MR 4log and low levels of NK cells are associated with higher molecular relapse after imatinib discontinuation: Results of a prospective trial

Peripheral lymphocyte subsets as predicting factors for molecular recurrence after imatinib discontinuation in a phase 2 imatinib discontinuation trial in patients with chronic myeloid leukemia

INTRODUCTION

Treatment-free remission (TFR) is successful in half of the patients with chronic myeloid leukemia who discontinue Imatinib (IM) after sustained molecular response.

METHODS

In a prospective trial, we used pioglitazone for 3 months before stopping IM in 30 patients. Percentages of peripheral blood lymphocyte subsets were assessed before and after treatment. The relation of these data with duration of IM treatment and TRF were examined.

RESULTS

The median time of IM treatment was 117.6 months. After discontinuation, 11 patients had molecular recurrence after 5.2 months (2.4 - 30). The observation time for those remaining in TFR was 46 (26 - 56) months. The independent factors for the maintenance of TFR were the duration of IM treatment and the percentage of double-positive T cells at IM stop.

CONCLUSION

A longer treatment with imatinib was associated with a longer TFR after discontinuation. Pioglitazone could act as an immunomodulator, increasing DP T cells which may contribute to prevent relapse.

Kinetics of BCR::ABL1 transcript levels and molecular relapse after tyrosine kinase inhibitors discontinuation in chronic myeloid leukemia patients: preliminary results from the DES-CML study

Tyrosine kinase inhibitors (TKI) have revolutionized the treatment of patients with chronic myeloid leukemia. Patients who achieve sustained deep molecular response are eligible for treatment discontinuation. DES-CML is an ongoing, phase 2 multicentric discontinuation trial. Adult patients with CML in chronic phase with typical BCR::ABL1 transcripts, stable deep molecular response (MR4.5 IS) for two years, and no previous resistance were eligible. Patients underwent a phase of TKI dose de-escalation for six months before discontinuation. TKI was reintroduced at the previous dose if the patient lost major molecular response (MMR) at any time. This study aimed to assess the impact of BCR-ABL transcript kinetics during TKI de-escalation and discontinuation phases on treatment-free survival. So far, the study recruited 41 patients, and 38 patients discontinued therapy (4 were in the second discontinuation attempt). Eleven patients lost MMR, one during the de-escalation phase and ten after discontinuation. 24-month treatment-free survival was 66% (95% CI: 48-84%) in a median follow-up of 7 (1-30) months. No patient lost hematological response or had disease progression. A higher rate of molecular relapses occurred in patients with fluctuating BCR::ABL1 levels after the discontinuation phase (with loss of MR4.5, but no loss of MMR) (P=0.04, HR-4.86 (1.03-22.9) but not confirmed in the multivariate analysis. The longer duration of TKI treatment (P=0.03, HR-1.02, 95%CI - 1.00-1.04) and MMR (P=0.004, HR-0.95, 95%CI - 0.92-098) were independent factors of a lower relapse rate.

Exploration of treatment-free remission in CML, based on molecular monitoring

BACKGROUND

Typical chronic myelogenous leukemia (CML) is a myeloproliferative neoplasm caused by t(9; 22)(q34; q11) translocation. This chromosomal translocation forms the BCR::ABL1 fusion gene. The tyrosine kinase encoded by the BCR::ABL1 is considered to be the main pathogenic diver. BCR::ABL1 is not only a therapeutic target, but also a monitoring target. Monitoring of BCR::ABL1 reveals the progression of the disease and guides the next treatment. Now for CML, the target of treatment has been focused on treatment-free remission (TFR).

METHODS

We conducted a literature review of current developments of treatment-free remission and molecular monitoring methods.

RESULTS

More effective and sensitive CML monitoring methods such as digital droplet PCR (ddPCR) and next generation sequencing (NGS) have further studied the measurable residual disease (MRD) and clonal heterogeneity, which provides strong support for the exploration of TFR. We discussed some of the factors that may be related to TFR outcomes at the molecular level, along with some monitoring strategies.

CONCLUSION

Currently, predictive indicators for treatment-free remission outcomes and recurrence are lacking in clinical practice. In future, treatment-free remission research should focus on combining the clinical indicators with molecular monitoring and biological markers to personalize patient conditions and guide clinicians to develop individualized treatment plans, so that more patients with CML can achieve safer and stabler treatment-free remission.

Brazilian chronic myeloid leukemia working group recommendations for discontinuation of tyrosine kinase inhibitors in chronic myeloid leukemia in clinical practice

Introduction

Treatment-free remission (TFR) is a new goal of chronic myeloid leukemia (CML) therapy. TFR is feasible when the patient has achieved a deep and stable molecular response and met the criteria required to ensure its success. Treatment discontinuation should not be proposed to the CML patient if minimum conditions are not met. In Brazil, for example, molecular tests (BCR::ABL1) are not broadly available, making it difficult to monitor the patients adequately.

Objective

In this sense, providing TFR recommendations for Brazilian physicians are therefore necessary. These recommendations include the main criteria checklist to start the TKIs treatment discontinuing process in patients diagnosed with CML and the population-eligible characteristics for treatment discontinuation.

Method

Age, risk score at diagnosis, TKI treatment duration, BCR::ABL1 transcripts type, depth of the molecular response for treatment discontinuation, treatment adherence, patient monitoring and withdrawal syndrome are essential factors to consider in TFR. After TKI discontinuation, BCR::ABL1 transcripts monitoring should be more frequent. When a major molecular response loss is observed during the monitoring of a patient in TFR, the TKI treatment should be resumed.

Conclusion

These recommendations should serve as a basis for medical professionals interested in proposing TKI discontinuation for CML patients in clinical practice. It is important to highlight that, despite the benefits of TFR for the patients and the health system, it should only be feasible following the minimum standards proposed in this recommendation.

Challenges in Chronic Myeloid Leukemia Management in South America

PURPOSE OF REVIEW

Chronic myeloid leukemia (CML) management in developing countries has improved in the last years, but the availability of therapeutic resources, monitoring, reimbursement, and financial issues may be a challenge and interfere with the best practices and results of CML treatment. This review points out the main challenges in CML management in South America.

RECENT FINDINGS

In this review, we describe the access to tyrosine kinase inhibitors and monitoring in different countries of South America. We also address the ongoing discontinuation trials, the progress, and limitations of hematopoietic stem cell transplantation in the last years. There are still many challenges for achieving the best outcomes for CML patients in South America. The continuous efforts to provide continuous education, access to tyrosine kinase inhibitors, and monitoring, providing reference centers for CML management and hematopoietic stem cell transplantation may improve patients' outcomes.