Purpose Modulating sialylation of therapeutic glycoproteins
may be used to influence their clearance and systemic exposure.
We studied the effect of low and high sialylated IL4–10
fusion protein (IL4–10 FP) on in vitro and in vivo bioactivity and
evaluated the effect of differential sialylation on pharmacokinetic
Methods CHO cell lines producing low (IL4–10 FP lowSA)
and high sialylated (IL4–10 FP highSA) fusion protein were
generated. Bioactivity of the proteins was evaluated in an
LPS-stimulated whole blood assay. Pharmacokinetics were
studied in rats, analyzing plasma levels of IL4–10 FP upon
intravenous injection. In vivo activity was assessed in an inflammatory
pain mice model upon intrathecal injection.
Results IL4–10 FP lowSA and IL4–10 FP highSA had similar
potency in vitro. The pharmacokinetics study showed a 4-fold
higher initial systemic clearance of IL4–10 FP lowSA, whereas
the calculated half-life of both IL4–10 FP lowSA and IL4–10
FP highSA was 20.7 min. Finally, both IL4–10 FP glycoforms
inhibited persistent inflammatory pain in mice to the same
Conclusions Differential sialylation of IL4–10 fusion protein
does not affect the in vitro and in vivo activity, but clearly results
in a difference in systemic exposure. The rapid systemic clearance
of low sialylated IL4–10 FP could be a favorable characteristic
to minimize systemic exposure after administration
in a local compartment.