BackgroundBAY 81-8973 is a full-length, unmodified, recombinant human factor VIII (FVIII) for the treatment of hemophilia A.ObjectiveThe aim of this study was to compare the pharmacokinetic (PK) profile of BAY 81-8973 with antihemophilic factor (recombinant) plasma/albumin-free method (rAHF-PFM)Patients/MethodsIn this phase I, open-label, crossover study, men aged 18–65 years with severe hemophilia A and ≥150 exposure days to FVIII were randomized to receive a single intravenous infusion of 50 IU/kg BAY 81-8973 or rAHF-PFM, followed by crossover to a single infusion of the other treatment. FVIII levels were measured in plasma over 48 h using one-stage and chromogenic assays. PK parameters, including area under the curve from time zero to the last data point (AUClast; primary outcome) and half-life (t ½) were calculated. A population PK model was developed to simulate various treatment scenarios.ResultsEighteen patients were randomized and analyzed. Using both assays, geometric mean (coefficient of variation [%CV]) AUClast was significantly higher, and t ½ was significantly longer, for BAY 81-8973 versus rAHF-PFM (one-stage, AUClast: 1660 IU·h/dL [29.4] vs. 1310 IU·h/dL [29.0], p < 0.0001; one-stage, t ½: 14.5 [25.7] vs. 11.7 h [27.3], p < 0.0001). Simulations showed that median time to 1 IU/dL was approximately 27% longer for BAY 81-8973 versus rAHF-PFM over doses of 25–50 IU/kg; plasma levels >1 IU/dL could be maintained with 14.4 IU/kg BAY 81-8973 or 39.1 IU/kg rAHF-PFM 3×/week.ConclusionsBAY 81-8973 showed a superior PK profile versus rAHF-PFM. The same FVIII trough threshold level could be achieved with lower doses of BAY 81-8973 versus rAHF-PFM.ClinicalTrials.gov: NCT02483208.

Uncoupling of oxidative phosphorylation represents a potential target for the treatment of hyperglycemia and insulin resistance in obesity and type 2 diabetes. The present study investigated whether the expression of uncoupling protein 1 in skeletal muscles of transgenic (mUCP1 TG) mice modulates insulin action in major insulin target tissues in vivo. Euglycemic-hyperinsulinemic clamps (17 pM x kg lean body mass(-1) x min(-1)) were performed in 9-mo-old hemizygous male mUCP1 TG mice and wild-type (WT) littermates matched for body composition. mUCP1 TG mice exhibited fasting hypoglycemia and hypoinsulinemia compared with WT mice, whereas fasting hepatic glucose production rates were comparable in both genotypes. mUCP1 TG mice were markedly more sensitive to insulin action compared with WT mice and displayed threefold higher glucose infusion rates, enhanced skeletal muscle and white adipose tissue glucose uptake, and whole body glycolysis rates. In the absence of alterations in plasma adiponectin concentrations, acceleration of insulin-stimulated glucose turnover in skeletal muscle of mUCP1 TG mice was accompanied by increased phosphorylated Akt-to-Akt and phosphorylated AMP-activated protein kinase (AMPK)-to-AMPK ratios compared with WT mice. UCP1-mediated uncoupling of oxidative phosphorylation in skeletal muscle was paralleled by AMPK activation and thereby stimulated insulin-mediated glucose uptake in skeletal muscle.

We evaluated the effect of skeletal muscle mitochondrial uncoupling on energy and glucose metabolism under different diets. For 3 mo, transgenic HSA-mUCP1 mice with ectopic expression of uncoupling protein 1 in skeletal muscle and wild-type littermates were fed semisynthetic diets with varying macronutrient ratios (energy % carbohydrate-protein-fat): HCLF (41:42:17), HCHF (41:16:43); LCHF (11:45:44). Body composition, energy metabolism, and insulin resistance were assessed by NMR, indirect calorimetry, and insulin tolerance test, respectively. Gene expression in different organs was determined by real-time PCR. In wild type, both high-fat diets led to an increase in body weight and fat. HSA-mUCP1 mice considerably increased body fat on HCHF but stayed lean on the other diets. Irrespective of differences in body fat content, HSA-mUCP1 mice showed higher insulin sensitivity and decreased plasma insulin and liver triglycerides. Respiratory quotient and gene expression indicated overall increased carbohydrate oxidation of HSA-mUCP1 but a preferential channeling of fatty acids into muscle rather than liver with high-fat diets. Evidence for increased lipogenesis in white fat of HSA-mUCP1 mice suggests increased energy dissipating substrate cycling. Retinol binding protein 4 expression in white fat was increased in HSA-mUCP1 mice despite increased insulin sensitivity, excluding a causal role in the development of insulin resistance. We conclude that skeletal muscle mitochondrial uncoupling does not protect from the development of obesity in all circumstances. Rather it can lead to a "healthy" obese phenotype by preserving insulin sensitivity and a high metabolic flexibility, thus protecting from the development of obesity associated disturbances of glucose homeostasis.

FVIII activity of BAY 94-9027 was accurately measured with most commonly used one-stage assays used in routine clinical practice. The chromogenic assay was also accurate. It is recommended that clinical laboratories identify and avoid specific inappropriate reagents, such as the APTT-SP and PTT-A, in their one-stage assays for FVIII monitoring.

Introduction: BAY 81-8973 is a full-length, unmodified, recombinant human factor VIII (FVIII) with the same primary amino acid sequence as sucrose-formulated recombinant FVIII but produced with certain more advanced manufacturing technologies. Aim: This global laboratory study evaluated variability in measurement of BAY 81-8973 using one-stage and chromogenic assays compared with antihaemophilic factor (recombinant) plasma/ albumin-free method (rAHF-PFM; Advate â ) under assay conditions routinely used in clinical laboratories. Methods: BAY 81-8973 or rAHF-PFM was spiked into FVIII-deficient plasma at 0.043 (low), 0.375 (medium) and 0.865 (normal) IU mL À1. Participating laboratories analysed blinded samples and normal plasma in triplicate using their routine assay, reagents and standards. Results were analysed for intra-and interlaboratory variability. Results: Forty-one laboratories in 11 countries participated in the study. One-stage assay and chromogenic assays were used by 40 and 10 laboratories, respectively; 9 laboratories used both assays. Intralaboratory variability was <11% for both assays and both products at all concentrations. Interlaboratory variability was highest at the low concentration in the chromogenic and one-stage assay for BAY 81-8973 (60.0% and 33.7%, respectively) and rAHF-PFM (51.0% and 30.8%) and was lowest at the normal concentration (BAY 81-8973, 5.4% and 14.0%; rAHF-PFM, 5.8% and 12.4%), which was similar to the plasma control (6.6% and 10.3%). The chromogenic:one-stage assay ratio ranged from 0.95 (low concentration) to 1.10 (normal concentration) for BAY 81-8973 and 0.96-1.18 for rAHF-PFM. Conclusions: BAY 81-8973 can be accurately measured in plasma using the one-stage and chromogenic assays routinely used in clinical laboratories without a product-specific standard.

BAY 81-8973 is a full-length, unmodified recombinant human factor VIII (FVIII) approved for the treatment of hemophilia A. BAY 81-8973 has the same amino acid sequence as the currently marketed sucrose-formulated recombinant FVIII (rFVIII-FS) product and is produced using additional advanced manufacturing technologies. One of the key manufacturing advances for BAY 81-8973 is introduction of the gene for human heat shock protein 70 (HSP70) into the rFVIII-FS cell line. HSP70 facilitates proper folding of proteins, enhances cell survival by inhibiting apoptosis, and potentially impacts rFVIII glycosylation. HSP70 expression in the BAY 81-8973 cell line along with other manufacturing advances resulted in a higher-producing cell line and improvements in the pharmacokinetics of the final product as determined in clinical studies. HSP70 protein is not detected in the harvest or in the final BAY 81-8973 product. However, because this is a new process, clinical trial safety assessments included monitoring for anti-HSP70 antibodies. Most patients, across all age groups, had low levels of anti-HSP70 antibodies before exposure to the investigational product. During BAY 81-8973 treatment, 5% of patients had sporadic increases in anti-HSP70 antibody levels above a predefined threshold (cutoff value, 239 ng/mL). No clinical symptoms related to anti-HSP70 antibody development occurred. In conclusion, addition of HSP70 to the BAY 81-8973 cell line is an innovative technology for manufacturing rFVIII aimed at improving protein folding and expression. Improved pharmacokinetics and no effect on safety of BAY 81-8973 were observed in clinical trials in patients with hemophilia A.

Essentials• Discrepancies can exist in factor VIII activity measured by the one-stage or chromogenic assays.• LEOPOLD trial data were used to assess clinical impact of BAY 81-8973 potency assignment assay.• Efficacy was not affected by the assay used for potency assignment and dosing of BAY 81-8973.• Either assay may be used to measure factor VIII activity after BAY 81-8973 infusion.

The use of quality control (QC) samples in bioanalysis is well established and consistent with regulatory guidance. However, a systematic evaluation of whether QC samples serve the intended purpose of improving data quality has not been undertaken. The Translational and ADME Sciences Leadership Group (TALG) of the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ) conducted an evaluation to assess whether closer agreement is observed when comparing pharmacokinetic data from two passed runs, than when comparing data from failed and passed (retest) runs. Analysis of data collected across organizations, molecular types and analytical platforms, revealed that bioanalytical methods are very reproducible; and that QC samples improve the overall quality of pharmacokinetic concentration data and justifies their continued use.