Abstract LB_C05: A novel approach to convert non-resectable pancreatic cancer with major artery involvement using endovascular activation of Padeliporfin by vascular-targeted photodynamic therapy

Abstract

Abstract Pancreatic cancer is a fatal disease: the patient usually has a very poor prognosis and limited treatment options. It is projected to be the second leading cause of cancer-related death by 2030. It is estimated that 80% of patients have metastatic or localized disease with vascular involvement at presentation, not amenable to surgery. Thus, a therapy that will convert unresectable, due to vascular involvement, tumors to resectable is an unmet medical need. We developed a novel treatment relying on endovascular activation of a photosensitizer Padeliporfin, by a vascular-targeted photodynamic therapy (VTP) to clear the artery from the encasing tumor enabling surgery. Padeliporfin is administered intravenously and activated locally by illumination via an optical fiber, deployed within the tumor encased artery by an angioplasty procedure under fluoroscopy. In a proof-of-concept study in normal swine model, treatment induced areas of ablation in normal pancreatic parenchyma while sparing the artery and other major structures in it’s vicinity. Drug and light doses used were proved effective in other solid tumors in preclinical and clinical studies. Safety was evaluated in a controlled study comprised of 12 pigs subjected to Padeliporfin VTP in a superior mesenteric artery (SMA). Two light doses were tested. Control groups received no drug or no illumination and drug. Follow up was 48 hours or seven days post treatment. Clinical observations and blood test results did not reveal any signs of decreased wellness without differences between treated and control groups. Lipase results were unchanged compared to the baseline. Amylase levels were within the normal range in all animals. Histopathology findings 48 hours post VTP in the SMA and surrounding tissues were similar in treated and control animals. Observed changes were manifested as small lesions consistent with angioplasty procedure impact, involving less than 25% of the media circumference. Small foci of coagulative necrosis were observed in the pancreatic parenchyma in the vicinity of SMA. In the seven-day samples, there was media pressure necrosis in occasional sections of the artery in all groups involving less than 25% of the circumference, attributed to the angioplasty procedure. Minimal fibrosis in a few samples, consisted of focal areas of fibroblast proliferation, indicating early regeneration, with no architectural or thickness changes of the arterial wall. The tissues surrounding SMA as well as organs downstream to the treated artery were mostly within normal ranges. Our results demonstrate that endovascular Padeliporfin VTP is feasible and has an acceptable safety profile together with evidence of ability to ablate pancreatic tumors encasing major abdominal arteries. The efficacy is further supported by our studies showing effective tumor ablations in orthotopic mouse models especially in combination with immune modulating therapies. A phase I trial (NCT5918783) aims to evaluate the potential of this approach for converting unresectable pancreatic cancer patients to amenable for surgery. Citation Format: Dina Preise, Yaniv Cohen, Genia Alpert, Zachary Sacks, Tamar Yechezkel, Natalia Kudinova, Eyal Morag, Ehud Willenz, Julia Rothman, Keren Brook, Inna Krasnopolskaya, Lilach Agemy, Sofia Zilber, Hooman Yarmohammadi, David Kelsen, David Perry, Avigdor Scherz. A novel approach to convert non-resectable pancreatic cancer with major artery involvement using endovascular activation of Padeliporfin by vascular-targeted photodynamic therapy [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_C05.