Tumor response criteria and biomarkers associated with increased survival following adenoviral p53 gene therapy (ADVEXIN) in patients with recurrent squamous cell carcinoma of the head and neck (SCCHN)

6057 Background: There is a growing body of data indicating that conventional WHO and RECIST criteria do not optimally identify tumor responses associated with increased survival. Methods: We compared several response criteria to assess the efficacy of intratumoral adenoviral p53 gene therapy (Advexin) in a Phase 2 trial of 106 patients with recurrent SCCHN. Results: The percentage of patients with tumor responses defined by reductions in bi-dimensional tumor area by CT scans of 50%, 30%, 25%, 10% or stable disease of > 3 months were 8%, 10%, 11%, 16% and 20% respectively. The median survival for the entire population was 5.9 months while the responder populations defined by tumor decreases of 50%, 30%, 25%, 10% or stable disease > 3 months had median survivals of 40.8, 17.0, 13.7, 12.3 and 11.4 months respectively. There was a statistically significant increase in median survival for each of the responder populations compared to non-responders (p < 0.0009 for each comparison by logrank test). Statistical...