Mitochondrial DNA mutations are associated with impaired oxidative phosphorylation and enhanced imatinib response in chronic myeloid leukemia.

Mitochondrial DNA (mtDNA) mutations are frequently observed in cancer, but their clinical and functional significance in chronic myeloid leukemia (CML) remains incompletely defined. Here, we show that a distinct mtDNA mutational landscape is associated with mitochondrial metabolic programs and response to imatinib therapy in CML. We performed comprehensive profiling of somatic mtDNA mutations in 120 patients with chronic-phase CML. At diagnosis, 241 somatic mtDNA mutations were identified in 92 patients, including 29 homoplasmic mutations. In a clinically annotated cohort of 79 imatinib-treated patients, a higher number of mtDNA mutations (≥3 mutations) and higher variant allele frequency were associated with superior molecular responses, and remained significant in multivariable analyses. mtDNA mutational patterns were associated with distinct metabolic phenotypes in CD34+ leukemic stem/progenitor cells. Suboptimal responders exhibited increased mitochondrial respiration, spare respiratory capacity, mitochondrial content, and enrichment of mitochondrial biogenesis and lipid metabolic programs, consistent with enhanced oxidative phosphorylation dependence. In contrast, favorable responders displayed higher mtDNA mutational burden together with reduced respiratory reserve and increased mitophagy-related programs. Pharmacologic Complex I inhibition reduced clonogenic potential and enhanced imatinib sensitivity. Collectively, these findings identify mtDNA mutational states as a biomarker of metabolic fitness and therapeutic response in CML, while supporting further investigation of mitochondrial metabolism as a potential therapeutic vulnerability in CML.