Management of adverse events associated with tyrosine kinase inhibitors in chronic myeloid leukemia

Asciminib monotherapy in patients with chronic-phase chronic myeloid leukemia with the T315I mutation after ≥1 prior tyrosine kinase inhibitor: 2-year follow-up results

Asciminib targets the BCR::ABL1 myristoyl pocket, maintaining activity against BCR::ABL1T315I, which is resistant to most approved adenosine triphosphate-competitive tyrosine kinase inhibitors. We report updated phase I results (NCT02081378) assessing safety/tolerability and antileukemic activity of asciminib monotherapy 200 mg twice daily in 48 heavily pretreated patients with T315I-mutated chronic-phase chronic myeloid leukemia (CML-CP; data cutoff: January 6, 2021). With 2 years' median exposure, 56.3% of patients continued receiving asciminib. Overall, 62.2% of evaluable patients achieved BCR::ABL1 ≤1% on the International Scale (IS); 47.6% and 81.3% of ponatinib-pretreated and -naive patients, respectively, achieved BCR::ABL1IS ≤1%. Of 45 evaluable patients, 48.9% achieved a major molecular response (MMR, BCR::ABL1IS ≤0.1%), including 34.6% and 68.4% of ponatinib-pretreated and -naive patients, respectively. MMR was maintained until data cutoff in 19 of 22 patients who achieved it. The most common grade ≥3 adverse events (AEs) included increased lipase level (18.8%) and thrombocytopenia (14.6%). Five (10.4%) patients experienced AEs leading to discontinuation, including 2 who discontinued asciminib and died due to COVID-19; these were the only deaths reported. These results show asciminib's effectiveness, including in almost 50% of ponatinib pretreated patients, and confirm its risk-benefit profile, supporting its use as a treatment option for T315I-mutated CML-CP.

Imatinib-Induced Bone Marrow Aplasia in Chronic Myelogenous Leukemia

Imatinib is a tyrosine kinase inhibitor (TKI) and is a commonly used medication for treatment of chronic myelogenous leukemia (CML). Aplastic anemia is a very uncommon complication of Gleevec, and only a few cases are reported in the literature. We present a case of a 63-year-old Asian female who was initiated on imatinib for treatment of CML with good response in cell counts. Four months after Gleevec initiation, the patient was admitted to the hospital with extreme fatigue and noted to have severe pancytopenia. Patient received multiple blood transfusions. Finally, the patient underwent bone marrow biopsy, which showed concern for aplastic anemia with marked hypocellular bone marrow. Gleevec was held, blood counts were monitored, and supportive care was given. Patient had slow recovery of her blood counts. There remains scarcity of data on this topic and no criteria exist to predict the myelosuppression with TKI therapy. Our case report aims to reemphasize the need for increased research on myelosuppression with TKI therapy.

Screening and Activity Evaluation of Novel BCR-ABL/T315I Tyrosine Kinase Inhibitors

INTRODUCTION

Chronic myeloid leukemia (CML) is a kind of malignant tumor formed by the clonal proliferation of bone marrow hematopoietic stem cells. BCR-ABL fusion protein, found in more than 90% of patients, is a vital target for discovering anti- CML drugs. Up to date, imatinib is the first BCR-ABL tyrosine kinase inhibitor (TKI) approved by the FDA for treating CML. However, the drug resistance problems appeared for many reasons, especially the T135I mutation, a "gatekeeper" of BCR-ABL. Currently, there is no long-term effective and low side effect drug in clinical.

METHODS

This study intends to find novel TKIs targeting BCR-ABL with high inhibitory activity against T315I mutant protein by combining artificial intelligence technology and cell growth curve, cytotoxicity, flow cytometry and Western blot experiments.

RESULTS

The obtained compound was found to kill leukemia cells, which had good inhibitory efficacy in BaF3/T315I cells. Compound no 4 could induce cell cycle arrest, cause autophagy and apoptosis, and inhibit the phosphorylation of BCR-ABL tyrosine kinase, STAT5 and Crkl proteins.

CONCLUSION

The results indicated that the screened compound could be used as a lead compound for further research to discover ideal chronic myeloid leukemia therapeutic drugs.

Adverse effects of tyrosine kinase inhibitors in cancer therapy: pathophysiology, mechanisms and clinical management

Since their invention in the early 2000s, tyrosine kinase inhibitors (TKIs) have gained prominence as the most effective pathway-directed anti-cancer agents. TKIs have shown significant utility in the treatment of multiple hematological malignancies and solid tumors, including chronic myelogenous leukemia, non-small cell lung cancers, gastrointestinal stromal tumors, and HER2-positive breast cancers. Given their widespread applications, an increasing frequency of TKI-induced adverse effects has been reported. Although TKIs are known to affect multiple organs in the body including the lungs, liver, gastrointestinal tract, kidneys, thyroid, blood, and skin, cardiac involvement accounts for some of the most serious complications. The most frequently reported cardiovascular side effects range from hypertension, atrial fibrillation, reduced cardiac function, and heart failure to sudden death. The potential mechanisms of these side effects are unclear, leading to critical knowledge gaps in the development of effective therapy and treatment guidelines. There are limited data to infer the best clinical approaches for the early detection and therapeutic modulation of TKI-induced side effects, and universal consensus regarding various management guidelines is yet to be reached. In this state-of-the-art review, we examine multiple pre-clinical and clinical studies and curate evidence on the pathophysiology, mechanisms, and clinical management of these adverse reactions. We expect that this review will provide researchers and allied healthcare providers with the most up-to-date information on the pathophysiology, natural history, risk stratification, and management of emerging TKI-induced side effects in cancer patients.

Asciminib monotherapy in patients with CML-CP without BCR::ABL1 T315I mutations treated with at least two prior TKIs: 4-year phase 1 safety and efficacy results

Asciminib is approved for patients with Philadelphia chromosome-positive chronic-phase chronic myeloid leukemia (CML-CP) who received ≥2 prior tyrosine kinase inhibitors or have the T315I mutation. We report updated results of a phase 1, open-label, nonrandomized trial (NCT02081378) assessing the safety, tolerability, and antileukemic activity of asciminib monotherapy 10-200 mg once or twice daily in 115 patients with CML-CP without T315I (data cutoff: January 6, 2021). After ≈4-year median exposure, 69.6% of patients remained on asciminib. The most common grade ≥3 adverse events (AEs) included increased pancreatic enzymes (22.6%), thrombocytopenia (13.9%), hypertension (13.0%), and neutropenia (12.2%); all-grade AEs (mostly grade 1/2) included musculoskeletal pain (59.1%), upper respiratory tract infection (41.7%), and fatigue (40.9%). Clinical pancreatitis and arterial occlusive events (AOEs) occurred in 7.0% and 8.7%, respectively. Most AEs occurred during year 1; the subsequent likelihood of new events, including AOEs, was low. By data cutoff, among patients without the indicated response at baseline, 61.3% achieved BCR::ABL1 ≤ 1%, 61.6% achieved ≤0.1% (major molecular response [MMR]), and 33.7% achieved ≤0.01% on the International Scale. MMR was maintained in 48/53 patients who achieved it and 19/20 who were in MMR at screening, supporting the long-term safety and efficacy of asciminib in this population.

Life threatening hepatotoxicity induced by Nilotinib

INTRODUCTION

Tyrosine kinase inhibitor had changed the prognosis of chronic myeloid leukemia (CML) and the overall survival had reached 95%. Unfortunately, adverse events (AEs) remain an obstacle to following successful treatment in CML impairing the quality of life and sometimes endangering the lives of patients. To this end, we show this clinical case to discuss strategies to deal with rare AEs in a way to preserve the patient's life and to maintain not only a good response to treatment but also confidence and compliance of the patient.

CASE REPORT

We report the case of a 57-year-old woman diagnosed with CML at the chronic phase who developed rare life-threatening hepatotoxicity (major cytolysis and prothrombin time fall) secondary to Nilotinib used as second-line treatment. This complication settled despite an optimal molecular response.

MANAGEMENT AND OUTCOME

We discuss below the follow-up and management in our center and according to the literature with more sophisticated pharmacological methods.

DISCUSSION

Although we used to monitor disease molecular response to treatment, we need solutions and manuscripts for monitoring drug dose parameters to avoid unusual dangerous effects risking the patient life. We conclude that monitoring the disease as well as the treatment pharmacokinetics is mandatory to better carry on CML patients.

[French Chronic Myeloid Leukemia Intergroup 2022 recommendations for managing the risk of cardiovascular events on ponatinib in chronic myeloid leukemia]

Tyrosine kinase inhibitors targeting the BCR-ABL1 oncoprotein represent an outstanding progress in chronic myeloid leukemia and long-term progression-free survival has become a reality for a majority of patients. However, tyrosine kinase inhibitors may at best chronicize rather than cure the disease thus current recommendation is to pursue treatment indefinitely. As a consequence, high quality treatment and care must integrate optimal disease control and treatment tolerability. Tyrosine kinase inhibitors have an overall favorable safety profile in clinical practice since most adverse events are mild to moderate in intensity. However, recent evidence has emerged that new generation tyrosine kinase inhibitors may sometimes damage vital organs and if not adequately managed, morbidity and mortality may increase. The 3rd generation tyrosine kinase inhibitor ponatinib is licensed for the treatment of chronic, accelerated or blast phase chronic myeloid leukaemia patients who are resistant to dasatinib or nilotinib; intolerant of dasatinib or nilotinib and for whom further treatment with imatinib is not clinically appropriate; or who express the T315I mutation. Ponatinib represents an important therapeutic option but it is associated with an increased risk of cardiovascular events. The purpose of this article by the France Intergroupe des Leucémies Myéloïdes Chroniques is to provide an overview of ponatinib efficacy and cardiovascular safety profile and to propose practical recommendations with the goal to minimize the risk and severity of cardiovascular events in ponatinib-treated patients.

Chronic myeloid leukaemia

Tyrosine-kinase inhibitors have changed the natural history of chronic myeloid leukaemia in such a way that patients with adequate access to these agents, who are properly managed, and who respond well to this treatment can expect a near-normal life expectancy. Achieving this goal requires an adequate understanding of the patient's treatment goals, careful monitoring for the achievement of optimal response hallmarks, implementation of proper interventions according to the attainment of such endpoints, adequate recognition and management of adverse events, and acknowledgment of the relevance of comorbidities. Treatment with tyrosine-kinase inhibitors, once considered lifelong, has become terminable for at least some patients, and promising new agents are emerging for those whose disease does not respond to any of the multiple therapeutic options currently available. If these advances reach all patients with chronic myeloid leukaemia, cure might eventually become a reality in most instances.

Computational and Biological Investigations on Abl1 Tyrosine Kinase: A Review

Abl1 tyrosine kinase is a validated target for the treatment of chronic myeloid leukemia. It is a form of cancer that is difficult to treat and much research is being done to identify new molecular entities and to tackle drug resistance issues. In recent years, drug resistance of Abl1 tyrosine kinase has become a major healthcare concern. Second and third-generation TKI reported better responses against the resistant forms; still they had no impact on long-term survival prolongation. New compounds derived from natural products and organic small molecule inhibitors can lay the foundation for better clinical therapies in the future. Computational methods, experimental and biological studies can help us understand the mechanism of drug resistance and identify novel molecule inhibitors. ADMET parameters analysis of reported drugs and novel small molecule inhibitors can also provide valuable insights. In this review, available therapies, point mutations, structure-activity relationship and ADMET parameters of reported series of Abl1 tyrosine kinase inhibitors and drugs are summarised. We summarise in detail recent computational and molecular biology studies that focus on designing drug molecules, investigation of natural product compounds and organic new chemical entities. Current ongoing research suggests that selective targeting of Abl1 tyrosine kinase at the molecular level to combat drug resistance in chronic myeloid leukemia is promising.

Biomineralization-inspired dasatinib nanodrug with sequential infiltration for effective solid tumor treatment

The complex blood environment, heterogenic enhanced permeability and retention (EPR) effect, and dense matrix comprise the primary "leakage obstacles" impeding specific accumulation and penetration of nanodrugs against solid tumors, thus forming a key bottleneck for their clinical application. Herein, we present a biomineralization-inspired dasatinib (DAS) nanodrug (CIPHD/DAS) that sequentially permeates all of the abovementioned hindrances for efficient treatment of solid tumors. CIPHD/DAS exhibited a robust hybrid structure constructed from an iRGD-modified hyaluronic acid-deoxycholic acid organic core and a calcium phosphate mineral shell. In vitro and in vivo data demonstrated the mechanism of sequential tumoral infiltration was based on mineral-stiffened blood circulation with decreased premature drug leakage, iRGD-endowed tumor-specific transendothelial transport for "first-order promotion of accumulation" and DAS-mediated restoration of fibrotic stromal homeostasis for "second-order promotion of penetration". Resultantly, CIPHD/DAS showed remarkable distal drug availability in desmoplastic 4T1/CAFs orthotropic mouse models and significantly suppressed tumor growth and metastasis. This optimized strategy with sequential permeabilization of the capital "leakage obstacles" validates a promising paradigm to conquer the "impaired delivery and penetration" associated bottleneck of nanodrugs in the clinical treatment of solid tumors.

Dasatinib-induced Nonspecific Interstitial Pneumonia That Developed 7 Years after the Initiation of Dasatinib

We report the case of a 56-year-old man with chronic myeloid leukemia (CML) who developed dasatinib-induced interstitial lung disease (ILD) 7 years after starting dasatinib, a BCR-ABL1 inhibitor. The patient presented with dyspnea. Chest imaging showed diffuse ground-glass opacities. A surgical lung biopsy showed cellular non-specific interstitial pneumonia (NSIP). Corticosteroid treatment ameliorated his condition. Bosutinib, another BCR-ABL1 inhibitor, was successfully re-instituted. The present case and relevant literature suggest that dasatinib-induced ILD can present as NSIP after an extended period, responds to corticosteroids, and is amenable to re-challenge at a lower-dose or with alternative BCR-ABL1 inhibitors.

Allelic polymorphisms of KIRs and antitumor immunity against chronic myeloid leukemia

The development of BCR-ABL1 tyrosine kinase inhibitors (TKIs) markedly improved the prognosis of patients with chronic myeloid leukemia (CML). Approximately 50% of patients who achieve deep molecular response (DMR) remain in treatment-free remission (TFR) even after discontinuation of TKIs. Although TKIs may achieve clinical "cure" after TKI treatment for specific periods, there are no reliable biomarkers for predicting the response to TKIs and the probability of TFR in CML. An increase in natural killer (NK) cells in the peripheral blood of TKI-treated CML patients is correlated with better outcomes, suggesting that TKIs induce antitumor NK cell immunity against CML cells. Killer immunoglobulin-like receptors (KIRs) are highly polymorphic NK cell receptors that play important roles in the regulation of immune responses. The identification of allelic polymorphisms of KIRs by next-generation sequencing uncovered novel aspects of KIRs. Here we summarize the current knowledge of the genetic and immunological aspects of KIRs and discuss the association between allelic polymorphisms of KIRs and TKI-treated CML.

Treatment-free remission after first-line dasatinib discontinuation in patients with chronic myeloid leukaemia (first-line DADI trial): a single-arm, multicentre, phase 2 trial

BACKGROUND

A previous dasatinib discontinuation (DADI) trial showed that 31 (49%) of 63 patients with chronic-phase chronic myeloid leukaemia who were treated with second-line or subsequent dasatinib could discontinue the drug safely. However, the safety and efficacy of discontinuing first-line dasatinib remains unclear. In this trial (the first-line DADI trial) we aimed to assess molecular relapse-free survival at 6 months after discontinuation of dasatinib in patients with chronic myeloid leukaemia who had been treated with first-line dasatinib and had maintained deep molecular response for at least 1 year.

METHODS

The first-line DADI trial was a single-arm, multicentre, phase 2 trial done at 23 hospitals in Japan. Patients with newly diagnosed chronic-phase chronic myeloid leukaemia without hepatosplenomegaly and extramedullary mass, who received at least 24-month dasatinib treatment and had a sustained deep molecular response (defined as BCR-ABL1/ABL1 international scale ≤0·0069% in at least four successive samples spanning a 12 month period) were enrolled. Other eligibility criteria were an age of 15 years or older, an Eastern Cooperative Oncology Group performance status score of 0-2, and no primary organ dysfunction. The primary outcome was molecular relapse-free survival (also known as treatment-free remission) after discontinuation of dasatinib at 6 months and was analysed in all patients who completed the 12-month consolidation phase. Safety was assessed in all patients who received treatment. This study closed early due to accrual and is registered with the UMIN Clinical Trials Registry (UMIN000011099).

FINDINGS

Between Sept 20, 2013 and July 12, 2016, 68 patients who had a deep molecular response after receiving first-line dasatinib for at least 24 months were enrolled and assigned to the consolidation phase. Nine patients were excluded during the consolidation phase and one patient was excluded after study completion because of meeting exclusion criteria. 58 patients discontinued dasatinib and were assessed. 32 (55%) of 58 patients had treatment-free remission at 6 months after dasatinib discontinuation, and median follow-up was 23·3 months (IQR 11·7-31·0). Treatment-free remission at 6 months was 55·2% (95% CI 43·7-69·6). No non-haematological adverse events worse than grade 2 occurred before dasatinib discontinuation. The most common haematological adverse event was anaemia (14 [21%] of 68 treated patients); three (4%) of 68 treated patients had grade 3 neutropenia and one (1%) had grade 4 lymphopenia.

INTERPRETATION

Our findings suggest that dasatinib could be safely discontinued after first-line treatment in patients with chronic myeloid leukaemia who had received at least 36 months of therapy and sustained deep molecular response; however, further confirmation in larger trials is needed.

FUNDING

Epidemiological and Clinical Research Information Network.

Towards a Personalized Treatment of Patients with Chronic Myeloid Leukemia

PURPOSE OF REVIEW

Treatment goals and ambitions have even been upwardly revised since demonstration was made that under certain conditions, treatment-free remission was possible. Herein, we will discuss on how to try tailoring treatment choices to the unique characteristics of each patient.

RECENT FINDINGS

Since the first-generation ATP-competitive TKI imatinib was made available in the clinic in 2001, second-generation drugs such as dasatinib, nilotinib and bosutinib and the third-generation TKI ponatinib have broadened the therapeutic armamentarium, providing effective salvage against intolerance and different types of resistance, or as frontline options. Management and outcomes of patients with chronic myeloid leukemia have been revolutionized by the discovery, development, and approval of BCR-ABL tyrosine kinase inhibitors (TKIs). Most patients can now expect a near-to normal life expectancy and acceptable quality of life on life-long treatment, providing awareness and avoidance of harmful adverse events, which depend on each TKI safety profile and patient personal background.

Skin lesions in chronic myeloid leukemia patients during dasatinib treatment

Purpose

In our work we sought to define the prevalence rates of cutaneous events during dasatinib therapy in chronic myeloid leukemia (CML) patients and to investigate the clinical and pathological characteristics of these reactions.

Patients and methods

In our institution, 67 CML patients were treated with dasatinib. it was given as first line treatment in 26 (39%) and subsequent treatment in 41 (61%) CML patients. Flow cytometry analysis of peripheral blood and cutaneous biopsy was done on all CML patients with dermatological lesions appearing during dasatinib treatment.

Results

Among 67 CML patients, 4 (5.9%) showed skin lesions during dasatinib treatment. The cutaneous manifestations were not generalized but mainly located on the back, abdomen, thorax or leg regions. The patients did not show peripheral lymphocytosis at the time when skin lesions appeared. Overall, histological analysis showed that the skin lesions were characterized by a mild perivascular small CD8+ T lymphocytes infiltrate with minimal epidermotropism.

Conclusion

The unusual T cytotoxic cutaneous infiltrate demonstrated in our CML cases could be the expression of a dasatinib-promoted lymphocyte expansion. However, the heterogeneity of the dermatologic manifestations reported in our CML patients could also be related to unknown factors specific to each CML patient. Our work highlights the finding that skin lesions may be associated with dasatinib treatment and that they should not be confused with viral or bacterial infections but rather interpreted as the clinical expression of lymphocytosis promoted by this TKI.

Evaluation of anemia after long-term treatment with imatinib in chronic myeloid leukemia patients in chronic phase

Introduction

The incidence of grade 3–4 anemia was reported to be 3% with imatinib therapy for newly diagnosed chronic myeloid leukemia (CML) in the chronic phase (CP). However, there are few data regarding the causes and the development of anemia after long-term treatment. This study aimed to evaluate the incidence of anemia after at least two years of imatinib treatment of CML patients in the CP and to identify other contributing causes of anemia in this population.

Patients and methods

We performed a retrospective analysis of 97 CML patients in the CP treated with imatinib for at least two years. We analyzed the hemoglobin (Hb) levels of CML patients at diagnosis, upon initiation of treatment with imatinib and after two years of imatinib treatment, and investigated other causes of anemia in this population.

Results

Most of the patients presented Hb levels below the normal range (80.4%) after the second year of treatment, 17.9% grade 2 and 1.3% grade 3. In 13 cases (16.7%), anemia was attributed to resistance and in 13 cases (16.7%) the following causes were identified: iron deficiency (n = 5), hypothyroidism (n = 2), vitamin B12 deficiency (n = 3), acquired immune deficiency syndrome (AIDS) (n = 1), pulmonary tuberculosis (n = 1) and renal toxicity (n = 1). In 52 patients (66.6%), there were no other factors contributing to anemia, except imatinib treatment.

Conclusion

Regular follow-up is required to identify the causes of anemia not related to CML or imatinib toxicity. The importance of investigating secondary causes of anemia should be emphasized, especially in patients with good adherence to treatment and satisfactory therapeutic response.

Interruption or Discontinuation of Tyrosine Kinase Inhibitor Treatment in Chronic Myeloid Leukaemia: A Retrospective Cohort Study (SPARKLE) in Belgium

OBJECTIVES

To assess interruptions/discontinuations of tyrosine kinase inhibitor (TKI) treatment in Belgian patients with chronic myeloid leukaemia (CML).

METHODS

This retrospective study included patients with TKI interruptions/discontinuations of ≥4 continuous weeks (no clinical trial context) between May 2013 and May 2016. Data collection took place between October 2016 and February 2017.

RESULTS

All 60 participants (69 interruptions/discontinuations) had chronic-phase CML and 75% had at least a major molecular response (≥MMR) at interruption/discontinuation. Most interruptions/discontinuations occurred while on imatinib (36/69; 49%) and dasatinib (20/69; 29%). Most interruptions/discontinuations occurred due to side effects/intolerance (46/69; 67%); other reasons included a wish to conceive (6/69; 9%) and attempts to achieve treatment-free remission (TFR) (6/69; 9%). Interruptions due to side effects occurred later for imatinib- or dasatinib-treated patients than for those on nilotinib or ponatinib. Treatment was re-initiated in 62% (43/69) of cases. Most interruptions caused by side effects/intolerance were followed by treatment changes. All 4 patients with ≥MR 4.5 at interruption/discontinuation and ≥11-month follow-up who had not restarted treatment maintained the response.

CONCLUSION

Although TKIs are used for long-term CML treatment, physicians sometimes recommend interruptions/discontinuations. In this study, interruptions/discontinuations were mainly caused by side effects or intolerance, rather than TFR attempts.

Haematological adverse events associated with tyrosine kinase inhibitors in chronic myeloid leukaemia: A network meta-analysis

AIMS

Despite their overall favourable safety profile, tyrosine kinase inhibitors (TKIs) are related to severe adverse events including haematological toxicities such as anaemia, leucopenia, neutropenia and thrombocytopenia. We designed a systematic review and network meta-analysis of randomised controlled trials to compare safety among TKIs (bosutinib, dasatinib, imatinib, nilotinib, ponatinib and radotinib) used by patients diagnosed with chronic myeloid leukaemia.

METHODS

We obtained data from the PubMed, Scopus, Web of Science, and SciELO databases. The Bayesian approach was used for direct and indirect comparisons, and the treatments were ranked by the surface under the cumulative ranking curve (SUCRA).

RESULTS

Seventeen studies were included in the network meta-analysis. Our data show that dasatinib was generally considered worse than the other TKIs, with SUCRA values ​​for 140 mg dasatinib of 90.3% for anaemia, 87.4% for leucopenia, 90.6% for neutropenia and 97.2% for thrombocytopenia. In addition, nilotinib was shown to be safer, with SUCRA values ​​for 600 and 800 mg doses of 21.9 and 35.8% for anaemia, 23.8 and 14.6% for leucopenia, 33.0 and 17.7% for neutropenia, and 28.7 and 32.6% for thrombocytopenia, respectively.

CONCLUSION

Dasatinib appeared as the least safe drug for chronic myeloid leukaemia, probably because it binds to multiple key kinase targets, being more prone to cause serious haematological adverse events. Nilotinib demonstrated a safer profile, mostly due to its selective binding capacity.

Early and sustained deep molecular response achieved with nilotinib in high Sokal risk chronic myeloid leukemia patients

BACKGROUND

Nilotinib (Tasigna®) is a second-generation tyrosine kinase inhibitor that shows faster and deeper molecular responses (MR) in comparison to Imatinib as initial therapy in chronic phase chronic myeloid leukemia (CML). Efficacy and safety data for nilotinib in the Asian population is scarce, particularly in Pakistan. We aimed to determine the MR to nilotinib and its safety profile in patients with chronic phase CML.

PATIENTS AND METHODS

This observational study was conducted among 173 patients with newly diagnosed CML presenting in the chronic phase. Most patients (50.1%) had a high Sokal score at diagnosis. All patients received nilotinib 600 mg/day. The hematological and molecular responses were assessed at 3 and 6 months respectively and thereafter at 6-monthly intervals. Long-term event free survival (EFS), transformation free survival (TFS), overall survival (OS) and adverse events were observed.

RESULTS

Cumulative incidence of major MR (MMR) was 86% and deep MR (DMR ie MR 4.0 and MR4.5) was 39%. Early MMR and DMR after 6 months of therapy were achieved by 74.9% and 37% of patients, respectively. Two-year EFS, TFS and OS rates for all patients were 91.9%, 92% and 92.3%, respectively. At median follow-up of 24 months, 81% and 49% of patients sustained MMR and DMR, respectively. The main adverse events were weight gain (4.6%) and abdominal pain (4%).

CONCLUSION

This study showed promising results in terms of achievement of early and sustained DMR in chronic phase CML, therefore, we recommend nilotinib as frontline treatment in Pakistani population.

Front-line imatinib treatment in children and adolescents with chronic myeloid leukemia: results from a phase III trial

A total of 156 patients (age range 1.3-18.0 years, median 13.2 years; 91 (58.3%) male) with newly diagnosed CML (N = 146 chronic phase (CML-CP), N = 3 accelerated phase (CML-AP), N = 7 blastic phase (CML-BP)) received imatinib up-front (300, 400, 500 mg/m², respectively) within a prospective phase III trial. Therapy response, progression-free survival, causes of treatment failure, and side effects were analyzed in 148 children and adolescents with complete data. Event-free survival rate by 18 months for patients in CML-CP (median follow-up time 25 months, range: 1-120) was 97% (95% CI, 94.2-99.9%). According to the 2006 ELN-criteria complete hematologic response by month 3, complete cytogenetic response (CCyR) by month 12, and major molecular response (MMR) by month 18 were achieved in 98, 63, and 59% of the patients, respectively. By month 36, 86% of the patients achieved CCyR and 74% achieved MMR. Thirty-eight patients (27%) experienced imatinib failure because of unsatisfactory response or intolerance (N = 9). In all, 28/148 patients (19%) underwent stem cell transplantation (SCT). In the SCT sub-cohort 2/23 patients diagnosed in CML-CP, 0/1 in CML-AP, and 2/4 in CML-BP, respectively, died of relapse (N = 3) or SCT-related complications (N = 2). This large pediatric trial extends and confirms data from smaller series that first-line imatinib in children is highly effective.

Chronic myelogenous leukemia on target

Chronic myelogenous leukemia (CML) is commonly treated with tyrosine kinase inhibitors (TKIs) that inhibit the pro-leukemic activity of the BCR-ABL1 oncoprotein. Despite the therapeutic progress mediated by TKI use, off-target effects, treatment-induced drug resistance, and the limited effect of these drugs on CML stem cells (SCs) are major drawbacks frequently resulting in insufficient or unsustainable treatment. Therefore, intense research efforts have focused on development of improved TKIs and alternative treatment strategies to eradicate CML SCs. Alongside efforts to design superior protein inhibitors, the need to overcome the poor therapeutic effect of TKIs on CML SCs has led to a renaissance of antisense strategies, as they are reported as effective in more primitive cell types. Despite the greater drug design flexibility offered by antisense sequence variability and remarkable chemical improvements, antisense drugs exhibit unacceptable levels of off-target effects, precluding them from large-scale clinical testing. Recent advances in antisense drug design have led to a pioneering mRNA recognition concept that may offer a helping hand in eliminating off-target effects, and has potential to bridge the gap between research and clinical practice.

VEGFR2-targeted fusion antibody improved NK cell-mediated immunosurveillance against K562 cells

MHC class I polypeptide-related sequence A (MICA), which is normally expressed on cancer cells, activates NK cells via NK group 2-member D pathway. However, some cancer cells escape NK-mediated immune surveillance by shedding membrane MICA causing immune suppression. To address this issue, we designed an antibody-MICA fusion targeting tumor-specific antigen (vascular endothelial growth factor receptor 2, VEGFR2) based on our patented antibody (mAb04) against VEGFR2. In vitro results demonstrate that the fusion antibody retains both the antineoplastic and the immunomodulatory activity of mAb04. Further, we revealed that it enhanced NK-mediated immunosurveillance against K562 cells through increasing degranulation and cytokine production of NK cells. The overall data suggest our new fusion protein provides a promising approach for cancer-targeted immunotherapy and has prospects for potential application of chronic myeloid leukemia.

Combined targeting of BCL-2 and BCR-ABL tyrosine kinase eradicates chronic myeloid leukemia stem cells

BCR-ABL tyrosine kinase inhibitors (TKIs) are effective against chronic myeloid leukemia (CML), but they rarely eliminate CML stem cells. Disease relapse is common upon therapy cessation, even in patients with complete molecular responses. Furthermore, once CML progresses to blast crisis (BC), treatment outcomes are dismal. We hypothesized that concomitant targeting of BCL-2 and BCR-ABL tyrosine kinase could overcome these limitations. We demonstrate increased BCL-2 expression at the protein level in bone marrow cells, particularly in Lin(-)Sca-1(+)cKit(+) cells of inducible CML in mice, as determined by CyTOF mass cytometry. Further, selective inhibition of BCL-2, aided by TKI-mediated MCL-1 and BCL-XL inhibition, markedly decreased leukemic Lin(-)Sca-1(+)cKit(+) cell numbers and long-term stem cell frequency and prolonged survival in a murine CML model. Additionally, this combination effectively eradicated CD34(+)CD38(-), CD34(+)CD38(+), and quiescent stem/progenitor CD34(+) cells from BC CML patient samples. Our results suggest that BCL-2 is a key survival factor for CML stem/progenitor cells and that combined inhibition of BCL-2 and BCR-ABL tyrosine kinase has the potential to significantly improve depth of response and cure rates of chronic-phase and BC CML.

How I manage relapse of chronic myeloid leukaemia after stopping tyrosine kinase inhibitor therapy

During the last 10 years, clinical trials formally demonstrated that about 50% of patients with chronic phase (CP) chronic myeloid leukaemia (CML) who achieve and maintain deep molecular responses for a prolonged period of time during treatment with imatinib or new generation tyrosine kinase inhibitors (TKIs) may successfully stop their anti-leukaemic therapy. Based on the accumulated knowledge from abundant clinical trial experience, TKI discontinuation is becoming an important goal to achieve and is about to enter clinical practice. This review focuses on relapse definition, laboratory tests to identify relapse and relapse management after TKI discontinuation.

Long-Term Side Effects of Tyrosine Kinase Inhibitors in Chronic Myeloid Leukemia

Most patients with chronic myeloid leukemia have deep and durable responses when treated with BCR-ABL1 tyrosine kinase inhibitors (TKIs). Imatinib (the first approved TKI), nilotinib, and dasatinib are used in newly diagnosed, relapsed or intolerant patients, while bosutinib and ponatinib are used only in relapsed or intolerant patients. Previously the drug of choice was related to the likelihood of response and, to a small extent, patient comorbidities. The long-term toxicities, particularly cardiopulmonary side effects, are now impacting treatment choice, making patient comorbidities of significant concern. About 10 % of patients do not tolerate their initial BCR-ABL1 TKI and an increasing number are developing long-term side effects, particularly with the second generation drugs. Side effects of the five drugs reviewed here highlight the differences between cardiovascular, pulmonary, gastrointestinal, and endocrine toxicities, as well as possible second malignancies. There is increasing evidence that patients whose disease is controlled by TKI's will have greater impact on their quality of life from comorbidities or drug adverse events than from the disease itself. Research into management of long-term toxicities is needed.

BCR-ABL1 tyrosine kinase inhibitors for the treatment of chronic myeloid leukemia

The management of chronic myeloid leukemia with BCR-ABL1 tyrosine kinase inhibitors has evolved chronic myeloid leukemia into a chronic, manageable disease. A patient-centered approach is important for the appropriate management of chronic myeloid leukemia and optimization of long-term treatment outcomes. The pharmacist plays a key role in treatment selection, monitoring drug–drug interactions, identification and management of adverse events, and educating patients on adherence. The combination of tyrosine kinase inhibitors with unique safety profiles and individual patients with unique medical histories can make managing treatment difficult. This review will provide up-to-date information regarding tyrosine kinase inhibitor-based treatment of patients with chronic myeloid leukemia. Management strategies for adverse events and considerations for drug–drug interactions will not only vary among patients but also across tyrosine kinase inhibitors. Drug–drug interactions can be mild to severe. In instances where co-administration of concomitant medications cannot be avoided, it is critical to understand how drug levels are impacted and how subsequent dose modifications ensure therapeutic drug levels are maintained. An important component of patient-centered management of chronic myeloid leukemia also includes educating patients on the significance of early and regular monitoring of therapeutic milestones, emphasizing the importance of adhering to treatment in achieving these targets, and appropriately modifying treatment if these clinical goals are not being met. Overall, staying apprised of current research, utilizing the close pharmacist–patient relationship, and having regular interactions with patients, will help achieve successful long-term treatment of chronic myeloid leukemia in the age of BCR-ABL1 tyrosine kinase inhibitors.

Bosutinib induced pleural effusions: Case report and review of tyrosine kinase inhibitors induced pulmonary toxicity

Tyrosine kinase inhibitors are known to cause pulmonary complications. We report a case of bosutinib related bilateral pleural effusions in a patient with chronic myeloid leukemia. Characteristics of the pleural fluid are presented. We also discuss other tyrosine kinase inhibitors induced pulmonary toxicities, including pulmonary hypertension and interstitial lung disease.

Management of CML-blast crisis

Tyrosine kinase inhibitors (TKI) have moderately improved survival in BC, but a median survival of less than 1 year is still unsatisfactory. This article reviews the various tests required for diagnosis of BC, features at diagnosis, treatment modalities (intensive chemotherapy, TKI, allo-SCT and a selection of investigational agents), options of prevention and predictors of progression. The best prognosis is observed in patients that achieve a 2nd CP. Allo-SCT probably further improves prognosis of patients in 2nd CP. The choice of TKI should be directed by the mutation profile of the patient. BC can be prevented. A careful analysis of risk factors for progression may help. Current treatment options are combined in a concluding strategy for the management of BC.

European LeukemiaNet recommendations for the management and avoidance of adverse events of treatment in chronic myeloid leukaemia

Most reports on chronic myeloid leukaemia (CML) treatment with tyrosine kinase inhibitors (TKIs) focus on efficacy, particularly on molecular response and outcome. In contrast, adverse events (AEs) are often reported as infrequent, minor, tolerable and manageable, but they are increasingly important as therapy is potentially lifelong and multiple TKIs are available. For this reason, the European LeukemiaNet panel for CML management recommendations presents an exhaustive and critical summary of AEs emerging during CML treatment, to assist their understanding, management and prevention. There are five major conclusions. First, the main purpose of CML treatment is the antileukemic effect. Suboptimal management of AEs must not compromise this first objective. Second, most patients will have AEs, usually early, mostly mild to moderate, and which will resolve spontaneously or are easily controlled by simple means. Third, reduction or interruption of treatment must only be done if optimal management of the AE cannot be accomplished in other ways, and frequent monitoring is needed to detect resolution of the AE as early as possible. Fourth, attention must be given to comorbidities and drug interactions, and to new events unrelated to TKIs that are inevitable during such a prolonged treatment. Fifth, some TKI-related AEs have emerged which were not predicted or detected in earlier studies, maybe because of suboptimal attention to or absence from the preclinical data. Overall, imatinib has demonstrated a good long-term safety profile, though recent findings suggest underestimation of symptom severity by physicians. Second and third generation TKIs have shown higher response rates, but have been associated with unexpected problems, some of which could be irreversible. We hope these recommendations will help to minimise adverse events, and we believe that an optimal management of them will be rewarded by better TKI compliance and thus better CML outcomes, together with better quality of life.

Recognizing Endocrinopathies Associated With Tyrosine Kinase Inhibitor Therapy in Children With Chronic Myelogenous Leukemia

Side effects of tyrosine kinase inhibitor (TKI) treatment vary in children and adults with chronic myelogenous leukemia (CML). As children have a much longer life expectancy than adults, TKI therapy may continue for decades and with long-term consequences that differ from adults. Children may develop endocrinopathies related to "off-target" effects of TKIs, such as delayed growth, changes in bone metabolism, thyroid abnormalities, and effects on puberty and fertility. These endocrinopathies present additional challenges for pediatric patients with CML. This review critically evaluates the literature on long-term endocrine side effects of TKIs in the pediatric CML population and provides suggested recommendations.

Best Practices in Chronic Myeloid Leukemia Monitoring and Management

: Optimal use of current therapeutic opportunities for chronic myeloid leukemia patients requires integration of clinical and laboratory monitoring. Assessment of molecular response (MR) by real-time quantitative polymerase chain reaction is the most sensitive way to monitor tyrosine kinase inhibitor (TKI) treatment efficacy. Besides major molecular response, which has emerged as a safe haven for survival since the initial studies of first-line imatinib treatment, two additional MR milestones have recently been defined: early molecular response and deep molecular response. The achievement of such MR milestones within defined time points during therapy is thought to draw the ideal trajectory toward optimal long-term outcome and, possibly, successful treatment discontinuation. Sensitive and reproducible MR measurement and proper interpretation of MR results are therefore critical to correctly inform therapeutic decisions. In patients who do not achieve an optimal response to TKI therapy, BCR-ABL1 mutation screening should also be performed, because it may deliver useful information for TKI choice. This review aims to help clinicians apply and translate the latest response definitions and clinical recommendations into practice. We provide a critical update on how these recommendations have incorporated MR levels in the clinical decision algorithms and how detection of BCR-ABL1 mutations should be interpreted. We also include a practical guide for pathologists and molecular biologists to best perform molecular testing and for hematologists and oncologists to best integrate it into routine practice.

IMPLICATIONS FOR PRACTICE

Ever-more-potent therapeutic strategies have been developed for chronic myeloid leukemia (CML) in parallel with the evolution of therapeutic goals and the refinement of response definitions and monitoring schemes and procedures. Terminology and methodology continue to evolve rapidly, making it difficult for busy hematology/oncology professionals to keep abreast of the newest developments. Optimal CML patient management results from the timely and rational use of molecular testing, the critical assessment of the power and pitfalls of current technology, and the appropriate interpretation and contextualization of results.

BCR-ABL Mutation-Guided Therapy for CML Blast Crisis: A Case Report

The management of patients with chronic myeloid leukemia (CML) in advanced phases is challenging and requires the consideration of different treatment approaches, including targeted therapy with tyrosine kinase inhibitors, cytotoxic chemotherapy, and allogeneic stem cell transplantation. Here, we present the case of a patient with CML in mixed phenotype blast phase illustrating the integration of these strategies and demonstrating the need for close monitoring of treatment response in order to individually adjust treatment regimens.