Background: FcRn controls the long serum half-life of albumin. Results: A single amino acid substitution of albumin considerably improved binding to FcRn and extended serum half-life in mice and rhesus monkeys. Conclusion: Serum half-life of albumin may be tailored by engineering the FcRn-albumin interaction. Significance: This study reports on engineered albumin that may be attractive for improving the serum half-life of biopharmaceuticals.

properties of recombinant factor VIII: first-in-human trial of glycoPEGylated recombinant factor VIII in patients with hemophilia A. J Thromb Haemost 2013; 11: 670-8.Summary. Background: N8-GP is a recombinant factor VIII (FVIII) with a site-directed glycoPEGylation for the purpose of half-life prolongation. Objectives: To evaluate the safety and pharmacokinetic profiles of N8-GP in comparison with those of the patients' previous FVIII products. Patients/Methods: This dose-escalation trial included previously treated patients with severe hemophilia A who received one of three dose levels (25, 50 or 75 U kg À1) of N8-GP and FVIII product. Each dose escalation was preceded by safety and pharmacokinetic assessment. The trial was registered at www.clinicaltrials.gov (NCT01205724). Results: Twenty-six patients each received one dose of their previous FVIII product followed by the same, single dose of N8-GP. N8-GP, at any tested dose, was well tolerated, with a low frequency of adverse events. No new inhibitors against FVIII or N8-GP and no binding antibodies against N8-GP developed during the trial. The pharmacokinetics of N8-GP were dose-linear. The incremental recovery of N8-GP was 0.025 [(U mL À1 )/ (U kg À1 )]. The clearance was 1.79 mL À1 h À1 kg À1 . The estimated time from dosing of 50 U kg À1 N8-GP to a plasma activity of 1% was 6.5 days (range: 3.6-7.9 days). The mean terminal half-life of N8-GP was 19.0 h (range: 11.6-27.3 h), 1.6-fold longer than that of the patients' previous products. Conclusions: A single dose of up to 75 U kg À1 N8-GP was well tolerated in patients with hemophilia A, with no safety concerns. N8-GP had a prolonged half-life, and FVIII:C activity remained at > 1% for longer than the patient's previous product. These results indicate that N8-GP has the potential to reduce dosing frequency during prophylaxis.

Discrepancies between the one-stage clotting assay and the chromogenic method, and also among different variations of each method, have been a significant challenge for one B-domain deleted FVIII product. N8 is a B-domain truncated FVIII product developed by Novo Nordisk. The comparison of N8 and Advate(®) was performed in an international, multicentre, randomized and blinded field study of simulated postinfusion samples. Overall, Advate(®) and N8 performed similarly in the one-stage assay. In the one-stage clotting assay, the measured mean FVIII levels of Advate(®) vs. N8 were 0.046/0.047, 0.24/0.24, 0.58/0.60 and 0.82/0.83 IU mL(-1) for the target values of 0.03, 0.2, 0.6 and 0.9 IU mL(-1) , respectively. In the chromogenic assays, the concentration estimates showed a tendency towards higher N8 values as compared with Advate(®) ; the measured FVIII levels of Advate(®) vs. N8 were 0.030/0.032, 0.22/0.24, 0.65/0.74 and 0.98/1.08 IU mL(-1) for the target values of 0.03, 0.2, 0.6 and 0.9 IU mL(-1) , respectively. In the one-stage assays, the measured values were above 150% of target at the lowest concentration, decreasing to around 90% of target at the highest concentration. In contrast, the chromogenic assays were close to target at the lowest concentration and consistently above target at the three highest concentrations. Therefore, the ratio of chromogenic/one-stage potencies was concentration dependent, ranging from 0.66 to 1.30. The SSC plasma standard was similar in both. Assay variability was similar for both compounds. The results show that N8 can be reliably measured in plasma without the need for a separate N8 standard.

Fluorescence in situ hybridization with chromosome 6- and chromosome 7-specific probes was used to assess the extent of chromosome abnormalities in developing bovine blastocysts at 7-8 days after insemination in vivo or in vitro. Interphase nuclei (N = 10 946) were analyzed from 151 blastocysts produced in vitro and from 28 blastocysts recovered from superovulated animals. This revealed that 72% (109 of 151) of the in vitro-produced blastocysts were mixoploid, i.e., were a mixture of normal, diploid, and polyploid cells. However, only a small fraction of the total number of cells were chromosomally abnormal. Of the mixoploid blastocysts, 83% (91 of 109) contained less than 10% polyploid cells, 13% (14 of 109) contained 11-25% polyploid cells, and only 4% (4 of 109) of the blastocysts had more than 25% polyploid cells per blastocyst. In contrast, a significantly lower proportion (25%) of mixoploidy was found in 28 bovine blastocysts developed in vivo (p < 0.0001). All of the mixoploid blastocysts that had developed in vivo contained less than 10% polyploid cells. No entirely aneuploid blastocysts, i. e., blastocysts in which all cells had the same type of chromosome abnormality, were found in either of the groups. Taken together, the most common chromosome abnormalities observed were diploid-triploid mixoploidies and diploid-tetraploid mixoploidies. Thus, our results confirm earlier reports that morphologically normal bovine blastocysts developed in vivo are often mixoploids. We further show that in vitro-produced bovine blastocysts have a high rate of mixoploidy. Although the difference in mixoploidy rate detected in this study may not be general, it is an interesting phenomenon for further studies.

No abstract