Abstract 3245: Preclinical evaluation of the imipridone family of small molecules, including analogues of clinical-stage anti-cancer small molecule ONC201, reveals potent anti-cancer effects of ONC212

Abstract

Abstract We previously identified a novel, potent anti-cancer small molecule ONC201, which upregulates the integrated stress response (ISR) through ATF4/CHOP/DR5 and acts as a dual inactivator of Akt and ERK, leading to TRAIL gene activation. After completing a first-in-human phase I clinical trial that revealed exceptional safety, therapeutic pharmacokinetic (PK) profile and tumor engagement, ONC201 is under investigation in several advanced cancer Phase I/II trials. Given the unique imipridone core chemical structure of ONC201, we synthesized a family of analogues in an effort to identify additional chemical family members with distinct therapeutic properties. Based on in vitro potency improvements in human cancer cell lines and therapeutic window approximations with normal human fibroblasts, select analogues were investigated in animals for toxicity, maximum tolerated dose (MTD), and antitumor efficacy. ONC212 is one of the most promising new imipridones that was further evaluated to establish the PK profile, oral bioavailability, and efficacy in tumor types that are less sensitive to ONC201. Compared to ONC201, we noted distinct and more rapid kinetics of activity as well as improved potency in multiple human cancer cell lines in vitro. ONC212 has a broad therapeutic window, an acceptable PK profile, and is orally well-tolerated in mice. With no evidence of toxicity at efficacious doses in both colon and triple negative breast cancer, we have begun further evaluation of antitumor efficacy studies in ONC201-resistant tumor types. Efficacy studies with ONC212 are ongoing in melanoma models that are sensitive to ONC212 but less sensitive to ONC201 in vitro. Preliminary data indicates potent tumor growth reduction by ONC212 in vivo in ONC201-resistant melanoma xenografts. With a wide safety margin, potent antitumor activity in ONC201-insenstive tumors, and drug-like characteristics, ONC212 is being further developed as a drug candidate from the new imipridone class of compounds that complements the spectrum of activity of ONC201. Citation Format: Jessica Wagner, C. Leah Kline, Gary Olson, Bhaskara Nallaganchu, Richard Pottorf, Varun Prabhu, Martin Stogniew, Joshua Allen, Wafik El-Deiry. Preclinical evaluation of the imipridone family of small molecules, including analogues of clinical-stage anti-cancer small molecule ONC201, reveals potent anti-cancer effects of ONC212 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3245. doi:10.1158/1538-7445.AM2017-3245