Adverse events associated with tyrosine kinase inhibitors for the treatment of chronic myeloid leukemia

Perspectives of data science in preclinical safety assessment

The data landscape in preclinical safety assessment is fundamentally changing because of not only emerging new data types, such as human systems biology, or real-world data (RWD) from clinical trials, but also technological advancements in data-processing software and analytical tools based on deep learning approaches. The recent developments of data science are illustrated with use cases for the three factors: predictive safety (new in silico tools), insight generation (new data for outstanding questions); and reverse translation (extrapolating from clinical experience to resolve preclinical questions). Further advances in this field can be expected if companies focus on overcoming identified challenges related to a lack of platforms and data silos and assuring appropriate training of data scientists within the preclinical safety teams.

Response and Adherence to Nilotinib in Daily practice (RAND study): an in-depth observational study of chronic myeloid leukemia patients treated with nilotinib

Introduction

This comprehensive observational study aimed to gain insight into adherence to nilotinib and the effect of (non)adherence on exposure (C_min) and treatment outcomes.

Methods

Chronic myeloid leukemia (CML) patients using nilotinib were followed for 12 months. Adherence was measured by Medication Event Monitoring System (MEMS), pill count, and Medication Adherence Report Scale (MARS-5). Nilotinib C_min and patient-reported outcomes (i.e., quality of life, side effects, beliefs, satisfaction) were measured at baseline, 3, 6, and 12 months.

Results

Sixty-eight patients (57.5 ± 15.0 years, 49% female) participated. Median adherence to nilotinib (MEMS and pill count) was ≥ 99% and adherence < 90% was rare. Self-reported nonadherence (MARS-5) increased in the first year of treatment to a third of patients. In line with the strong beliefs in the necessity of taking nilotinib, forgetting to take a dose was more prevalent than intentionally adjusting/skipping doses. Nilotinib C_min were generally above the therapeutic target in 95% of patients. Patients reported a variety of side effects, of which fatigue was most frequent. The mean C_min was higher in patients who reported severe itching and fatigue. The overall 1-year MMR rate ranged from 47 to 71%.

Conclusion

Substantial nonadherence (< 90%) to nilotinib was rare and nilotinib C_min were generally above the therapeutic target. Lack of response in our group of patients was not related to nonadherence or inadequate C_min. Nevertheless, a considerable number of patients experienced difficulties in adhering to the twice daily fasted dosing regimen, emphasizing the importance of continuous support of medication adherence in CML.

Clinical trial registration

NTR3992 (Netherlands Trial Register, www.trialregister.nl)

Electronic supplementary material

The online version of this article (10.1007/s00228-020-02910-3) contains supplementary material, which is available to authorized users.

Needs for information and reasons for (non)adherence in chronic myeloid leukaemia: Be aware of social activities disturbing daily routines

OBJECTIVES

To obtain insight into patients' reasons for medication (non)adherence in chronic myeloid leukaemia (CML) and needs and wishes regarding information and communication.

METHODS

A mixed-method study on the basis of a questionnaire and semi-structured interviews. The CML patient advocacy group asked patients to participate.

RESULTS

Sixty-one patients (54 ± 12 years, 43% male) using imatinib, dasatinib or nilotinib participated. Fifteen patients (25%) reported to miss an intake at least once a month. Most were not worried about missing an intake and did not discuss missed intakes with their healthcare provider (HCP). Social activities disturbing daily routines and the wish to avoid side effects resulted in nonadherence. Patients wanted extensive and understandable information provided timely on all aspects of CML treatment, in particular on side effects, and a more supportive HCP attitude.

CONCLUSIONS

Nonadherence to CML medication does not cause concern in all patients and is not discussed pro-actively. HCP have a clear role in supporting medication adherence in CML and must be aware that social activities disturbing daily routines contribute to nonadherence. HCP should discuss (non)adherence in a direct manner, motivate patients to play an active role in managing their medication and timely provide extensive and understandable information on all aspects of CML.

Intolerance to tyrosine kinase inhibitors in chronic myeloid leukemia: the possible role of ponatinib

INTRODUCTION

In spite of the proven efficacy of the tyrosine kinase inhibitor (TKI), imatinib, in chronic myeloid leukemia (CML), many patients develop intolerance and discontinue therapy in the long-term. Second-generation TKIs (dasatinib, nilotinib, bosutinib) and the third-generation TKI, ponatinib, have added opportunities but also complexity in the settings of CML treatment.

AREAS COVERED

Different definitions of intolerance have been used through several clinical trials, making the published data non homogenous. In most cases, only the severity of acute adverse events (AEs), graded by conventional scales such as Common Terminology Criteria for Adverse Events, was reported. Limited attention to long-term events or more in general, to the impact of AEs on patient quality of life (QoL), remains a problem. Ponatinib is active against all BCR-ABL1 mutants, including T315I, and is widely used to treat patients who developed resistance to other TKIs in any CML phase; however, only limited data is available on the possible role of ponatinib for intolerant patients.

EXPERT OPINION

We review the different definitions of intolerance used in sponsored trials and in clinical practice, and we discuss how such definitions impact on the management of AEs. We summarize how to evaluate QoL during treatment with TKIs and how to include ponatinib among possible option for intolerant patients.

Genetic predisposition and induced pro-inflammatory/pro-oxidative status may play a role in increased atherothrombotic events in nilotinib treated chronic myeloid leukemia patients

Several reports described an increased risk of cardiovascular (CV) events, mainly atherothrombotic, in Chronic Myeloid Leukemia (CML) patients receiving nilotinib. However, the underlying mechanism remains elusive. The objective of the current cross-sectional retrospective study is to address a potential correlation between Tyrosine Kinase Inhibitors (TKIs) treatment and CV events. One hundred and 10 chronic phase CML patients in complete cytogenetic response during nilotinib or imatinib, were screened for CV events and evaluated for: traditional CV risk factors, pro/anti-inflammatory biochemical parameters and detrimental ORL1 gene polymorphisms (encoding for altered oxidized LDL receptor-1). Multivariate analysis of the whole cohort showed that the cluster of co-existing nilotinib treatment, dyslipidaemia and G allele of LOX-1 polymorphism was the only significant finding associated with CV events. Furthermore, multivariate analysis according to TKI treatment confirmed IVS4-14 G/G LOX-1 polymorphism as the strongest predictive factor for a higher incidence of CV events in nilotinib patients. Biochemical assessment showed an unbalanced pro-inflammatory cytokines network in nilotinib vs imatinib patients. Surprisingly, pre-existing traditional CV risk factors were not always predictive of CV events. We believe that in nilotinib patients an induced “inflammatory/oxidative status”, together with a genetic pro-atherothrombotic predisposition, may favour the increased incidence of CV events. Prospective studies focused on this issue are ongoing.

Development of a protease-resistant reporter to quantify BCR-ABL activity in intact cells

A peptidase-resistant ABL kinase substrate was developed by identifying protease-susceptible bonds on an ABL substrate peptide and replacing flanking amino acids with non-native amino acids. After an iterative design process, the lead, or designed, peptide X-A possesses a six-fold longer life in a cytosolic lysate than that of the starting peptide. The catalytic efficiency (kcat/KM) of purified ABL kinase for the lead peptide (125 s-1 μM-1) is similar to that of the starting peptide (103 s-1 μM-1) demonstrating preservation of the peptide's ability to serve as a kinase substrate. When incubated in cytosolic lysates, the lead peptide is slowly degraded into 4 fragments over time. In contrast, when loaded into intact cells, the peptide is metabolized into 5 fragments, with only 2 of the fragments corresponding to those in the lysate. Thus the two environments possess differing peptidase activities, which must be accounted for when designing peptidase-resistant peptides. In both settings, the substrate is phosphorylated by BCR-ABL providing a readout of BCR-ABL activity. A small panel of tyrosine kinase inhibitors verified the substrate's specificity for BCR-ABL/ABL kinase activity in both lysates and cells in spite of the multitude of other kinases present. The designed peptide X-A acts as a long-lived BCR-ABL kinase reporter in the leukemic cells possessing the BCR-ABL mutation.