BCAA metabolic reprogramming identifies BCKDK as a therapeutic target in cancer

INTRODUCTION: Branched-chain keto acid dehydrogenase kinase (BCKDK) is a mitochondrial kinase that suppresses branched-chain amino acid (BCAA) oxidative catabolism by phosphorylating and inhibiting the branched-chain α-keto acid dehydrogenase complex. Beyond this canonical metabolic function, accumulating evidence indicates that aberrant BCKDK activation contributes to tumor metabolic rewiring, signaling adaptation, malignant progression and therapy resistance. AREAS COVERED: This review summarizes the regulatory position of BCKDK in BCAA catabolism, its context-dependent functions across tumor types, and recent progress in BCKDK inhibitor development. Although selected non-oncological studies are discussed to inform inhibitor mechanism, pharmacology and safety, this review focuses on the oncology relevance of BCKDK. Particular attention is given to the transition from early proof-of-concept inhibitors to BT2-derived allosteric compounds, Pfizer-developed clinical candidates, and emerging non-BT2 scaffolds or alternative binding regions. A PubMed search was conducted to identify relevant studies on BCKDK, BCAA metabolism, cancer progression and BCKDK-targeted inhibitors. EXPERT OPINION: BCKDK is unlikely to function as a universal pan-cancer target. Its therapeutic value will depend on identifying tumor contexts with true BCKDK dependency, especially those relying on BCKDK-driven metabolic adaptation or downstream signaling. For BCKDK inhibitors, future development should integrate biochemical potency with mechanism-aligned conformational effects, long-term pharmacological consequences and biomarker-supported patient stratification.