Citations

Abstract Background: Etirinotecan pegol (EP) is a long-acting Top1 inhibitor providing sustained levels of active metabolite throughout the entire chemotherapy cycle. The phase 3 BEACON trial compared EP to treatment of physician's choice (TPC) in patients with advanced breast cancer, demonstrating a non-statistically significant 2.1 month difference in survival favoring EP in the intent to treat population. A novel aspect of the BEACON trial is to explore the utility of biomarkers measured in CTCs for predicting efficacy with EP. Pre- and post-treatment CTCs were isolated from blood of 77% of the 852 BEACON patients. Target-specific pharmacodynamic biomarkers for EP measured in CTCs were analyzed to identify patients most responsive to treatment with EP. Methods: Donation of blood samples for CTC analysis was voluntary. Participating BEACON patients had serial (baseline, Cycle 2 Day 1 [C2D1], Cycle 4 Day 1 [C4D1], End of Treatment) 7.5-mL whole blood samples drawn in EDTA tubes and shipped within 96 hours ambient to ApoCell (Houston, TX) for processing. PBMCs were separated by Ficoll® gradient, and CTCs were isolated using ApoStream® technology. Isolated cells were deposited on three slides and stained for DAPI, CD45, cytokeratin markers, as well as Top1, Top2, Ki67, γH2AX, Rad51, ABCG2, and TUNEL. Biomarkers were quantified by iCys® laser scanning cytometer equipped with image analysis software, and correlated with OS using Cox multiple regression and Kaplan-Meier analyses. Results: The CTC substudy yielded 611 pre-treatment, 519 C2D1, 268 C4D1, and 431 End of Treatment samples. Among the successfully processed blood samples, 98% had detectable CTCs, with a median of 63, 46, 51, and 57 CTCs/mL at baseline, C2D1, C4D1, and End of Treatment, respectively. Cox regression analyses of CTC number and percentage of Top1, Top2, Ki67, or TUNEL positive CTCs identified a correlation for post-treatment number of Top1-positive CTCs with OS in patients receiving EP. To assess the impact of Top1-positive CTCs, patients were classified as Top1-High (> median) or Top1-Low (≤ median) based on the percent of Top1-positive CTCs at baseline. Among the Top1-High patients at baseline, significantly improved OS (HR 0.54, p=0.007) was observed for those who converted to Top1-Low after their first treatment with EP (C2D1), but not TPC (HR 1.12, p=0.613). These results suggest that decreased number of Top1-positive CTCs may reflect EP target engagement with Top1, as these patients derived the most benefit from treatment. Conclusions: CTC collection and analysis was successfully incorporated into the phase 3 BEACON study, with 77% patient participation. CTC detection rate using ApoStream® was high, permitting evaluation of biomarkers at baseline and post-treatment. Significantly improved OS was observed in patients who had a decreased number of Top1-positive CTCs following cycle 1 of EP. Citation Format: Rugo HS, Cortes J, Awada A, O'Shaughnessy J, Twelves C, Im S-A, Hannah AL, Lu L, Sy S, Caygill K, Zajchowski D, Davis DW, Hoch U, Perez EA. Early change in topoisomerase 1 (Top1) positive circulating tumor cells (CTCs) is associated with overall survival (OS) in patients with advanced breast cancer after treatment with etirinotecan pegol. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-13-02.

Abstract Background: Nal-IRI (MM-398, nanoliposomal irinotecan) is designed for extended circulation relative to free irinotecan and to exploit leaky tumor vasculature for enhanced drug delivery to tumors. Tumor deposition of nal-IRI and subsequent conversion to SN-38 in both neoplastic cells and tumor associated macrophages (TAM) may positively correlate with response to therapy. In phase I studies of nal-IRI, activity has been shown in metastatic breast cancer (MBC), pancreatic and colorectal cancer. Ferumoxytol (FMX) is an iron-oxide superparamagnetic nanoparticle that has been used off-label for its MRI contrast properties. FMX has long-circulating pharmacokinetics and is taken up by TAMs with similar distribution patterns to nal-IRI in preclinical models. A single site pilot study established the feasibility of performing quantitative FMX MRI. Thirteen patients with advanced cancer (3 with ER/PR+ MBC) were imaged with FMX MRI and treated with nal-IRI. Median tumor lesion FMX uptake in the pilot study was 32.6 and 34.5 μg/mL at 1 h and 24 h, respectively. Lesions with FMX uptake above the median were associated with greater reductions in tumor size following treatment with nal-IRI as determined by CT lesion measurements. The relationship between FMX levels in tumor lesions and nal-IRI activity may serve as a potential biomarker for nal-IRI deposition and response in solid tumors. This study has been expanded to include additional MBC patients to further evaluate the technical feasibility of FMX MRI at multiple study sites, and to evaluate activity of nal-IRI in patients with MBC. Trial Design: Three cohorts of 10 patients with MBC in the following categories will be enrolled: ER and/or PR positive/HER2-negative, triple negative (TNBC) and MBC with brain metastases. An imaging phase will be followed by a treatment phase. The imaging phase consists of a baseline MRI scan, FMX infusion, and follow-up MRI scans at 1-4 and 24 h after infusion. The treatment phase begins 1-6 days after imaging and consists of nal-IRI 80 mg/m2 q2w. A pretreatment biopsy is required for correlative studies. Study Objectives: The primary objective of this multisite expansion is to investigate the feasibility of FMX quantitation in tumor lesions at multiple lesion sites in breast cancer. The secondary objective is to characterize the efficacy of nal-IRI in patients with metastatic breast cancer. Eligibility Criteria: The key inclusion criteria include patients with MBC, ECOG 0 or 1 with adequate bone marrow reserve and no prior topoisomerase 1 inhibitor or anti-VEGF treatment. ER and/or PR positive/HER2-negative and TNBC patients must have had 1-3 prior lines of chemotherapy in the metastatic setting and have at least 2 measurable lesions. Patients with brain metastasis must be neurologically stable and have new or progressive brain metastases after prior radiation therapy with at least one lesion measuring ≥ 1 cm in longest diameter on gadolinium-enhanced MRI. Status: This trial is currently recruiting patients. Citation Format: Sachdev JC, Ramanathan RK, Raghunand N, Anders C, Munster P, Minton S, Northfelt D, Blanchette S, Campbell K, Lee H, Klinz SG, Hendriks BS, Moyo V, Fitzgerald JB, Korn RL. A phase 1 study in patients with metastatic breast cancer to evaluate the feasibility of magnetic resonance imaging with ferrumoxytol as a potential biomarker for response to treatment with nanoliposomal irinotecan (nal-IRI, MM-398). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-02-14.

Abstract Purpose: The initiation, progression, and maintenance of pancreatic ductal adenocarcinoma (PDAC) results from the interplay of genetic and epigenetic events. While the genetic alterations of PDAC have been well characterized, epigenetic pathways regulating PDAC remain, for the most part, elusive. The goal of this study was to identify novel epigenetic regulators contributing to the biology of PDAC. Experimental Design: In vivo pooled shRNA screens targeting 118 epigenetic proteins were performed in two orthotopic PDAC xenograft models. Candidate genes were characterized in 19 human PDAC cell lines, heterotopic xenograft tumor models, and a genetically engineered mouse (GEM) model of PDAC. Gene expression, IHC, and immunoprecipitation experiments were performed to analyze the pathways by which candidate genes contribute to PDAC. Results: In vivo shRNA screens identified BRD2 and BRD3, members of the BET family of chromatin adaptors, as key regulators of PDAC tumor growth. Pharmacologic inhibition of BET bromodomains enhanced survival in a PDAC GEM model and inhibited growth of human-derived xenograft tumors. BET proteins contribute to PDAC cell growth through direct interaction with members of the GLI family of transcription factors and modulating their activity. Within cancer cells, BET bromodomain inhibition results in downregulation of SHH, a key mediator of the tumor microenvironment and canonical activator of GLI. Consistent with this, inhibition of BET bromodomains decreases cancer-associated fibroblast content of tumors in both GEM and xenograft tumor models. Conclusions: Therapeutic inhibition of BET proteins offers a novel mechanism to target both the neoplastic and stromal components of PDAC. Clin Cancer Res; 22(16); 4259–70. ©2016 AACR.

Human cytomegalovirus (HCMV) is a widely prevalent herpes virus which establishes a state of chronic infection. The establishment of CMV‐specific immunity controls viral reactivation and leads to the accumulation of very large numbers of virus‐specific T cells which come to dominate the immune repertoire. There is concern that this may reduce the immune response to heterologous infections and HCMV infection has been associated with reduced survival in elderly people. Patients with chronic lymphocytic leukemia (B‐CLL) suffer from a state of immune suppression but have a paradoxical increase in the magnitude of the CMV‐specific T cell and humoral immune response. As such, there is now considerable interest in how CMV infection impacts on the clinical outcome of patients with B‐CLL. Utilizing a large prospective cohort of patients with B‐CLL (n = 347) we evaluated the relationship between HCMV seropositivity and patient outcome. HCMV seropositive patients had significantly worse overall survival than HCMV negative patients in univariate analysis (HR = 2.28, 95% CI: 1.34–3.88; P = 0.002). However, CMV seropositive patients were 4 years older than seronegative donors and this survival difference was lost in multivariate modeling adjusted for age and other validated prognostic markers (P = 0.34). No significant difference was found in multivariate modeling between HCMV positive and negative patients in relation to the time to first treatment (HR = 1.12, 95% CI: 0.68–1.84; P = 0.65). These findings in a second independent cohort of 236 B‐CLL patients were validated. In conclusion no evidence that HCMV impacts on the clinical outcome of patients with B‐CLL was found. Am. J. Hematol. 91:776–781, 2016. © 2016 Wiley Periodicals, Inc.

Abstract Rationale The management of severe and refractory hypoxemia in critically ill adult patients is practice based. Variability across individual practitioners and institutions is not well documented. Objectives To conduct a nationwide survey of critical care physicians in the United States regarding accepted definitions and management strategies for severe and refractory hypoxemia. Methods A web-based survey was distributed to a stratified random sample of adult intensivists listed in the American Medical Association Physician Masterfile. The survey was generated by using a mixed-methods approach. Measurements and Main Results: In the survey, 4,865 e-mails were sent and 791 (16.3%) were opened. Among those who opened the e-mail message, 50% (n = 396) responded, representing 8.1% of total surveys sent. Seventy-two percent stated that their institutions lacked a protocol for identification and management of severe or refractory hypoxemia in the setting of acute respiratory failure. While the majority of respondents used low-Vt ventilation (81%), high positive end-expiratory pressure (86%), recruitment maneuvers (89%), and either bolus or infusion neuromuscular blockade (94%), there was marked variability in the use of specific rescue strategies as tier 1 or 2 interventions: prone position (27.8% vs. 47.8%, respectively), extracorporeal membrane oxygenation (2.3% vs. 51.2%, respectively), airway pressure release ventilation (49% vs. 34.5%, respectively), inhaled vasodilators (30.1% vs. 40%, respectively), and high-frequency oscillatory ventilation (7.8% vs. 40%, respectively). The variability was partly explained by providers’ expertise with particular rescue strategies (77.7%), advance directives (70.1%), the training of allied health staff (62.3%), and institutional availability (53.8%). Conclusions U.S. adult critical care physicians predominantly employ lung-protective ventilation for severe hypoxemia. A wide variation in other rescue strategies is noted, which is partly explained by user expertise and availability. Less than 30% institutions have formal protocols for management of refractory hypoxemia.

Abstract Antibody-directed chemotherapy (ADC) offers an advantage over conventional chemotherapy because it provides antibody-directed targeting, with resultant improvement in therapeutic efficacy and reduced toxicity. Despite extensive research, with notable exceptions, broad clinical application of ADC remains elusive; major hurdles include the instability of antibody–chemotherapy linkers and reduced tumor toxicity of the chemotherapy when bound to the antibody. To address these challenges, we have developed a platform technology that utilizes the nab-paclitaxel formulation of paclitaxel, Abraxane, in which hydrophobic paclitaxel is suspended in 130-nm albumin nanoparticles and thus made water-soluble. We have developed a method to noncovalently coat the Abraxane nanoparticle with recombinant mAbs (anti-VEGF, bevacizumab) and guide Abraxane delivery into tumors in a preclinical model of human A375 melanoma. Here, we define the binding characteristics of bevacizumab and Abraxane, demonstrate that the chemotherapy agent retains its cytotoxic effect, while the antibody maintains the ability to bind its ligand when the two are present in a single nanoparticle (AB160), and show that the nanoparticle yields improved antitumor efficacy in a preclinical human melanoma xenograft model. Further data suggest that numerous therapeutic monoclonal IgG1 antibodies may be utilized in this platform, which has implications for many solid and hematologic malignancies. Cancer Res; 76(13); 3954–64. ©2016 AACR.

Background: Clinical misdiagnosis, particularly at early disease stages, is a roadblock to finding new therapies for Lewy body disorders. Biopsy of a peripheral site might provide improved diagnostic accuracy. Previously, we reported, from both autopsy and needle biopsy, a high prevalence of submandibular gland synucleinopathy in Parkinson’s disease (PD). Here, we report on an extension of these studies to subjects with dementia with Lewy bodies (DLB) and other Lewy body disorders in 228 autopsied subjects from the Arizona Study of Aging and Neurodegenerative Disorders. Objective: To provide an estimate of the prevalence of histological synucleinopathy in the submandibular glands of subjects with PD and other Lewy body disorders. Methods: Submandibular gland sections from autopsied subjects were stained with an immunohistochemical method for α-synuclein phosphorylated at serine 129. Included were 146 cases with CNS Lewy-type synucleinopathy (LTS), composed of 46 PD, 28 DLB, 14 incidental Lewy body disease (ILBD), 33 Alzheimer’s disease with Lewy bodies (ADLB) and 2 with progressive supranuclear palsy and Lewy bodies (PSPLB). Control subjects included 79 normal elderly, 15 AD, 12 PSP, 2 conticobasal degeneration (CBD) and 2 multiple system atrophy (MSA). Results: Submandibular gland LTS was found in 42/47 (89%) of the PD subjects, 20/28 (71%) DLB, 4/33 (12%) ADLB and 1/9 (11%) ILBD subjects but none of the 110 control subjects. Conclusions: These results provide support for further clinical trials of in vivo submandibular gland diagnostic biopsy for PD and DLB. An accurate peripheral biopsy diagnosis would assist subject selection for clinical trials and could also be used to verify other biomarkers.

AbstractGenetic risk scores were used as unconfounded instruments for specific lipid traits (Mendelian randomization) to assess whether circulating lipids causally influence prostate cancer risk. Data from 22,249 prostate cancer cases and 22,133 controls from 22 studies within the international PRACTICAL consortium were analyzed. Allele scores based on single nucleotide polymorphisms (SNPs) previously reported to be uniquely associated with each of low‐density lipoprotein (LDL), high‐density lipoprotein (HDL), and triglyceride (TG) levels, were first validated in an independent dataset, and then entered into logistic regression models to estimate the presence (and direction) of any causal effect of each lipid trait on prostate cancer risk. There was weak evidence for an association between the LDL genetic score and cancer grade: the odds ratio (OR) per genetically instrumented standard deviation (SD) in LDL, comparing high‐ (≥7 Gleason score) versus low‐grade (<7 Gleason score) cancers was 1.50 (95% CI: 0.92, 2.46; P = 0.11). A genetically instrumented SD increase in TGs was weakly associated with stage: the OR for advanced versus localized cancer per unit increase in genetic risk score was 1.68 (95% CI: 0.95, 3.00; P = 0.08). The rs12916‐T variant in 3‐hydroxy‐3‐methylglutaryl‐CoA reductase (HMGCR) was inversely associated with prostate cancer (OR: 0.97; 95% CI: 0.94, 1.00; P = 0.03). In conclusion, circulating lipids, instrumented by our genetic risk scores, did not appear to alter prostate cancer risk. We found weak evidence that higher LDL and TG levels increase aggressive prostate cancer risk, and that a variant in HMGCR (that mimics the LDL lowering effect of statin drugs) reduces risk. However, inferences are limited by sample size and evidence of pleiotropy.