Tyrosine kinase inhibitors in Ph+ acute lymphoblastic leukaemia: facts and perspectives

Two tyrosine kinase inhibitors (TKIs), imatinib and dasatinib, are registered for the treatment of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukaemia (ALL) in adults. Other two TKIs (nilotinib and ponatinib) have been tested in the second-line, can offer an alternative in the patients who fail the first-line, and can acquire a role also in the first-line. Here, we provide a summary of the reports of TKIs, used alone, and in combination with chemotherapy. TKIs are very effective alone and with corticosteroids and are likely to improve substantially the outcome when they are combined with standard or dose-adapted chemotherapy. While the complete haematologic remission rate is always very high, close to 100 %, the cytogenetic and molecular remission rates are lower, so that TKIs are still considered as a complement to chemotherapy and as a bridge to allogeneic stem cell transplantation (allo-SCT). However, many patients relapse before transplant, and many patients still relapse, even if they have been submitted to allo-SCT. A proper use of TKIs, the introduction of ponatinib, and of "new generation" TKIs should improve further on the outcome of Ph+ ALL.