GENE THERAPY OF MALIGNANT MESOTHELIOMA USING E1 DELETED ADENOVIRUS

恶性间皮瘤（MM）是一种肿瘤，目前还没有有效的治疗方法。 我们进行了一项I期临床试验，以评估胸膜内递送含有由劳斯肉瘤病毒（RSV）启动子驱动的单纯疱疹病毒胸苷激酶基因（HSVtk）的重组腺病毒（rAd）进入MM患者胸膜腔的安全性和可行性，然后用抗病毒药物更昔洛韦（GCV）全身治疗14天。 先前在MM动物模型中实施rAd. RSVtk-GCV方案导致肿瘤负荷显著降低和生存期延长，全身毒性最小。 该临床试验是一项剂量递增研究，旨在确定rAd. RSVtk的最大耐受胸膜内剂量。26名患者已经完成了高达1.0 × 10 12空斑形成单位（pfu）Ad.RSVtk剂量水平的治疗，并发症最少。 毒性反应包括病毒滴注后的低烧、贫血、肝功能测试的一过性升高和滴注部位附近的水疱性皮疹。 通过DNA PCR、原位杂交和免疫组化，对选定的基因递送后活检样本进行评估，发现tk基因转移的证据呈剂量依赖性。 在载体给药后活检样品的IHC分析中观察到嗜中性粒细胞占优势的炎症反应。 患者产生针对腺病毒载体的体液和细胞免疫应答的显著证据。 总之，Ad.RSVtk/GCV基因治疗MM患者是安全的，似乎有证据表明TK基因以剂量依赖性方式转移，并且重组腺病毒在递送到胸膜间隙时引起强烈的免疫应答。

Malignant mesothelioma (MM) is a neoplasm for which no effective therapy currently exists. We conducted a Phase I clinical trial to assess the safety and feasibility of intrapleural delivery of recombinant adenovirus (rAd) containing the Herpes Simplex Virus thymidine kinase gene (HSVtk) driven by the Rous Sarcoma Virus (RSV) promoter into the pleural space of patients with MM followed by systemic treatment with the antiviral drug ganciclovir (GCV) for 14 days. Prior implementation of the rAd.RSVtk -GCV protocol in animal models of MM resulted in significant reduction of tumor burden and prolongation of survival with minimal systemic toxicity. The clinical trial was a dose escalation study designed to determine the maximally-tolerated intrapleural dose of rAd.RSVtk. Twenty-six patients have completed treatment at dose levels up to l.0x10 12 plaque forming units (pfu) Ad.RSVtk with minimal complications. Toxicities seen include low-grade fever after viral instillation, anemia, transient elevation of liver function tests, and vesicular skin eruptions near the instillation site. Evaluation of selected post-gene delivery biopsy samples revealed eavidence of tk gene transfer via DNA PCR, in situ hybridization, and immunohistochemistry in a dose-dependent fashion. Neutrophil-predominant inflammatory responses were seen on IHC analysis of post-vector administration biopsy samples. Patients develop significant evidence of humoral and cellular immune responses against the adenoviral vector. In summary, Ad.RSVtk/GCV gene therapy is safe in MM paatients, there appears to be evidence of TK gene transfer in a dose-dependent fashion, and recombinant adenoviruses elicit strong immune responses when delivered into the pleural space.