Neoadjuvant Vascular Targeted Photodynamic Therapy In Urothelial Cancer: Preclinical Data.

321Background: Recurrence and progression following surgical treatment of locally advanced urothelial cancer is high spurring a need to develop effective, well-tolerated neoadjuvant strategies. We examined the efficacy and immunotherapeutic mechanism of neoadjuvant sub-ablative vascular targeted photodynamic therapy (sbVTP) in urothelial cancer. Methods: Following urothelial tumor implantation, mice were randomized to receive neoadjuvant sbVTP (WST-11; TOOKAD Soluble, Steba Biotech, France) or sham treatment 17 days prior to surgical resection. Therapeutic efficacy was evaluated by local and systemic response and survival studies. Immunohistochemistry and flow cytometry were used to elucidate mechanism. Kaplan-Meier, Mann-Whitney and Fischer exact test were used to analyze the data. All statistical tests were two-sided. Results: On the day of surgery, tumor volume was 1222 mm3 (95% CI 976-1468 mm3) vs. 135 mm3 (95% CI 66-204 mm3, p u003c 0.0001) and systemic progression was 30% vs. 7% (pu003c0.05), for control vs...