ALBERT

Description: Abstract 1868 Background ARRY-520 is a kinesin spindle protein (KSP) inhibitor that has demonstrated clinical activity in patients with relapsed and refractory multiple myeloma (MM). Although ARRY-520 is administered IV, it displays variable pharmacokinetics (PK) among patients. The degree of binding of certain drugs to serum proteins can alter their free fraction (fu) and PK, with a possible impact on clinical activity. Alpha 1-acid glycoprotein (AAG) is an acute-phase reactant protein that is often elevated in the blood of patients with cancer, including multiple myeloma. We investigated the significance of the interaction of ARRY-520 with AAG, and other relevant blood proteins, using both in vitro models and clinical data. Methods Compound-protein binding was assessed using several in vitro assays. In addition, the effect of increasing concentrations of AAG on MM cell line viability was measured. Patient data were obtained from 3 clinical studies of ARRY-520: a Phase 1 solid tumor study, a Phase 1/2 AML study, and a Phase 1/2 study in MM. The MM Phase 2 portion consists of 2 separate, 2-stage cohorts. Cohort 1 evaluated ARRY-520 administered as a single agent, and cohort 2 investigated ARRY-520 in combination with low-dose dexamethasone (LoDex). The concentrations of multiple proteins, including AAG, and the degree of ARRY-520 total protein binding, were measured in pre- and post-dose blood samples for patients in the analysis. AAG levels in MM patients were further correlated with time-on-study and clinical response rate. Results ARRY-520 exhibits low micromolar affinity for AAG in in vitro assays, but not for other common serum proteins, such as albumin. To investigate whether AAG binding impacts biological activity, we found that increasing AAG concentrations within a clinically relevant range resulted in increasing IC50 values for ARRY-520 on MM cell line viability. Of other MM agents tested, none exhibited high affinity binding to AAG in vitro, and a range of AAG concentrations did not alter the cellular activity of these compounds. Pre-dose concentrations of AAG were measured using blood samples collected from patients on all 3 ARRY-520 studies (0.4 – 4.1 g/L AAG in solid tumor study; 0.5 – 2.4 g/L in AML study; 0.2 – 2.8 g/L in MM study). Post-dose blood samples from the MM study also indicated that AAG levels do not significantly change with time. The fu of ARRY-520 in blood was meaningfully reduced among patients with the highest AAG concentrations. Furthermore, AAG and fu were correlated with changes in clinical PK: CL and Vd decreased with increasing AAG, trends consistent with a lower fu. Among the MM patients, 72 patients were evaluable for AAG determination (27 from the dose-escalation portion, 27 from Cohort 1, and 18 from Stage 1 of Cohort 2). Across all of these cohorts, the group of patients with AAG above an empirically-determined cutoff of 1.1 g/L showed a decreased median time on study (1.5 months vs 4.7 months) and no clinical responses (0/19 vs 12/53) as compared to patients below this cutoff. For example, as reported separately, ARRY-520 in combination with LoDex showed a promising 22% overall response rate (≥PR) in the 1st-stage of Cohort 2. In this cohort, 6 patients were determined to have AAG concentrations above the empirical cutoff. None of these patients had clinical benefit. Excluding these 6 patients would significantly improve the overall response rate (≥PR) from 22% (4/18) to 33% (4/12). Summary AAG has been proposed as a prognostic marker for MM disease severitya. Our preliminary data suggest that AAG levels can affect the free fraction of ARRY-520 in blood over a clinically relevant range both preclinically and in clinical studies. In retrospective analysis, patients with higher AAG levels show a lower fu and therefore may not achieve sufficient exposure to gain therapeutic benefit from ARRY-520. In preclinical analyses, this effect is specific to ARRY-520, suggesting that AAG levels may be predictive for ARRY-520 activity relative to other MM drugs. We hypothesize that prospective screening for AAG may enable exclusion of patients who may not achieve therapeutic exposure to ARRY-520, increasing the overall activity of ARRY-520 and preventing exposure of non-responders to an ineffective therapeutic dose. Further, experiments are currently underway to investigate the relevance of other acute-phase proteins in blood. Disclosures: Tunquist: Array BioPharma: Employment. Off Label Use: ARRY-520 alone and with dexamethasone for the treatment of relapsed/refractory multiple myeloma. ARRY-520 is not currently approved for any indication. Brown:Array BioPharma: Employment. Hingorani:Array BioPharma: Employment. Lonial:Millennium Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Meyers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Onyx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees. Kaufman:Millenium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy. Zonder:Celgene: Honoraria, Research Funding; Millenium: Honoraria, Research Funding. Orlowski:Array BioPharma: Honoraria, Membership on an entity's Board of Directors or advisory committees. Shah:Array BioPharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx: Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau. Hilder:Array BioPharma: Employment. Ptaszynski:Array BioPharma: Consultancy. Koch:Array BioPharma: Employment. Litwiler:Array BioPharma: Employment. Walker:Array BioPharma: Employment.

Description: A sediment core from Lake BC01 (75"10.945?N, 111"55.181?W, 225"m asl) on south-central Melville Island, NWT, Canada, provides the first continuous postglacial environmental record for the region. Fossil pollen results indicate that the postglacial landscape was dominated by Poaceae and Salix, typical of a High Arctic plant community, whereas the Arctic herb Oxyria underwent a gradual increase during the late Holocene. Pollen-based climate reconstructions suggests the presence of a cold and dry period ~12,000"cal yr BP, possibly representing the Younger Dryas, followed by warmer and wetter conditions from 11,000 to 5000"cal yr BP, likely reflective of the Holocene Thermal Maximum. The climate then underwent a gradual cooling and drying from 5000"cal yr BP to the present, suggesting a late Holocene neoglacial cooling. Diatom preservation was poor prior to 5000"cal yr BP, when conditions were warmest, suggesting that diatom dissolution may in part be climatically controlled. Diatom concentrations were highest ~4500"cal yr BP but then decreased substantially by 3500"cal yr BP and remained low before recovering slightly in the 20th century. An abrupt warming occurred during the past 70 yr at the site, although the magnitude of this warming did not exceed that of the early Holocene.

Description: Late-Holocene environmental and climatic conditions were reconstructed from diatom assemblages in sediment cores from four western Montana lakes: Crevice Lake, Foy Lake, Morrison Lake, and Reservoir Lake. The lakes show synchroneity in timing of shifts in diatom community structure, but the nature of these changes differs among the lakes. Two of the sites provide highly resolved records of hydrologic balance, while the other two stratigraphic sequences primarily record temperature impact on lake thermal structure. All four lakes show significant change in five discrete intervals: 2200–2100, 1700–1600, 1350–1200, 800–600, and 250 cal yr BP. The similarities in the timing of change suggest overlying regional climatic influences on lake dynamics. The 800–600 cal yr BP shift is evident in other paleorecords throughout the Great Plains and western US, associated with the transition from the Medieval Climate Anomaly to the Little Ice Age. Large-scale climatic mechanisms that influence these lake environments may result from atmospheric circulation patterns that are driven by interactions between Pacific and Atlantic sea-surface temperatures, which are then locally modified by topography.

Description: This paper presents a new approach for the expected cost-to-go functions modeling used in the stochastic dynamic programming (SDP) algorithm. The SDP technique is applied to the long-term operation planning of electrical power systems. Using state space discretization, the Convex Hull algorithm is used for constructing a series of hyperplanes that composes a convex set. These planes represent a piecewise linear approximation for the expected cost-to-go functions. The mean operational costs for using the proposed methodology were compared with those from the deterministic dual dynamic problem in a case study, considering a single inflow scenario. This sensitivity analysis shows the convergence of both methods and is used to determine the minimum discretization level. Additionally, the applicability of the proposed methodology for two hydroplants in a cascade is demonstrated. With proper adaptations, this work can be extended to a complete hydrothermal system.

Description: Mood disorders and schizophrenia are common and complex disorders with consistent evidence of genetic and environmental influences on predisposition. It is generally believed that the consequences of disease, gene expression, and allelic heterogeneity may be partly the explanation for the variability observed in treatment response. Correspondingly, while effective treatments are available for some patients, approximately half of the patients fail to respond to current neuropsychiatric treatments. A number of peripheral gene expression studies have been conducted to understand these brain-based disorders and mechanisms of treatment response with the aim of identifying suitable biomarkers and perhaps subgroups of patients based upon molecular fingerprint. In this review, we summarize the results from blood-derived gene expression studies implemented with the aim of discovering biomarkers for treatment response and classification of disorders. We include data from a biomarker study conducted in first-episode subjects with schizophrenia, where the results provide insight into possible individual biological differences that predict antipsychotic response. It is concluded that, while peripheral studies of expression are generating valuable results in pathways involving immune regulation and response, larger studies are required which hopefully will lead to robust biomarkers for treatment response and perhaps underlying variations relevant to these complex disorders.