Future Management Of Chronic Myeloid Leukemia: From Dose Optimization To New Agents

BACKGROUND

The outcome of chronic myeloid leukemia (CML) patients in chronic phase has changed after the introduction of tyrosine kinase inhibitors (TKIs). The life expectancy is actually similar to that of the general population. Although outstanding results achieved, about 20-30% of patients failed to achieve molecular milestones or experience a severe toxicity and need to switch to a second line.

OBJECTIVE

The aim of this review is to report about possible future management in CML, from dose optimization to avoid long-term off-target events to new agents for the treatment of resistant and/or intolerant patients.

METHODS

Broad research on Medline, Embase and archives from EHA and ASH congresses, was performed.

RESULTS

New TKIs have been developed to counteract resistance and/or intolerance, in the setting of T315I mutated patients. The benefits of ponatinib dose optimization have been recently reported in the OPTIC trial. New trials to test the dose optimization are ongoing.

CONCLUSION

Reduction of the standard dose could be performed to reduce the specific TKI toxicity. Selective TKIs could be prescribed in the future as third line treatment.

Myelodysplastic Syndromes with Isolated 20q Deletion: A New Clinical-Biological Entity?

Aims: To define the peculiar features of patients with the deletion of the chromosome 20 long arm (del20q), data from 69 patients with myelodysplastic syndromes (MDSs) and isolated del20q, followed by the Gruppo Romano-Laziale Sindromi Mielodisplastiche (GROM-L) and Ospedale Torrette of Ancona, were collected and compared with those of 502 MDS patients with normal karyotype (NK-MDS). Results: Compared to the NK-MDS group, patients with del20q at diagnosis were older (p = 0.020) and mainly male (p = 0.006). They also had a higher rate of bone marrow blast < 5% (p = 0.004), a higher proportion of low and int-1 risk according to IPSS score (p = 0.023), and lower median platelet (PLT) count (p < 0.001). To date, in the del20q cohort, 21 patients (30.4%) received no treatment, 42 (61.0%) were treated with erythropoiesis-stimulating agents (ESA), 3 (4.3%) with hypomethylating agents, and 3 (4.3%) with other treatments. Among 34 patients evaluable for response to ESA, 21 (61.7%) achieved stable erythroid response according to IWG 2006 criteria and 13 (38.2%) were resistant. Nine patients (13.0%) progressed to acute myeloid leukaemia (AML) after a median time from diagnosis of 28 months (IR 4.1−51.7). The median overall survival (OS) of the entire cohort was 60.6 months (95% CI 54.7−66.4). the 5-year cumulative OS was 55.9% (95% CI 40.6−71.2). Conclusion: According to our results, we hypothesize that MDSs with isolated del 20q may represent a distinct biological entity, with peculiar clinical and prognostic features. The physio-pathological mechanisms underlying the deletion of the chromosome 20 long arm are still unclear and warrant future molecular analysis.

Emerging concepts for assessing and predicting treatment-free remission in chronic myeloid leukemia patients

INTRODUCTION

In chronic myeloid leukemia (CML) patients who have reached a deep and sustained reduction of residual disease can attempt a discontinuation. The 'treatment-free remission' (TFR) has become a real long-term endpoint for 30-40% of chronic phase patients.

AREAS COVERED

In this review, we focus our attention on possible prognostic features who can predict the success of tyrosine kinase inhibitors discontinuation and how we can assess the minimal residual disease (MRD) during the TFR phase. Broad research was made on Medline, Embase and archives from EHA and ASH congresses.

EXPERT OPINION

Median duration of TKI therapy and of deep molecular response are the main prognostic factors identified in most trials and real-life experiences on discontinuation. Immunological pathways have been proposed as possible control on successful TFR as also early molecular response dynamics. Appropriate molecular monitoring by RQ-PCR in the TFR phase has been proposed by several international recommendations and digital droplet PCR (ddPCR) seems to have a possible role in the future for a better identification of candidate to this possible therapeutic strategy.

Acute promyelocytic leukemia (APL) in very old patients: real-life behind protocols

BACKGROUND

Acute promyelocytic leukemia (APL) is uncommon among subjects aged ≥ 70 years and the better therapeutic strategy represents an unmet clinical need.

MATERIALS AND METHODS

This prompted us to explore our real-life data on a retrospective cohort of 45 older APL patients (≥ 70 years) consecutively diagnosed at eight different hematologic institutions in Latium, Italy, from July 1991 to May 2019.

RESULTS

Two patients (4.4%) died from early hemorrhagic complications before treatment could begin. Twenty-two patients (51.1%) (Group A) were enrolled or treated according to standard clinical protocols, while 21 (48.8%) (Group B) received an ATRA-based personalized approach due to poor performance status. Morphologic complete remission (CR) after induction therapy was achieved in 33 patients (76.7%) with 100% of patients in Group A and 52.3% in Group B (p < 0.001). Molecular CR was documented in 30 patients (69.7%) [20/22 (90.9%) in Group A and 10/21 (47.6%) in Group B (p = 0.002)]. Ten patients (23.2%) died during induction therapy, all in Group B. Five-year overall survival (OS) of the entire cohort was 46.1% (95% CI 28.2-64.0), with 72.6% (95% CI 42.9-100) in Group A vs. 27.2% (95% CI 7.5-46.9) in the Group B (p = 0.001).

CONCLUSIONS

The present analysis highlights that almost half of the patients received sub-optimal induction treatments and registered dismal outcomes demonstrating the importance of adopting standard therapies instead of modified or reduced personalized approaches also in the setting of frail older patients.

Asciminib: an investigational agent for the treatment of chronic myeloid leukemia

Introduction: Tyrosine kinase inhibitors (TKIs) have drastically changed the outcome of chronic myeloid leukemia (CML) patients. However, a subset of patients experienced resistance and/or intolerance and need to switch to other agents. Resistance to second-generation TKIs used in first-line treatment is less of an issue when compared to imatinib in first line. New drugs that are able to improve efficacy, without long-term off-target effects are needed. Allosteric inhibitors such as asciminib (ABL001) were created to overcome resistance and off-target toxicity.Areas covered: In this review, we report the mechanism of action, pharmacokinetic data, and the clinical trial results of asciminib tested in chronic phase CML patients.Expert Opinion: Asciminib, the first example of allosteric inhibition, could be a promising approach as third-line therapy and in the subset of patients with T315I mutation that, for coexistent comorbidities, cannot receive other drugs. Future results will probably help to move the drug to earlier lines of treatment.

Measuring prognosis in chronic myeloid leukemia: what's new?

Introduction: The outcome of chronic myeloid leukemia (CML) patients in chronic phase has changed after the introduction of tyrosine kinase inhibitors (TKIs). The life expectancy is actually similar to that of the general population. Prognostic stratification at baseline is part of a patient-centered approach to decide the best therapeutic approach.Areas covered: In this review, the current prognostic factors examined at baseline are detailed and the meaning is explained. A broad research on Medline, Embase and archives from EHA and ASH congresses, was performed. Prognostic factors have been divided into patient-related (age, gender, comorbidities, etc.) and disease-related (additional cytogenetic abnormalities, type of transcript, etc). New information about genomic data and the potential role of patient-reported outcomes is also discussed.Expert Opinion: Prognostic factors at baseline should be considered to evaluate the long-term probability of disease-related death, the possible toxicity, and the projected long-term overall survival. The genomic assessment would provide the basis for a genomic-based risk and help in oriented decision-making process.

Clinical and Prognostic Features of Essential Thrombocythemia: Comparison of 2001 WHO Versus 2008/2016 WHO Criteria in a Large Single-center Cohort

BACKGROUND

According to 2008/2016 classification of the World Health Organization (WHO), a platelet (PLT) count ≥ 450 × 10⁹/L, reduced from the previously published WHO 2001 indicated level ≥ 600 × 10⁹/L, was considered the new PLT threshold for the diagnosis of essential thrombocythemia (ET).

PATIENTS AND METHODS

To validate this important diagnostic change in a setting of current clinical practice, we retrospectively analyzed clinical and hematologic features at diagnosis and during follow-up of 162 patients with ET, diagnosed in our center from January 2008 to December 2017. We subdivided patients according to PLT value at baseline into Group A (PLT ≥ 600 × 10⁹/L) (124 patients; 76.5%) and Group B (PLT ≥ 450 × 10⁹/L < 600 × 10⁹/L) (38 patients; 23.5%).

RESULTS

Among clinical features, only the median value of leukocytes (P < .001) was significantly higher in Group A. Cytostatic treatment was administered in 103 patients, with a significantly higher rate in patients of group A (P < .001). After a median follow-up of 42.4 months (interquartile range, 22.1-70.6 months), 8 thrombotic events were recorded in the entire cohort, without differences between the 2 groups (P = .336). The 5-year overall survival (OS) of the entire cohort was 96.9% (95% confidence interval, 92.6%-100%), without differences between the 2 groups (P = .255).

CONCLUSIONS

Our data indicate a substantial homogeneity among patients with ET regardless of the PLT count at diagnosis, thus confirming the usefulness of the 2008/2016 WHO diagnostic criteria.

Long-term follow-up of late chronic phase chronic myeloid leukemia patients treated with imatinib after interferon failure: a single center experience

We report the long-term outcome of 139 patients treated with imatinib in late chronic phase after IFN failure. Median follow-up was 16.6 years and the estimated 18-year OS was 64.8%. 18-year EFS and PFS were 69% and 64.4%, respectively. Fifty (36%) patients stopped imatinib, 72% received a second line. b2a2 transcript was associated with a significantly inferior 18-year OS (p = 0.008), FFS (p = 0.036), PFS (p = 0.013) compared to the b3a2 type, whilst the type of transcript did not influence the time to response achievement. Failure to achieve MMR at 12 months significantly reduced the chance of reaching a DMR (p = 0.001). Imatinib discontinuation after achieving a sustained deep molecular response was attempted in 14 patients; 12 (86%) are still in treatment-free remission (TFR) at the last follow-up. Our experience confirms the long-term efficacy of imatinib after IFNα failure in real-life setting and documents the possibility of attempting a TFR in this subset of patients.

Optimizing health-related quality of life in patients with chronic myeloid leukemia treated with tyrosine kinase inhibitors

Introduction: The current treatment landscape of chronic myeloid leukemia (CML) is challenging for several reasons, and health-related quality of life (HRQOL) data may be of critical importance to help physicians and patients make more informed decisions.Areas covered: A systematic literature search was performed in PubMed to identify the most recent studies (between April 2016 and June 2020) assessing the impact of tyrosine kinase inhibitors (TKIs) on adult CML patients' HRQOL. Studies assessing treatment discontinuation were also considered. For each study, we evaluated characteristics of CML patients included, treatment information and basic HRQOL data, including questionnaires used, and summary findings.Expert opinion: Valuable information can be gleaned from recent CML studies including a HRQOL assessment; however, major gaps remain in our knowledge. These include, for example, a better understanding of the impact of second- and third-generation TKIs on patients' HRQOL compared to imatinib therapy. Also, the benefits of TKI treatment discontinuation, in terms of symptom burden and HRQOL, are yet to be fully elucidated. More research efforts are needed in this area to generate high-quality evidence that can facilitate decision-making.

Real-life comparison of nilotinib versus dasatinib as second-line therapy in chronic phase chronic myeloid leukemia patients

Tyrosine kinase inhibitors (TKIs), the backbone of treatment for chronic phase chronic myeloid leukemia patients (CP-CML), have changed the long-term outcome of the disease. Nonetheless, over 20% of patients fail front-line therapy due to intolerance or resistance. A head-to-head comparison of dasatinib and nilotinib as second-line treatment outside of sponsored clinical trials has not been reported. We retrospectively analyzed 131 CP-CML patients who, after front-line imatinib failure, switched to a second-line therapy with nilotinib (59, 45%) or dasatinib (72, 55%). Median duration of second-line treatment was 33 months (range 2-100). The reason for switching therapy was resistance in 83.2% and intolerance in 16.8% of patients. The overall survival of the entire cohort at 7 years was 78.9%, while it was 72% and 85.6% for patients treated with dasatinib and nilotinib, respectively (p=0.287). With regard to efficacy after 12 months of treatment, 108 patients were evaluable for molecular response: 47% achieved a major molecular response and 18.2% a deep molecular response with dasatinib, compared to 38% and 16.2% with nilotinib (p=ns). We observed 35% of grade 3-4 adverse events, more frequently in the dasatinib group (47%) compared to the nilotinib group (22%), without affecting molecular responses. Our study suggests that, in the real-life setting, dasatinib and nilotinib used as second-line treatment in CP-CML are equally effective, with high molecular response rates and an acceptable tolerability.

Low-density lipoprotein (LDL) levels and risk of arterial occlusive events in chronic myeloid leukemia patients treated with nilotinib

Recommendations for dyslipidemia management aimed at reducing arterial occlusive events (AOEs) have been recently published. So far, no data have been reported on the management of dyslipidemia in chronic myeloid leukemia (CML) patients treated with nilotinib. We investigated 369 CML adult patients, stratified according to the new Systematic Coronary Risk Evaluation (SCORE) scoring system. Plasma levels of cholesterol, HDL, LDL, and triglycerides were measured prior to the start of nilotinib and after 3, 6, and 12 months. The 5-year cumulative incidence of AOEs was 15.9%. Patients with cholesterol levels > 200 mg/dL and LDL > 70 mg/dL 3 months after treatment showed a significantly higher incidence of AOEs (21.9 ± 4.6% vs 6.2 ± 2.5, P = 0.003). Patients belonging to the high and very high SCORE risk group showed a significant increase of AOEs (34.4 ± 6% vs 10 ± 2.1%, P < 0.001). In multivariate analysis, both high cholesterol and LDL levels and a high and very high SCORE risk remained significantly associated with the risk of AOEs (P = 0.008; HR = 3.5; 95% CI = 1.4-8.7 and P < 0.001; HR = 4.4; 95% CI = 2-9.8, respectively). Overall, 78 patients (21.1%) presented dyslipidemia at the time of CML diagnosis and 88 (23.3%) after starting nilotinib, but only 26 of them (29.5%) were treated with statins.Low LDL and cholesterol plasma levels are associated with a significant lower risk of AOEs in CML patients treated with nilotinib in the real life.

Erythropoietin treatment in chronic phase chronic myeloid leukemia patients treated with frontline imatinib who developed late anemia

BACKGROUND

Role of erythropoietin (EPO) in the treatment of late anemia in patients with Chronic Myeloid Leukemia (CML) is still undefined.

METHODS

Fifty CML patients treated at 14 institutions with frontline imatinib for at least 12 months and in stable complete cytogenetic response who developed a late chronic anemia treated with EPO were retrospectively evaluated.

RESULTS

Median time from imatinib start to EPO treatment was 42.2 months [interquartile range (IQR) 20.8-91.9]. Median Hb value at EPO starting time was 9.9 g/dL (IQR 8.9-10.3): Eleven patients (22.0%) were transfusion dependent. Alpha-EPO (40 000 UI weekly) was employed in 37 patients, beta-EPO (30 000 UI weekly) in 9 patients, zeta-EPO (40 000 UI weekly) in 2 patients, and darbepoetin (150 mcg/weekly) in the remaining 2 patients. On the whole, 41 patients (82.0%) achieved an erythroid response, defined as a stable (>3 months) improvement >1.5 g/dL of Hb level, and 9 patients (18.0%) indeed resulted resistant. Among responding patients, 10 relapsed after a median time from EPO start of 20.7 months (IQR 10.8-63.7). No EPO-related toxicity was observed.

CONCLUSIONS

Results of EPO treatment for late chronic anemia during long-lasting imatinib therapy are encouraging, with a high rate of response.

Balanced and unbalanced chromosomal translocations in myelodysplastic syndromes: clinical and prognostic significance

Prognostic role of chromosomal translocations (CT) in myelodysplasia (MDS) was retrospectively analyzed in 77 patients from GROM-L registry. Forty (51.9%) balanced, 28 (36.4%) unbalanced and 9 (11.7%) concomitant balanced and unbalanced CT were identified. Five-year overall survival (OS) of the entire cohort was 34.5% (CI 95% 22.5-46.5). Five-year OS of patients with unbalanced CT was significantly shorter than that of patients carrying balanced CT [22.3% (CI 95% 4.0-40.6) vs 44.0% (CI 95% 26.7-61.3) (p = 0.042)]. Five-year OS of patients with CT included in complex karyotype (CK) was significantly shorter than that of patients with isolated CT or CT with another abnormality [5.5% (CI 95% 0-15.7) vs 42.9% (CI 95% 21.3-64.5) and vs 4% (CI 95% 31.6-79.2) (p < 0.001)]. Presence of CT in MDS characterizes a more aggressive outcome only when associated with CK.

Predictive factors for response and survival in elderly acute myeloid leukemia patients treated with hypomethylating agents: a real-life experience

Predictive factors of response to hypomethylating agents (HMA) in elderly acute myeloid leukemia (AML) patients remain unclear in the real-life setting and no direct comparison between azacitidine (AZA) and decitabine (DEC) has been carried out. We retrospectively evaluated 110 AML patients treated with HMA (78 AZA, 32 DEC) as first-line therapy outside of clinical trials. Median age was 75 years (range 58-87). The median overall survival (OS) of the entire cohort was 8.0 months (95% CI 6.1-10), without significant differences among the subgroups: AZA 8.8 months vs DEC 6.3 months (p = 0.291). HMA treatment yielded an overall response rate (ORR) of 40% (AZA 37% vs DEC 47%, p = 0.237). A stable disease (SD) after 4 HMA cycles was not associated with a worse survival outcome compared with an early optimal response. Factors independently associated with a better OS were transfusion independence during treatment (p = 0.049), achievement of an optimal response to treatment (p < 0.001), and a baseline hemoglobin level ≥ 9.25 (p = 0.018). A bone marrow (BM) blast count ≥ 30% (p < 0.001) and a therapy-related AML (p = 0.008) remain poor survival predictors. Of the available biologic features, an adverse risk category according to the ELN classification was significantly associated with a shorter survival over the intermediate risk category (p = 0.034). Disease progression remains the primary cause of death. Infectious complications were more severe (p = 0.036) and occurred earlier (p = 0.006) in the DEC group compared with that of the AZA group. In conclusion, clinical prognostic factors associated to response and survival have been identified without significant associations concerning overall outcomes between the two HMAs.

Early intracranial haemorrhages in acute promyelocytic leukaemia: analysis of neuroradiological and clinico-biological parameters

Acute promyelocytic leukaemia (APL) represents a modern success of precision medicine. However, fatalities occurring within the first 30 days of induction treatment, in particular intracranial haemorrhage (ICH), remain the main causes of death. We studied the clinico-biological characteristics of 13 patients with APL who experienced ICH. Compared to 85 patients without this complication, patients with ICH were older and more frequently had high-risk APL. Moreover, positivity for the 'swirl' sign at neuroradiological imaging and hydrocephalus were predictors of a fatal outcome, together with lower fibrinogen, prolonged international normalized ratio (INR) and higher lactate dehydrogenase levels.