Pancreatic ductal adenocarcinoma upregulates CD73, potentially contributing to immune surveillance evasion. Combining oleclumab (CD73 inhibitor) and durvalumab with chemotherapy may identify an effective treatment option.
Side-chain oxysterols, such as 25-hydroxycholesterol (25-HC), are key regulators of cholesterol homeostasis. New evidence suggests that the alteration of membrane structure by 25-HC contributes to its regulatory effects. We have examined the role of oxysterol membrane effects on cholesterol accessibility within the membrane using perfringolysin O (PFO), a cholesterol-dependent cytolysin that selectively binds accessible cholesterol, as a sensor of membrane cholesterol accessibility. We show that 25-HC increases cholesterol accessibility in a manner dependent on the membrane lipid composition. Structural analysis of molecular dynamics simulations reveals that increased cholesterol accessibility is associated with membrane thinning, and that the effects of 25-HC on cholesterol accessibility are driven by these changes in membrane thickness. Further, we find that the 25-HC antagonist LY295427 (agisterol) abrogates the membrane effects of 25-HC in a nonenantioselective manner, suggesting that agisterol antagonizes the cholesterol-homeostatic effects of 25-HC indirectly through its membrane interactions. These studies demonstrate that oxysterols regulate cholesterol accessibility, and thus the availability of cholesterol to be sensed and transported throughout the cell, by modulating the membrane environment. This work provides new insights into how alterations in membrane structure can be used to relay cholesterol regulatory signals.
TPS8604 Background: Neoadjuvant platinum-based CT plus IO prolongs event-free survival (EFS) and increases pathological complete response (pCR) rate in patients with resectable NSCLC vs CT alone (Forde et al. N Engl J Med 2022). IO+IO+CT combinations have the potential to further improve pCR and survival outcomes. The phase 2 NeoCOAST-2 study (NCT05061550) is evaluating multiple neoadjuvant IO+IO+CT combinations in patients with resectable, early stage NSCLC. Novel IO molecules being evaluated include the anti-CD73 monoclonal antibody (mAb), oleclumab; the anti-NKG2A mAb, monalizumab; and the PD-1/CTLA-4 bispecific mAb, volrustomig. The latter recently demonstrated durable responses vs a PD-1 inhibitor plus CT as first-line treatment for patients with metastatic NSCLC (ESMO 2022; LBA56). Here we describe the NeoCOAST-2 study design. Methods: This randomized, open-label, multicenter study will enrol approximately 210 patients with previously untreated, histologically/cytologically confirmed, resectable Stage IIA–IIIB (AJCC 8 th edition) NSCLC. Patients will be stratified by PD-L1 expression ( < 1% vs ≥1%) and receive treatment with durvalumab + oleclumab + CT, durvalumab + monalizumab + CT, or volrustomig + CT every 3 weeks for 4 cycles prior to surgery, followed by adjuvant durvalumab + oleclumab, durvalumab + monalizumab, or volrustomig for up to 1 year or until disease progression per RECIST v1.1. Surgery should occur within 40 days after the last dose of neoadjuvant therapy and adjuvant therapy should commence within 10 weeks after surgery. The primary endpoints are pCR rate (per blinded independent pathologist review) and safety and tolerability. Secondary endpoints include investigator-assessed EFS, disease-free survival and overall survival, feasibility to surgery, major pathological response rate, objective response rate following neoadjuvant therapy, pharmacokinetics, immunogenicity, and changes in circulating tumor DNA. The study is currently recruiting patients across the US, Europe, Canada, and Asia. Clinical trial information: NCT05061550 .
