Our team pioneered the concept of oral signal transduction therapy and disease stabilization endpoints with our work with CAI. Expansion of our approach to signal transduction therapy combinations continues and we have added microproteomic techniques with which to analyze proof of concept and illustration of mechanism of drug modulation of signal pathway in tumor samples. Our driving hypothesis is that combinations focusing on signaling steps in series or in parallel may affect the pathway in a fashion such that there will be a need for less drug for the same or better outcome. We reported ability to demonstrate presence of target, activation of target, and modulation of target in core tissue biopsies obtained on our Phase II trials of imatinib and gefitinib in ovarian cancer patients. The biochemical observations coupled with the lack of single agent/limited target activity has led to our current focus on coupling agents in series to address key signaling hubs or receptor/downstream target points. We hypothesize that rational combination therapy with which to yield molecular cooperativity could result in greater overall signal disruption and thus more potential clinical benefit. Our phase I/II trial of sorafenib and bevacizumab, combination anti-angiogenic anti-signaling therapy in series, resulted in 47% partial responses in 19 ovarian cancer patients, with benefits seen in other cancers. The phase II trial in ovarian cancer is accruing and has entered second stage of accrual. Extensive translational endpoints have been incorporated in the phase II study;the phase I analyses confirmed target presence and modulation at the single agent evaluation. No notable differences were seen in pharmacokinetics, pharmacogenomics of the limited and heterogenous population studied, or in genetic/genomic correlations. A statistically significant reduction in DCE-MRI endpoints was observed. A second study, targeting EGFR and VEGFR2 in parallel with a single agent, vandetanib, has been completed, without activity. Biochemical endpoints are under analysis. The ovarian cancer serum proteomics multi-institutional repository trial for women in first remission of advanced stage ovarian cancer is accruing. In addition, our Gynecologic Oncology Group study collecting serum from women undergoing surgical diagnosis of a pelvic mass has completed its accrual of 2000 patients. These samples are to be used to develop a proteomic signature of malignancy v. benign disease. Those cases will be analyzed in collaboration with Dr. Tom Conrads, now of U-Pittsburgh. In follow up of findings of Dr. Weinstein late of the CCR, and our own laboratory studies, we have a clinical trial, approval pending, to examine the clinical activity of pegylated L-asparaginase. Our group identified a clear anti-angiogenic activity of asparaginase that will be assessed in endpoints in the clinical trial. L-asparaginase does not cause apoptosis of endothelial cells, but markedly inhibits functions necessary for sprouting, outgrowth, and remodeling. In addition, it inhibits interactions between ovarian cancer cells and the endothelium in heterotypic interaction studies. No change in production of classical pro-angiogenic cytokines were observed. Our group has initiated a trial for molecular targeting of high risk women (BRCA1/2 mutation-associated cancers). The phase I study of olaparib, an oral inhibitor of polyADP-ribose polymerase (PARP), in combination with carboplatin is now on intermittent dosing and accruing. An amendment has opened to accrual to examine this combination in women with phenocopy disease, low genetic risk triple negative breast cancer and high grade serous epithelial ovarian cancer. Translational proof of concept and mechanism studies are planned for an expansion cohort and will be addressed in collaboration with CCR colleagues. A queue of studies is under development to advance a concerted effort for treatment of this unique and rare group of women. Preliminary data for a combination have been generated in the laboratory and as study design generated. It will also serve as a nidus from which to re-invigorate breast cancer as a clinical activity in the Branch. Other preclinical concepts are advancing within the laboratory, building upon our previous clinical and laboratory findings and focusing on the role of the interactive tumor microenvironment. In addition, at least one novel agent has been developed by pharma and functional argument of the target done by our group;collaborative development is under discussion. Collaborative work has continued on novel applications of CAI. It is active against chronic myelogenous leukemia (CML) cells in culture, reducing activation of the bcr/abl oncogenic fusion protein. New results demonstrate that CAI is active not only in wild type CML, but also in CML resistant to imatinib by through mutation of bcr/abl and also bcr/abl mutants conferring resistance to both imatinib and dasatinib. In both cases, reduction in total and activated bcr/abl was demonstrated. Further studies are examining the protein targets of this inhibition. These data should be considered for translation to the clinic.
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