IDH Mutant Cholangiocarcinoma: Pathogenesis, Management, and Future Therapies

Mutations in isocitrate dehydrogenase (IDH) genes are among the most frequently encountered molecular alterations in cholangiocarcinoma (CCA). These neomorphic point mutations endow mutant IDH (mIDH) with the ability to generate an R-enantiomer of 2-hydroxyglutarate (R2HG), a metabolite that drives malignant transformation through aberrant epigenetic signaling. As a result, pharmacologic inhibition of mIDH has become an attractive therapeutic strategy in CCAs harboring this mutation. One such inhibitor, ivosidenib, has already undergone clinical validation and received FDA approval in this disease, but there is still much work to be done to improve outcomes in mIDH CCA patients. In this publication we will review the pathogenesis and treatment of mIDH CCA with special emphasis on novel agents and combinations currently under investigation.