Dubost Valérie, Wuersch Kuno, Penraat Kelley, Johnson Eric, Wekkeli Anja, Ramakrishna Ramprasad, Piequet Aline, Greiner Géeraldine, Jivkov Magali, Erard Esther, Hansen Regine, Brees Dominique, Hartmann Andreas, Balavenkatraman Kamal Kumar, Nunes Jairo
Novartis Institute for Biomedical Research, Basel, Switzerland.
Novartis Institute for Biomedical Research, Cambridge, Massachusetts, USA.
Toxicol Pathol. 2025 Jan;53(1):95-106. doi: 10.1177/01926233241311277. Epub 2025 Jan 30.
The safety of a 2'--methoxyethyl antisense oligonucleotide (ASO) was investigated in Mauritius cynomolgus monkeys in a 41-week Good Laboratory Practice (GLP) toxicity study after multiple intrathecal (IT) administrations. Histopathological examination revealed ectopic formation of lymphoid follicles in the spinal cord (SC) at the injection site at all doses and the presence of granular material in neurons of the SC in high-dose animals. The granular material was seen in all the segments of the SC, but mainly in the lumbar segment and persisted at the end of the 26-week recovery period, while the lymphoid follicles showed a reversibility trend. Findings associated with repeated IT administration of ASOs have been described in nonhuman primate (NHP) toxicity studies, specifically in the brain, but findings in the SC are rarely reported. In the present study, we report a high incidence of findings in the SC compared to brain, especially in the lumbar segment in proximity to IT injection sites. An extensive panel of immunohistochemistry markers showed that the ectopic lymphoid follicle formation (LFF) had a cellular composition and organization consistent with tertiary lymphoid structure (TLS) without associated axonal damage in the adjacent nervous tissue. In situ hybridization with an miRNA probe complementary to the ASO revealed that the granular material represented a dose-dependent ASO accumulation in the cytoplasm of neurons without inducing cell death or apoptosis. Glial and ependymal cells in the SC also showed dose-dependent accumulation of the ASO preceding detection of granular material by hematoxylin and eosin (H&E). Based on these molecular localization data, the presence of LFF in SC suggests a chronic local immune activation. Considering the absence of neuronal dysfunction or injury and transient clinical signs previously reported with other 2'- ASOs, the presence of TLS and ASO was considered non-adverse.
在一项为期41周的良好实验室规范（GLP）毒性研究中，对毛里求斯食蟹猴进行多次鞘内注射（IT）后，研究了2'-甲氧基乙基反义寡核苷酸（ASO）的安全性。组织病理学检查显示，所有剂量组在注射部位的脊髓（SC）均出现异位淋巴滤泡形成，高剂量组动物的脊髓神经元中存在颗粒物质。颗粒物质在脊髓的所有节段均可见，但主要在腰段，并且在26周恢复期结束时仍然存在，而淋巴滤泡呈现出可逆趋势。与ASO重复鞘内给药相关的发现已在非人灵长类动物（NHP）毒性研究中有所描述，特别是在大脑中，但脊髓中的发现很少被报道。在本研究中，我们报告与大脑相比，脊髓中发现的发生率较高，尤其是在靠近鞘内注射部位的腰段。一系列广泛的免疫组织化学标志物显示，异位淋巴滤泡形成（LFF）具有与三级淋巴结构（TLS）一致的细胞组成和组织结构，且相邻神经组织中无相关轴突损伤。用与ASO互补的miRNA探针进行原位杂交显示，颗粒物质代表神经元细胞质中剂量依赖性的ASO积累，未诱导细胞死亡或凋亡。在苏木精和伊红（H&E）检测到颗粒物质之前，脊髓中的神经胶质细胞和室管膜细胞也显示出ASO的剂量依赖性积累。基于这些分子定位数据，脊髓中LFF的存在表明存在慢性局部免疫激活。考虑到先前报道的其他2'-ASO不存在神经元功能障碍或损伤以及短暂的临床体征，TLS和ASO的存在被认为是非不良的。
