Using autologous (131)I-fibrinogen, we made studies of the metabolism and distribution of fibrinogen in 10 patients with hemophilia A. In two patients simultaneous studies of autologous (131)I-fibrinogen and homologous (125)I-fibrinogen prepared from healthy donors' plasma were carried out. The average value for the plasma volume was 42.1 +/- 8.8 ml/kg; for the plasma fibrinogen concentration, 349 +/- 90 mg/100 ml; for the intravascular fibrinogen, 144 +/- 32 mg/kg; for the interstitial fibrinogen, 30 +/- 11 mg/kg; for the slower half-life of (131)I-fibrinogen, 2.34 +/- 0.17 days; for the transcapillary transfer rate of fibrinogen, 109 +/- 37 mg/kg per day; and for the catabolic and synthetic rates of fibrinogen, 51.7 +/- 13.1 mg/kg per day. Comparison of these results with those of the previous study in healthy male subjects showed that in patients with hemophilia A the catabolic and synthetic rates of fibrinogen are markedly increased, whereas the plasma fibrinogen concentration, intravascular and interstitial fibrinogen, and the transcapillary transfer rate of fibrinogen are not significantly different. The simultaneous studies of autologous (131)I-fibrinogen and normal homologous (125)I-fibrinogen in two subjects revealed that the two preparations behaved very similarly. Based on these findings, we concluded that our present findings are not due to the qualitative difference between the hemophilia A and normal fibrinogens, but that they are due to the difference in the host condition with respect to the fibrinogen metabolism, which is either an increased rate of direct breakdown of fibrinogen or an increased rate of fibrinogen breakdown after fibrin formation, or both.
Abstract Objective Recombinant monoclonal therapeutic antibodies like lecanemab, which target amyloid beta in Alzheimer's disease, offer a promising approach for modifying the disease progression. Due to its relatively short half‐life, lecanemab administered as a bi‐monthly infusion (typically 10 mg/kg) has a relatively brief half‐life. Interaction with abundant plasma proteins binder in the bloodstream can affect pharmacokinetics of drugs, including their half‐life. In this study, we investigated potential plasma protein binding (PPB) interaction to lecanemab using lecanemab biosimilar. Methods Lecanemab biosimilar used in this study was based on publicly available sequences. ELISA and western blotting were used to assess lecanemab biosimilar immunoreactivity in the fractions of human plasma obtained through size exclusion chromatography. The binding of lecanemab biosimilar to candidate plasma binders was confirmed by western blotting, ELISA, and surface plasmon resonance analysis. Results Using a combination of equilibrium dialysis, ELISA, and western blotting in human plasma, we first describe the presence of likely PPB partners to lecanemab biosimilar and then identify fibrinogen as one of them. Utilizing surface plasmon resonance, we confirmed that lecanemab biosimilar does bind to fibrinogen, although with lower affinity than to monomeric amyloid beta. Interpretation In the context of lecanemab therapy, these results imply that fibrinogen levels could impact the levels of free antibodies in the bloodstream and that fibrinogen might serve as a reservoir for lecanemab. More broadly, these results indicate that PPB may be an important consideration when clinically utilizing therapeutic antibodies in neurodegenerative disease.
Abstract Background Therapeutic monoclonal antibodies targeting amyloid beta‐protein (Ab), such as lecanemab, represent a promising approach for disease‐modification in Alzheimer’s disease (AD). Due to its relatively short half‐life, lecanemab is given as a bi‐monthly infusion (typically 10mg/kg). Binding to high abundance plasma proteins (PPB) can influence the pharmacokinetics of drugs in the blood, including their half‐life. Method In this study, we investigated the potential of PPB for lecanemab using a biosimilar synthetized from publicly available lecanemab sequence (Lec‐bs). Lec‐bs biosimilar immunoreactivity was assessed in human plasma fractions obtained by size exclusion chromatography using both ELISA and Western blotting. The binding of lec‐bs to candidate PPB was validated through Western blotting, ELISA, and surface plasmon resonance analysis. Result Using a combination of equilibrium dialysis, ELISA, and Western blotting of human plasma, we first describe the presence of likely PPB for Lec‐bs, and then identify fibrinogen as a probable major plasma protein binding partner for Lec‐bs. Utilizing surface plasmon resonance, we confirmed that Lec‐bs binds to fibrinogen, albeit with lower affinity (318 µM) than to monomeric Ab (324 nM). Conclusion In the context of lecanemab therapy, these results suggest that fibrinogen levels may influence free antibody levels in blood and that fibrinogen may act as a reservoir for lecanemab. More broadly, these results indicate that PPB may be an important consideration for the clinical use of therapeutic antibodies in neurodegenerative disease.
Recombinant monoclonal therapeutic antibodies like lecanemab, which target amyloid beta in Alzheimer's disease, offer a promising approach for modifying the disease progression. Due to its relatively short half-life, Lecanemab, administered as a bi-monthly infusion (typically 10mg/kg) has a relatively brief half-life. Interaction with abundant plasma proteins binder in the bloodstream can affect pharmacokinetics of drugs, including their half-life. In this study we investigated potential plasma protein binding interaction to lecanemab using lecanemab biosimilar.
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