Therapy of chronic myeloid leukemia with imatinib mesylate in Brazil: a study of 98 cases

Chronic myeloid leukemia patients in Tunisia: epidemiology and outcome in the imatinib era (a multicentric experience)

Data are limited in developing countries regarding the clinicopathologic features and response to therapy of chronic myeloid leukemia (CML) in the era of imatinib (IM). The objective of this study is to report on the clinicoepidemiologic features of CML in Tunisia, to evaluate the long-term outcome of patients in chronic (CP) or accelerated phase (AP) treated with IM 400 mg daily as frontline therapy, and to determine imatinib's efficacy and safety. From October 2002 to December 2014, 410 CML patients were treated with IM in six Tunisian departments of hematology. Response (hematologic, cytogenetic, and molecular responses) and outcome-overall survival (OS), event-free survival (EFS), and progression-free survival (PFS)-were evaluated. The following prognostic factors were analyzed for their impact on the European leukemia net (ELN) response, OS, EFS, and PFS at 5 years: age, sex, leukocyte count, Sokal score, European Treatment and Outcome Study (EUTOS) score, CML phase, time to starting IM, and impact of adverse events. The median age was 45 years (3-85 years). Two hundred ten (51.2%) patients were male. Splenomegaly was present in 322 of the 410 (79%). Additional cytogenetic abnormalities were encountered in 25 (6.3%) patients. At diagnosis, 379 (92.4%) patients were in CP, 31 (7.6%) were in AP. The Sokal risk was low in 87 (22.5%), intermediate in 138 (35.7%), and high in 164 patients (41.9%). The EUTOS risk was low in 217 (74%), and high in 77 (26%) patients. The rates of cumulative complete cytogenetic response (CCyR), major molecular response (MMR), and molecular response 4/5 log (MR4.5) in CP/AP-CML patients were 72, 68.4, and 46.4%, respectively. The median time to reach CCyR, MMR, and MR4.5 was 6 months (3-51), 18 months (3-72), and 24 months (3-100), respectively. According to the ELN criteria, optimal, suboptimal response, and failure were noted in 206 (51.8%), 61 (15.3%), and 125 (31.4%) patients, respectively. Five-year event-free survival (EFS), progression-free survival (PFS), and overall survival (OS) were 81, 90, and 90%, respectively. By multivariate analysis, AP, high EUTOS risk, and baseline WBC ≥ 150G/l remained independent predictive factors of non-optimal response to IM. The adverse events (AE) of IM were moderate and tolerable. With the caveats that the monitoring of the disease was not optimal, response rates were similar to those reported in previous studies. It is clear to us that improvements should be made in treatment of AP-CML and high Sokal risk group of CP-CML. The frontline use of second-generation tyrosine kinase inhibitor (TKI) is expected to improve the results of the first-line treatment of these high-risk Tunisian patients, but cost and accessibility of this therapy remain the problems in developing countries.

Fluorescent In Situ Hybridization Monitoring and Effect of Detected Early Responses in the Outcome of Patients With Chronic Phase Chronic Myeloid Leukemia: A Report From a Latin American Country

INTRODUCTION

The cytogenetic hallmark of chronic myeloid leukemia (CML) is the Philadelphia chromosome. Monitoring the response in patients receiving therapy is a standard of care. The present study was conducted to assess the monitoring adherence and reliableness of fluorescent in situ hybridization (FISH) as a monitoring tool and the effect of a complete cytogenetic response (CCyR) assessed by FISH on the prognosis of patients in a chronic phase (CP)-CML cohort.

MATERIALS AND METHODS

We retrospectively analyzed the data from 63 newly diagnosed CP-CML patients treated with imatinib mesylate at a dose of 400 mg/day as frontline therapy. The clinical data and cytogenetic test results at diagnosis and during monitoring were collected. The cytogenetic monitoring adherence assessment rates were measured. A correlation between chromosome banding analysis (CBA) and FISH was performed. The CCyR assessed by FISH was defined as < 1% BCR-ABL1(+) nuclei. The Kaplan-Meier method was used for overall survival analysis and time-to-event estimates.

RESULTS

The cytogenetic monitoring assessment adherence was 50.8% at 3 months, 93.5% at 6 months, 96.7% at 12 months, and 88.6% at 18 months. The Pearson correlation coefficient showed a significantly positive association (r = 0.84; P < .001) between CBA and FISH. The median follow-up duration after imatinib mesylate initiation was 60 months. A CCyR was achieved in 90.4% of patients within the first 18 months of therapy. At 3 months, 31 patients underwent a FISH evaluation, and 13 (41.9%) had achieved a CCyR. The patients who did not achieve a CCyR at 3 months had a significantly inferior probability of 5-year failure-free survival (38% vs. 94%; P = .001) and progression-free survival (80% vs. 100%; P = .043) compared with those with a CCyR.

CONCLUSION

We found improved monitoring adherence compared with the previous reports of Latin American populations. In countries with a high incidence of failure for CBA and a lack of real-time polymerase chain reaction standardization, FISH is a sensitive monitoring tool. In our cohort, patients not achieving an early CCyR, as tested by FISH, were a poor prognosis subgroup with worse rates of failure-free survival and progression-free survival.

Accelerated phase chronic myeloid leukemia: evaluation of clinical criteria as predictors of survival, major cytogenetic response and progression to blast phase

Background

Published criteria defining the accelerated phase in chronic myeloid leukemia are heterogeneous and little is known about predictors of poor outcome.

Methods

This is a retrospective study of 139 subjects in the accelerated phase of chronic myeloid leukemia treated with imatinib at a single center in Brazil. The objective was to identify risk factors for survival, major cytogenetic response and progression to blast phase in this population. The factors analyzed were: blasts 10–29%, basophils ≥ 20%, platelets > 1 × 10⁶/μL or <1 × 10⁵/μL and white blood cells > 1 × 10⁵/μL in the peripheral blood, as well as clonal evolution, splenomegaly, hemoglobin < 10 g/dL, time between diagnosis of chronic myeloid leukemia and imatinib treatment, and hematologic toxicity.

Results

Risk factors for poor survival in multivariate analysis were Grades 3–4 hematologic toxicity (p-value = 0.001), blasts 10–29% (p-value = 0.023), and hemoglobin < 10 g/dL (p-value = 0.04). Risk factors for not achieving major cytogenetic response were blasts 10–29% (p-value = 0.007), hemoglobin < 10 g/dL (p-value = 0.001), and previous use of interferon (p-value = 0.032). Risk factors for progression to the blast phase were hemoglobin < 10 g/dL (p-value = 0.005), basophils ≥ 20% (p-value = 0.023), and time from diagnosis of chronic myeloid leukemia to imatinib treatment > 12 months (p-value = 0.030).

Conclusion

These data indicate that patients with the above risk factors have a worse prognosis. This information can guide the therapy to be used.

Imatinib mesylate in children and adolescents with cancer

Imatinib is an inhibitor of the BCR-ABL fusion gene product that characterizes chronic myeloid leukemia (CML), and of the related tyrosine kinases c-KIT and platelet-derived growth factor (PDGF) receptor. The drug is now included as front-line therapy for CML and Philadelphia chromosome-positive acute lymphoblastic leukemia in children and adolescents, though valid concerns about serious late sequelae remain unresolved and are important issues for further study. European and North American consortia have conducted phase I and II clinical trials of imatinib in children and adolescents with brain and other solid tumors that have provided little evidence of efficacy.

Treatment of chronic myeloid leukemia in the imatinib era

BACKGROUND

There is paucity of data from developing countries on the efficacy and safety of imatinib mesylate in chronic myeloid leukemia (CML). The primary objective of this study was to document complete and partial cytogenetic responses to imatinib in all phases of CML. Secondary objectives included evaluations of complete hematologic response, safety, time to progression, and survival.

METHODS

Two hundred seventy-five patients in all phases of CML who received treatment with imatinib from January 2001 to December 2005 were included in the study. All patients had on bone marrow or BCR-ABL positive in peripheral blood by polymerase chain reaction.

RESULTS

After a median follow-up of 18 months, major cytogenetic responses (Ph <35%) in chronic phase (CP), accelerated phase (AP), and blastic phase (BP) were documented in 61%, 57%, and 28% of patients, respectively. A complete cytogenetic response was observed in 39.4%, 35.7%, and 14.3% of patients in CP, AP, and BP, respectively; and a complete hematologic response was observed in 90%, 86%, and 30%, respectively. The median time to progression at 18 months was 91% in CP and 68% in AP. The overall survivals in CP, AP, and BP at 18 months was 92%, 74%, and 38%, respectively.

CONCLUSIONS

Impressive hematologic, cytogenetic, and molecular responses to imatinib were observed, similar to the responses reported in patients from Western countries. Patients had good compliance, toxicity was limited, and overall quality of life was improved markedly. The results indicated that the biology of CML is not different in patients from developing countries.