GENE TRANSFER OF THE CYSTIC FIBROSIS TRANSMEMBRANE REGULATOR

宿主免疫反应和低载体效率阻止了有效的囊性纤维化（CF），这是一种常见的、致命的遗传疾病。CF疾病的肺替代标志物需要大量患者或较长的研究时间。CF基因转移载体肺检测的另一种替代方法是使用上颌窦作为CF肺病的替代模型。腺相关病毒载体（AAV-CFTR）在I期剂量递增研究和II期临床试验中使用，将CFTR cDNA转移到CF患者上颌窦呼吸上皮细胞中。这是首个测量CFTR基因转移临床终点的CF基因治疗II期研究。方法：随机、非盲、剂量递增、受试者内、AAV-CFTR的I期临床试验在10例有上颌窦造口的CF患者中进行。一项随机、双盲、安慰剂对照、受试者内II期临床试验正在进行中，22名患者中有16名入选。这项II期研究在22例双侧α 0.05和β 0.20的患者中检测到鼻窦炎复发率降低50%。结果：在I期研究中，在治疗两周后获得的活检中，观察到最高水平的基因转移在每细胞0.1-1 AAV-CFTR载体拷贝范围内。持续观察长达10周。6例患者中有5例观察到窦间上皮电位差（TEPD）对药物干预反应的剂量依赖性变化。通过RT-PCR检测，在2例受测患者中有2例观察到表达。其他II期结果正在等待研究的完成和盲法的打破。两项研究都显示很少或没有炎症或免疫反应。结论：AAV-CFTR给药上颌窦导致成功的、剂量依赖性的基因转移到上颌窦，鼻窦TEPD的改变提示功能作用，很少或没有细胞病变或宿主免疫反应。AAV载体可能用于CFTR基因转移和其他体内基因转移治疗，因此有必要进一步研究AAV载体。

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.