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Imatinib dose reduction in CML
A
Figure 4. Factors influencing the probabilities of molecular relapse-free survival after imatinib dose reduction to 400 mg/day. (A) Impact of time to major molecular response (MMR) and molecular relapse- free survival. (B) Impact of interval between MMR and imatinib dose reduction and molecular relapse- free survival. At 12 months (mo), horizontal cross- bars indicate the upper and lower limit of the 95% confidence interval (CI) for the estimated probability.
B
and rapid MR are mechanistically linked. For example,
immuno-biological features such as CD86+ plasmacytoid
dendritic cell counts were recently shown to be associated
with both TFR rate and rapid, deep MR under TKI thera- py.31,32
With 68 patients and 7 events only, the cutoffs and our prognostic analyses remain exploratory and should be con- firmed independently. In summary, here we show that if MMR was achieved within 13 months on 800 mg ima- tinib, a reduction of treatment intensity to 400 mg imatinib is feasible with a high probably that MMR will be main- tained. From these results, we speculate that a switch from a second-generation TKI to 400 mg imatinib is unlikely to
lead to a loss of MMR. This is no trivial speculation because there are no data to support it, and a prospective clinical trial investigating a switch from second-generation TKI to imatinib will probably never be performed.
Funding
This work was supported by the “Deutsche Forschungsgemeinschaft, DFG, Klinische Forschergruppe 210 “Genetics of Drug resistance in Cancer”, and the Deutsche José Carreras Leukämiestiftung (AR12/12), the “Anneliese Pohl Stiftung” and the EUTOS 2016 program (Novartis) to AB. The CML-Study IV has been supported by the German Government (BMBF 01GI0270); Deutsche Krebshilfe (Nr.
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