Prognostic Significance of Early Molecular Response in Patients Diagnosed with Chronic Myeloid Leukemia in Chronic Phase Treated with Nilotinib as a First-Line Therapy

Background: Chronic myeloid leukemia (CML) is one of malignant hematologic disorders arises from hematopoietic stem cells. BCR-ABL transcript levels on the international scale at 3 and 6 months are defined as indicators of the early efficacy of first line TKI treatment. Aim: To investigate the impact of early molecular response (EMR; BCR-ABL ≤ 10% on the International scale at 3 or 6 months) on outcome of the newly diagnosed CML in chronic phase treated with Nilotinib. Patients and Methods: The study was enrolled from 2018 to 2020 at Nasser Institute for Research and Treatment.This is a prospective cohort study done on 94 newly diagnosed CML cases in Chronic Phase. Results: : A statistically significant difference was detected between patients not achieved EMR with peripheral blasts ≥5%, when compared to others achieved EMR with peripheral blasts <5% (P<0.001). 75% of patients not achieved EMR were ≥55 years age at diagnosis; and 90% of patients achieved EMR were <55 years of age at diagnosis with (P<0.001). 25% of cases not achieved EMR were compliant, while other cases achieved EMR were compliant with (P<0.001).Overall survival remained higher in patients who achieved EMR (N=90) compared to patients who did not achieve EMR (N=4) (P=0.0001). Conclusion: EMR is an important prognostic significance for CML patients received treatment with Nilotinib. Patients who achieved EMR had significantly better outcome. Achieving MR3.0 should be the aim in patents with CML-CP who have a 3-month BCR-ABL ≤ 10% and 6-month BCR-ABL ≤ 10%.