Excellent outcomes of 2G-TKI therapy after imatinib failure in chronic phase CML patients

Final report of TKI discontinuation trial with dasatinib for the second attempt of treatment-free remission after failing the first attempt with imatinib: Treatment-free Remission Accomplished by Dasatinib (TRAD) study

Multiple studies have reported a significant treatment-free remission (TFR) rate of 50%-60% in patients with chronic myeloid leukaemia (CML) who discontinue tyrosine kinase inhibitor (TKI) therapy. However, the remaining half of these patients still require re-initiation of TKI therapy for leukaemia control. It remains unclear if TKI drugs should be switched for re-therapy in patients who failed the first TFR (TFR1) attempt. Our study attempted to determine whether dasatinib therapy after TFR1 failure post-imatinib discontinuation could improve the likelihood of TFR2. Of 59 patients who lost molecular response after imatinib discontinuation for TFR1, 55 patients (93.2%) were treated with dasatinib, of whom 49 (89.1%) regained MR4.5 or deeper response, with a median time of 1.85 months to achieve MR4.5. Dasatinib was discontinued in 35 patients for TFR2 attempt, of whom 26 patients (74.28%) lost MMR and 6 (17.14%) MR4. Risk factor analysis for the TFR2 after dasatinib discontinuation suggested three significant factors: (1) doubling time of BCR::ABL1 transcript following TFR1 attempt, (2) rapid regaining of molecular response following dasatinib therapy and (3) undetectable BCR::ABL1 transcript prior to TFR2 attempt. The present study showed that dasatinib does not increase the TFR2 rate in general, but a selected group of patients could benefit from this approach.

Determinants of frontline tyrosine kinase inhibitor choice for patients with chronic-phase chronic myeloid leukemia: A study from the Registro Italiano LMC and Campus CML

BACKGROUND

Imatinib, dasatinib, and nilotinib are tyrosine kinase inhibitors (TKIs) approved in Italy for frontline treatment of chronic-phase chronic myeloid leukemia (CP-CML). The choice of TKI is based on a combined evaluation of the patient's and the disease characteristics. The aim of this study was to analyze the use of frontline TKI therapy in an unselected cohort of Italian patients with CP-CML to correlate the choice with the patient's features.

METHODS

A total of 1967 patients with CP-CML diagnosed between 2012 and 2019 at 36 centers throughout Italy were retrospectively evaluated; 1089 patients (55.4%) received imatinib and 878 patients (44.6%) received a second-generation (2G) TKI.

RESULTS

Second-generation TKIs were chosen for most patients aged <45 years (69.2%), whereas imatinib was used in 76.7% of patients aged >65 years (p < .001). There was a predominant use of imatinib in intermediate/high European long-term survival risk patients (60.0%/66.0% vs. 49.7% in low-risk patients) and a limited use of 2G-TKIs in patients with comorbidities such as hypertension, diabetes, chronic obstructive pulmonary disease, previous neoplasms, ischemic heart disease, or stroke and in those with >3 concomitant drugs. We observed a greater use of imatinib (61.1%) in patients diagnosed in 2018-2019 compared to 2012-2017 (53.2%; p = .002). In multivariable analysis, factors correlated with imatinib use were age > 65 years, spleen size, the presence of comorbidities, and ≥3 concomitant medications.

CONCLUSIONS

This observational study of almost 2000 cases of CML shows that imatinib is the frontline drug of choice in 55% of Italian patients with CP-CML, with 2G-TKIs prevalently used in younger patients and in those with no concomitant clinical conditions. Introduction of the generic formulation in 2018 seems to have fostered imatinib use.

Prognosis in Chronic Myeloid Leukemia: Baseline Factors, Dynamic Risk Assessment and Novel Insights

The introduction of tyrosine kinase inhibitors (TKIs) has changed the treatment paradigm of chronic myeloid leukemia (CML), leading to a dramatic improvement of the outcome of CML patients, who now have a nearly normal life expectancy and, in some selected cases, the possibility of aiming for the more ambitious goal of treatment-free remission (TFR). However, the minority of patients who fail treatment and progress from chronic phase (CP) to accelerated phase (AP) and blast phase (BP) still have a relatively poor prognosis. The identification of predictive elements enabling a prompt recognition of patients at higher risk of progression still remains among the priorities in the field of CML management. Currently, the baseline risk is assessed using simple clinical and hematologic parameters, other than evaluating the presence of additional chromosomal abnormalities (ACAs), especially those at "high-risk". Beyond the onset, a re-evaluation of the risk status is mandatory, monitoring the response to TKI treatment. Moreover, novel critical insights are emerging into the role of genomic factors, present at diagnosis or evolving on therapy. This review presents the current knowledge regarding prognostic factors in CML and their potential role for an improved risk classification and a subsequent enhancement of therapeutic decisions and disease management.

Turkey real-life data: demographic features, treatment results and effects of comorbidities in chronic myeloid leukemia

Aim:

This study aimed to identify patient characteristics, treatment patterns and outcomes and to evaluate the effects of presence of comorbidities at diagnosis in chronic phase (CP)-chronic myeloid leukemia (CML) patients in Turkey.

Materials & methods:

Hospital records between 2005 and 2018 were retrospectively reviewed.

Results:

Of 861 CP-CML patients included, 31% had at least one comorbidity at diagnosis. Sex, cardiovascular disease status at diagnosis and molecular (at least major) and cytogenetic (partial and complete) responses were the independent predictors of survival.

Conclusion:

The response rates of CP-CML patients to the tyrosine kinase inhibitors were satisfactory. In addition to tolerability and side effect profiles of drugs, comorbidity status of patients should also be considered in treatment choice in CML patients.

This study aimed to identify patient characteristics, treatment patterns and outcomes and to evaluate the effects of presence of comorbidities at diagnosis in chronic phase (CP)-chronic myeloid leukemia (CML) patients in Turkey. Hospital records of patients between 2005 and 2018 were retrospectively reviewed. Of the included 861 CP-CML patients, 31% had at least one comorbidity at diagnosis. The survival of the patients was affected by sex, cardiovascular disease status at diagnosis, and molecular (at least major) and cytogenetic (partial and complete) responses. The response rates of CP-CML patients to the tyrosine kinase inhibitors were satisfactory. In addition to tolerability and side effect profiles of drugs, comorbidity status of patients should also be considered in treatment choice in CML patients.

Economic Model to Evaluate the Cost-Effectiveness of Second-Line Nilotinib Versus Dasatinib for the Treatment of Philadelphia Chromosome-Positive Chronic Myeloid Leukemia (CML-CP) in Italy

OBJECTIVE

The aim of this study was to evaluate the cost effectiveness of second-line nilotinib versus dasatinib for the treatment of Philadelphia chromosome-positive chronic myeloid leukemia (CML-CP) patients who are intolerant or resistant to imatinib and can transition to treatment-free remission (TFR).

METHODS

A partitioned survival model was developed to compare the cost effectiveness of nilotinib versus dasatinib. The model was developed from the Italian healthcare payer perspective and included the following health states: on second-line tyrosine kinase inhibitor (TKI), off second-line TKI, accelerated phase/blastic crisis, TFR, and death. Progression-free and overall survival curves were derived from patient-level data that compared nilotinib and dasatinib as second-line therapy in CML-CP patients who were resistant or intolerant to imatinib. Drug costs, healthcare costs, and adverse event costs were based on real-world evidence and publicly available databases. Cost effectiveness was estimated over a 40-year time horizon. Scenario analyses were performed by adjusting time horizon, TFR parameters, costs, and utilities.

RESULTS

Second-line nilotinib resulted in greater time spent in TFR (0.91 life-years), increased quality-adjusted life-years (QALYs) (1.89), increased life-years (2.16), and decreased per-patient costs (- 38,760 €). Therefore, nilotinib was strongly dominant compared with dasatinib in the base-case analysis. Nilotinib remained strongly dominant in most scenario analyses including shorter time horizon, exclusion of TFR, and varying TKI drug costs.

CONCLUSIONS

While the model showed that nilotinib treatment of imatinib-intolerant or resistant CML-CP patients was more effective and less costly than dasatinib treatment, there is considerable uncertainty in the findings.

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.

Dasatinib treatment long-term results among imatinib-resistant/intolerant patients with chronic phase chronic myeloid leukemia are favorable in daily clinical practice

To evaluate long-term real-life results of dasatinib therapy among chronic phase chronic myeloid leukemia patients resistant or intolerant to imatinib, we retrospectively analyzed data of 118 patients treated in centers participating in the database INFINITY. With median follow-up of 37 months, estimated 5-year cumulative incidences of complete cytogenetic and major molecular responses were 78% and 68%, respectively. The estimated 5-year probability of overall survival (OS) and event-free survival (EFS) were 86% and 83%, respectively. Both OS and EFS were significantly improved among patients with BCR-ABL1 transcript level ≤10% at 3 months. Dasatinib toxicity was tolerable however persistent in almost half our patients, even after years of therapy. Pleural effusion occurred in 29% of patients and was responsible for 30% of dasatinib discontinuations. Our results confirmed very good efficacy and acceptable toxicity of dasatinib in second line setting and support the evidence and importance of high-quality real-life CML patient management.

Tyrosine Kinase Inhibitor Sequencing in Patients with Chronic Myeloid Leukemia

The management of chronic myeloid leukemia (CML) has been revolutionized by the discovery of tyrosine kinase inhibitors (TKIs) against BCR-ABL1 oncogenic fusion protein. Imatinib, the first BCR-ABL1 TKI, was introduced into clinical practice in the early 2000s. In the following years, the so-called second-generation TKIs (2GTKIs)—dasatinib, nilotinib, and bosutinib were approved, initially for patients resistant to imatinib, and subsequently for front-line treatment. With multiple TKIs available, selection of first-line therapy is challenging. CML risk, patient characteristics and potential toxicities of different TKIs play a fundamental role, in particular when deciding between imatinib and 2GTKIs as frontline treatment. So, when deciding front-line therapy for a patient with CML in the chronic phase (CML-CP), clinicians must consider both the long-term outcomes, such as overall survival and progression-free survival, as well as safety, tolerance and possible treatment discontinuation. This paper offers a practical algorithmic approach for the sequential use of commercially available TKIs in patients with CML-CP along with the data available in the literature.

Tyrosine Kinase Inhibitors Available for Chronic Myeloid Leukemia: Efficacy and Safety

Chronic myeloid leukemia (CML) is currently a disease in which patients can enjoy a near normal life-expectancy. However, since the majority of patients will need to remain on treatment indefinitely, physicians in care of CML patients need be familiar with the indications and toxicities of all approved tyrosine kinase inhibitors (TKI). In clinical practice, there are five TKI (imatinib, nilotinib, dasatinib, bosutinib, and ponatinib) that are available in different scenarios and have distinct safety profiles. Decisions regarding first line treatment must be based on CML risk, comorbidities, and patients expectations. Despite the excellent outcome, half of the patients will eventually fail (due to intolerance or resistance) to first line treatment, with many of them requiring a third or even further lines of therapy. When selecting for such patients, it is essential to distinguish between failure and intolerance to previous TKIs. In the present review, we will address all these issues from a practical point of view.