Evaluation of a novel Pan-RAS/β-Catenin inhibitor, ADT-030, for treatment of pancreatic cancer.
Authors: Piazza Gary A , Bandi Reddy DS , Ganji Pumachandra N , Foote Jeremy B , Keeton Adam B , Mattox Tyler Ernest , Chen Xi , Hardy Cherlene , Berry Kristy , Maxuitenko Yulia , Manne Upender , Buchsbaum Donald J , El-Rayes Bassel F. , Boyd Michael R 
Published: June 2024

e15084

Background: Pancreatic ductal adenocarcinoma (PDAC) remains a formidable challenge due to its late diagnosis and limited treatment options. KRAS mutations and activation of Wnt/β-catenin pathway components that drive aberrant signaling cascades resulting in uncontrolled cellular proliferation and metastasis occur in a majority of PDAC patients. The development of mutant specific KRAS inhibitors has emerged as a promising approach to counter the oncogenic impact of KRAS mutations, although have limited use for PDAC given the complex mutational landscape, while inhibitors of Wnt/β-catenin signaling remain elusive. Novel target-directed drugs that effectively tackle the complex mutational status in KRAS mutant PDAC are urgently needed. A novel pan-RAS/β-catenin inhibitor, ADT-030, was evaluated in mouse tumor models of PDAC harboring KRASG12C or KRASG12D mutations. Methods: PDAC cell lines 2838c3 (KRASG12D), MIA PaCa-2 (KRASG12C), and BxPC-3 (RASWT) were utilized to evaluate in vitro growth inhibitory potency and selectivity of ADT-030. Assays for colony formation, apoptosis, and cell cycle, along with western blotting for RAS signaling were also conducted. A murine model involving 2838c3-Luc KRASG12D PDAC cells injected into the pancreas of C57BL/6J mice was used to evaluate in vivo antitumor activity of ADT-030. ADT-030 was administered orally once daily at dosages of 50, 100, and 150mg/kg body weight, 5x/week for 4 weeks. Tumor growth was monitored by bioluminescence imaging using an IVIS Xenogen system. Body weights were measured twice weekly. Pancreatic tumors were collected and weighed at the end of treatment. Results: ADT-030 produced potent inhibition of proliferation of human and murine PDAC cells harboring KRASG12D and KRASG12C mutations. Annexin V assay revealed the capacity of ADT-030 to trigger apoptosis, specifically in KRAS mutant cells with minimal impact on BxPC3 RASWT cells. Cell cycle analysis using Propidium Iodide staining revealed the ability of ADT-030 to arrest cells in the G2/M phase of the cell cycle. Western blot for detecting the key RAS signaling molecule P-ERK1/2 showed decreased levels following ADT-030 treatment. Other experiments revealed that ADT-030 and related analogs simultaneously suppress both MAPK/AKT signaling and β-catenin transcriptional activity (doi: 10.1186/s13048-022-01050-9). In an orthotopic xenograft model in which 2838c3-Luc cells were implanted in the pancreas, oral administration of 50, 100, and 150mg/kg of ADT-030 was well tolerated and inhibited tumor growth by 64.2%, 72.8%, and 80%, respectively, after 4 weeks of treatment. Conclusions: These compelling results position ADT-030 as a novel dual pan-RAS/β-catenin inhibitor for combating the challenges posed by complex mutations in PDAC and other RAS driven cancers and support its clinical evaluation as a valuable therapeutic alternative to mutant-specific KRAS inhibitors.