Background: Leukemia inhibitory factor (LIF) is an immunosuppressive cytokine linked to tumor growth and metastasis. LIF overexpression correlates with poor prognosis and chemoresistance in multiple tumor types including PDAC. Preclinical data show that LIF promotes an immunosuppressive tumor microenvironment, hindering cytotoxic CD8+ T cell recruitment; low T cell infiltration also correlates with mortality in patients with PDAC. Preclinical studies show LIF-blocking antibodies sensitize tumors to PD-1/PD-L1 inhibition, inhibit epithelial-mesenchymal transition, and prolong survival in combination with CT. In patients with PDAC, higher LIF levels correlate with more aggressive pathology, elevated CA19-9 (a PDAC biomarker), and lower response and survival rates. AZD0171 (formerly MSC-1), a first-in-class, humanized, IgG1 monoclonal antibody, binds specifically and potently to LIF, preventing downstream signaling. In a phase 1 dose escalation study (NCT03490669), AZD0171 monotherapy had manageable safety and led to stable disease (SD) in 34.2% of patients with advanced solid tumors across all dose levels. AZD0171 + CT may improve survival outcomes vs CT alone. Based on preclinical data, AZD0171 may function to stimulate antitumor immune response, and combination with the PD-L1 inhibitor durvalumab could prolong that response and overcome peripheral tolerance in patients with metastatic PDAC.

Methods: This is a phase 2, open-label, single-arm, multicenter study of AZD0171 + durvalumab and CT in treatment-naive patients with metastatic PDAC (NCT04999969). Eligible patients must have an ECOG performance status 0 or 1, a Gustave Roussy Immune Score 0 or 1, ≥1 measurable target lesion per RECIST v1.1, and confirmed presence of tumoral CD8+ T cells. Patients with central nervous system metastasis, history of leptomeningeal disease or cord compression, a thromboembolic event ≤3 months prior to study treatment, unresolved grade ≥2 toxicities from prior therapy, or a sensitizing mutation or tumor characteristic for which there is a preferred treatment, are excluded. As PDAC is poorly immune infiltrated, a novel clinical trial assay will be used to select for patients who have existing resident CD8+ T cells and may therefore be more likely to respond. About 115 patients will receive intravenous AZD0171, durvalumab and CT until disease progression or unacceptable toxicity. The primary endpoints are safety and overall survival (OS) rate at 12 months. Secondary endpoints include objective response rate, disease control rate (confirmed response or SD ≥16 weeks), duration of response, median progression-free survival (PFS), PFS rate at 4 months, median OS, pharmacokinetics, pharmacodynamics (changes in serum CA19-9 level and tumor CD8+ T cell infiltration) and immunogenicity. The trial is currently recruiting.

Citation Format: Grainne O'Kane, Teresa Macarulla, Fiyinfolu Balogun, Antoine Hollebecque, Matthew J. Reilley, Sreenivasa R. Chandana, Jim Eyles, Oluwaseun Ojo, Philip Overend, Douglas C. Palmer, Nadia Luheshi, Mayukh Das, Antoine Italiano, Joan Seoane. A phase 2 trial of first-line AZD0171 + durvalumab and chemotherapy (CT) in patients with metastatic pancreatic ductal adenocarcinoma (PDAC) and CD8+ T cell infiltration [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT126.