Trials In Progress: A Phase Ii Study Of In Situ Therapeutic Vaccination Against Refractory Solid Cancers With Intratumoral Poly-Iclc

166Background: Poly-ICLC, a RNA complex, can activate dendritic cells and trigger NK cells to kill tumor cells. It can be given intramuscularly (IM) to induce systemic inflammation and intratumorally (IT) to induce immune infiltration of tumors. Methods: In this phase II study, eligible subjects are head and neck, and skin cancer patients with refractory or metastatic disease. In each treatment cycle, one accessible tumor site was targeted for IT injection of 1 mg of Poly-ICLC 3 times a week for 2 weeks followed by IM boosters biweekly for 6 weeks and then a 2 week rest period. Tumor biopsies were performed at baseline, week 3, and week 26. Pre- and post-vaccination tumors were evaluated by quantitative immunohistochemistry (IHC) and RNA sequencing. Blood samples were collected at baseline and prior to each cycle for immune response evaluations. Results: A phase I pilot portion of this study showed 1 patient who achieved clinical benefit with stable disease (progression-free survival of 6 months). Poly-IC...