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Therapeutic monoclonal antibodies (mAbs) exert their effects via binding to specific target molecules, which is expected to show rare off-target adverse reactions. However, nonclinical evaluation of mAbs is difficult because they often lack reactivity toward orthologous targets in animals. During the nonclinical evaluation of mAbs, not only the target molecules but fragment crystallizable (Fc) receptors, which regulate the immune effector functions and pharmacokinetic properties of mAbs, should be considered. In this review, factors for extrapolating nonclinical study results to clinical settings are discussed by focusing on Fc receptors. The human Fcγ receptor family consists of FcγRI, IIa, IIb, IIIa, and IIIb; Fcγ receptors in laboratory animals are structurally and functionally different from those in humans. In addition, interactions between human IgG-Fc, a component of therapeutic mAbs, and animal Fcγ receptors are still not fully understood. With regard to neonatal Fc receptor (FcRn), related molecules comprising the FcRn family are not known; however, critical amino acid residues involved in IgG binding are different between human and mouse. In case of next-generation mAbs with a novel structure or mode of action, knowledge from related drugs is limited. To ensure safety of next-generation mAbs, a thorough understanding of the differences in Fc receptors among species and the interactions between mAbs and Fc receptors is required, and the appropriateness of the nonclinical study design should be carefully examined prior to conducting clinical studies.

Recently, several novel cellular therapy products and biological drugs are being developed to treat various previously untreatable diseases. One of the most important issues regarding these innovations is how to ensure safety over infectious agents, including viruses and prions, in the earliest treatments with these products. The object of this study is a risk assessment of cases of human infectious with the agents and to present a sample risk management plan based on a collaboration among the National Institute of Health Sciences, universities, marketing authorization holders, and scientific societies. There are three subjects of study: (1) the viral safety of cellular therapy products, (2) the viral safety of biological drugs, and (3) the safety of prions. In this report, we describe the objects of the study, the project members, the study plan outline, and the ongoing plans. The results of the viral risk identification and the risk analysis of cellular therapy products will also be described, based on a review of the literature and case reports obtained during the first year of this project.

Glycosylation of cells is known to alter with several biological events such as cell differentiations and proliferations as well as some diseases. "Glycomic approaches", comprehensive qualitative and quantitative glycan analyses of the cells, have become increasingly important as a means of discovering biomarkers that have the potential of being used as disease diagnostic markers and molecular markers for cell characterizations. In this paper, we introduce a method of quantitative glycan profiling by liquid chromatography/mass spectrometry with a combination of an isotope tagging method. In addition, we demonstrate the potential of glycan profiling as a tool for the identification of differentiated human bone marrow mesenchymal stem cell (hMSC) and non-differentiated hMSC.

Heparin is widely used as an anticoagulant for the treatment and prevention of thrombotic disorders. Recently, hundreds of cases of anaphylactic reaction as adverse effects were reported by the presence of contaminating oversulfated chondroitin sulfate (OSCS) in some heparin preparations. In addition, these heparin preparations often contaminated dermatan sulfate (DS). Unfortunately, the Japanese Pharmacopoeia (JP) does not include appropriate purity tests. In the present paper, we show that capillary electrophoresis (CE) is a powerful tool for the analysis of OSCS and DS in heparin preparations. CE method shows high resolution and good quantification of OSCS in heparin preparations. This method (OSCS method) was evaluated for accuracy (93.7 %), repeatability (R.S.D.=2.11), linearity (R(2)=0.9996), detection limit (0.1% OSCS) and specificity. In contrast, DS was not able to be detected in high sensitivity by OSCS method. However, a modified CE method (DS method) using the buffer at lower pHs showed good parameters for accuracy (88.1%), repeatability (R.S.D.=1.99), linearity (R(2)=0.9998), detection limit (0.25% DS) and specificity. In conclusion, CE will be an alternative to the NMR method which is being adopted for purification test of heparin sodium in the present version of JP.

We have previously reported on peptide mapping of recombinant human erythropoietin (rhEPO) by liquid chromatography/mass spectrometry (LC/MS). Using this method, both peptides and glycosylation at each glycosylation site can be elucidated based on the mass chromatogram and mass spectrum. In this study, we evaluated the mass spectrometric peptide mapping with regard to its use in comparability assessment of both protein parts and carbohydrates parts in glycoprotein products. Models of closely related glycoprotein products used in this study are rhEPOs produced from three different sources. We demonstrated that the mass spectrometric peptide mapping can elucidate the identity of protein part, and differences in site-specific carbohydrates heterogeneity due to acetylation and sulfation among the three rhEPOs. Our method can thus be useful in comparability assessment of therapeutic glycoproteins.