to measure drug combination effects. For K562, the effects of imatinib alone at 0.15 mM are similar to those of imatinib at half the concentration, plus nilotinib at the equivalent of half the concentration of imatinib (considering the approximately 30-fold potency difference between the 2 compounds). This study supports our finding that the combination of imatinib + nilotinib is at least additive for the K562 cell line using the established protocol of Chou and Talalay,2 which entails dose-response curves that include the IC50 of each compound being investigated, as well as concentrations 4×, 2×, 0.5×, and 0.25× IC50 for the purpose of isobologram generation.
REFERENCES
1. Weisberg E, Manley PW, Breitenstein W, et al. Characterization of AMN107, a selective inhibitor of native and mutant Bcr-Abl. Cancer Cell. 2005;7:129-141.
2. Chou T-C, Talalay P. Quantitative analysis of dose-effect relationships: the combined effects of multiple drugs or enzyme inhibitors. Adv Enz Regul. 1984;22:27-55.
|
|
