Bengt Simonsson

Chronic Myeloid Leukemia: An Update of Concepts and Management Recommendations of European LeukemiaNet

PURPOSE To review and update the European LeukemiaNet (ELN) recommendations for the management of chronic myeloid leukemia with imatinib and second-generation tyrosine kinase inhibitors (TKIs), including monitoring, response definition, and first- and second-line therapy. METHODS These recommendations are based on a critical and comprehensive review of the relevant papers up to February 2009 and the results of four consensus conferences held by the panel of experts appointed by ELN in 2008. RESULTS Cytogenetic monitoring was required at 3, 6, 12, and 18 months. Molecular monitoring was required every 3 months. On the basis of the degree and the timing of hematologic, cytogenetic, and molecular results, the response to first-line imatinib was defined as optimal, suboptimal, or failure, and the response to second-generation TKIs was defined as suboptimal or failure. CONCLUSION Initial treatment was confirmed as imatinib 400 mg daily. Imatinib should be continued indefinitely in optimal responders. Suboptimal responders may continue on imatinb, at the same or higher dose, or may be eligible for investigational therapy with second-generation TKIs. In instances of imatinib failure, second-generation TKIs are recommended, followed by allogeneic hematopoietic stem-cell transplantation only in instances of failure and, sometimes, suboptimal response, depending on transplantation risk.

European LeukemiaNet recommendations for the management of chronic myeloid leukemia: 2013

Advances in chronic myeloid leukemia treatment, particularly regarding tyrosine kinase inhibitors, mandate regular updating of concepts and management. A European LeukemiaNet expert panel reviewed prior and new studies to update recommendations made in 2009. We recommend as initial treatment imatinib, nilotinib, or dasatinib. Response is assessed with standardized real quantitative polymerase chain reaction and/or cytogenetics at 3, 6, and 12 months. BCR-ABL1 transcript levels ≤10% at 3 months, <1% at 6 months, and ≤0.1% from 12 months onward define optimal response, whereas >10% at 6 months and >1% from 12 months onward define failure, mandating a change in treatment. Similarly, partial cytogenetic response (PCyR) at 3 months and complete cytogenetic response (CCyR) from 6 months onward define optimal response, whereas no CyR (Philadelphia chromosome-positive [Ph+] >95%) at 3 months, less than PCyR at 6 months, and less than CCyR from 12 months onward define failure. Between optimal and failure, there is an intermediate warning zone requiring more frequent monitoring. Similar definitions are provided for response to second-line therapy. Specific recommendations are made for patients in the accelerated and blastic phases, and for allogeneic stem cell transplantation. Optimal responders should continue therapy indefinitely, with careful surveillance, or they can be enrolled in controlled studies of treatment discontinuation once a deeper molecular response is achieved.

Predicting complete cytogenetic response and subsequent progression-free survival in 2060 patients with CML on imatinib treatment: the EUTOS score

The outcome of chronic myeloid leukemia (CML) has been profoundly changed by the introduction of tyrosine kinase inhibitors into therapy, but the prognosis of patients with CML is still evaluated using prognostic scores developed in the chemotherapy and interferon era. The present work describes a new prognostic score that is superior to the Sokal and Euro scores both in its prognostic ability and in its simplicity. The predictive power of the score was developed and tested on a group of patients selected from a registry of 2060 patients enrolled in studies of first-line treatment with imatinib-based regimes. The EUTOS score using the percentage of basophils and spleen size best discriminated between high-risk and low-risk groups of patients, with a positive predictive value of not reaching a CCgR of 34%. Five-year progression-free survival was significantly better in the low- than in the high-risk group (90% vs 82%, P = .006). These results were confirmed in the validation sample. The score can be used to identify CML patients with significantly lower probabilities of responding to therapy and survival, thus alerting physicians to those patients who require closer observation and early intervention.

Clonal expansion of T/NK-cells during tyrosine kinase inhibitor dasatinib therapy.

Dasatinib, a broad-spectrum tyrosine kinase inhibitor (TKI), predominantly targets BCR-ABL and SRC oncoproteins and also inhibits off-target kinases, which may result in unexpected drug responses. We identified 22 patients with marked lymphoproliferation in blood while on dasatinib therapy. Clonality and immunophenotype were analyzed and related clinical information was collected. An abrupt lymphocytosis (peak count range 4–20 × 109/l) with large granular lymphocyte (LGL) morphology was observed after a median of 3 months from the start of therapy and it persisted throughout the therapy. Fifteen patients had a cytotoxic T-cell and seven patients had an NK-cell phenotype. All T-cell expansions were clonal. Adverse effects, such as colitis and pleuritis, were common (18 of 22 patients) and were preceded by LGL lymphocytosis. Accumulation of identical cytotoxic T cells was also detected in pleural effusion and colon biopsy samples. Responses to dasatinib were good and included complete, unexpectedly long-lasting remissions in patients with advanced leukemia. In a phase II clinical study on 46 Philadelphia chromosome-positive acute lymphoblastic leukemia, patients with lymphocytosis had superior survival compared with patients without lymphocytosis. By inhibiting immunoregulatory kinases, dasatinib may induce a reversible state of aberrant immune reactivity associated with good clinical responses and a distinct adverse effect profile.

Comparison of imatinib 400 mg and 800 mg daily in the front-line treatment of high-risk, Philadelphia-positive chronic myeloid leukemia: a European LeukemiaNet Study

Imatinib mesylate (IM), 400 mg daily, is the standard treatment of Philadelphia-positive (Ph(+)) chronic myeloid leukemia (CML). Preclinical data and results of single-arm studies raised the suggestion that better results could be achieved with a higher dose. To investigate whether the systematic use of a higher dose of IM could lead to better results, 216 patients with Ph(+) CML at high risk (HR) according to the Sokal index were randomly assigned to receive IM 800 mg or 400 mg daily, as front-line therapy, for at least 1 year. The CCgR rate at 1 year was 64% and 58% for the high-dose arm and for the standard-dose arm, respectively (P = .435). No differences were detectable in the CgR at 3 and 6 months, in the molecular response rate at any time, as well as in the rate of other events. Twenty-four (94%) of 25 patients who could tolerate the full 800-mg dose achieved a CCgR, and only 4 (23%) of 17 patients who could tolerate less than 350 mg achieved a CCgR. This study does not support the extensive use of high-dose IM (800 mg daily) front-line in all CML HR patients. This trial was registered at www.clinicaltrials.gov as #NCT00514488.

Combination of pegylated IFN-alpha 2b with imatinib increases molecular response rates in patients with low- or intermediate-risk chronic myeloid leukemia

Biologic and clinical observations suggest that combining imatinib with IFN-α may improve treatment outcome in chronic myeloid leukemia (CML). We randomized newly diagnosed chronic-phase CML patients with a low or intermediate Sokal risk score and in imatinib-induced complete hematologic remission either to receive a combination of pegylated IFN-α2b (Peg-IFN-α2b) 50 μg weekly and imatinib 400 mg daily (n = 56) or to receive imatinib 400 mg daily monotherapy (n = 56). The primary endpoint was the major molecular response (MMR) rate at 12 months after randomization. In both arms, 4 patients (7%) discontinued imatinib treatment (1 because of blastic transformation in imatinib arm). In addition, in the combination arm, 34 patients (61%) discontinued Peg-IFN-α2b, most because of toxicity. The MMR rate at 12 months was significantly higher in the imatinib plus Peg-IFN-α2b arm (82%) compared with the imatinib monotherapy arm (54%; intention-to-treat, P = .002). The MMR rate increased with the duration of Peg-IFN-α2b treatment (< 12-week MMR rate 67%, > 12-week MMR rate 91%). Thus, the addition of even relatively short periods of Peg-IFN-α2b to imatinib markedly increased the MMR rate at 12 months of therapy. Lower doses of Peg-IFN-α2b may enhance tolerability while retaining efficacy and could be considered in future protocols with curative intent.

Serum Deoxythymidine Kinase Gives Prognostic Information in Chronic Lymphocytic Leukemia

A recently developed deoxythymidine kinase assay, utilizing iodine‐125‐iodo‐deoxyuridine as substrate and capable of detecting enzyme activity in serum from healthy humans, was used in an investigation of sera from 55 untreated patients with chronic lymphocytic leukemia (CLL). When confined to the study, the patients were classified as having progressive or indolent disease and according to Rai stage. The results showed a significant correlation between serum deoxythymidine kinase activity (S‐TK) and disease status, i.e., higher values were found in patients with progressive disease, compared to those with indolent disease. S‐TK also correlated with Rai stage. S‐TK values of more than 40 times the normal value were found in some patients. All patients with S‐TK > 8.4 units had a disease that was or became progressive during the observation period. Within the patient group with indolent disease two groups that differed with regard to prognosis could be distinguished according to their initial S‐TK values. In longitudinal studies of 18 patients with indolent disease, S‐TK was found to exceed 8.4 units only on one occasion during an observation period of up to 68 months. In patients with indolent disease, a transition to progressive disease was parallelled by an increase in S‐TK. Studies of S‐TK levels in 18 patients receiving treatment showed that S‐TK decreased during successful therapy. S‐TK was also found to increase when the disease was reactivated. From these results it is concluded that S‐TK could be used as a prognostic marker for the individual CLL patient. Furthermore, S‐TK seems to be useful for longitudinal follow‐up studies of disease status, both in indolent disease and in progressive disease during treatment.

Marked erythropoietin increase before fall in Hb after treatment with cytostatic drugs suggests mechanism other than anaemia for stimulation

Summary. Serum erythropoietin (Epo) was measured in 23 patients before, during and after intensive cytostatic treatment courses for acute leukaemia or before bone marrow transplantation. A marked increase was seen in all patients, starting 1 or 2 d after initiation of treatment. A peak was reached after about 7 d, at levels as high as 1450 IU/l, after which Epo fell rapidly, even in patients who were anaemic at that time. In 13 of the patients there was no fall in Hb level that could explain the increase in Epo. The increase was too large to be explained by an altered Epo metabolism or marrow utilization. Cytostatic drugs cause an increase in Epo production not mediated through anaemia, possibly initiated by a cytostatic effect on the kidneys or by an unknown stimulatory factor, responsive to bone marrow inhibition.

Tyrosine kinase inhibitor usage, treatment outcome, and prognostic scores in CML: report from the population-based Swedish CML registry

Clinical management guidelines on malignant disorders are generally based on data from clinical trials with selected patient cohorts. In Sweden, more than 95% of all patients diagnosed with chronic myeloid leukemia (CML) are reported to the national CML registry, providing unique possibilities to compile population-based information. This report is based on registry data from 2002 to 2010, when a total of 779 patients (425 men, 354 women; median age, 60 years) were diagnosed with CML (93% chronic, 5% accelerated, and 2% blastic phase) corresponding to an annual incidence of 0.9/100,000. In 2002, approximately half of the patients received a tyrosine kinase inhibitor as initial therapy, a proportion that increased to 94% for younger (<70 years) and 79% for older (>80 years) patients during 2007-2009. With a median follow-up of 61 months, the relative survival at 5 years was close to 1.0 for patients younger than 60 years and 0.9 for those aged 60 to 80 years, but only 0.6 for those older than 80 years. At 12 months, 3% had progressed to accelerated or blastic phase. Sokal, but not European Treatment and Outcome Study, high-risk scores were significantly linked to inferior overall and relative survival. Patients living in university vs nonuniversity catchment areas more often received tyrosine kinase inhibitors up front but showed comparable survival.

Mobilization of CD34+ cells by glycosylated and nonglycosylated G‐CSF in healthy volunteers — a comparative study

Abstract: In vitro studies indicate that lenograstim (glycosylated G–CSF) is more potent than filgrastim (nonglycosylated G–CSF) on a weight for weight basis. However, such a difference has not yet been shown in vivo. The primary objective of this trial was to compare the efficacy of equivalent doses (μg) of lenograstim and filgrastim in mobilizing CD34+ cells. Thirty‐two healthy male volunteers, median age 27 yr (19–44 yr), were randomized to receive either lenograstim 10 μg/kg followed by filgrastim 10 μg/kg or vice versa with a washout period of a minimum 4 wk. Both drugs were administered as s.c. injections once daily for 5 d (d 1–5). CD34+ cells were mobilized with a similar kinetics, peaking at median d 6 (5–6) for both drugs. A significant difference in favour of lenograstim was shown for peak number of CD34+ cells/μl blood (104±38 vs. 82±35, mean±l SD, p<0.0001, paired t‐test, n=30) and number of CFU‐GM/μl blood at d 6 (14.6±8.4 vs. 10.2±4.6, p<0.0001), respectively. There was no difference in the d 6 number of CD3+ cells. Both drugs were generally well tolerated and did not differ with respect to number of adverse events. In conclusion, lenograstim 10 μg/kg/d mobilizes PBPC more efficiently than the identical dose of filgrastim, indicating a difference in in vivo potency between the two G–CSFs.