WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT • The plasma pharmacokinetics (PK) of second generation antisense oligonucleotides (ASOs) are fairly well understood with well conserved pharmacokinetic properties across species, moderate clearance and extensive volume of distribution. WHAT THIS STUDY ADDS • The tissue distribution and exposure and the pharmacodynamic (PD) or target inhibition following ASO administration are not yet well understood leading to still fairly empiric early clinical development strategies. This paper illustrates how preclinical PK and PD data were used to predict more accurately the ASO tissue exposure in humans and to support the early clinical development strategy. AIMS To predict the concentration and target inhibition profiles of the survivin inhibitor antisense oligonucleotide LY2181308 in humans. METHODS An indirect pharmacokinetic/pharmacodynamic (PK/PD) model was built to predict the inhibition of survivin mRNA and protein in humans following LY2181308 dosing. Plasma and tissue PK data from cynomolgus monkeys were analyzed by non‐linear mixed effect modelling techniques. Human PK parameters were predicted using allometric scaling. Assumptions about the pharmacodynamic parameters were made based upon the target and tumour growth inhibition data from mouse xenograft models. This enabled the prediction of the clinical PK/PD profiles. RESULTS Following a 750 mg dose, LY2181308 tumour concentrations ranging from 18.8 to 54 µg g−1 were predicted to lead to 50 to 90% target inhibition. In humans, LY2181308 tumour concentrations from 13.9 to 52.8 µg g−1 (n = 4, LY2181308 750 mg) were observed associated with a median survivin mRNA and protein inhibition of 20% ± 34 (SD) (n = 9) and 23% ± 63 (SD) (n = 10), respectively. The human PK parameters were adequately estimated: central Vd, 4.09 l (90% CI, 3.6, 4.95), distribution clearances, 2.54 (2.36, 2.71), 0.0608 (0.033, 0.6) and 1.67 (1.07, 2.00) l h−1, peripheral Vds, 25 900 (19 070, 37 200), 0.936 (0.745, 2.07) and 2.51 (1.01, 2.922) l, mean elimination clearance 23.1 l h−1 (5.6, 33.4) and mean terminal half‐life, 32.7 days (range 22–52 days). CONCLUSION The model reasonably predicted LY2181308 PK in humans. Overall, the integration of preclinical PK/PD data enabled to appropriately predict dose and dosing regimen of LY2181308 in humans with pharmacologically relevant survivin inhibition achieved at 750 mg.

Glucagon-like insulinotropic peptide (GLP-1) and its analogs are of interest because of their therapeutic potential in type II diabetes. LY315902 is a GLP-1-(7-37)-OH analog with a modified N-terminus (IP7), an octanoic acid (C8) acylated on the lysine residue at position 34, and a substitution with arginine at position 26. We developed a sensitive and specific radioimmunoassay (RIA) for the determination of immunoreactive LY315902 in the plasma of animals. A homobifunctional cross-linker was used to couple the nonacylated form of LY315902 [IP7-R26-GLP-1-(7-37)-OH] to carrier proteins to enhance its immunogenicity. Following immunization, animal antisera were screened by RIA for the presence of LY315902 antibodies. One rabbit produced a high-affinity antiserum that display insignificant cross-reactivity against two forms of native GLP-1 and possible major metabolites of LY315902. In this RIA method, plasma samples were combined with radioiodinated LY315902 and rabbit anti-IP7-R26-GLP-1-(7-37)-OH serum, and then incubated overnight at room temperature. The bound forms of LY315902 were separated by polyethylene glycol assisted second antibody precipitation. The sensitivity of the assay was estimated to be 19 pM. Inter-assay precision (%CV) and accuracy (recovery) for quality control samples in dog plasma ranged from 8.0% to 14.7% and 92.8% to 107.3%, respectively. By applying this assay to measure plasma concentrations of immunoreactive LY315902 in dogs following twice daily subcutaneous injections of LY315902, we determined that the plasma half-life of LY315902 is significantly longer than that of native GLP-1-(7-37)-OH. We concluded that the structural modifications which were made to produce LY315902 prolonged its plasma half-life. The extended plasma half-life of LY315902 correlated well with its prolonged pharmacology in dogs.

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Solid deposits in some oilfield pipelines and oil-processing equipment include calcium salts of C80−82 polycyclic tetracarboxylic acids (“ARN” acids) probably originating from Archaea. It is thought that such deposits form once calcium in seawater comes into contact with crude oils containing the acids, under relevant conditions. The deposits may cause restriction or blockage of pipelines and equipment, with considerable consequent costs for downtime and cleaning. The accurate measurement of the concentrations of the acids in oils is an important requirement for the development of mathematical models for the prediction of the formation of oilfield deposits. We have now identified, in a deposit from one North Sea oilfield pipeline, in addition to the known C80−82 polycyclic tetracarboxylic acids, a hitherto unreported ester of C80 (“ARN”) acids. We report the evidence for the identification and suggest reasons for the occurrence of the ester. Quantitative analyses which exclude determination of such esters may underestimate the potential for oils to cause flow problems. Calculations for computer models based on such data might then be in error.

Introduction: The iron transporter ferroportin is a membrane protein expressed in enterocytes that absorb dietary iron, macrophages of the spleen and liver that recycle iron from old red blood cells (RBCs), and hepatocytes that store and release iron according to body needs. Hepcidin (HEPC) regulates the absorption, plasma concentrations, and tissue distribution of iron through interactions with ferroportin, leading to degradation of ferroportin. LY2928057 (LY), a humanized immunoglobulin (IgG4) monoclonal antibody, binds to ferroportin and prevents the HEPC-mediated degradation of ferroportin without affecting iron efflux. Objectives: Objectives were to assess safety, tolerability, and pharmacokinetic (PK) and pharmacodynamic (PD) properties of LY in patients with chronic kidney disease (CKD) on hemodialysis (HD) after intravenous (IV) multiple doses of LY. The study, compliant with Helsinki declaration, was approved by institutional ethic review board and subjects provided written informed consent prior to enrolment. Methods: CKD patients (N=21) received IV doses (300, 600, or 1000 mg every 2 weeks; total, 3 doses) of LY following discontinuation (when LY treatment was initiated) of erythropoiesis-stimulating agents (ESAs) and IV iron. Seven CKD patients received placebo. Safety assessments included: standard laboratory safety tests, vital signs, ECGs, and anti-drug antibodies. PD data comprised serum iron, transferrin saturation (TSAT), ferritin, HEPC, RBC count and hemoglobin (Hb). PK samples (up to 3 months post last dose) were assayed using a validated enzyme-linked immunosorbent assay method. LY PK data were analyzed using standard non-compartmental PK analysis. Summary statistics were used to describe LY PD data (parameters and ratios relative to baseline). A Bayesian analysis of the absolute change in Hb at week 6 relative to baseline was performed with the following success criterion: >60 % posterior probability of ≥0.8 g/dL difference between any LY dose group and placebo. Results - Safety CKD patients (19 of 28 were male), with mean (SD) age and weight of 53.6 (8) years and 87.35 (18) kg, participated. LY was well tolerated; serious adverse events (syncope, anemia, hypertension, respiratory failure/staphylococcal sepsis/pneumonia) were reported by 3 patients. These were not attributed to study drug. Results - Pharmacokinetics LY maximum concentrations were generally measured at the end of the 30-min infusion and concentrations decreased thereafter in a multiexponential manner. LY area under the concentration time curve (AUC or exposure) increased greater than dose proportionally from 300 to 600 mg and was roughly dose proportional from 600 to 1000 mg. This observation is consistent with binding, target-mediated clearance. LY volume of distribution was small (mean 4L) and LY clearance was low (mean 0.09 L/h) in the 600 to 1000 mg dose range, leading to a mean terminal half-life of 8 days (ranging from 5.5 to 13 days). The dosing of LY during HD did not significantly alter LY exposure. Results - Pharmacodynamics A dose-related increase in iron, with a maximum effect approximately 24 h after dose, was observed. Iron values returned to baseline in approximately 2-weeks post-LY dose. Concurrently, an increase in TSAT was observed (Figure 1). In addition, a decrease in ferritin levels was observed (Figure 2, after third dose, approximately 12% and 20% decrease relative to baseline at the 600 and 1000 mg doses, respectively). HEPC levels increased following LY administration. This is likely explained by the feed-back regulatory response of the body to the iron increase. Figure 3 illustrates that RBC and Hb declined to a lesser extent with LY 600 mg and 1000 mg dose levels compared to 300 mg dose levels and placebo treatment. The Bayesian analysis determined a posterior probability of 58% (less than 60%), for a greater than 0.8 g/dL difference between LY treatment and placebo, in the absolute change in Hb at week 6 relative to baseline Conclusion LY in CKD patients was well tolerated; no safety signals or trends were identified. Expected changes in PD markers (serum iron, HEPC, TSAT, ferritin, RBC, and Hb) were observed after LY administration; however, the effect on Hb did not meet the pre-defined success criterion. It is possible that co-administration of an ESA with LY is required for the increased iron to be optimally used for Hb synthesis in RBC. Disclosures Barrington: Eli Lilly and Company: Employment, Equity Ownership. Sheetz:Eli Lilly and Company: Employment, Equity Ownership. Callies:Eli Lilly and Company: Employment, Equity Ownership. Waters:Eli Lilly and Company: Employment. Berg:Eli Lilly and Company: Employment, Equity Ownership. Pappas:Eli Lilly and Company: Employment. Marbury:Olando Clinical Research Center: Employment, Equity Ownership. Berg:Davita Clinical Research: Employment, Other: Full time employee of Davita Clinical Research, one of the research sites.