Dr. Hobbs on the Role of Molecular Testing to Determine Resistance in CML

Gabriela Hobbs, MD, clinical director of Leukemia Service and assistant in medicine at Massachusetts General Hospital, discusses the role of molecular testing to determine resistance in chronic myeloid leukemia (CML).

In CML, BCR-ABL1 kinase domain mutational testing is an important tool to guide treatment decisions, says Hobbs. However, because patients with CML rarely present with de novo mutations, ABL1 testing is not typically indicated up front. Instead, patients who do not meet their treatment milestones per National Comprehensive Cancer Network or European Leukemia Net guidelines should undergo testing to determine if they have acquired resistance, Hobbs explains.

Although acquired resistance mutations are rare, their presence can inform treatment selection, Hobbs says. For example, patients with T315I mutations are not going to benefit from second-generation TKIs. Instead, these patients should receive ponatinib (Iclusig) and be considered for transplant, concludes Hobbs.