[Analysis on tyrosine kinase inhibitor discontinuation in patients with chronic myeloid leukemia in the real world: experience from single center]

A Retrospective Cohort Study of Upfront Nilotinib in Chronic Myeloid Leukemia: A Single-Center Experience

Context Nilotinib is a second-generation BCR-ABL1 tyrosine kinase inhibitor used in the treatment of chronic myeloid leukemia (CML).

Aims We aim to evaluate the responses and safety of upfront Nilotinib therapy in Indian CML patients.

Setting and Design We retrospectively reviewed the medical records of CML patients who received Nilotinib as an upfront treatment at our center between January 1, 2011 and October 15, 2019.The follow-up was taken till March 31, 2020.

Results Forty One patients ( n = 36 chronic phase and five accelerated-phase CML) received frontline Nilotinib. Median age was 39 years (21–63) with male-to-female ratio of 1.1: 1. At 3 months, 96.9% patients achieved BCR-ABL of ≤10% at international scale. By the end of 12 months, 71.5% patients achieved major molecular response (BCR-ABL ≤0.1%) and 91.4% patients achieved complete cytogenetic response assessed by BCR-ABL polymerase chain reaction of ≤1%. Common toxicities observed were weight gain, thrombocytopenia, corrected QT prolongation, and elevated serum amylase in 14 (34.1%), 7(17.07%), 4(9.7%), and 4(9.7%) patients, respectively. Overall, five patients had loss of response with further progression and death in three patients. At a median of 43.7 months, 38 patients survived with estimated 3 year event-free survival and overall survival of 65 ± 9 and 93 ± 5%.

Conclusion This study showed remarkable good response with upfront Nilotinib in Indian patients with CML.

[Severe hematologic toxicity and its impact on treatment response in newly diagnosed patients with chronic myeloid leukemia receiving tyrosine kinase-inhibitor therapy]

Objectives: To explore the incidence and factors of severe leukopenia and/or thrombocytopenia in newly diagnosed patients with chronic myeloid leukemia (CML) to probe their impacts on cytogenetic and molecular responses, progression free survival (PFS) and overall survival (OS) . Methods: Data of newly diagnosed patients with CML in the chronic phase (CP) and/or accelerated phase (AP) were retrospectively collected and analyzed. Results: 855 CML patients [including 744 (87%) in the CP and 111 (13.0%) in the AP] were included in this study. 523 (61.2%) patients were male with a median age of 39 years (range, 14-87 years) . 749 (87.6%) patients received imatinib, 93 (10.9%) nilotinib, and 13 (1.5%) dasatinib, respectively as front-line therapy. At a median treatment of 1 month (range, 0.1-7.0 months) , 137 (16.0%) developed ≥grade 3 leukopenia and/or thrombocytopenia and recovered 0.6 month (range, 0.3-6.5 months) . Multivariate analysis showed that female gender (OR=1.5, 95%CI 1.0-2.2, P=0.033) , WBC ≥100×109/L (OR=1.9, 95%CI 1.3-2.8, P=0.001) , CP in Sokal high-risk (OR=2.2, 95%CI 1.2-3.9, P=0.005) , AP with ≥15% blast cells in blood or bone marrow (OR=5.1, 95%CI 1.9-13.3, P=0.001) were factors associated with higher incidence of ≥grade 3 leukopenia and/or thrombocytopenia. Severe leukopenia and/or thrombocytopenia with time of drug discontinuance >2 weeks was associated with lower probabilities of achieving complete cytogenetic (OR=0.4, 95%CI 0.3-0.6, P<0.001) , severe leukopenia and/or thrombocytopenia, no matter the time of drug discontinuance >2 weeks or ≤2 weeks, were associated with lower probabilities of achieving major molecular responses (OR=0.3, 95%CI 0.2-0.5, P<0.001; OR=0.7, 95%CI 0.5-1.0, P=0.036) and MR4.5 (OR=0.2, 95%CI 0.1-0.5, P=0.002; OR=0.7, 95%CI 0.4-1.1, P=0.110) ; however, those had no impacts on PFS and OS. Conclusions: Severe leukopenia and/or thrombocytopenia were common adverse events during TKI therapy. Female patients, WBC ≥100×109/L at diagnosed, CP in Sokal high-risk, CML-AP with ≥15% blast cells in blood or bone marrow were at high risk for higher incidence of severe leukopenia and/or thrombocytopenia. Those severe adverse events had impacts on lower cytogenetic and molecular response.

[Efficacy and safety of domestic dasatinib as second-line treatment for chronic myeloid leukemia patients in the chronic phase]

Objective: To investigate the efficiency and safety of domestic tyrosine kinase inhibitor (TKI) dasatinib (Yinishu) as second-line treatment for patients with chronic myeloid leukemia in chronic phase (CML-CP). Methods: A retrospective analysis of clinical data of CML-CP patients who received domestic dasatinib as second-line treatment in the CML collaborative group hospitals of Hubei province from March 2016 to July 2018 was performed. The optimal response rate, the cumulative complete cytogenetic response (CCyR), the cumulative major molecular responses (MMR), progression free survival (PFS), event free survival (EFS) and adverse effects (AEs) of the patients were assessed at 3, 6 and 12 months of treatment. Results: A total of 83 CML-CP patients were enrolled in this study. The median follow-up time was 23 months. The optimal response rates at 3, 6 and 12 months in 83 CML-CP patients treated with dasatinib were 77.5% (54/71), 72.6% (61/75) and 60.7% (51/69), respectively. By the end of follow-up, the cumulative CCyR and MMR rates were 65.5% (55/80) and 57.1% (48/73), respectively. The median time to achieving CCyR and MMR was 3 months. During follow-up time, the PFS rate was 94.0% (79/83) and the EFS rate was 77.4% (65/83). The most common non-hematological AEs of dasatinib were edema (32.5%), rash itching (18.1%) and fatigue (13.3%). The common hematological AEs of dasatinib were thrombocytopenia (31.3%), leukopenia (19.3%) and anemia (6.0%). Conclusion: Domestic dasatinib was effective and safe as the second-line treatment of CML-CP patients and it can be used as an option for CML-CP patients.