Design, synthesis and biological evaluation of symmetric thiadiazole carboxamide derivative as glutaminase inhibitor

Metabolic reprogramming toward glutamine anaplerosis is a well-established vulnerability in tumors harboring co-occurring KRAS and KEAP1 mutations, creating a dependency on glutaminase (GLS)-mediated glutaminolysis for survival and growth. Although allosteric GLS inhibitors such as BPTES (Bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide) and later-generation analogs such as CB-839 (Telaglenastat) have pharmacologically validated this target, their clinical utility has been constrained by suboptimal drug-like properties, including poor solubility and bioavailability. To overcome these limitations, we developed TRG-192, a novel symmetric amidothiadiazole derivative engineered with a distinct chemical scaffold to enhance physicochemical and pharmacokinetic profiles. In vitro characterization revealed that TRG-192 is a potent GLS inhibitor (IC₅₀ = 68 nM). This biochemical potency translated to a functional effect in a cellular model of glutamine dependence, as evidenced by a significant depletion of intracellular glutamate pools in LDK378-resistant (LR) cells. Furthermore, TRG-192 demonstrated a favorable preclinical safety profile in initial toxicological assessments. Collectively, these data-encompassing potent target engagement, functional on-target activity, and preliminary safety-provide a compelling rationale for the advancement of TRG-192 into in vivo efficacy studies.