Platelet Activation by Antisense Oligonucleotides (ASOs) in the Göttingen Minipig, including an Evaluation of Glycoprotein VI (GPVI) and Platelet Factor 4 (PF4) Ontogeny

Abstract

Antisense oligonucleotide (ASO) is a therapeutic modality that enables selective modulation of undruggable protein targets. However, dose- and sequence-dependent platelet count reductions have been reported in nonclinical studies and clinical trials. The adult Göttingen minipig is an acknowledged nonclinical model for ASO safety testing, and the juvenile Göttingen minipig has been recently proposed for the safety testing of pediatric medicines. This study assessed the effects of various ASO sequences and modifications on Göttingen minipig platelets using in vitro platelet activation and aggregometry assays. The underlying mechanism was investigated further to characterize this animal model for ASO safety testing. In addition, the protein abundance of glycoprotein VI (GPVI) and platelet factor 4 (PF4) was investigated in the adult and juvenile minipigs. Our data on direct platelet activation and aggregation by ASOs in adult minipigs are remarkably comparable to human data. Additionally, PS ASOs bind to platelet collagen receptor GPVI and directly activate minipig platelets in vitro, mirroring the findings in human blood samples. This further corroborates the use of the Göttingen minipig for ASO safety testing. Moreover, the differential abundance of GPVI and PF4 in minipigs provides insight into the influence of ontogeny in potential ASO-induced thrombocytopenia in pediatric patients.

An Updated Comprehensive Pharmacovigilance Study of Drug‐Induced Thrombocytopenia Based on FDA Adverse Event Reporting System Data

“…[79][80][81] Autoimmune dysregulation and antiplatelet IgG antibody production in hATTR patients has been suggested as a potential mechanism for inotersen-induced thrombocytopenia. 82,83 The study and clinical trials presented contradictory results and there were fewer pharmacovigilance studies and case reports on inotersen. Therefore, whether inotersen was one of the risk factors for thrombocytopenia and the complex immune mechanisms that lead to thrombocytopenia requires further study.…”

Nucleic acid-based therapeutics for the treatment of central nervous system disorders

“…The number of PS backbone modifications helps promote systemic and CNS distribution of NBTs, with more PS modifications resulting in better distribution ( Crooke et al, 2020a ). Specifically, ASOs containing a PS content of 80% have proven especially successful in regard to distribution and efficacy ( Sewing et al, 2017 ; Valenzuela et al, 2023 ). However, the presence of PS modifications above 40% in siRNA can negatively impact the efficacy of RNA induced silencing complex (RISC) loading and promote off target effects and toxicity ( Biscans et al, 2020 ; Halloy et al, 2022 ).…”