AML is a highly lethal hematologic malignancy responsible for approximately 9000 deaths annually in the US. Therapy for the disease has not changed substantially in several decades, despite extensive clinical trials of cytotoxic chemotherapy. Thus, novel therapeutic approaches are necessary. Investigators at the University of Pennsylvania have demonstrated activation of the PI3 kinase pathway in nearly all primary AML samples and activation of this pathway is necessary for AML cell survival. Inhibition of PI3K's downstream effector, mammalian target of rapamycin (mTOR), using the clinically available reagent rapamycin dramatically enhances chemosensitivity of AML blasts and AML stem cells in preclinical models yet has minimal toxicity to normal marrow elements. We therefore completed a Phase I clinical trial demonstrating that safety of rapamycin and etoposide-based chemotherapy in relapsed/refractory AML. However, this trial was neither successful in validating target inhibition nor did it demonstrate an obvious advantage of the combination regimen in remission induction. To refine our approach, we performed a subsequent pilot study in which we tested a novel schedule of rapamycin and chemotherapy and I optimized a novel flow cytometric application to provide pharmacodynamic monitoring of mTOR inhibition in AML blasts. This demonstrated conclusive target inhibition during therapy and suggested that rapamycin improved chemotherapy response rate. Based upon these data, we propose in this application to: 1) Perform a Phase II clinical trial of rapamycin plus chemotherapy and establish a preliminary estimate of efficacy of the regimen's efficacy, 2) Perform pharmacodynamic analysis of samples from patients on this trial in order to determine if rapamycin inhibits mTOR signaling in leukemia cells, and 3) Study mechanisms of resistance to rapamycins using samples from the clinical trial and laboratory based approaches. Successful completion of this 5-year research plan will serve as practical and formal training and help establish my career as a translational researcher investigating the integration of signal transduction inhibitors into clinical therapeutics for AML.

Public Health Relevance

Approximately 12,000 cases of AML are diagnosed yearly in the United states but few patients are cured with existing therapy. This research project focuses on novel, targeted therapy as well as rigorous in-tumor pharmacodynamic target validation. As the PI3K pathway is implicated in the biology and chemotherapy response of many solid and hematologic malignancies, the project's findings may have far-reaching impact.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Mentored Patient-Oriented Research Career Development Award (K23)
Project #
5K23CA141054-03
Application #
8320343
Study Section
Subcommittee G - Education (NCI)
Program Officer
Lim, Susan E
Project Start
2010-09-03
Project End
2015-08-31
Budget Start
2012-09-01
Budget End
2013-08-31
Support Year
3
Fiscal Year
2012
Total Cost
$172,368
Indirect Cost
$12,768
Name
University of Pennsylvania
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104