Fig. 4

Pharmacokinetic analysis of trastuzumab and trastuzumab-Fc variants in hFcRn transgenic mice. a– d Serum concentrations of trastuzumab (black line) and trastuzumab-Fc variants, including trastuzumab-DHS a (yellow), trastuzumab-PFc29 b (purple), trastuzumab-YML c (red), and trastuzumab-EML d (green), were measured over a 7-week period following intravenous administration (5 mg/kg, n = 3). Error bars represent standard deviations. Trastuzumab-YML demonstrated the most extended serum persistence among the Fc variants, highlighting its superior pharmacokinetic properties. e Fold improvement in serum half-life (t_₁/₂) of trastuzumab-Fc variants relative to wild-type trastuzumab. Trastuzumab-YML achieved the most significant extension in t_₁/₂, surpassing other variants, including trastuzumab-DHS, trastuzumab-PFc29, and trastuzumab-EML, further emphasizing its potential as a next-generation Fc-engineered therapeutic