Adenoviral p53 gene therapy for lung cancer

To determine the feasibility, safety, humoral immune response, and biological activity of multiple intratumoral injections of Ad5CMV-p53, and to characterize the pharmacokinetics of Ad5CMV-p53 in patients with advanced non-small cell lung cancer (NSCLC). Fifteen patients with histologically confirmed NSCLC and p53 mutations were enrolled into this phase I trial. Nine patients received escalating dose levels of Ad5CMV-p53 (1 × 109 to 1 × 1011 plaque-forming units[PFU]) as monotherapy once every 4 weeks. Six patients were treated on a 28-day schedule with Ad5CMV-p53 in combination with intravenous administration of cisplatin (80 mg/m2). Patients were monitored for toxicity, vector distribution, antibody formation, and tumor response. Fifteen patients received a total of 63 intratumoral injections of Ad5CMV-p53 without dose-limiting toxicity. The most common treatment-related toxicity was a transient fever. Specific p53 transgene expression was detected using reverse-transcriptase polymerase chain reaction in biopsied tumor tissues throughout the period of treatment despite of the presence of neutralizing anti-adenovirus antibody. Distribution studies revealed that the vector was detected in the gargle and plasma, but rarely in the urine. Thirteen of 15 patients were assessable for efficacy; one patient had a partial response (squamous cell carcinoma at the carina), 10 patients had stable disease, with three lasting ≥9 months, and 2 patients had progressive disease. Multiple courses of intratumoral Ad5CMV-p53 injection alone or in combination with intravenous administration of cisplatin were feasible and well tolerated in advanced NSCLC patients, and appeared to provide clinical benefit