Abstract 2643: Design and discovery of novel oral INV-88 macrophage migration inhibitory factor (MIF) inhibitors: Potent anti-tumor activity in vitro and in vivo
Authors: Gaweco Anderson , Chung Vincent , Tilley Jefferson , Windsor William , Stouch Terry , Ellingboe John , Crichlow Gregg , Sabanas Philipp , Sebesta Christian 
Published: June 2022

Background: MIF is a pleiotropic cytokine critically implicated in tumorigenesis. Tumor cell- and immune effector cell-derived MIF are localized to exosomal, extracellular, cytoplasmic and intranuclear compartments. MIF activates MAPK and PI3K signal transduction, inhibits apoptosis, promotes angiogenesis, elicits premetastatic niche formation and resolves DNA replication stress; contributing to unperturbed cancer cell growth and metastasis. MIF overexpression in several cancers is a negative prognostic indicator associated with poor overall patient survival.

Methods & Results: Active novel INV-88 MIF inhibitors were discovered using structure-based drug design against critical MIF pharmacophoric binding sites guided by high-resolution X-ray crystallography (Brookhaven) of INV-88 compound:hu-MIF protein bound complexes. Following an iterative medicinal chemistry campaign; stringent biochemical, pharmacological and ADMET funnel screening identified promising INV-88 lead candidates with potent antitumor activities. Strong MIF binding by INV-88 compounds was demonstrated using thermal shift and fluorescence polarization assays. Profound in vitro antitumor pharmacological properties of INV-88 were established on several murine & human tumor cell lines (HCT116, MeWo, DU145, 4T1, B16-F10, CT26). INV-88 inhibitors demonstrated potent anti-proliferative effects down to nM IC50 potencies and impeded 3D spheroid growth & viability. Disruption of MIF:CD74/CD44-mediated MAPK and PI3K signal transduction pathways by INV-88 compounds blocked ERK and AKT phosphorylation leading to decreased pERK1/2 and pAKT levels. INV-88 inhibitors increased Caspase-3/7, p53 and Bax but decreased Bcl-2 levels. INV-88 lead compounds inhibited tumor MIF protein production in 2D & 3D cell culture systems with concomitant pan-inhibition of tumorigenic proinflammatory cytokine (TNF-α, IL-1β, IL-6, and IL-8) expression by stromal cells. Optimal ADMET properties of INV-88 compounds enabled oral dosing of select INV-88 clinical candidate compounds in mouse syngeneic B16-F10 melanoma and CT26 colon carcinoma models. Mice were dosed daily with INV-88 or vehicle per oral gavage starting in BALB/c and in C57/BL6 mice upon demonstrating palpable tumors after s.c. implantation of CT26 and B16-F10 tumor cells, respectively. Tumor growth inhibition was observed with rates of 71% on Day 24 (CT26) and 75% on Day 20 (B16-F10). INV-88 treatment significantly inhibited CT26 [p&lt;0.0001] and B16-F10 tumor growth [p&lt;0.0001] versus controls. INV-88 was well-tolerated by tumor-bearing mice which exhibited normal body condition scores and body weight.

Conclusion: The data presented highlight the potential therapeutic utility of pharmacological MIF inhibition with oral INV-88 new chemical entities as a novel immunotherapeutic treatment modality for cancer.

Citation Format: Anderson Gaweco, Vincent Chung, Jefferson Tilley, William Windsor, Terry Stouch, John Ellingboe, Gregg Crichlow, Philipp Sabanas, Christian Sebesta. Design and discovery of novel oral INV-88 macrophage migration inhibitory factor (MIF) inhibitors: Potent anti-tumor activity in vitro and in vivo [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 2643.