Plasma Protein Binding of an Antisense Oligonucleotide Targeting Human ICAM-1 (ISIS 2302)

Abstract

In vitro ultrafiltration was used to determine the plasma protein-binding characteristics of phosphorothioate oligonucleotides (PS ODNs). Although there are binding data on multiple PS ODNs presented here, the focus of this research is on the protein-binding characteristics of ISIS 2302, a PS ODN targeting human intercellular adhesion molecule-1 (ICAM-1) mRNA, which is currently in clinical trials for the treatment of ulcerative colitis. ISIS 2302 was shown to be highly bound (> 97%) across species (mouse, rat, monkey, human), with the mouse having the least degree of binding. ISIS 2302 was highly bound to albumin and, to a lesser, extent alpha2-macroglobulin and had negligible binding to alpha1-acid glycoprotein. Ten shortened ODN metabolites (8, 10, and 12-19 nucleotides [nt] in length, truncated from the 3' end) were evaluated in human plasma. The degree of binding was reduced as the ODN metabolite length decreased. Three additional 20-nt (20-mer) PS ODNs (ISIS 3521, ISIS 2503, and ISIS 5132) of varying sequence but similar chemistry were evaluated. Although the tested PS ODNs were highly bound to plasma proteins, suggesting a commonality within the chemical class, these results suggested that the protein-binding characteristics in human plasma may be sequence dependent. Lastly, drug displacement studies with ISIS 2302 and other concomitant drugs with known protein-binding properties were conducted to provide information on potential drug interactions. Coadministered ISIS 2302 and other high-binding drugs evaluated in this study did not displace one another at supraclinical plasma concentrations and, thus, are not anticipated to cause any pharmacokinetic interaction in the clinic as a result of the displacement of binding to plasma proteins.

Cross-Species Pharmacokinetic Comparison from Mouse to Man of a Second-Generation Antisense Oligonucleotide, ISIS 301012, Targeting Human Apolipoprotein B-100

“…Protein binding assay. An ultrafiltration method (Watanabe et al, 2006) was used to assess whole-plasma protein binding characteristics of ISIS 301012. In brief, Millipore Corporation (Bedford, MA) Ultrafree-MC filters (mol.…”

Evaluation of Multiple-Turnover Capability of Locked Nucleic Acid Antisense Oligonucleotides in Cell-Free RNase H-Mediated Antisense Reaction and in Mice

“…Thus, interpreting these data, we must take into account the differences between experimental buffer conditions used here and physiological conditions. For instance, it is known that longer PS-DNAs are more likely to form stronger undesirable complexes with proteins and inactivate RNase H to reduce their efficacy (Gao et al, 1992;Watanabe et al, 2006). As in this system, there are limited accompanying components such as inorganics, proteins, and lipids, and effects including such length-dependent factors may not have been considered.…”

Quantum Mechanical Studies of DNA and LNA

“…The interaction/binding of oligonucleotides to proteins is an important parameter influencing toxicity, plasma half-life, tissue accumulation, cellular uptake, and activity of antisense oligonucleotides (Beltinger et al, 1995;Prakash et al, 2002;Watanabe et al, 2006;Lai et al, 2007aLai et al, , 2007bStein et al, 2009). Since H-bonding to folded protein structures (e.g., OB fold) is important for oligonucleotide-protein binding we can assume that structural and MEP complementarity are determinants for binding/interaction to take place.…”