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，因为它对患者是安全的；在床边进行的；和fda批准的常规药物然而，迄今为止，它用于基因传递是无效的；没有达到安全原则；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（DRGs）的初级感觉神经元通过LP，即鞘内（IT），使用自互补重组腺相关病毒血清型8 （sc-rAAV8）。在大鼠慢性神经性疼痛模型中，单次给予表达镇痛基因前内啡肽（pp¿EP）或大鼠抗炎基因白介素-10 （rIL10/F129S）突变形式的sc-rAAV8可显著（p<0.0001）缓解3个月的症状，这是一个重要的功能结果。本应用的假设是，sc-rAAV8通过LP是治疗难治性慢性疼痛的可行基因递送产品，可由专业研究中心以外的临床医生使用。为了研究/建立临床翻译的潜力，我们提出以下具体目标：通过体视学定量“封闭”vs中的DRG转导。“打开”IT空间，表征对IT媒介的血清学免疫，并确定器官分布。目标2。确定神经性疼痛模型中最强的候选治疗基因，并确定是否与传统疼痛治疗有药理协同作用。目标3。为了测试这种方法在一种新的大鼠模型上的抗感知效果，这种模型反映了无法治愈的癌症患者的疼痛，这可能是未来的临床试验场景。目标4。目的：检测IT sc-rAAV8能否有效转导大型动物DRG神经元。意义和未来展望：慢性疼痛影响着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）。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患者重度疼痛临床开发的候选方法。IT sc-rAAV8可以作为机制验证试验的工具，例如验证小胶质细胞激活作为人类治疗靶点，也可能成为治疗其他顽固性慢性疼痛的新药。

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.