Innate and adaptive immunotherapy: An orchestration of immunogenic cell death by overcoming immune suppression and activating NK and T cell therapy in patients with third line or greater metastatic pancreatic cancer

e15787 Background: Pancreatic cancer has multiple mechanisms to prevent immune recognition that lead to the creation of an immune suppressive tumor microenvironment. We hypothesize that sustained response against pancreatic cancer requires a coordinated approach that: 1. reverses the immune-suppressive tumor microenvironment, 2. induces immunogenic tumor cell death and 3. reengages NK and T-cell tumor response against a 4. cascade of tumor antigens. To test this hypothesis, we have developed a temporospatial approach that combines metronomic low-dose chemotherapy, SBRT, cryopreserved allogeneic NK cells, yeast and adenoviral tumor-associated antigen vaccines, an IL-15RαFc superagonist, and checkpoint inhibition. Methods: A phase 1b trial in patients with recurrent metastatic pancreatic cancer was initiated. Treatment occurred in 3-week cycles of low-dose chemotherapy (aldoxorubicin, cyclophosphamide, oxaliplatin, nab-paclitaxel, 5-FU/L), antiangiogenic therapy (bevacizumab), SBRT, allogeneic CD16 NK-92 cells (haNK), IL-15RαFc (N-803), adenoviral CEA vaccine, yeast Ras vaccine, and an IgG1 PD-L1 inhibitor, avelumab. The primary endpoint is incidence of treatment-related adverse events (TRAEs). Secondary endpoints include ORR, DCR, PFS, and OS. Results: 12 subjects with 3rd-line or greater metastatic pancreatic cancer were treated. All treatment was administered in an outpatient setting. AEs were primarily hematologic and managed by planned chemo dose reduction. Grade ≥3 TRAEs were observed in 9 out of 12 subjects, predominately chemotherapy-related neutropenia. 9 out of 12 subjects (75%) had a best response of stable disease (≥ 8 weeks). Median PFS is 7.1 months (4.4 – 8.8) and median OS is 8.2 months (5.7 – 9.7) with 1 subject continuing treatment. Conclusions: These preliminary data suggest that low-dose chemo-radiation combined with innate and adaptive immunotherapy can be administered safely in an outpatient setting. Preliminary OS of 8.2 months is encouraging for this heavily-pretreated population. Clinical trial information: NCT03586869.