Investigation into the Mechanism(s) That Leads to Platelet Decreases in Cynomolgus Monkeys During Administration of ISIS 104838, a 2'-MOE-Modified Antisense Oligonucleotide. Toxicol Sci 2018 Aug 01;164(2):613-626
Date
05/31/2018Pubmed ID
29846725DOI
10.1093/toxsci/kfy119Scopus ID
2-s2.0-85055179292 (requires institutional sign-in at Scopus site) 27 CitationsAbstract
ISIS 104838, a 2'-O-methoxyethyl (2'-MOE)-modified antisense oligonucleotide (ASO), causes a moderate, reproducible, dose-dependent, but selflimiting decrease in platelet (PLT) counts in monkeys and humans. To determine the etiology of PLT decrease in cynomolgus monkeys, a 12-week repeat dose toxicology study in 5 cynomolgus monkeys given subcutaneous injections of ISIS 104838 (30-60 mg/kg/week). Monkeys were also injected intravenously with 111Indium(In)-oxine-labeled PLTs to investigate PLT sequestration. In response to continued dosing, PLT counts were decreased by 50%-90% by day 30 in all monkeys. PLT decreases were accompanied by 2- to 4.5-fold increases in immunoglobulin M(IgM), which were typified by a 2- to 5-fold increase in antiplatelet factor 4 (antiPF4) IgM and antiPLT IgM, respectively. Monocyte chemotactic protein 1 increased upon dosing of ISIS 104838, concomitant with a 2- to 6-fold increase in monocyte-derived extracellular vesicles (EVs), indicating monocyte activation but not PLT activation. Despite a 2- to 3-fold increase in von Willebrand factor antigen in all monkeys following ASO administration, only 2 monkeys showed a 2- to 4-fold increase in endothelial EVs. Additionally, a ∼60 - 80%% increase in PLT sequestration in liver and spleen was also observed. Collectively, these results suggest the overall increase in total IgM, antiPLT IgM and/or antiPF4 IgM, in concert with monocyte activation contributed to increased PLT sequestration in spleen and liver, leading to decreased PLTs in peripheral blood.
Author List
Narayanan P, Shen L, Curtis BR, Bourdon MA, Nolan JP, Gupta S, Hoffmaster C, Zhou F, Christian B, Schaubhut JL, Greenlee S, Burel SA, Witztum JL, Engelhardt JA, Henry SPAuthor
Brian Curtis PhD Director in the Platelet & Neutrophil Immunology Laboratory department at BloodCenter of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsBlood Platelets
Chemokine CCL2
Extracellular Vesicles
Female
Immunoglobulin G
Immunoglobulin M
Liver
Macaca fascicularis
Monocytes
Oligonucleotides, Antisense
P-Selectin
Phosphorothioate Oligonucleotides
Platelet Count
Spleen
von Willebrand Factor