Abstract CT021: Phase I study of an oxidative phosphorylation inhibitor IM156 in patients with advanced solid tumors
Authors: Rha Sun Young , Beom Seung Hoon Beom Seung Hoon , Kim Gun Min , Shin Young Geun , Yim Dong-Seok , Kim Hyo Song , Chang Jong Hee , Cheong Jae-Ho , Lee Young Woo , Chong Yun Seon , O’Neill Vincent , Yoo Sang Hee , Janku Filip 
Published: August 2019

Background: IM156 is a novel oral potent biguanide, which has anticancer activity through AMPK activation and reduction of oxidative phosphorylation. Inhibition of oxidative phosphorylation (OXPHOS) is detrimental to OXPHOS dependent cancer cells, which are prone to energy stress. Preclinical experiments demonstrated that IM156 can be effective in glioblastoma, gastric cancer and other solid tumors.

Methods: This is an open label, first-in-human, single center, dose-escalation study (NCT03272256) using the 3+3 design to determine the maximum tolerated dose and/or recommended Phase II dose, dose limiting toxicities (DLT), safety, pharmacokinetics, pharmacodynamics and preliminary signals of anticancer efficacy of IM156 in patients with advanced solid tumors. Eligible patients are adults with advanced solid tumors refractory to standard therapies with adequate performance status (ECOG &lt;2) and organ function with measurable disease per RECIST 1.1 (or RANO for gliomas). IM156 is administered orally every other day starting on day 1 of each 28 days cycle.

Results: To date, 12 patients (gastric cancer, 5; endometrial cancer, 2; ovarian cancer, 2; other, 3) were enrolled to 4 dose levels (100mg to 800 mg orally every other day). There have been no DLTs or &gt;other grade 3 treatment-related adverse events (AEs). Most frequent AEs included nausea (67% of patients), vomiting (17%), diarrhea (23%), insomnia (17%), epigastric and abdominal pain (17%), weakness (8%), neuropathy (8%) and fatigue (8%); however, there were all grade 1 except for four grade 2 episodes (nausea, 2; insomnia, 1; diarrhea, 1; epigastric pain, 1). Mild elevations (&lt;5 mmol/L) in lactate levels were noted anecdotally. The best response was stable disease in 5 patients (gastric cancer, 2; ovarian cancer, 1; endometrial cancer, 1; colorectal, 1). Pharmacokinetic studies demonstrated dose proportional increase in Cmax and AUC, which were approaching expected efficacious range. Observed terminal half-life supported possible change of the schedule to daily oral administration. Pharmacodynamic marker studies are on-going.

Conclusion: IM156 has been well tolerated with manageable AE profile. The dose escalation continues with a planned change from every other day administration to daily dosing.

Citation Format: Sun Young Rha, Seung Hoon Beom Seung Hoon Beom, Gun Min Kim, Young Geun Shin, Dong-Seok Yim, Hyo Song Kim, Jong Hee Chang, Jae-Ho Cheong, Young Woo Lee, Yun Seon Chong, Vincent O’Neill, Sang Hee Yoo, Filip Janku. Phase I study of an oxidative phosphorylation inhibitor IM156 in patients with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT021.