Structural and functional characterization of a specific antidote for ticagrelor.

Abstract

Ticagrelor is a direct-acting reversibly binding P2Y12 antagonist and is widely used as an antiplatelet therapy for the prevention of cardiovascular events in acute coronary syndrome patients. However, antiplatelet therapy can be associated with an increased risk of bleeding. Here, we present data on the identification and the in vitro and in vivo pharmacology of an antigen-binding fragment (Fab) antidote for ticagrelor. The Fab has a 20 pM affinity for ticagrelor, which is 100 times stronger than ticagrelor's affinity for its target, P2Y12. Despite ticagrelor's structural similarities to adenosine, the Fab is highly specific and does not bind to adenosine, adenosine triphosphate, adenosine 5'-diphosphate, or structurally related drugs. The antidote concentration-dependently neutralized the free fraction of ticagrelor and reversed its antiplatelet activity both in vitro in human platelet-rich plasma and in vivo in mice. Lastly, the antidote proved effective in normalizing ticagrelor-dependent bleeding in a mouse model of acute surgery. This specific antidote for ticagrelor may prove valuable as an agent for patients who require emergency procedures.

• Authors: Andrew Buchanan, Philip Newton, Susanne Pehrsson, Tord Inghardt, Thomas Antonsson, Peder Svensson, Tove Sjögren, Linda Öster, Annika Janefeldt, Ann-Sofie Sandinge, Feenagh Keyes, Mark Austin, Jennifer Spooner, Peter Gennemark, Mark Penney, Garnet Howells, Tristan Vaughan, Sven Nylander
• Journal: Blood (Blood) Vol. 125 Issue 22 Pg. 3484-90 (May 28 2015) ISSN: 1528-0020 [Electronic] United States
• PMID: 25788700 (Publication Type: Journal Article)
• Copyright: © 2015 by The American Society of Hematology.

Chemical References

• Antibodies
• Antibodies, Neutralizing
• Antidotes
• Broadly Neutralizing Antibodies
• Immunoglobulin Fab Fragments
• PB-2452
• Ticagrelor
• Adenosine

Topics

• Adenosine (analogs & derivatives, antagonists & inhibitors, immunology)
• Animals
• Antibodies (isolation & purification, metabolism)
• Antibodies, Neutralizing (chemistry, pharmacology)
• Antibody Specificity
• Antidotes (chemistry, pharmacology)
• Broadly Neutralizing Antibodies
• CHO Cells
• Cricetinae
• Cricetulus
• Crystallography, X-Ray
• Hemorrhage (prevention & control)
• Humans
• Immunoglobulin Fab Fragments (pharmacology)
• Mice
• Models, Molecular
• Platelet Aggregation (drug effects)
• Protein Engineering
• Ticagrelor