Development of a Preclinical PK/PD Model to Assess Antitumor Response of a Sequential Aflibercept and Doxorubicin-Dosing Strategy in Acute Myeloid Leukemia.

Development of a Preclinical PK/PD Model to Assess Antitumor Response of a Sequential Aflibercept and Doxorubicin-Dosing Strategy in Acute Myeloid Leukemia.

AAPS J. 2013 Apr 3;
Fetterly GJ, Aras U, Lal D, Murphy M, Meholick PD, Wang ES

Timing of the anti-angiogenic agent with respect to the chemotherapeutic agent may be crucial in determining the success of combination therapy in cancer. We investigated the effects of sequential therapy with the potent VEGF inhibitor, aflibercept, and doxorubicin (DOX) in preclinical acute myeloid leukemia (AML) models. Mice were engrafted with human HL-60 and HEL-luciferase leukemia cells via S.C. and/or I.V. injection and treated with two to three doses of aflibercept (5-25 mg/kg) up to 3-7 days prior to doxorubicin (30 mg/kg) administration. Leukemia growth was determined by local tumor measurements (days 0-16) and systemic bioluminescent imaging (days 0-28) in animals receiving DOX (3 mg/kg) with or without aflibercept. A PK/PD model was developed to characterize how prior administration of aflibercept altered intratumoral DOX uptake. DOX concentration-time profiles were described using a four-compartment PK model with linear elimination. We determined that intratumoral DOX concentrations were 6-fold higher in the aflibercept plus DOX treatment group versus DOX alone in association with increased drug uptake rates (from 0.125 to 0.471 ml/h/kg) into tumor without affecting drug efflux. PD modeling demonstrated that the observed growth retardation was mainly due to the combination of DOX plus TRAP group; 0.00794 vs. 0.0043 h(-1). This PK/PD modeling approach in leukemia enabled us to predict the effects of dosing frequency and sequence for the combination of anti-VEGF and cytotoxic agents on AML growth in both xenograft and marrow, and may be useful in the design of future rational combinatorial dosing regimens in hematological malignancies. HubMed – drug


Stem cell maintenance and disease progression in chronic myeloid leukemia.

Int J Hematol. 2013 Apr 4;
Ito T

Chronic myeloid leukemia (CML) is a cancer of blood cells driven by the BCR-ABL1 oncogenic protein tyrosine kinase, which is the product of a reciprocal chromosomal translocation known as the Philadelphia chromosome. Discovery of tyrosine kinase inhibitors targeting the BCR-ABL1 kinase revolutionized CML therapy, but these drugs are unable to eradicate the disease due to the presence of a drug-insensitive stem cell population that sustains continued growth of the malignant cells. Resistance to therapies also increases the risk of relapse and disease progression to a more advanced phase. This review discusses emerging issues in CML research, and describes recent progress in elucidating the mechanisms of CML stem cell maintenance and disease progression. HubMed – drug


Icaritin induces AML cell apoptosis via the MAPK/ERK and PI3K/AKT signal pathways.

Int J Hematol. 2013 Apr 3;
Li Q, Huai L, Zhang C, Wang C, Jia Y, Chen Y, Yu P, Wang H, Rao Q, Wang M, Wang J

Icaritin, a hydrolytic product of icaritin, is isolated from the traditional Chinese medicinal herb epimedium. Icaritin inhibits the proliferation of several tumor cell lines, but its effect on acute myeloid leukemia (AML) and underlying mechanisms remain to be identified. In the present study, we demonstrated that icaritin inhibits the proliferation of human AML cell lines NB4, HL60, and U937, in a dose- and time-dependent manner. Importantly, icaritin showed anti-leukemia activity on bone marrow mononuclear cells from 15 newly diagnosed AML patients. Flow cytometry analyses indicated that icaritin induces AML cells apoptosis. Icaritin induced activation of caspase-9, -3, -7 and the cleavage of PARP as measured by Western blotting. Icaritin downregulates p-ERK and p-AKT and inhibits the expression of c-myc. These results suggest that icaritin is a promising candidate drug for the treatment of AML. The underlying mechanisms of icaritin anti-AML activity are associated with inhibition of the MAPK/ERK and PI3K/AKT signals and downregulation of c-myc. HubMed – drug