Clinical characteristics of chronic myeloid leukemia with T315I mutation and the efficacy of ponatinib / 南方医科大学学报

OBJECTIVE@#To analyze the clinical features of chronic myeloid leukemia (CML) with T315 I mutation (CML-T315I) and compare the effectiveness of different treatments.@*METHODS@#We retrospectively analyzed the clinical data and outcomes of 19 patients with CML-T315I receiving different treatments. The T315 I mutations in these patients were detected by examination of BCR-ABL kinase domain (KD) mutation by RTQ-PCR and Sanger sequencing. The relapse following the treatments, defined as hematological, cytogenetic and molecular biological recurrences, were analyzed in these patients.@*RESULTS@#Of the 19 patients with CML-T315I, 14 (73.7%) were in CML-CP stage at the initial diagnosis, and 13 (81.2%) were high-risk patients based on the Sokal scores. All the 19 patients were treated with TKI after the initial diagnosis, and during the treatment, 15 (78.9%) patients were found to have additional chromosomal aberrations, and 10 (52.6%) had multiple mutations; 13 (68.4%) of the patients experienced disease progression (accelerated phase/blast crisis) before the detection of T315I mutation, with a median time of 40 months (5-120 months) from the initial diagnosis to the mutation detection. After detection of the mutation, 12 patients were treated with ponatinib and 7 were managed with the conventional chemotherapy regimen, and their overall survival rates at 3 years were 83.3% and 14.2%, respectively ( < 0.001).@*CONCLUSIONS@#CML patients resistant to TKI are more likely to have T315I mutations, whose detection rate is significantly higher in the progressive phase than in the chronic phase. These patients often have additional chromosomal aberrations and multiple gene mutations with poor prognoses and a high recurrence rate even after hematopoietic stem cell transplantation. Long-term maintenance therapy with ponatinib may improve the prognosis and prolong the survival time of the patients.

Clinical analysis of adult Philadelphia chromosome-positive acute lymphoblastic leukemia with p16 gene deletion / 中华血液学杂志

Objective@#To investigate the clinical implications of p16 gene deletion in adult Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) .@*Methods@#Retrospective analysis of clinical, immunophenotypic, cytogenetics, molecular characteristics and prognosis of 80 newly diagnosed Ph+ ALL patients with p16 deletion.@*Results@#Of 80 adult Ph+ ALL, the prevalence of p16 gene deletion was 31.3%. p16 gene deletion carriers frequently accompanied with high WBC counts (WBC≥30×109/L) and CD20 expression. The incidence of complex chromosome abnormality in p16 gene deletion group was higher than that in non-deletion group, with alternations in chromosome 7, 8, 19 and der (22) more frequently observed. There was no difference occurred between patients with or without p16 gene deletion in complete remission (CR) rate following induction chemotherapy combined with tyrosine kinase inhibitors (TKIs) . However, after three cycles of chemotherapy, the MMR and CMR rate in the p16 gene deletion group was lower than patients with wild-type p16 gene (P=0.034, P=0.036) . The p16 gene deletion patients showed no significant differences in MMR, CMR and relapse rate between Imatinib or Dasatinib plus chemotherapy (P>0.05) . Deletion of p16 gene was significantly associated with poor outcomes including worse overall survival (OS) (37.1% vs 54.1%, P=0.037) , lower disease free-survival (DFS) (12.4% vs 45.9%, P=0.026) , and increased cumulative incidence of relapse (P=0.033) . Among the 25 patients with p16 deletion, 14 underwent allo-HSCT and the median survival was 21 months, better than that of patients received chemotherapy alone (12 months) (P=0.030) .@*Conclusion@#This study indicated that deletion of p16 was associated with poor prognosis in adult Ph+ ALL, and the utility of second-generation TKI (Dasatinib) does not necessarily have an edge on efficacy over Imatinib, but allo-HSCT has the potential of elongating life expectancy. It is an important significance to define the status of p16 in Ph+ ALL for predicting prognosis and guiding therapy decision-making.

Clinical significance of cytogenetic monitoring in chronic myeloid leukemia / 中华血液学杂志

Objective@#To analyze the association of cytogenetic abnormalities with the prognosis of chronic myeloid leukemia (CML) patients in tyrosine kinase inhibitors (TKI) era.@*Methods@#Karyotype analysis of chromosome G-banding was carried out in 387 newly diagnosed CML patients by short-term culture of bone marrow cells. The correlation of cytogenetic abnormalities and CML progression was explored in combination with ABL tyrosine point mutations.@*Result@#Of 387 patients with positive BCR-ABL fusion gene assayed by fluorescence in situ hybridization (FISH) technique, 94.1% (364/387) patients were Ph positive and 5.9% (23/387) Ph negative; 320 patients (87.9%) had a translocation t (9;22) (q34;q11) and 5 (1.4%) a variant translocation t (v;22) . Additional cytogenetic aberrations (ACA) at diagnosis were found in 10.7% (39/387) Ph+ patients, major route ACA in 22 (56.4%) cases and minor route ACA in 15 (38.5%) cases and 2 patients (5.1%) lacked the Y chromosome (−Y) ; 23.4% (71/303) patients occurred ACA during TKI treatment and the most frequent abnormalities were abnormal chromosome numbersd, which were likely associated with high proportion of disease progression (χ2=168.21, P<0.001) and ABL tyrosine point mutations (χ2=29.04, P<0.001) . Newly diagnosed CML-CP patients with t (9;22) (q34;q11) had a longer event-free survival (EFS) and disease-free survival (DFS) rates than that of patients with ACA (P=0.037; P=0.003) , while the overall survival (OS) had no significant differences (P=0.209) . As for CML-CP patients that occurred ACA during TKI therapy would have a marked low OS, EFS and DFS (all P<0.001) compared with no ACA occurred patients. Survival of advanced patients that occurred ACA were dramatically reduced.@*Conclusion@#ACA often emerged during the disease progress in CML patients, regular and timely detection of chromosomes karyotype and ABL tyrosine point mutations during TKI treatment was important for therapeutic evaluation, progress and prognosis of CML.

Correlation between point mutation in ABL kinase and clinical outcome of chronic myeloid leukemia patients / 中华血液学杂志

<p><b>OBJECTIVE</b>To analyze the association of different types of ABL tyrosine point mutations and imatinib resistance to probe the relation between ABL tyrosine point mutations and the prognosis of patients with chronic myeloid leukemia (CML).</p><p><b>METHODS</b>Nested reverse transcriptasepolym erase chain reaction was performed on samples from 70 patients to amplify the ABL kinase domain. Then, the amplified product was purified and sequenced in both direction. The homologous analysis was performed in combination of clinical data.</p><p><b>RESULTS</b>The ABL domain point mutations were detected in 32 patients (45.7%) including 16 patients in chronic phase (CP), 6 patients in accelerated phase(AP)and 10 patients in blast phase (BP), which were detected as T315I, E255K, C475Y, Y253H, G321W, G250E, F317L, E258K, F359V, E459K and F311I, respectively. Sokal score with intermediate and high risk and Ph+ chromosome with complex karyotype were important risk factors for ABL domain point mutations. The 5-year overall survival (OS) was not significantly different between the patients with or without ABL domain point mutations (78.1% vs 84.2%, P=0.985), while the 5-year cumulative event-free survival (EFS) of two groups were 34.4% and 68.4% (P=0.034), respectively. The rate of complete cytogenetic response was higher in patients treated with allogenic hematopetic stem cell transplantation (allo-HSCT) compared with patients merely treated with second-generation tyrosine kinase inhibitors or chemotherapeutics (P=0.001).</p><p><b>CONCLUSION</b>Patients with ABL domain point mutations had poor efficacy and prognosis compared to those without ABL domain point mutations. Detection of ABL domain point mutations in CML-CP was helpful for the adjustment of therapeutic options and improvement of prognosis. And allo-HSCT was a more effective therapy for patients with advanced phase.</p>

Long-term outcomes of nilotinib treatment for chronic myelogenous leukemia patients with imatinib resistance or intolerance / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the long-term clinical efficacy and safety of nilotinib in the treatment of chronic myelogenous leukemia (CML) patients with imatinib resistance or intolerance.</p><p><b>METHODS</b>Twenty-six CML patients with imatinib resistance or intolerance received nilotinib treatment at the dose of 400 mg once or twice daily. The patients were followed up for nearly 5 years with regular monitoring of the hematologic, cytogenetic and molecular biological markers and recording of the clinical manifestations and biochemical indicators to evaluate the therapeutic effect and adverse events.</p><p><b>RESULTS</b>The median duration of nilotinib therapy was 17 (1-56) months, and the patients were follow up for a median of 51 months. At the last follow-up, 16 (61.5%) patients achieved a complete hematologic response, 13 (50.0%) achieved a major cytogenetic response, 9 (34.6%) achieved a complete cytogenetic response, and 7 (26.9%) achieved a major molecular response accumulatively. Nonhematologic adverse events were mostly of grade l or 2. The most common adverse effects possibly related to nilotinib were increased bilirubin (69.2%) and rash (57.7%). Grade 3 or 4 hematologic adverse events included thrombocytopenia (53.8%), neutropenia (26.9%) and anemia (19.2%). The patients in chronic and remission phase had better efficacy and fewer hematological side effects than those in advanced phase.</p><p><b>CONCLUSION</b>Nilotinib is an effective and safe treatment option for imatinib-resistant or -intolerant CML patients, especially for those in chronic and remission phase.</p>