sc-rAAV8 via Lumbar Puncture as Spinal Analgesic Drug Delivery Systems

描述（由申请人提供）：腰椎穿刺（LP）是一种有吸引力的神经系统新疗法，因为它对患者安全;在床边进行; FDA批准用于常规药物。然而，它用于基因递送迄今为止是无效的;不符合安全原则;并且未能靶向神经元。我们已经开发了高效的基因转移到背根神经节（DRG）的初级感觉神经元通过LP，即鞘内（IT），使用自身互补的重组腺相关病毒血清型8（sc-rAAV 8）。在大鼠慢性神经性疼痛模型中，表达镇痛基因前内啡肽原（pp <$EP）或大鼠抗炎基因白细胞介素-10（rIL 10/F129 S）的突变形式的sc-rAAV 8的单次施用导致症状高度显著（p<0.0001）缓解=3个月，这是重要的功能结果。本申请的假设是，通过LP的sc-rAAV 8是临床医生在专业研究中心之外可使用的用于顽固性慢性疼痛的可行基因递送产品。为了研究/建立临床翻译的潜力，我们提出了以下具体目标：目标1。通过体视学在“封闭”与“开放”IT空间中定量DRG转导，表征对IT载体的血清学免疫，并确定器官分布。目标二。在神经病理性疼痛模型中确定最强的候选治疗基因，并确定是否与常规疼痛治疗有药理学协同作用。目标3。为了测试该方法在一种新的大鼠模型中的抗伤害效果，该模型反映了患有不可治愈癌症的患者的疼痛，这是一种可能的未来临床试验方案。目标4。为了测试IT sc-rAAV 8是否有效地转导大型动物中的DRG神经元。意义和未来前景：慢性疼痛影响5000万美国人，仅在美国每年就造成超过1000亿美元的成本（如PA-07-282所述）。该申请提出了一种基因治疗方法，如果研究计划成功，将成为晚期恶性肿瘤严重疼痛患者临床开发的候选者。IT sc-rAAV 8可以作为机制验证试验的工具，例如验证小胶质细胞活化作为人类的治疗靶点，也可能成为治疗顽固性慢性疼痛的新药。 公共卫生相关性：慢性疼痛影响5000万美国人，仅在美国每年就产生> 1000亿美元的成本（如PA-07-282所述）。脊髓穿刺是一种有吸引力的方法，可以为神经系统提供新型疗法，治疗各种疾病，尤其是疼痛。原因是脊髓作为一个“疼痛之门”，能够敞开，从而促进疼痛信号的传递，或“关闭”，从而控制疼痛。脊椎穿刺对病人是安全的;在床边进行; FDA批准的常规药物。我们开发了一种基因治疗方法，通过脊椎穿刺给予新的基因载体，控制疼痛。具体地，我们在大鼠模型中发现，通过我们的方法，一种严重类型的疼痛，慢性神经性疼痛可以控制>3个月。在本申请中提出的研究中，我们希望进一步研究和改进我们的方法，以评估它是否是未来开发用于人类的可行治疗方法，特别关注晚期癌症的严重疼痛。

DESCRIPTION (provided by applicant): Lumbar puncture (LP) is an attractive route for delivering novel therapies to the nervous system because it is safe in patients; performed at the bedside; and FDA-approved for conventional drugs. However, its use for gene delivery has to date been ineffective; has not met safety principles; and has failed to target neurons. We have developed highly effective gene transfer to the primary sensory neurons of the dorsal root ganglia (DRGs) via LP, i.e. intrathecally (IT), using self-complementary recombinant adeno-associated virus serotype 8 (sc-rAAV8). A single administration of sc-rAAV8 expressing the analgesic gene prepro-¿-endorphin (pp¿EP) or a mutant form of the rat anti- inflammatory gene interleukin-10 (rIL10/F129S) led to highly significant (p<0.0001) relief of symptoms for =3 months in a rat chronic neuropathic pain model, an important functional outcome. The hypothesis of this application is that sc-rAAV8 via LP is a viable gene delivery product for intractable chronic pain usable by clinicians outside of specialized research centers. In order to investigate/establish the potential for clinical translation, we propose the following Specific Aims: Aim 1. To quantify DRG transduction by stereology in the "closed" vs. "open" IT space, characterize serological immunity to the IT vector, and determine organ distribution. Aim 2. To identify the strongest candidate therapeutic gene in the neuropathic pain model and to define if there is pharmacological synergy with conventional pain treatments. Aim 3. To test the antinociceptive efficacy of the approach in a new rat model reflecting pain in patients with incurable cancer, a possible future clinical trial-scenario. Aim 4. To test if IT sc-rAAV8 effectively transduces DRG neurons in large animals. Significance & future perspective: Chronic pain affects 50 million Americans and incurs costs of >$100 billion/year in the US alone (as stated in PA-07-282). This application proposes a gene therapy approach, which, if the Research Plan succeeds, will become a candidate for clinical development in patients with severe pain from advanced malignancies. IT sc-rAAV8 may serve as a tool for proof-of-mechanism trials, e.g. to validate microglial activation as therapeutic target in humans, and may also become a new drug for otherwise intractable chronic pain. Public Health Relevance: Chronic pain affects 50 million Americans and incurs costs of >$100 billion/year in the US alone (as stated in PA-07-282). Spinal tap is an attractive route for delivering novel therapies to the nervous system for a variety of diseases but particularly for pain. The reason is that the spinal cord functions as a "pain gate" able to open wide and thereby to facilitate pain signal transfer or to "close" and thereby control pain. A spinal tap is is safe in patients; performed at the bedside; and FDA-approved for conventional drugs. We have developed a gene therapy method administering new gene vectors by spinal tap, which control pain. Specifically, we find in a rat model that a severe type of pain, chronic neuropathic pain can be controlled for >3 months by our approach. In the research proposed in this application, we wish to study and improve our approach further in order to evaluate, whether it is a viable treatment approach for future development for human use with a special focus on severe pain from advanced cancer.