One of the enduring legacies from the development of imatinib (Gleevec®/Glivec®) for the treatment of chronic myeloid leukemia (CML) is the long-term survival data from the IRIS (International Randomized Interferon versus STI571) trial that enrolled 1106 patients between June 2000 and January 2001.
Hagop Kantarjian, M.D. Professor and Chair, Department of Leukemia at The University of Texas MD Anderson Cancer Center in Houston told the 2012 Chemotherapy Foundation Symposium (also known as the Greenspan Meeting in honor of the late Ezra Greenspan, M.D.) that:
the 10 year survival rate is 85% in patients treated with imatinib, and that this rises to 90% if you exclude deaths not related to CML.
No second-generation tyrosine kinase inhibitor (e.g. nilotinib, dasatinib, bosutinib) has yet to show a superior long-term survival benefit to imatinib. Dr Kantarjian noted that “whatever comes as a new treatment in the frontline therapy has to be able to beat that time, of a 10 year survival, if there is a big cost difference.”
The IRIS trial survival data for imatinib remains the gold standard by which other tyrosine kinase inhibitors will be judged.
In other words, notwithstanding the myriad of published CML data that shows second generation TKIs offer a deeper or more rapid molecular response, there’s still no data that shows you will actually live longer if you take any of them instead of imatinib.
That’s not to say there are no benefits to the newer second generation TKIs.