A novel approach to reverse Warburg metabolism in patients with recurrent glioblastoma: A phase II pharmacodynamic study of dichloroacetate.

Background: Glioblastomas are characterized by the Warburg effect, driven by upregulation of pyruvate dehydrogenase kinase (PDK), which inhibits pyruvate dehydrogenase complex (PDC), leading to lactate accumulation. Dichloroacetate (DCA) is a potent and safe PDK inhibitor that crosses the blood-brain barrier, reverses Warburg metabolism, and reduces lactate levels. Methods: This trial (RO1FD007271) evaluated the pharmacodynamics and pharmacokinetics of oral DCA in recurrent glioblastoma patients requiring surgical debulking. The primary endpoint was decreased PDC phosphorylation (p-PDHA1) in resected tumors. Patients received either 1 week of DCA or no DCA prior to surgery. All patients received DCA postoperatively. Enhancing and non-enhancing tumor tissue, and serial plasma DCA and lactate levels were analyzed. Results: 37 patients were enrolled (median age = 60 years). In DCA-treated patients, the contrast-enhancing tumor had lower p-PDHA1, PDK4, HIF1-α, VEGF-α, and PGK1 expression (all Conclusions: In recurrent glioblastomas, DCA was safe, well-tolerated, and promoted aerobic respiration. It reduced markers of tumor cell proliferation and lowered plasma lactate. Although no clinical benefit was noted, further studies of combination therapy are indicated, given the known association between poor cancer outcomes and elevated PDK expression and lactate levels.