Citations

AbstractCarfilzomib is a next-generation, selective proteasome inhibitor being evaluated for the treatment of relapsed and refractory multiple myeloma. In this open-label, single-arm phase 2 study (PX-171-003-A1), patients received single-agent carfilzomib 20 mg/m2 intravenously twice weekly for 3 of 4 weeks in cycle 1, then 27 mg/m2 for ≤ 12 cycles. The primary endpoint was overall response rate (≥ partial response). Secondary endpoints included clinical benefit response rate (≥ minimal response), duration of response, progression-free survival, overall survival, and safety. A total of 266 patients were evaluable for safety, 257 for efficacy; 95% were refractory to their last therapy; 80% were refractory or intolerant to both bortezomib and lenalidomide. Patients had median of 5 prior lines of therapy, including bortezomib, lenalidomide, and thalidomide. Overall response rate was 23.7% with median duration of response of 7.8 months. Median overall survival was 15.6 months. Adverse events (AEs) were manageable without cumulative toxicities. Common AEs were fatigue (49%), anemia (46%), nausea (45%), and thrombocytopenia (39%). Thirty-three patients (12.4%) experienced peripheral neuropathy, primarily grades 1 or 2. Thirty-three patients (12.4%) withdrew because of an AE. Durable responses and an acceptable tolerability profile in this heavily pretreated population demonstrate the potential of carfilzomib to offer meaningful clinical benefit. This trial was registered at www.clinicaltrials.gov as #NCT00511238.

Abstract Some studies show that childbearing at older age is associated with lower risk of endometrial cancer, but whether the association is independent of number of children or other factors still requires clarification. We pooled individual-level data from epidemiologic studies in the Epidemiology of Endometrial Cancer Consortium (E2C2). Data on age at last birth and/or last pregnancy were available from 14 studies: 11 case-control studies and 3 cohort studies; the latter were analyzed using a nested case-control design. A total of 9,613 endometrial cancer cases and 17,112 controls were included in the analysis. The majority of women were White (82%) and older than 55 years (69%). We estimated the effects of age at last birth using data from 12 studies and age at last pregnancy using data from 10 studies on the risk of endometrial cancer by calculating odds ratios (OR) and 95% confidence intervals (95% CI) using logistic regression models. Potential confounders included in the analysis were race, body mass index, parity, age at menarche, age at first birth, oral contraceptive use, postmenopausal hormone use, smoking status, and report of diabetes. After adjusting for potential confounders, a reduction in endometrial cancer risk was observed in women with increasing age at last birth (P trend <0.0001) and age at last pregnancy (P trend <0.0001). The OR per five-year increase in age at last birth and age at last pregnancy was 0.90 (95%CI: 0.86, 0.94) and 0.91 (95% CI: 0.87, 0.95), respectively. Women who had their last child at an age >40 years were at a 34% decreased risk compared with women who had their last child at an age <25 years (95% CI: 0.52, 0.82). Compared to women with age at last pregnancy <25 years, those with age at last pregnancy >40 years had a 30% decreased risk of endometrial cancer (95%CI: 0.57, 0.86). Inverse associations were observed for Whites and Asians in race-specific analysis and also in analysis restricted to women with at least 2 births. In this large pooled analysis, we show that late age at last birth or last pregnancy is a strong and independent protective factor for endometrial cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1900. doi:10.1158/1538-7445.AM2011-1900

Abstract MUC1 is over expressed and aberrantly glycosolated in >60% of pancreatic ductal adenocarcinomas. Over expression of MUC1 in pancreatic cancer is known, however the functional role has yet to be fully elucidated due to a dearth of appropriate models. In the present study, we have generated mouse models that spontaneously develop pancreatic ductal adenocarcinoma (KC), which are either Muc1 null (KCKO) or express human MUC1 as a self antigen (KCM). We show that PDA mice lacking Muc1 have significantly slower tumor progression, with tumor weight reaching up to a third of the KCM tumor and half of KC tumor. One out of 10 KCKO mice developed secondary metastasis versus 6 out of 10 and 3 out of 10 KCM and KC respectively. Cell lines derived from KCKO tumors have significantly lower tumorigenic capacity compared to cells derived from KCM tumors. Therefore, mice with KCKO tumors had a significant survival benefit compared to mice bearing the KCM tumors. In vitro, the KCKO cells have reduced proliferation and invasion compared to KCM cells and failed to respond to exogenous epidermal growth factor (EGF), platelet-derived growth factor (PDGF), or matrix metalloproteinase-9 (MMP9) stimuli. Further, significantly fewer KCKO cells entered the G2M phase of the cell cycle compared to the KCM cells, consequently more KCKO cells were observed at the S-phase of the cell cycle. Proteomics and western blotting analysis revealed a complete loss of cdc-25c expression, phosphorylation of MAPK, as well as a significant decrease in Nestin and Tubulin α-2 chain expression in KCKO cells. Treatment of the KCM cells with a MEK1/2 inhibitor, U0126, completely abrogated the enhanced proliferation of the KCM cells but had minimal effect on KCKO cells, strongly suggesting that MUC1 is necessary for MAPK activity and downstream oncogenic signaling. This is the first study to utilize a Muc1-null PDA mouse in order to fully elucidate the oncogenic role of MUC1, both in vivo and in vitro. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1070. doi:10.1158/1538-7445.AM2011-1070

Abstract Introduction: Pancreatic cancer is the fourth leading cause of cancer-related death in United States. Most human pancreatic cancers overexpress MUC1, which is associated with high metastasis and poor prognosis of the disease. We have recently shown that MUC1 initiates the process of epithelial to mesenchymal transition (EMT) and promotes metastasis in pancreatic cancer cells via signaling through the seven tyrosines present in its cytoplasmic tail (CT) motif. When the 7 tyrosines were mutated to phenylalanine, EMT was completely abrogated. Since TGF-β has been extensively studied as a mediator of EMT and invasion in pancreatic cancer, we hypothesized that MUC1 may be inducing its effect through regulating TGF-β production and signaling. We also aimed at identifying the specific tyrosine residue(s) responsible for MUC1 induced EMT. Method: We made the following plasmids containing a) full length MUC1 (MUC1), b) all 7 tyrosine residues of MUC1 CT were mutated to Phenylalanine (Y0), c) Y6 (Tyrosine 6 present, the rest replaced by Phenylalanine), d) Y7 (Tyrosine 7 present, the rest replaced by Phenylalanine), e) Y2,5 (Tyrosine 2 and 5 present, the rest replaced by Phenylalanine), f) Y3,6,7 (Tyrosine3, 6 and 7 present, the rest replaced by Phenylalanine) and g) empty vector (Neo). These plasmids were stably expressed in human pancreatic cancer cell lines, BxPC3 and Su86.86 that express low levels of endogenous MUC1. We first assessed the levels of functional TGF-β secreted by BxPC3 Neo, MUC1 and Y0 cells as well as the levels of TGF-βI and II receptors. We then treated these cells with exogenous human recombinant TGF-β and assessed both, the process of EMT and the capacity to invade through growth-reduced matrigel. Results: We found that BxPC3.MUC1 cells produced strikingly larger amounts of TGF-β compared to BxPC3 Neo and Y0 cells. We also found that MUC1-expressing cells became more invasive in response to exogenous TGF-β while the Y0 cells did not respond to exogenous TGF-β although the receptor levels were similar in all three cell lines. However, none of the mutants of MUC1 CT could rescue the function of full length MUC1, in the context of induction of EMT. Conclusion: 1) We believe that TGF-β mediated EMT and TGF-β signal propagation requires the tyrosine residue of MUC1, which is evident from the data that mutating the tyrosine residues in MUC1CT abrogates TGF-β mediated EMT in these cells. 2) Induction of EMT by MUC1 is a complex process, which involves a particular combination of tyrosine residues of MUC1. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2910. doi:10.1158/1538-7445.AM2011-2910

Abstract Background: Activation of oncology trials is a lengthy and complex process. Recent literature has identified numerous opportunities to improve activation timelines1, 2. The Multiple Myeloma Research Consortium (MMRC) has implemented several processes to identify and overcome myeloma clinical trial activation barriers within the consortium network of 14 North American cancer centers. We examined the impact of these processes preand post- implementation and also compared activation times with published clinical trial metrics data. Methods/Results: 12 MMRC-facilitated trials had sufficient trial data available for review within the study period of May 2006 to March 2009. Activation time was defined as the time from a center's receipt of the final clinical trial protocol from the sponsor, to the time the first patient was enrolled into a trial at any MMRC participating center. The earlier group (EG) of MMRC trials (n=7) required a mean of 257 calendar days for activation, comparable to the mean published data of 251 calendar days1. The more recent group (RG) of MMRC trials (n=5) required a mean of 158 calendar days for activation, representing a 38% shortening of activation time. Additionally, implementation of standardized processes and rigorous project management resulted in a reduction in activation times for all MMRC centers in a given trial from a mean of 7.5 months to a mean of 5.1 months. Improving the mean time of several several specific steps in the process including time to initial protocol review submission from receipt (EG=37 vs. RG=19 days), scientific review committee time (EG=98 vs. RG=55 days), and the time from trial opening to first patient dosed (EG=74 vs. RG=27 days) contributed to the overall decrease in activation times. The EG metrics data are comparable to published data1 for each process step. Conclusion: The MMRC member institutions have seen substantial improvements in trial activation times and are in the process of implementing additional processes to further improve protocol development and trial conduct metrics. The efficiencies and process improvements realized from application of rigorous MMRC project management resources and the standardization of contracting and other key activities may be applied in other areas of oncology clinical trials beyond multiple myeloma. With increasing numbers of new oncology agents to be evaluated and greater pressure on trial sponsors to introduce efficiencies into trial timelines, overcoming such barriers is of critical importance. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B58.

AbstractWhile arterial hypertension and renal dysfunction are well recognized complications of renal irradiation, the mechanisms that trigger the development of these complications are unknown. Recently, it was reported that the endothelium is a major target in radiation injury. Because dysfunction of the endothelial cells may lead or contribute to the development of hypertension and renal dysfunction in radiation nephropathy, we tested the hypothesis that endothelium-dependent vasodilation is impaired in radiated kidneys prior to the onset of hypertension. To test this hypothesis, we used Long-Evans rats that had undergone left nephrectomy (3 weeks earlier) and irradiation (3000 r’s) to the right kidney 8 days earlier (mean blood pressures in the irradiated rats were not different than in the controls). We then measured the changes in renal blood flow (RBF) induced by endothelium-dependent (acetylcholine and bradykinin) and -independent (nitroprusside, norepinephrine, and angiotensin II) vasoactive agents. We found that the increases in RBF induced by the endothelium-dependent but not independent vasodilators were markedly impaired in the irradiated kidneys. Blocking nitric oxide synthesis with nitrol-arginine methyl ester in sham rats mimicked the blunted responsiveness of the irradiated rats, whereas indomethacin (an inhibitor of prostaglandin synthesis) had no effect on either sham or irradiated rats. Finally, the RBF responses to the endothelium-independent vasoconstrictors, norepinephrine and angiotensin II, were not altered in the irradiated kidneys. These results suggest that renal irradiation causes endothelial dysfunction (prior to the onset of hypertension) but spares the vascular smooth muscle cells.

Background —As endothelin binds to ET A receptors, it stimulates vascular smooth muscle cell proliferation and may thus be pivotally involved in the pathogenesis of restenosis. This study assessed the ability of a potent and selective ET A antagonist to reduce neointimal hyperplasia in a porcine coronary artery stented injury model. Methods and Results —Fifty-five pigs were randomized to receive placebo or the oral ET A -selective antagonist ABT147627 twice daily for 28 days in one of three doses: 0.75 mg/kg (low), 3.75 mg/kg (mid), and 10.0 mg/kg (high). Each underwent oversized stent deployment in two randomly assigned major epicardial coronary arteries. Three animals (5.5%) died as a consequence of stent thrombosis within 24 hours of the procedure. The remaining 52 animals (13 pigs per group) survived without complication until predetermined euthanasia at 28 days. In the placebo group, mean injury score was 1.73±0.80, with a mean neointimal response of 0.45±0.24 mm. By comparison, the low-dose group had a similar mean injury score of 1.79±0.75 with reduced neointimal response, 0.36±0.22 mm ( P <0.01). Mean injury score in the mid-dose animals was significantly greater than in the placebo group (1.94±0.92; P <0.05). The neointimal hyperplasia associated with this injury was less than with placebo, although the difference did not reach statistical significance (0.40±0.25 mm; P =0.05). In the high-dose pigs, mean injury score was also significantly greater than in the placebo arm (1.93±0.73; P <0.05). Despite this, neointimal response was also significantly less (0.37±0.37 mm; P <0.01). Conclusions —Oral, selective ET A receptor antagonism significantly reduced neointimal hyperplasia forming over porcine coronary stented injuries in the first 28 days. This strategy may have clinical potential for the limitation and treatment of coronary restenosis after percutaneous revascularization.