Some B-ALL is “Philadelphia-chromosome positive” (Ph+), meaning the leukemia cells carry a BCR-ABL1 fusion gene that makes an always-on growth signal. Tyrosine kinase inhibitors — imatinib, dasatinib, ponatinib — block that signal. Added to chemotherapy, and increasingly paired with immunotherapy, they have turned a once high-risk subtype into one with much better outcomes. The same drug class is the mainstay of chronic myeloid leukemia (CML).
Taken by mouth every day, alongside chemotherapy and continued per protocol. The specific TKI is chosen by the leukemia’s mutation profile and side-effect considerations, and response is followed with molecular (BCR-ABL1) testing.
Ongoing daily therapy with molecular monitoring to track response. Depending on protocol and whether a transplant is planned, some patients can eventually reduce or stop under specialist guidance.