Data from: Formulation and toxicology evaluation of the intrathecal AYX1 DNA-decoy in Sprague Dawley rats

The longevity of pain after surgery is debilitating and limits the recovery of patients. AYX1 is a double-stranded, unprotected, 23 base-pair oligonucleotide designed to reduce acute post-surgical pain and prevent its chronification with a single intrathecal perioperative dose. AYX1 mimics the DNA sequence normally bound by EGR1 on chromosomes, a transcription factor transiently induced in the dorsal root ganglia—spinal cord network following a noxious input. AYX1 binds to EGR1 and prevents it from launching waves of gene regulation that are necessary to maintain pain over time. A formulation suitable for an intrathecal injection of AYX1 was developed, including a specific ratio of AYX1 and calcium so the ionic homeostasis of the cerebrospinal fluid is maintained and no impact on neuromuscular control is produced upon injection. A GLP toxicology study in naïve Sprague Dawley rats was conducted using 3 dose levels up to the maximum feasible dose. Clinical observations, neurobehavioral observations, clinical pathology and histopathology of the nervous system and peripheral tissues were conducted. An additional nonGLP study was conducted in the spared nerve injury model of chronic neuropathic pain in which EGR1 is induced in the dorsal root ganglia and spinal cord. Similar testing was performed, including a modified Irwin test to assess a potential impact of AYX1 on autonomic nervous system responses, locomotion, activity, arousal, sensorimotor, and neuromuscular function. No AYX1-related adverse events were observed in any of the studies and the no-observed-adverse-effect-level was judged to be the maximum feasible dose.

术后疼痛的长期迁延会严重损害患者健康，并显著阻碍其康复进程。AYX1是一种双链、无保护的23碱基对寡核苷酸（oligonucleotide），通过单次鞘内（intrathecal）围手术期给药，可用于减轻急性术后疼痛并阻止其转为慢性疼痛。AYX1可模拟染色体上EGR1正常结合的DNA序列；EGR1是一类在有害刺激下，于背根神经节（dorsal root ganglia）与脊髓网络中瞬时诱导表达的转录因子（transcription factor）。AYX1可与EGR1结合，阻断其启动维持慢性疼痛所需的持续性基因调控级联反应。研究团队开发了适用于鞘内注射的AYX1制剂，该制剂按特定比例复配AYX1与钙离子，以维持脑脊液（cerebrospinal fluid）的离子稳态，且给药后不会对神经肌肉控制产生不良影响。针对未接触受试物的斯普拉格-道利（Sprague Dawley）大鼠开展了符合药品非临床研究质量管理规范（Good Laboratory Practice, GLP）的毒理学研究，设置3个剂量梯度，最高至最大可行剂量。研究涵盖临床观察、神经行为学观察、临床病理学检测，以及神经系统与外周组织的组织病理学检查。此外，研究团队还在背根神经节与脊髓中诱导了EGR1表达的spared神经损伤（spared nerve injury）慢性神经病理性疼痛模型中开展了非GLP研究。本次研究采用改良Irwin试验，以评估AYX1对自主神经系统反应、运动功能、活动度、觉醒状态、感觉运动功能及神经肌肉功能的潜在影响。所有研究中均未观察到与AYX1相关的不良事件，未观察到不良效应的最大剂量被判定为最大可行剂量。