Project Summary/Abstract: The current standard-of-care for stage IIB-IVA cervical cancer includes the chemotherapeutic drug, cisplatin, in conjunction with local radiotherapy. However, the five-year survival in most stage IIB-IVA cervical cancer patients is ~30%, suggesting that an additional treatment strategy (e.g. immunotherapy) is needed to improve patient outcomes. We recently found that chemotherapy with cisplatin or radiotherapy induce a transient accumulation of dendritic cells in tumor loci that creates a window-of-opportunity wherein intratumoral (i.t.) protein/peptide antigen administration can effectively prime and expand local tumor antigen-specific CD8+ T cells, leading to synergistic therapeutic antitumor effects. Furthermore, this combination treatment leads to the presentation of antigenic peptide by immunosuppressive stromal cells of the tumor, which are thus rendered susceptible to antigen-specific CD8+ T cell-mediated killing. Together, this results in potent antigen-specific CD8+ T cell immune responses and antitumor effects. TA-CIN is a tandem fusion protein composed of HPV16 L2-E7-E6 and is administered as a filterable aggregrate to promote uptake by antigen- presenting cells. Because cervical cancer is accessible to injection and concurrent chemoradiation serves as the standard care for stage IIB-IVA cervical cancer, we will vaccinate stage IIB-IVA cervical cancer patients with TA- CIN i.t. during their chemoradiotherapy. Several clinical trials indicate that TA-CIN has an outstanding safety profile. With the recent approval of an anti-PD-1 antibody, Pembrolizumab, to treat advanced cervical cancer, we will evaluate i.t. TA-CIN vaccination with concomitant immune checkpoint blockade therapy to achieve enhanced immune and therapeutic responses in a novel spontaneous cervicovaginal carcinoma preclinical model. The Specific Aims of this study are to (1) evaluate the safety of TA-CIN i.t. administration during chemoradiation in patients with stage IIB-IVA HPV16(+) or HPV16(–) cervical cancer;; (2) characterize HPV16 E6/E7-specific T cell-mediated and L2-specific humoral immune responses in stage IIB-IVA cervical cancer patients i.t. vaccinated with TA-CIN;; (3) determine the subset population of immune cells infiltrating the tumor bed, local expression of PD-1 and PD-L1, and apoptotic tumor cell death in HPV16-associated stage IIB-IVA cervical cancer patients receiving i.t. TA-CIN vaccination;; and (4) characterize the HPV16(+) antigen-specific CD8+ T cell-mediated immune responses and therapeutic antitumor effects in a spontaneous HPV16 E6/E7- expressing cervicovaginal carcinoma model treated with i.t. TA-CIN vaccination with or with...