CIN Regression in patients treated with PDS0101 [ 14]. Avelumab (anti -PD-L1) and M 7824 (anti- PD-L1/TGF - βR2 ) Studies in the LITB were the first to describe [15, 16] avelumab, a fully human anti -PD-L1 Ig G1 MAb, and its ability to mediate ADCC for a range of human carcinoma cells employing NK cells as effectors. Avelumab (Bavencio) has since been approved by the FDA for the therapy of Merkel cell carcinoma (the first d rug approved for this indication) and second line urothelial carcinomas. We have also shown that endogenous IL -12 will enhance avelumab -mediated NK lysis, thus 14 Abbreviated Title: Combo Immunotx in HPV Cancers Version Date: 05.12.2023 forming the basis for the combined use of avelumab or M7824 with NHS -IL12. The first -in-human clinical study of avelumab with over 1,700 patients was led by Gulley with the dose escalation and initial PK and PD done entirely within the CCR [16]. Because of the activity t his s tudy was amended to include multiple expansion cohorts internationally . Because PD -L1 is also expressed on some immune cell subsets, our finding [17] that there were no adverse events in the patients treated with avelumab above that seen with other anti -PD-L/PD -L1 MAbs was important for planning further studies with avelumab or M7824. TGF -β is a well -known inhi bitor of immune cell function, especially in the TME [18-23]. Prior studies have indicated the advantage in t he use of a TGF -β inhibitor in combination with checkpoint therapy [ 24, 25] In collaboration with our CRADA partner EMD Serono, we have supported the development of a bifunctional fusion protein aimed at bringing a TGF -β TRAP to tumor cells via binding to PD -L1. M7824 is a novel fusion protein consisting of anti PD -L1 antibody linked to the extracellular domain of two TGF- βR2 (serving as a TGF -β TRAP) (Figure 3). Fig ure 3. Schematic drawings of Avelumab and M7824. We were the first to report [26, 27] that M7824 (a) mediates ADCC, (b) increases tumor cell gene expression of molecules involved in T -cell trafficking to the tumor, (c) enhances TRAIL - and antigen -specific CD8+ T -cell lysis of tumor cells, and (d) reduces TGF -β‒induced immunosuppressive activity. We have also recently demonstrated [ 28] in in vivo preclinical murine carcinoma models ( Figure 4A and B ) th at M7824 has the ability to decrease TGF -β‒ induced signaling in the TME. Specifically, phosphorylation of SMAD2 was significantly decreased in tumors following M7824 treatment, and not with an M7824(mut) molecule, devoid of the PD -L1 binding site (Figure 4C). In both breast and colon carcinoma murine models, M7824 decreased tumor burden and increased survival, which required both CD8+ and NK cell a ctivity (Figure 4D ). 15 Abbreviated Title: Combo Immunotx in HPV Cancers Version Date: 05.12.2023 Figure 4 (A) Comparison of anti -tumor activity of M7824, and M7824(mut) devoid of PD -L1 binding site in the EMT6 breast cancer model. (B) Accumulation of M7824 in the TME resulting in reduction of SMAD2 signaling (C) and increased T - and NK -cell activation (D). Knudson …Schlom J.