Effect of ANITVNITV peptide fusion on the bioactivity and pharmacokinetics of human IFN-α2b and a hyper-N-glycosylated variant.

Different strategies have been developed and successfully applied to biotherapeutics in order to improve their in vivo efficacy. The genetic fusion to natural or synthetic glycosylated peptides constitutes a promising strategy since it conserves the protein sequence and results in the improvement of the pharmacokinetic properties. The ANITVNITV peptide described by Perlmann and coworkers presents 9 amino acids and 2 potential N-glycosylation sites. Its fusion to FSH resulted in the increase of the molecular mass and negative charge of the protein. Consequently, the pharmacokinetics was considerably improved. The aim of the present study was to compare the influence of ANITVNITV peptide fusion on the physicochemical, biological and pharmacokinetic properties of native hIFN-α2b (IFNwt), which contains a single O-glycosylation site, and a hyperglycosylated variant (IFN4N), that bears, in addition, 4 N-linked glycans. The resulting molecules, IFNwtNter and IFN4NNter, evidenced a higher molecular mass and negative charge compared to IFNwt and IFN4N, respectively. Therefore, the pharmacokinetic properties of the new molecules were significantly improved. The molecules obtained by the synthetic peptide fusion strategy evidenced a decrease in their in vitro antiviral specific biological activities (SBA). However, in vitro antiproliferative SBA was differentially modified for IFNwtNter and IFN4NNter in comparison with the parental molecules. For IFNwtNter, a reduction in the antiproliferative SBA was also observed. Remarkably, the addition of the ANITVNITV peptide to the N-terminus of IFN4N had a positive impact on its growth-inhibitory activity. This feature together with its improved pharmacokinetics encourages the development of IFN4NNter as an IFN-α based biobetter.