Simona Luatti

Nilotinib for the frontline treatment of Ph(+) chronic myeloid leukemia.

Nilotinib has a higher binding affinity and selectivity for BCR-ABL with respect to imatinib and is an effective treatment of chronic myeloid leukemia (CML) after imatinib failure. In a phase 2 study, 73 early chronic-phase, untreated, Ph(+) CML patients, received nilotinib at a dose of 400 mg twice daily. The primary endpoint was the complete cytogenetic response (CCgR) rate at 1 year. With a median follow-up of 15 months, the CCgR rate at 1 year was 96%, and the major molecular response rate 85%. Responses were rapid, with 78% CCgR and 52% major molecular response at 3 months. During the first year, the treatment was interrupted at least once in 38 patients (52%). The mean daily dose ranged between 600 and 800 mg in 74% of patients, 400 and 599 mg in 18% of patients, and was less than 400 mg in 8% of patients. Dose interruptions were mainly due to nonhematologic and biochemical side effects. Myelosuppression was irrelevant. One patient progressed to blastic crisis after 6 months; one went off-treatment for lipase increase grade 4 (no pancreatitis). Nilotinib is safe and very active in early chronic-phase CML. These data support a role for nilotinib for the frontline treatment of CML. This study was registered at ClinicalTrials.gov as NCT00481052.

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

The findings of this study suggest that imatinib mesylate at a daily dose of 600 mg is effective and safe in the short-term treatment of chronic myeloid leukemia in blast crisis, but does not significantly modify longer-term outcome of this condition. See related perspective article on page 1765. 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).

The long-term durability of cytogenetic responses in patients with accelerated phase chronic myeloid leukemia treated with imatinib 600 mg: the GIMEMA CML Working Party experience after a 7-year follow-up.

The findings of this phase 2 multicenter trial indicate that imatinib may induce durable responses in patients with accelerated phase chronic myeloid leukemia. Background Imatinib mesylate is the first line treatment for chronic myeloid leukemia. The advent of imatinib increased survival significantly in patients in an advanced phase of the disease. However, few long-term data on the outcome of these patients based on large, prospective and controlled trials are available. Design and Methods A phase 2 multicenter trial of the use of imatinib 600 mg/daily in patients with accelerated phase chronic myeloid leukemia was sponsored and promoted by the Italian Cooperative Study Group on Chronic Myeloid Leukemia in 2001. Results One hundred and eleven patients were enrolled; the median follow-up of the 41 living patients is 82 months (range, 73–87). One hundred and seven patients (96%) returned to chronic phase and 79 patients (71%) achieved a complete hematologic response. Cumulative best rates of major cytogenetic response and complete cytogenetic response were 30% and 21%, respectively. All responses were maintained for a minimum of 4 weeks. At last follow-up, four patients were alive in complete remission after allogeneic transplant, 16 patients (14%) had switched to a second generation tyrosine kinase inhibitor and 21 patients (19%) were alive on imatinib therapy. No late toxicities were observed. Progression-free survival and event-free survival rates were 36.5% and 15%, respectively, at 7 years. The median survival time was 37 months, and was significantly associated with the achievement of a complete hematologic response or a complete cytogenetic response. Conclusions Imatinib may induce durable responses, associated with prolonged survival, in patients with accelerated phase chronic myeloid leukemia

Results of high-dose imatinib mesylate in intermediate Sokal risk chronic myeloid leukemia patients in early chronic phase: a phase 2 trial of the GIMEMA CML Working Party

Imatinib mesylate has become the treatment of choice for chronic myeloid leukemia (CML): the standard dose for chronic- phase (CP) CML is 400 mg daily. Response rates are different according to Sokal score, being significantly lower in intermediate and high Sokal risk patients. Phase 1 and 2 trials have shown a dose-response effect and high-dose imatinib trials in early CP CML showed better results compared with standard dose. Our study is the first prospective trial planned to evaluate the efficacy and tolerability of high-dose imatinib in previously untreated intermediate Sokal risk CML patients. Seventy-eight patients were treated with 400 mg imatinib twice daily: complete cytogenetic response (CCgR) rates at 12 and 24 months were 88% and 91%; moreover, at 12 and 24 months 56% and 73% of CCgR patients achieved a major molecular response. The incidence of adverse events was slightly higher than reported by the most important standard-dose trials. With a median follow-up of 24 months, 3 patients progressed to advanced phase. In intermediate Sokal risk newly diagnosed CML patients, high-dose imatinib induced rapid and high response rates, apparently faster than those documented in the International Randomized Study of IFN and Imatinib for the same risk category. These clinical trials are registered at www.clinicaltrials.gov as no. NCT00510926.

Chronic myeloid leukemia: a prospective comparison of interphase fluorescence in situ hybridization and chromosome banding analysis for the definition of complete cytogenetic response, a study of the GIMEMA CML WP

In chronic myeloid leukemia, different methods are available to monitor the response to therapy: chromosome banding analysis (CBA), interphase fluorescence in situ hybridization (I-FISH), and real-time quantitative polymerase chain reaction (RT-Q-PCR). The GIMEMA CML WP (Gruppo Italiano Malattie Ematologiche Adulto Chronic Myeloid Leukemia Working Party) has performed a prospective study to compare CBA and I-FISH for the definition of complete cytogenetic response (CCgR). Samples (n = 664) were evaluated simultaneously by CBA and I-FISH. Of 537 cases in CCgR, the number of positive nuclei by I-FISH was less than 1% in 444 cases (82.7%). Of 451 cases with less than 1% positive nuclei by I-FISH, 444 (98.4%) were classified as CCgR by CBA. The major molecular response rate was significantly greater in cases with I-FISH less than 1% than in those with I-FISH 1% to 5% (66.8% vs 51.6%, P < .001) and in cases with CCgR and I-FISH less than 1% than in cases with CCgR and I-FISH 1% to 5% (66.1% vs 49.4%, P = .004). I-FISH is more sensitive than CBA and can be used to monitor CCgR. With appropriate probes, the cutoff value of I-FISH may be established at 1%. These trials are registered at http://www.clinicaltrials.gov as NCT00514488 and NCT00510926.

Deletions of the Derivative Chromosome 9 Do Not Influence the Response and the Outcome of Chronic Myeloid Leukemia in Early Chronic Phase Treated With Imatinib Mesylate: GIMEMA CML Working Party Analysis

PURPOSE Deletions of the derivative chromosome 9 [der(9)] have been associated with a poor prognosis in chronic myeloid leukemia (CML) across different treatment modalities. In the imatinib era, the prognostic impact of der(9) deletions has been evaluated mainly in patients with late chronic-phase (CP) CML, giving partially conflicting results. Few data are available in the early CP setting. For this reason, in 2006, the European LeukemiaNet recommendations still considered der(9) deletions as a candidate adverse prognostic factor and required a careful monitoring of the patient. PATIENTS AND METHODS To investigate the prognostic value of der(9) deletions in early CP CML, we performed an analysis of three prospective imatinib trials of the Italian Group for Hematological Malignancies of the Adult (GIMEMA) CML Working Party. RESULTS A fluorescent in situ hybridization (FISH) analysis of bone marrow cells was performed at diagnosis; der(9) deletions were detected in 60 (12%) of 521 evaluable patients. At 60 months, the cumulative incidence of complete cytogenetic response and major molecular response-and the probability of event-free survival, failure-free survival, progression-free survival, and overall survival-in patients with and without deletions were not statistically different. CONCLUSION Our data strongly support the notion that, when investigated by FISH, der(9) deletions are not a poor prognostic factor in patients with early CP CML treated with imatinib.

Chromosome abnormalities additional to the Philadelphia chromosome at the diagnosis of chronic myelogenous leukemia: pathogenetic and prognostic implications

Additional chromosome abnormalities (ACAs) occur in less than 10% of cases at diagnosis of Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML). In some cases, on the basis of the persistence of the ACAs in Ph-negative cells after response to imatinib, a secondary origin of the Ph chromosome has been demonstrated. In this study, the possible prognostic value of this phenomenon was evaluated. Thirty-six Ph-positive CML patients were included in the study. In six patients, ACAs persisted after the disappearance of the Ph. A complete cytogenetic response (CCR) was obtained in five of these six patients, and five of six also had a high Sokal score. In all the other cases, ACAs disappeared together (in cases of response to therapy with imatinib) or persisted with the Ph (in cases of no response to imatinib). In the former cases, the primary origin of the Ph was demonstrated. CCR was obtained in 22 cases (17 with low to intermediate Sokal scores), while no response was observed in 8 patients (5 with a high Sokal score). Sokal score seems to maintain its prognostic value for patients in whom the Ph occurs as a primary event, but not in those in whom it occurs as a secondary one.

Pancreatic enzyme elevation in chronic myeloid leukemia patients treated with nilotinib after imatinib failure

An increase in the serum concentration of pancreatic enzymes (amylase and lipase) was reported in a proportion of imatinib-resistant and/or intolerant Philadelphia-positive chronic myeloid leukemia patients treated with nilotinib. This report describes chronic myeloid leukemia patients who developed serum lipase/amylase elevation during treatment with nilotinib. An increase in the serum concentration of pancreatic enzymes (amylase and lipase) was reported in a proportion of imatinib-resistant and/or intolerant Philadelphia-positive chronic myeloid leukemia patients treated with nilotinib. Acute pancreatitis was very rare, and the relevance of these laboratory alterations remains unknown. We report on 8 chronic myeloid leukemia patients who developed serum lipase/amylase elevation during treatment with nilotinib. After a median follow-up of 26 months, none of these patients developed an acute pancreatitis or clinical signs of pancreatic disease. Pancreatic hyperenzymemia never led to permanent drug discontinuation and required nilotinib temporary interruption in one case only. The median cumulative duration of dose interruptions and response to treatment were comparable in patients with or without pancreatic enzyme elevation. The mechanisms of action of nilotinib on pancreatic enzymes deserves to be investigated: however, in our experience, the relevance of pancreatic hyperenzymemia was clinically very limited.

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.

Molecular and cytogenetic characterization of a new case of t(5;17)(q35;q21) variant acute promyelocytic leukemia

Molecular and cytogenetic characterization of a new case of t(5;17)(q35;q21) variant acute promyelocytic leukemia