GENE TRANSFER OF THE CYSTIC FIBROSIS TRANSMEMBRANE REGULATOR

前言：宿主的免疫反应和载体的低效率阻碍了囊性纤维化的发生，囊性纤维化是一种常见的、致命的遗传性疾病。CF病的肺部替代标记物需要大量的患者或较长的研究时间。肺脏CF基因转移载体检测的另一种替代方法是使用上颌窦作为CF肺部疾病的替代模型。在一期剂量递增研究中使用腺相关病毒载体(AAV-CFTR)，然后在二期临床试验中将CFTR基因转移到CF患者上颌窦的呼吸道上皮细胞。这是第一个测量CFTR基因转移的临床终点的CF基因治疗II期研究。方法：采用随机、非盲法、剂量递增、受试者内、上颌窦内应用AAV-CFTRI期临床试验方法，对10例上颌窦瘘患者进行AAV-CFTR治疗。一项随机、双盲、安慰剂对照的受试者内II期临床试验正在进行中，22名患者中有16名参加了试验。II期研究的动力是检测鼻窦炎复发率下降50%，使用双侧阿尔法0.05和贝塔0.20的22名患者。结果：在I期研究中，在治疗两周后的活检组织中，观察到最高水平的基因转移在每个细胞0.1-1个AAV-CFTR载体拷贝范围内。持续观察长达10周。观察了6例受试者中5例对药物干预后窦跨上皮电势差(TEPD)反应的剂量依赖性变化。通过RT-PCR检测，在2名受试患者中观察到了2名患者的表达。其他第二阶段的结果正在等待研究完成和打破盲目。这两项研究都显示很少或根本没有炎症或免疫反应。结论：上颌窦注射AAV-CFTR可成功地、剂量依赖地将基因转移到上颌窦，鼻窦TEPD的改变提示了一种功能效应，几乎没有或没有细胞病变或宿主免疫反应。对AAV载体的进一步研究是有必要的，因为它们可能被证明对CFTR基因转移和其他体内基因转移治疗有用。

INTRODUCTION: The host immune response and low vector efficiency have prevented effective cystic fibrosis (CF), a common, fatal, genetic disease. Pulmonary surrogate markers of CF disease require large patient numbers or long study durations. An alternative to pulmonary testing of CF gene transfer vectors is use of the maxillary sinuses as a surrogate model of CF lung disease. An adeno-associated virus vector (AAV-CFTR) was used in a phase I dose-escalation study followed by a phase II clinical trial to transfer CFTR cDNA into respiratory epithelial cells of the maxillary sinus of CF patients. This is the first CF gene therapy phase II study measuring clinical endpoints of CFTR gene transfer. METHODS: A randomized, unblinded, dose-escalation, within-subjects, phase I clinical trial of AAV-CFTR was conducted in the maxillary sinus of 10 CF patients with antrostomies. A randomized, double-blind, placebo controlled, within-subjects phase II clinical trial is in progress with 16 of 22 patients enrolled. The phase II study is powered to detect a 50% decrease in sinusitis recurrence using 22 patients with two-sided alpha 0.05 and beta 0.20. RESULTS: In the phase I study, the highest level of gene transfer was observed in the range of 0.1-1 AAV-CFTR vector copy per cell in biopsies obtained two weeks after treatment. Persistence was observed for up to 10 weeks. Dose-dependent changes in sinus transepithelial potential difference (TEPD) responses to pharmacological intervention were observed in 5 of 6 tested patients. Expression, measured by RT-PCR, was observed in 2 of 2 tested patients. Other phase II results are pending completion of study and breaking of blind. Both studies demonstrated little or no inflammatory or immune responses. CONCLUSION: AAV-CFTR administration to the maxillary sinus results in successful, dose-dependent gene transfer to the maxillary sinus and alterations in sinus TEPD suggestive of a functional effect, with little or no cytopathic or host immune response. Further study is warranted for AAV vectors as they may prove useful for CFTR gene transfer and other in vivo gene transfer therapies.