Chronic myeloid leukemia in blast crisis treated with imatinib 600 mg: outcome of the patients alive after a 6-year follow-up

Background Imatinib mesylate is the first line treatment for chronic myeloid leukemia. In patients with advanced phase of the disease, the advent of imatinib significantly increased survival. However, few long-term data, based on large, prospective and controlled trials are available on the outcome of these patients. Design and Methods We conducted a phase II trial of imatinib 600 mg daily in patients with chronic myeloid leukemia in blast crisis. The return to chronic phase was defined as <15% blasts and <30% blasts plus promyelocytes in blood or bone marrow and <20% peripheral basophils. A complete hematologic response required the normalization of platelet and white cell differential counts and absence of extramedullary involvement. Cytogenetic response was assessed by the standard banding technique and rated as usual. Results Ninety-two patients were enrolled (20 with lymphoid blast crisis and 72 with myeloid blast crisis). Forty-six patients (50%) returned to chronic phase, and 24 patients (26%) achieved also a complete hematologic response. Sixteen patients (17%) had a cytogenetic response (9 complete, 1 partial, and 6 minor or minimal). The complete cytogenetic response was subsequently lost by all but two patients between 2 and 12 months after first having achieved it: the median duration of complete cytogenetic response was 7 months. All responses were sustained for a minimum of 4 weeks. The median survival of all the patients was 7 months. After a median observation time of 66 months, seven (8%) patients are alive. Three of these patients are on imatinib treatment (1 in complete hematologic remission, 1 in partial cytogenetic response and 1 in complete cytogenetic remission). Three patients are in complete remission after allogeneic stem cell transplantation. One patient is alive in blast crisis, on therapy with a second-generation tyrosine kinase inhibitor. Conclusions Imatinib was effective and safe in the short-term treatment of chronic myeloid leukemia in blast crisis, but longer-term outcome was not significantly influenced (ClinicalTrials.gov identifier: [NCT00514969][1]). [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00514969&atom=%2Fhaematol%2F93%2F12%2F1792.ato

Additional chromosomal abnormalities in Philadelphia-positive clone : adverse prognostic influence on frontline imatinib therapy: a GIMEMA Working Party on CML analysis

Additional chromosomal abnormalities (ACAs) in Philadelphia-positive cells have been reported in 3c 5% of patients with newly diagnosed chronic myeloid leukemia (CML) in chronic phase (CP). Few studies addressing the prognostic significance of baseline ACAs in patients treated with imatinib have been published previously. The European LeukemiaNet recommendations suggest that the presence of ACAs at diagnosis is a "warning" for patients in early CP, but there is not much information about their outcome after therapy with tyrosine kinase inhibitors. To investigate the role of ACAs in early CP CML patients treated with imatinib mesylate, we performed an analysis in a large series of 559 patients enrolled in 3 prospective trials of the Gruppo Italiano Malattie Ematologiche dell'Adulto Working Party on CML: 378 patients were evaluable and ACAs occurred in 21 patients (5.6%). The overall cytogenetic and molecular response rates were significantly lower and the time to response was significantly longer in patients with ACAs. The long-term outcome of patients with ACAs was inferior, but the differences were not significant. The prognostic significance of each specific cytogenetic abnormality was not assessable. Therefore, we confirm that ACAs constitute an adverse prognostic factor in CML patients treated with imatinib as frontline therapy

t(5;12)(q31;p13)/ETV6::ACSL6 and t(6;9)(p23;q34)/DEK::NUP214 concurrence in acute myeloid leukemia: an unusual association of two rare abnormalities

The translocation t(5;12)(q31;p13)/ETV6::ACSL6 is a rare cytogenetic abnormality, although it is reported in various myeloid malignancies. To date, only 16 cases of t(5;12) and ETV6::ACSL6 rearrangement, confirmed by either molecular or Fluorescence In Situ Hyridization (FISH) analysis, have been reported. Eosinophilia is a distinctive and common feature associated with this rearrangement. Although few cases have been described, the prognosis of patients with ETV6::ACSL6 is considered poor. We report two additional cases of t(5;12)(q31;p13)/ETV6::ACLS6 rearrangement and eosinophilia. Unusually, in our cases, the ETV6::ACSL6 rearrangement occurred at the relapse of Acute Myeloid Leukemia (AML) patients who had t(6;9)(p23;q34)/DEK::NUP214 rearrangement at disease onset. The concurrence of these two rare abnormalities has never been reported and may suggest a cooperative role of t(5;12) and t(6;9), leading to disease relapse. Moreover, at relapse, both cases presented with eosinophilia, further strengthening the association of t(5;12) with eosinophilia in myeloid malignancies. Given the poor prognosis and the non-responsiveness to tyrosine kinase inhibitors of cases of ETV6::ACSL6 rearrangement, in contrast to cases of ETV6::PDGFRB rearrangement, we recommend the introduction of testing for this abnormality in myeloid malignancies with eosinophilia

BCR-ABL1-associated reduction of beta catenin antagonist Chibby1 in chronic myeloid leukemia.

Beta Catenin signaling is critical for the self-renewal of leukemic stem cells in chronic myeloid leukemia. It is driven by multiple events, enhancing beta catenin stability and promoting its transcriptional co-activating function. We investigated the impact of BCR-ABL1 on Chibby1, a beta catenin antagonist involved in cell differentiation and transformation. Relative proximity of the Chibby1 encoding gene (C22orf2) on chromosome 22q12 to the BCR breakpoint (22q11) lets assume its involvement in beta catenin activation in chronic myeloid leukemia as a consequence of deletions of distal BCR sequences encompassing one C22orf2 allele. Forty patients with chronic myeloid leukemia in chronic phase were analyzed for C22orf2 relocation and Chibby1 expression. Fluorescent in situ hybridization analyses established that the entire C22orf2 follows BCR regardless of chromosomes involved in the translocation. In differentiated hematopoietic progenitors (bone marrow mononuclear cell fractions) of 30/40 patients, the expression of Chibby1 protein was reduced below 50% of the reference value (peripheral blood mononuclear cell fractions of healthy persons). In such cell context, Chibby1 protein reduction is not dependent on C22orf2 transcriptional downmodulation; however, it is strictly dependent upon BCR-ABL1 expression because it was not observed at the moment of major molecular response under tyrosine kinase inhibitor therapy. Moreover, it was not correlated with the disease prognosis or response to therapy. Most importantly, a remarkable Chibby1 reduction was apparent in a putative BCR-ABL1+ leukemic stem cell compartment identified by a CD34+ phenotype compared to more differentiated hematopoietic progenitors. In CD34+ cells, Chibby1 reduction arises from transcriptional events and is driven by C22orf2 promoter hypermethylation. These results advance low Chibby1 expression associated with BCR-ABL1 as a component of beta catenin signaling in leukemic stem cells

Circulating calreticulin is increased in myelofibrosis: Correlation with interleukin-6 plasma levels, bone marrow fibrosis, and splenomegaly

Myelofibrosis (MF) is a clonal neoplasia of the hemopoietic stem/progenitor cells associated with genetic mutations in the Janus kinase 2 (JAK2), myeloproliferative leukemia virus oncogene (MPL), and calreticulin (CALR) genes. MF is also characterized by a state of chronic inflammation. Calreticulin (CRT), as a multifunctional protein, is involved in a spectrum of cellular processes including inflammation, autoimmunity, and cancer initiation/progression. Based on this background, we hypothesised that in MF circulating CRT might reflect the inflammatory process. In the present study we show that circulating CRT is increased in MF patients compared to healthy controls. Also, in MF, CRT levels highly correlate with bone marrow fibrosis, splenomegaly, and Interleukin-6 (IL-6) plasma levels. In turn, higher IL-6 levels also correlated with disease severity in terms of increased spleen size, bone marrow fibrosis, number of circulating CD34+ cells, and lower hemoglobin values. These results demonstrate that the circulating CRT takes part in the inflammatory network of MF and correlates with aggressiveness of the disease