Locoregional lactate dehydrogenase inhibition potentiates therapy and overcomes treatment resistance in hepatocellular carcinoma

BACKGROUND AIMS: Metabolic inhibitors have demonstrated limited efficacy for cancer therapy due to metabolic plasticity and systemic toxicity. Locoregional therapies (LRT), such as transarterial embolization (TAE) or transarterial chemoembolization (TACE), generate ischemic stress that reprograms the tumor microenvironment (TME) toward glycolytic dependency, creating an opportunity to sensitize hepatocellular carcinoma (HCC) to metabolic inhibition. This study investigated whether pharmacologic inhibition of lactate dehydrogenase (LDH) with NCATS-SM1441 could exploit TAE-induced metabolic vulnerabilities to improve therapeutic efficacy in HCC. APPROACH RESULTS: Human HCC cell lines were exposed to replete or ischemic (TAE-like) conditions and treated with the LDH inhibitor NCATS-SM1441. Glucose/lactate flux, adenosine triphosphate (ATP) levels, and viability were assessed. In vivo, a diethylnitrosamine (DEN)-induced rat HCC model was treated with intraarterial NCATS-SM1441, TAE, or their combination. Drug distribution, tumor metabolism, necrosis, and survival were analyzed using mass spectrometry imaging, histopathology, T2-weighted magnetic resonance imaging (MRI), and survival metrics. Ischemic conditions induced LDHA expression and glycolytic flux, enhancing susceptibility to LDH inhibition. The combination of intraarterial NCATS-SM1441 before embolization increased intratumoral drug accumulation, reduced systemic exposure, and synergized with TAE to suppress lactate production, promote tumor necrosis, and significantly extend local progression-free survival. CONCLUSIONS: TAE conditions the TME to create a therapeutically targetable glycolytic dependency. Combining TAE with LDH inhibition overcomes key limitations of metabolic inhibitors as monotherapies, enhancing local control and survival with minimal systemic toxicity, supporting integration of metabolism-targeted agents with LRT for unresectable HCC.