Nilotinib is associated with a reduced incidence of BCR-ABL mutations versus imatinib in patients with newly diagnosed chronic myeloid leukemia in chronic phase
A partir de données portant sur des patients atteints d'une leucémie myéloïde chronique et inclus dans l'essai de phase III ENESTnd, cette étude analyse l'apparition de mutations du gène BCR-ABL associées à un traitement par imatinib ou nilotinib
In patients with chronic myeloid leukemia, BCR-ABL mutations contribute to resistance to tyrosine kinase inhibitor therapy. We examined the occurrence of treatment-emergent mutations and their impact on response in patients from the ENESTnd phase 3 trial. At the 3-year data cutoff, mutations were detected in approximately twice as many patients on imatinib 400 mg once daily (21 patients) than on nilotinib (11 patients each on nilotinib 300 mg twice daily and nilotinib 400 mg twice daily). The majority of mutations occurred in patients with intermediate or high Sokal scores. Most mutations (14 [66.7%]) emerging during imatinib treatment were imatinib-resistant, nilotinib-sensitive mutations. Incidence of the T315I mutation was low (found in 3, 2, and 3 patients on nilotinib 300 mg twice daily, nilotinib 400 mg twice daily, and imatinib, respectively) and mostly occurred in patients with high Sokal scores. Of the patients with emergent mutations, 1 of 11, 2 of 11, and 7 of 21 patients on nilotinib 300 mg twice daily, nilotinib 400 mg twice daily, and imatinib, respectively, progressed to accelerated phase (AP)/blast crisis (BC) on treatment. Overall, nilotinib led to fewer treatment-emergent BCR-ABL mutations than imatinib and reduced rates of progression to AP/BC in patients with these mutations. (Clinicaltrials.gov NCT00471497)