iNOS Gene Therapy to Prevent AV Graft Intimal Hyperplasia

一氧化氮（NO）介导血管平滑肌细胞（SMC）舒张，抑制血小板和白细胞粘附，并阻止SMC增殖。将NO递送至血管损伤部位防止内膜增生（IH）。全身性NO给药可能与不良反应如低血压相关。我们建议，通过使用腺病毒基因治疗技术的局部NO输送将局部增加NO的产生，并避免全身毒性。的 本申请选择的基因是诱导型NO合酶（iNOS）同种型，其产生高水平的NO而不依赖于钙流。与其他亚型相比，iNOS的酶活性更高，可能会产生更大的临床疗效，但基因转移效率更低。我们已经建立了腺病毒介导的iNOS基因传递到啮齿动物和猪血管损伤模型显着降低IH。局部血管给药的安全性 携带iNOS的腺病毒载体（AdiNOS）的有效性已经在猪中以及在全身递送至大鼠后得到证实。有了这些临床前有效性和安全性数据，iNOS治疗准备在人类疾病中进行评估。已制备临床级AdiNOS，并符合FDA关于RCA以及残留细胞DNA含量的要求。我们将评估iNOS基因转移抑制动静脉移植物中IH的安全性和有效性 血液透析（HD）患者。动静脉移植物的静脉血栓易于发生侵袭性IH，其发生率超过血管成形术或旁路手术。移植物动静脉衰竭是一种安全可行的研究iNOS基因治疗的动物模型。目标一：在一项I期临床试验中，评估腺病毒介导的iNOS基因转移至接受动静脉移植物植入以进行HD入路的患者体内的安全性。我们将进行剂量递增研究， 确定用于Aim II的腺病毒载体的最高和最安全剂量。将密切随访患者对腺病毒载体或iNOS给药的不良全身或局部反应的证据。AIM II：在II期临床试验中，通过测量移植物功能和通畅性，确定iNOS基因转移抑制HD植入的AV移植物中IH的疗效。在常规HD期间进行的无创多普勒成像和静脉阻力测量将允许监测移植物功能，而不会给患者带来额外风险。将评估的结局为一期移植物通畅率、辅助一期通畅率、二期通畅率和移植物翻修次数。该临床研究的信息将确定iNOS基因治疗的疗效。如果有益的话，这种疗法将应用于其他病因的IH，如血管成形术和外周和冠状动脉搭桥术。

Nitric oxide (NO) mediates vascular smooth muscle cell (SMC) relaxation, inhibits platelet and leukocyte adhesion, and prevents SMC proliferation. Delivery of NO to sites of vascular injury prevents intimal hyperplasia (IH). Systemic NO administration may be associated with adverse effects such as hypotension. We propose that local NO delivery through the use of adenoviral gene therapy techniques will locally augment NO production and avoid systemic toxicity. The gene of choice for this application is the inducible NO synthase (iNOS) isoform which produces high levels of NO independent of calcium fluxes. The greater enzymatic activity of iNOS as compared with the other isoforms may yield greater clinical efficacy with lower gene transfer efficiency. We have established that adenovirus mediated iNOS gene delivery to rodent and porcine models of vascular injury dramatically reduced IH. The safety of local vascular delivery of an adenoviral vector carrying iNOS (AdiNOS) has been demonstrated in pigs as well as following systemic delivery to rats. With these preclinical efficacy and safety data, iNOS therapy is ready to be evaluated in human disease. The clinical grade AdiNOS has been prepared and meets FDA requirements regarding RCA as well as residual cellular DNA content. We will evaluate the safety and efficacy of iNOS gene transfer to inhibit IH in arteriovenous (AV) grafts placed in hemodialysis (HD) patients. The venous anastomoses of AV grafts are prone to an aggressive form of IH that exceeds the incidence seen in angioplasty or bypass surgery. AV graft failure is a safe and feasible model in which to study iNOS gene therapy. AIM I: To assess the safety of adenovirus mediated iNOS gene transfer into patients undergoing AV graft placement for HD access in a Phase I clinical trial. We will perform dose escalation studies to determine the highest and safest dose of adenoviral vector to use in Aim II. Patients will be closely followed for evidence of adverse systemic or local reactions to adenviral vector or iNOS administration. AIM II: To determine the efficacy of iNOS gene transfer for the inhibition of IH in AV grafts placed for HD as measured by graft function and patency in a Phase II clinical trial. Noninvasive duplex imaging and venous resistance measurements made during routine HD will allow graft function to be monitored with no additional risk to the patient. The outcomes that will be assessed are primary graft patency, assisted primary patency, secondary patency, and number of graft revisions. The information from this clinical study will determine the efficacy of iNOS gene therapy. If beneficial, this therapy will be applied to other etiologies of IH such as following angioplasty and peripheral and coronary bypass.