Low-dose dasatinib 50 mg/day versus standard-dose dasatinib 100 mg/day as frontline therapy in chronic myeloid leukemia in chronic phase: A propensity score analysis

Senolytic combination of dasatinib and quercetin attenuates renal damage in diabetic kidney disease

BACKGROUND

Senolytic combination of dasatinib and quercetin (DQ) is the most studied senolytics drugs used to treat various age-related diseases. However, its protective activity against diabetic kidney disease (DKD) and underlying mechanisms are uncertain.

PURPOSE

To investigate the functions and potential mechanisms of the senolytics DQ on DKD.

METHODS

Diabetic db/db mice were administrated DQ or transfected with over-expressed PPARα or shPPARα vector. The positive control group was administered irbesartan. Renal function and fibrotic changes in kidney tissue were tested. Single-cell RNA-seq (scRNA-seq) was conducted to analyze the differential transcriptome between the diabetic and control mice. Molecular docking simulation was used to assess the combination of DQ and potential factors. Moreover, tubular epithelial cells under high-glucose (HG) conditions were incubated with DQ and transfected with or without over-expressed PPARα/siPPARα vector.

RESULTS

DQ significantly improved renal function, histopathological and fibrotic changes, alleviated lipid deposition, and increased ATP levels in mice with DKD. DQ reduced multiple fatty acid oxidation (FAO) pathway-related proteins and up-regulated PPARα in db/db mice. Overexpression of PPARα upregulated the expression of PPARα-targeting downstream FAO pathway-related proteins, restored renal function, and inhibited renal fibrosis in vitro and in vivo. Moreover, molecular docking and dynamics simulation analyses indicated the nephroprotective effect of DQ via binding to PPARα. Knockdown of PPARα reversed the effect of DQ on the FAO pathway and impaired the protective effect of DQ during DKD.

CONCLUSION

For the first time, DQ was found to exert a renal protective effect by binding to PPARα and attenuating renal damage through the promotion of FAO in DKD.

Successful maintenance of a sustained molecular response in CML patients receiving low-dose tyrosine kinase inhibitors

Background

The development of tyrosine kinase inhibitor (TKI) therapy has positively impacted the survival rates of patients with chronic myeloid leukemia (CML). It is common in medical practice to adjust the dosage of TKI downward because of TKI-associated adverse events, financial burden, comorbidity, or an attempt at treatment-free remission.

Objectives

This investigation sought to explore the feasibility of employing a reduced dosage of TKI for treating CML.

Design

This was a retrospective study.

Methods

Patients with CML in its chronic phase who had been on a reduced dose of TKI for a minimum of 3 months for various reasons in a practical clinical environment, irrespective of molecular response, were included. Regular molecular monitoring was performed, and changes in adverse events were recorded after dose reduction.

Results

This research included a total of 144 participants. Upon reducing the dosage, 136 of 144 patients achieved major molecular response or deeper, and 132 of 144 achieved molecular response 4 (MR4). Following a median observation period of 16 months, the calculated 1- and 2-year survival rates free from MR4 failure were estimated to be 96.5% (95% CI: 90.8-98.7) and 90.5% (95% CI: 81.3-95.3), respectively. MR4 failure-free survival was better in patients with longer MR4 durations (⩾34 months) before dose reduction (p = 0.02). The median interval from dose reduction to MR4 loss was 15 months. Improved TKI-associated adverse events after dose reduction were observed in 61.3% of patients.

Conclusion

Lowering the TKI dose can effectively preserve a deep molecular response over time while relieving adverse events caused by TKIs.

Incidence of pleural effusion with dasatinib and the effect of switching therapy to a different TKI in patients with chronic phase CML

Dasatinib is one of the second generation tyrosine kinase inhibitors (TKI) which is approved for the treatment of patients with chronic phase CML (CP-CML) both in the front line and in the second line setting. Pleural effusion (PE) is a unique toxicity associated with dasatinib use. Our aim was to study the incidence of pleural effusion in our cohort of patients who were treated with dasatinib for CP-CML and the safety upon TKI switch. A total of 390 patients were treated with dasatinib during their course of treatment for CP-CML. A total of 69 patients (17.6%) developed any grade of PE. About 33 (48%) patients developed CTCAE grade 2 PE, 34 (49%) grade 3 and only 1 patient developed grade 4 PE. Recurrence of PE was observed in 34 (49%) patients. While only 12 patients (17.3%) continued using dasatinib after development of PE, dasatinib was discontinued in the other 57 patients. Therapy was switched to bosutinib in 13 patients out of which 6 (46%) patients re-developed PE. While only 12.5% patients developed re-accumulation of pleural fluid in patients switched to imatinib, none of the patients switched to nilotinib re-developed PE. A change in TKI to bosutinib was associated with a 46% risk of recurrence of PE in patients who develop PE on dasatinib for the treatment of CP-CML. The incidence of recurrent PE was markedly lower in patient switched to imatinib or nilotinib.

Chronic myeloid leukaemia: Biology and therapy

Chronic myeloid leukaemia (CML) is caused by BCR::ABL1. Tyrosine kinase-inhibitors (TKIs) are the initial therapy. Several organizations have reported milestones to evaluate response to initial TKI-therapy and suggest when a change of TKI should be considered. Achieving treatment-free remission (TFR) is increasingly recognized as the optimal therapy goal. Which TKI is the best initial therapy for which persons and what depth and duration of molecular remission is needed to achieve TFR are controversial. In this review we discuss these issues and suggest future research directions.

Challenges in management of older patients with chronic myeloid leukemia

Tyrosine kinase inhibitors (TKIs) have significantly improved the survival of patients with chronic myeloid leukemia (CML), however, older patients are often underrepresented in pivotal trials. Approximately 20% of older adults never start treatment and face significant barriers to accomplish favorable outcomes. The treatment goal is to improve survival, prevent progression, and preserve quality of life. This is achieved through optimizing TKI doses and employing discontinuation strategies to attain treatment-free remission (TFR), a goal increasingly pursued by older patients. Imatinib may be favored as the front-line option for older individuals due to its side effect profile and cost. Bosutinib's favorable cardiovascular tolerability makes it a suitable second-line agent, but lower-dose dasatinib may likewise be an attractive option. The prevalence of comorbidities can preclude the use of second generation TKIs in some older patients. Optimal care for older patients with CML centers on personalized treatment, close monitoring, and proactive support.

Combination of dasatinib and venetoclax in newly diagnosed chronic phase chronic myeloid leukemia

BACKGROUND

The dual inhibition of the BCR::ABL1 tyrosine kinase and BCL-2 could potentially deepen the response rates of chronic myeloid leukemia in chronic phase (CML-CP). This study evaluated the safety and efficacy of the combination of dasatinib and venetoclax.

METHODS

In this phase 2 trial, patients with CML-CP or accelerated phase (clonal evolution) received dasatinib 50 mg/day for three courses; venetoclax was added in course 4 for 3 years. The initial venetoclax dose was 200 mg/day continuously but reduced later to 200 mg/day for 14 days, and to 100 mg/day for 7 days per course once a molecular response (MR)4.5 was achieved. After 3 years of combination, patients were maintained on single-agent dasatinib. The primary end point was the rate of major molecular response (MMR) by 12 months of combination.

RESULTS

Sixty-five patients were treated. Their median age was 46 years (range, 23-73). By 12 months of combination, the MMR, MR4, and MR4.5 rates were 86%, 53%, and 45%, respectively. After a median follow-up of 42 months, the 4-year event-free and overall survival rates were 96% and 100%, respectively. Outcomes with the combination were comparable to historical outcomes with single-agent dasatinib (cumulative 12-months MMR rate of 79% with both strategies). The incidence of grade 3-4 neutropenia was 22% with the combination and 11% with single-agent dasatinib (p < .001).

CONCLUSIONS

Treatment with dasatinib and venetoclax was safe and effective in CML-CP. The cumulative response rates with the combination were similar to those with single-agent dasatinib. Further follow-up is needed to evaluate the rates of durable deep molecular response and treatment-free remission.

Clinical Insights into Structure, Regulation, and Targeting of ABL Kinases in Human Leukemia

Chronic myeloid leukemia is a multistep, multi-lineage myeloproliferative disease that originates from a translocation event between chromosome 9 and chromosome 22 within the hematopoietic stem cell compartment. The resultant fusion protein BCR::ABL1 is a constitutively active tyrosine kinase that can phosphorylate multiple downstream signaling molecules to promote cellular survival and inhibit apoptosis. Currently, tyrosine kinase inhibitors (TKIs), which impair ABL1 kinase activity by preventing ATP entry, are widely used as a successful therapeutic in CML treatment. However, disease relapses and the emergence of resistant clones have become a critical issue for CML therapeutics. Two main reasons behind the persisting obstacles to treatment are the acquired mutations in the ABL1 kinase domain and the presence of quiescent CML leukemia stem cells (LSCs) in the bone marrow, both of which can confer resistance to TKI therapy. In this article, we systemically review the structural and molecular properties of the critical domains of BCR::ABL1 and how understanding the essential role of BCR::ABL1 kinase activity has provided a solid foundation for the successful development of molecularly targeted therapy in CML. Comparison of responses and resistance to multiple BCR::ABL1 TKIs in clinical studies and current combination treatment strategies are also extensively discussed in this article.

Dose modification dynamics of ponatinib in patients with chronic-phase chronic myeloid leukemia (CP-CML) from the PACE and OPTIC trials

Ponatinib, the only approved all known-BCR::ABL1 inhibitor, is a third-generation tyrosine-kinase inhibitor (TKI) designed to inhibit BCR::ABL1 with or without any single resistance mutation, including T315I, and induced robust and durable responses at 45 mg/day in patients with CP-CML resistant to second-generation TKIs in the PACE trial. However, cardiovascular toxicities, including arterial occlusive events (AOEs), have emerged as treatment-related AEs within this class of TKIs. The OPTIC trial evaluated the efficacy and safety of ponatinib using a novel, response-based, dose-reduction strategy in patients with CP-CML whose disease is resistant to ≥2 TKIs or who harbor T315I. To assess the dose-response relationship and the effect on the safety of ponatinib, we examined the outcomes of patients with CP-CML enrolled in PACE and OPTIC who received 45 mg/day of ponatinib. A propensity score analysis was used to evaluate AOEs across both trials. Survival rates and median time to achieve ≤1% BCR::ABL1IS in OPTIC were similar or better than in PACE. The outcomes of patients with T315I mutations were robust in both trials. Patients in OPTIC had a lower exposure-adjusted incidence of AOEs compared with those in PACE. This analysis demonstrates that response-based dosing for ponatinib improves treatment tolerance and mitigates cardiovascular risk.

Real-World Effectiveness of Dasatinib Versus Imatinib in Newly Diagnosed Patients With Chronic Myeloid Leukemia

INTRODUCTION

Limited data exist comparing dasatinib with imatinib in clinical practice. This study assessed real-world outcomes associated with first-line (1L) dasatinib or imatinib treatment of chronic myeloid leukemia (CML).

PATIENTS AND METHODS

This retrospective, observational, United States multisite cohort study analyzed electronic medical record data from adults with Philadelphia chromosome-positive (Ph+) CML in the chronic phase (CML-CP) after 1L dasatinib or imatinib between January 2014 and September 2018. Rates of and times to major molecular response (MMR) and deep molecular response (DMR) were assessed overall and in subgroups (low vs. intermediate/high risk, aged <65 vs. ≥65 years, low/normal vs. high body mass index [BMI]).

RESULTS

The dasatinib cohort (n = 309) experienced higher rates of MMR (n = 304, 79% vs. 65%, P < .001) and DMR (44% vs. 25%, P < .001) vs. the imatinib cohort with shorter median times to MMR (11.9 vs. 14.7 months, P < .001) and DMR (30.3 vs. 66.1 months, P < .001). Patients with intermediate-/high-risk disease and those aged <65 years had higher MMR and DMR rates and achieved response earlier with dasatinib (P < .01). Patients with low-risk disease treated with dasatinib had higher rates of DMR (60% vs. 32%, P = .01). Across BMI strata, rates of MMR and DMR were higher with dasatinib (P < .05).

CONCLUSIONS

Patients with CML-CP treated with 1L dasatinib achieved higher rates of, with shorter times to, MMR and DMR versus 1L imatinib. These clinically meaningful improvements were observed across subgroups.

Long-term follow-up of efficacy and safety in elderly patients with chronic myeloid leukemia treated with intermittent low dose dasatinib therapy

Intermittent low dose dasatinib therapy brought about a beneficial effect in elderly patients with chronic-phase chronic myeloid leukemia (CML-CP) without inducing severe adverse events (AEs). An 85-year-old male patient, who received twice-weekly, thrice-weekly, or four-times-weekly administration of 20 mg/day dasatinib after once-weekly administration, achieved a major molecular response two years after the start of dasatinib treatment and later sometimes achieved a deep molecular response, maintaining the efficacy for 11 years. The mean daily dose ranged from 5.7 mg to 11.4 mg. Furthermore, a 79-year-old male patient, who received thrice-weekly or every other day administration of 20 mg/day dasatinib after once-weekly administration, achieved a deep molecular response at four and half years after the start of dasatinib treatment. The mean daily dose is 8.6 mg. Intermittent low dose dasatinib therapy appears to be feasible in elderly patients with CML-CP. The goal of treatment in elderly patients with CML-CP appears to be different from that in younger patients, since they often suffer from serious AEs in the case of standard dose tyrosine kinase inhibitor therapy, followed by the dose reduction or cessation of treatment.

Twenty years of evolution of CML therapy: how the treatment goal is moving from disease to patient

The introduction of imatinib in 2000 opened the era of tyrosine kinase inhibitors (TKIs) for CML therapy and has revolutionized the life expectancy of CML patients, which is now quite like the one of the healthy aged population. Over the last 20 years, both the TKI therapy itself and the objectives have undergone evolutions highlighted and discussed in this review. The main objective of the CML therapy in the first 10 years after TKI introduction was to abolish the disease progression from the chronic to the blastic phase and guarantee the long-term survival of the great majority of patients. In the second 10 years (from 2010 to the present), the main objective of CML therapy moved from survival, considered achieved as a goal, to treatment-free remission (TFR). Two phenomena emerged: no more than 50-60% of CML patients could be candidates for discontinuation and over 50% of them molecularly relapse. The increased cumulative incidence of specific TKI off-target side effects was such relevant to compel to discontinue or reduce the TKI administration in a significant proportion of patients and to avoid a specific TKI in particular settings of patients. Therefore, the treatment strategy must be adapted to each category of patients. What about the patients who do not get or fail the TFR? Should they be compelled to continue the TKIs at the maximum tolerated dose? Alternative strategies based on the principle of minimal effective dose have been tested with success and they are now re-evaluated with more attention, since they guarantee survival and probably a better quality of life, too. Moving from treating the disease to treating the patient is an important change of paradigm. We can say that we are entering a personalized CML therapy, which considers the patients' age, their comorbidities, tolerability, and specific objectives. In this scenario, the new techniques supporting the monitoring of the patients, such as the digital PCR, must be considered. In the present review, we present in deep this evolution and comment on the future perspectives of CML therapy.

Adherence to tyrosine kinase inhibitor and clinical outcomes in patients with chronic myeloid leukemia

PURPOSE

To ensure optimal care for patients with chronic myeloid leukemia (CML), adherence to tyrosine kinase inhibitors (TKIs) has emerged as a critical component. The objective of this study was to assess the impact of TKIs adherence on clinical outcomes in a cohort of Chinese CML patients who received treatment with TKIs.

METHODS

This retrospective study employed a cross-sectional design utilizing questionnaires to assess adherence to TKIs in a sample of 398 patients diagnosed with CML. Adherence was measured using the Morisky Medication Adherence Scale (MMAS-8), which dichotomizes patients into low, medium, and high adherence groups.

RESULTS

Of the patients included in this study, 34.2% were classified as highly adherent, with 43.2% and 22.6% of patients categorized as having medium and low adherence, respectively. Compared to the low-adherence group, patients in the medium- and high-adherence groups exhibited significantly higher rates of achieving major molecular response (MMR) and lower rates of switching TKIs. Moreover, patients who failed to adhere to TKIs treatment demonstrated significantly lower event-free survival and failure-free survival compared to those in the high-adherence group. Notably, regular molecular monitoring and utilization of the "CML Academy" mobile application were positively associated with increased TKI adherence. On the other hand, patients receiving third-generation or above first-line TKIs treatment displayed reduced adherence.

CONCLUSION

The findings suggest that high adherence to TKIs treatment confers clinical benefits to patients with CML. Accordingly, the implementation of effective guidance and intervention measures aimed at promoting adherence to TKIs therapy in real-world settings is imperative.

Low-Dose Dasatinib (50 mg Daily) Frontline Therapy in Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia: 5-Year Follow-Up Results

BACKGROUND

Dasatinib is a BCR::ABL1 tyrosine kinase inhibitor approved as frontline therapy at a 100 mg daily for chronic myeloid leukemia in chronic phase (CML-CP). The use of a lower dose of dasatinib (50 mg daily) has demonstrated better tolerance and improved outcomes compared with the standard dose. Here, we report the updated results in a large cohort with a 5-year follow-up.

PATIENTS AND METHODS

Patients with newly diagnosed CML-CP were eligible. Entry and response-outcome criteria were standard. Dasatinib was given as 50 mg orally daily.

RESULTS

Eighty-three patients were included. At 3 months, 78 (96%) patients achieved BCR::ABL1 transcripts (IS) ≤10%, and at 12 months, 65 (81%) patients achieved BCR::ABL1 transcript (IS) ≤0.1%. The cumulative incidence of complete cytogenetic, major molecular, and deep molecular responses at 5 years were 98%, 95%, and 82%, respectively. Rates of failures due to resistance (n = 4; 5%) and toxicity (n = 4; 5%) were low. The 5-year overall survival was 96% and event-free survival 90%. No transformations to accelerated or blastic phase were observed. Grade 3 to 4 pleural effusions developed in 2% of patients.

CONCLUSION

Dasatinib 50 mg daily is an effective and safe treatment for newly diagnosed CML-CP.

Revisiting six established practices in the treatment of chronic myeloid leukaemia

After two decades of use in chronic myeloid leukaemia, the risks and benefits of established treatment practices for BCR::ABL1 tyrosine kinase inhibitors (TKIs) in the chronic myeloid leukaemia in chronic phase of the disease should be analysed. In this Viewpoint, we suggest that the use of lower than approved TKI doses in both front-line and later-line therapies would result in similar treatment efficacy, less toxicity, better treatment compliance, and reduced cost of care. The absence of an early molecular response might not warrant a change of a TKI, particularly for second-generation TKIs. Among patients in whom reaching a treatment-free remission is not a therapeutic goal or treatment-free remission is unlikely, changing TKIs to improve the depth of molecular response might result in more harm than good. Reducing the TKI dose in response to mild to moderate, or even serious, reversible side-effects might be better than changing the TKI. The availability of generic imatinib, generic dasatinib, and possibly later other generic second-generation TKIs would offer 90% of patients with chronic myeloid leukaemia an effective, safe, and affordable therapy that normalises life expectancy, and results in treatment-free remission status in 30-50% of patients over the long term. Finally, based on treatment value, any TKI that costs more than US$30 000-40 000 per year should be critically evaluated in relation to alternative modalities, such allogeneic haematopoietic stem-cell transplantation.

Real-world experience with ponatinib therapy in chronic phase chronic myeloid leukemia: impact of depth of response on survival and prior exposure to nilotinib on arterial occlusive events

We surveyed the performance of ponatinib, as salvage therapy, in a real-world setting of chronic phase chronic myeloid leukemia (CML-CP). Among 55 consecutive patients (median age 49 years) with relapsed/refractory CML-CP, 35 (64%) had failed ≥3 tyrosine kinase inhibitors (TKIs), 35 (64%) were pre-treated with nilotinib, and 14 (28%) harbored ABL1T315I. At start of ponatinib (median dose 30 mg/day), 40 patients were already in complete hematologic (CHR), 4 in complete cytogenetic (CCyR), 3 in major molecular (MMR) remission, while 8 had not achieved CHR (NR). Ponatinib improved the depth of response in 13 (33%), 3 (75%), 2 (66%), and 4 (50%) patients with CHR, CCyR, MMR, and NR, respectively (p = 0.02). At a median follow-up of 42 months, 13 (23%) deaths, 5 (9%) blast transformations, and 25 (45%) allogeneic transplants were recorded. Five/10-year post-ponatinib survival was 77%/58% with no significant difference when patients were stratified by allogeneic transplant (p = 0.94), ponatinib-induced deeper response (p = 0.28), or a post-ponatinib ≥CCyR vs CHR remission state (p = 0.25). ABL1T315I was detrimental to survival (p = 0.04) but did not appear to affect response. Prior exposure to nilotinib was associated with higher risk of arterial occlusive events (AOEs; 11% vs 0%; age-adjusted p = 0.04). Ponatinib starting/maintenance dose (45 vs 15 mg/day) did not influence either treatment response or AOEs. Our observations support the use of a lower starting/maintenance dose for ponatinib in relapsed/refractory CML-CP but a survival advantage for deeper responses was not apparent and treatment might not overcome the detrimental impact of ABL1T315I on survival. The association between prior exposure to nilotinib and a higher risk of post-ponatinib AOEs requires further validation.