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Background and Objective: When utilizing population pharmacokinetic (popPK) models for a priori dosage individualization, selecting the best model is crucial to obtain adequate doses. We developed and evaluated several model-selection and ensembling methods, using external evaluation on the basis of therapeutic drug monitoring (TDM) samples to identify the best (set of) models per patient for a priori dosage individualization. Methods: PK data and models describing both hospitalized patients (n = 134) receiving continuous vancomycin (26 models) and patients (n = 92) receiving imatinib in an outpatient setting (12 models) are included. Target attainment of four model-selection methods was compared with standard dosing: the best model based on external validation, uninformed model ensembling, model ensembling using a weighting scheme on the basis of covariate-stratified external evaluation, and model selection using covariates in decision trees that were subsequently ensembled. Results: Overall, the use of PK models improved the proportion of patients exposed to concentrations within the therapeutic window for both cohorts. Relative improvement of proportion on target for best model, unweighted, weighted, and decision trees were − 7.0%, 2.3%, 11.4%, and 37.0% (vancomycin method-development); 23.2%, 7.9%, 15.6%, and, 77.2% (vancomycin validation); 40.7%, 50.0%, 59.5%, and 59.5% (imatinib method-development); and 19.0%, 28.5%, 38.0%, and 23.8% (imatinib validation), respectively. Conclusions: The best (set of) models per patient for a priori dosage individualization can be identified using a relatively small set of TDM samples as external evaluation. Adequately performing popPK models were identified while also excluding poor-performing models. Dose recommendations resulted in more patients within the therapeutic range for both vancomycin and imatinib. Prospective validation is necessary before clinical implementation. [ABSTRACT FROM AUTHOR]

Nilotinib, a tyrosine kinase inhibitor that targets the Abelson tyrosine kinase (c-Abl) signaling pathway, is FDA-approved to treat chronic myeloid leukemia. Nilotinib has properties indicative of a possible utility in neuroprotection that have prompted exploration of repurposing the drug for the treatment of Alzheimer's disease (AD) and Parkinson's disease (PD). AD is a progressive age-related neurodegenerative disorder characterized by the deposition of extracellular amyloid-β plaques and intracellular neurofibrillary tangles. It is incurable and affects approximately 50 million patients worldwide. Nilotinib reduces c-Abl phosphorylation, amyloid-β levels, and dopaminergic neuron degeneration in preclinical AD models. This study explores the effects of nilotinib on amyloid processing and mitochondrial functioning in the SH-SY5Y human neuroblastoma cell line. SH-SY5Y cells were exposed to nilotinib (1, 5, and 10 µM). Real-time PCR and immunoblot analysis were performed to quantify the expression of genes pertaining to amyloid-β processing and neuronal health. Nilotinib did not significantly change APP, BACE1, or ADAM10 mRNA levels. However, BACE1 protein was significantly increased at 1 µM, and ADAM10 was increased at 10 µM nilotinib without affecting APP protein expression. Further, nilotinib treatment did not affect the expression of genes associated with neuronal health and mitochondrial functioning. Taken together, our findings do not support the efficacy of nilotinib treatment for neuroprotection. [ABSTRACT FROM AUTHOR]

The primary treatment for chronic myeloid leukemia (CML) involves first- and second-generation tyrosine kinase inhibitors (TKIs), such as imatinib, nilotinib, bosutinib, and dasatinib. However, these medications are ineffective against mutations in the kinase domain of the ABL1 protein, particularly in the protein with the T315I mutation. To address this, ponatinib (PNT), a third-generation inhibitor, was developed. Despite its efficacy in treating the BCR-ABL1T315I mutation, the use of PNT was briefly suspended in 2013 due to serious adverse effects but was subsequently reintroduced to the market. During the drug discovery and development process, it is rare to consolidate all information into a single article, as is the case with ponatinib. This review aims to compile and chronologically organize the research on the discovery of ponatinib using medicinal chemistry tools and computational methods. It includes in silico calculations, such as the octanol/water partition coefficient (cLogP) via SwissAdme, and 2D maps of intermolecular interactions through molecular docking. This approach enhances understanding for both specialists and those interested in medicinal chemistry and pharmacology, while also contextualizing future directions for further optimizations of ponatinib, facilitating the development of new analogs of this crucial inhibitor for the treatment of CML and Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL). [ABSTRACT FROM AUTHOR]

Introduction: Chronic myeloid leukemia is characterized by the dysregulated growth of granulocytes, driven by the Philadelphia chromosome translocation. The prevalence of CML is higher in men, with a median age of 57 years and a five-year survival rate of 85%. Tyrosine kinase inhibitors such as Imatinib have revolutionized CML treatment. However, resistance or intolerance to first-line Imatinib requires second-generation TKIs like Nilotinib and Dasatinib. This study aims to evaluate the response of patients treated with these TKIs at a hematology clinic. Methods: This retrospective study analyzed 100 randomly selected CML patients treated between 2020 and 2022. Data were collected on patient demographics, disease progression, treatment regimens, and response rates. Patients who started on Imatinib and later switched to second-line TKIs due to resistance or side effects were followed to assess treatment efficacy. Results: The cohort had a median age of 43 years, with 52% males and 48% females. Most patients (95%) initiated treatment with Imatinib, with 6% experiencing mild side effects and 4% severe side effects leading to treatment changes. In patients resistant to Imatinib, second-generation TKIs showed favorable responses: Dasatinib was effective in patients with advanced disease, while Nilotinib was useful for those intolerant to Imatinib. One patient resistant to both was successfully treated with Bosutinib, a third-generation TKI. Conclusion: Our findings highlight the efficacy of secondgeneration TKIs for managing Imatinib-resistant CML. Dasatinib and Nilotinib effectively managed disease progression, though side effects were a concern. The use of third-generation TKIs like Bosutinib provides additional therapeutic options for refractory cases. [ABSTRACT FROM AUTHOR]

Gynecomastia refers to the abnormal enlargement of the male breast caused by the proliferation of the glandular component of the breast, typically due to sexual hormone disturbance. Multiple medications have been linked to the development of gynecomastia with varying incidences. This adverse event has also been associated with TKIs such as imatinib, dasatinib, and rarely nilotinib. However, it is poorly described and regarded as a rare event. Herein, we present the first case of a CML patient who developed gynecomastia after switching from imatinib to flumatinib. The patient is an 82-year-old male. He was diagnosed with CML and initially treated with imatinib. However, the treatment response milestone after three months of imatinib was not achieved. Hence, flumatinib was used to replace imatinib. Unexpectedly, two weeks later, he developed gynecomastia. Gynecomastia usually causes distress to patients, and there are currently no clear mechanisms or management strategies for this condition. Inspired by this case and through a review of the literature, we propose possible mechanisms and management strategies for this rare adverse event associated with TKIs, along with future perspectives. This may assist others in dealing with this issue and stimulate research on it. [ABSTRACT FROM AUTHOR]

Background: To evaluate the outcomes of first‐line imatinib versus nilotinib treatment for chronic myeloid leukemia in the chronic phase (CML‐CP) in real‐world clinical practice. Methods: A propensity score analysis was performed to eliminate imbalances between the treatment groups. In the analysis, 163 patients in the nilotinib group and 163 patients in the matched imatinib group were retrospectively evaluated. Results: Nilotinib‐treated patients achieved complete cytogenetic response (CCyR) and major molecular response more rapidly than imatinib‐treated patients. However, there was no significant difference in 5‐year overall survival (OS) or progression‐free survival (PFS) between the two groups (OS: 94.3% vs. 90.5%, p = 0.602; PFS: 92.9% vs. 88.0%, p = 0.614). Nilotinib‐treated patients had a higher failure‐free survival (FFS) and event‐free survival (EFS) than imatinib‐treated patients (FFS: 71.7% vs. 54.3%, p = 0.040; EFS: 71.7% vs. 53.5%, p = 0.025). Conclusions: This retrospective analysis from clinical practice did not confirm any benefit of frontline nilotinib treatment for OS and PFS; however, it did demonstrate higher FFS and EFS in the nilotinib cohort. [ABSTRACT FROM AUTHOR]

Therapeutic drug monitoring (TDM) involves measuring and interpreting drug concentrations in biological fluids to adjust drug dosages. In onco‐hematology, TDM guidelines for oral molecular targeted therapies (oMTTs) are varied. This study evaluates a quantitative approach with a score to predict the clinical usefulness of TDM for oMTTs. We identified key parameters for an oMTT's suitability for TDM from standard TDM recommendations. We gathered oMTT pharmacological data, which covered exposure variability (considering pharmacokinetic (PK) impact of food and proton pump inhibitors), technical intricacy (PK linearity and active metabolites), efficacy (exposure‐response relationship), and safety (maximum tolerated dose, and exposure‐safety relationship). To assess the validity and the relevance of the score and define relevant thresholds, we evaluated molecules with prospective validation or strong recommendations for TDM, both in oncology and in other fields. By September 1, 2021, the US Food and Drug Administration (FDA) approved 67 oMTTs for onco‐hematological indications. Scores ranged from 15 (acalabrutinib) to 80 (sunitinib) with an average of 48.3 and a standard deviation of 15.6. Top scorers included sunitinib, sorafenib, cabozantinib, nilotinib, and abemaciclib. Based on scores, drugs were categorized into low (< 40), intermediate (≥ 40 and < 60), and high (≥ 60) relevance for TDM. Notably, negative controls generally scored around or under 40, whereas positive controls had a high score across different indications. In this work, we propose a quantitative and reproducible score to compare the potential usefulness of TDM for oMTTs. Future guidelines should prioritize the TDM for molecules with the highest score. [ABSTRACT FROM AUTHOR]

Background: Blood cancer is a significant contributor to mortality rates worldwide, and its prevalence is projected to rise on a global scale. This trend places considerable strain on healthcare systems and necessitates the expedited development of innovative treatments by pharmaceutical firms to remain competitive. Conventional pellets produce rapid plasma drug levels, but they might cause side effects, decrease effectiveness, and lead to poor therapeutic management. Ibrutinib and Nilotinib are employed to treat leukemia patients. Methodology: The current research aims to formulate, characterize, and anticancer effect of Nilotinib immediate release (NIR) and Ibrutinib sustained release (ISR) seal sugar-coated pellets. Micrometric properties estimated the characterization of the drug pellets, and surface morphology was estimated using scanning electron microscopy. Drug excipient compatibility studies, stability studies, and in-vitro drug release were accessed. Result & Discussion: The results of pellet formulations FNI-1 to FNI-5 showed that FNI-5 formulations showed 100±6.0 µm size and possessed excellent mechanical strength for giving pellets a good self-life; also, due to the higher drug content up to 99%, FNI-5 was the best suited for pellet formulation and because NIR showed 99.18 ± 2.12 drug release at 2h and ISR 99.03±3.74% up to 12h so that anticancer concentration maintained for prolonged period. The standard dose for cytotoxicity against the THP-1 cell line of Nilotinib was found to be 200 mg, and the maintenance oral dose of Ibrutinib was 140mg, with four times the intake of the drug up to 560 mg. In an in vitro study in FNI-5 (final formulation), the dose of Ibrutinib was reduced to 420 mg. Conclusion: A synergistic effect of Ibrutinib and nilotinib drugs was observed in the inhibition of cancer cell growth, with an IC50 value of 4.585 µg/mL

Background: Despite the promising of introduction of tyrosine kinase inhibitors (TKIs), chronic myeloid leukemia (CML) remains a significant cause of annual mortality. Red blood cell distribution width (RDW), neutrophil/lymphocyte ratio (NLR), and platelet/lymphocyte ratio (PLR) are parameters derived from a complete blood count (CBC) commonly used to diagnose anemia, autoimmune diseases, and inflammation. These parameters have been reported to have a strong association with various diseases, including hematologic malignancies. Objectives: The study aims to identify whether RDW, NLR, and PLR can act as predictors of survival in newly diagnosed and treated CML patients. Materials and Methods: The study involved 60 Iraqi patients (37 males, 23 females, aged 17–69 years) with CML at chronic phase, who were referred to the National Center of Hematology/Mustansiriyah University, Baghdad, from February 2022 to December 2022. Twenty were newly diagnosed (T0), and 40 were under TKI treatment (T+), with 20 on imatinib and 20 on nilotinib. Additionally, a control group of 20 age- and gender-matched healthy subjects was included. CBC assessed red blood cell (RBC) indices across all groups. Results: There was no significant difference in the age of CML patients at the onset of disease between males (34.5 ± 11.7 years) and females (34 ± 11.9 years). Likewise, there was no significant difference in the treatment of CML patients with imatinib or nilotinib between males (48% and 52%) and females (53.3% and 47.7%), respectively. Most RBC indices for patients and controls were within normal ranges without significant differences. However, RDW% in T0 was markedly elevated (20.4%), with about 80% showing anisocytosis, surpassing both T+ and controls, and exceeding the upper limit of normal. The total and differential white blood cell (WBC) counts were significantly higher in T0 compared to T+, exceeding their normal ranges. Additionally, the NLR was significantly higher in T0 (8.13) compared with T+ and controls (1.80 and 1.87, respectively). Platelet count, mean platelet volume, and platelet distribution width (PDW%) differed significantly among the three groups but remained within the normal range. However, PLR in T0 (31 ± 24) was significantly lower than those in T+ and controls (130 ± 43 and 102 ± 27, respectively). Conclusion: It can be concluded that the monitoring of some parameters in peripheral blood in CBC test (as a simple and inexpensive test) such as RDW%, NLR%, and PLR% during the therapy course of CML patients may act as predictive markers to evaluate the prognosis of disease in CML patients and the degree of response to certain TKI treatment.

Abstract Background Although immune checkpoint inhibitors (ICIs) have revolutionized the landscape of cancer treatment, only a minority of colorectal cancer (CRC) patients respond to them. Enhancing tumor immunogenicity by increasing major histocompatibility complex I (MHC-I) surface expression is a promising strategy to boost the antitumor efficacy of ICIs. Methods Dual luciferase reporter assays were performed to find drug candidates that can increase MHC-I expression. The effect of nilotinib on MHC-I expression was verified by dual luciferase reporter assays, qRT-PCR, flow cytometry and western blotting. The biological functions of nilotinib were evaluated through a series of in vitro and in vivo experiments. Using RNA-seq analysis, immunofluorescence assays, western blotting, flow cytometry, rescue experiments and microarray chip assays, the underlying molecular mechanisms were investigated. Results Nilotinib induces MHC-I expression in CRC cells, enhances CD8+ T-cell cytotoxicity and subsequently enhances the antitumor effects of anti-PDL1 in both microsatellite instability and microsatellite stable models. Mechanistically, nilotinib promotes MHC-I mRNA expression via the cGAS-STING-NF-κB pathway and reduces MHC-I degradation by suppressing PCSK9 expression in CRC cells. PCSK9 may serve as a potential therapeutic target for CRC, with nilotinib potentially targeting PCSK9 to exert anti-CRC effects. Conclusion This study reveals a previously unknown role of nilotinib in antitumor immunity by inducing MHC-I expression in CRC cells. Our findings suggest that combining nilotinib with anti-PDL1 therapy may be an effective strategy for the treatment of CRC.

Abstract Background The therapeutic landscape of chronic myeloid leukaemia (CML) has been transformed by tyrosine kinase inhibitors (TKI). Nilotinib, showed higher rates of major molecular response than imatinib, however associated with higher cardiovascular (CV) toxicity. We sought to describe the CV events associated with nilotinib in a real-world population and assess the predictive value of the HFA-ICOS risk score. Methods The HFA-ICOS baseline risk was calculated for patients with CML treated with nilotinib beween 2006 and 2021. The primary end point was the incidence of all CV events. The secondary end point was the incidence of ischaemic events. Survival analysis evaluated the risk (hazard ratio [HR]) of events stratified by baseline risk category, whilst on nilotinib therapy. Results Two hundred and twenty-nine eligible patients were included. The incidence of CV events was 20.9% (95% CI: 15.7–26.2%) following a median duration of treatment of 34.4 months. The secondary end point occurred in 12.7% (95% CI: 8.4–16.9%) of the population. Patients with higher HFA-ICOS baseline score had higher rates of CV events (low: 11.2%, medium: 28.2% [HR: 2.51, 95% CI: 1.17–5.66], high/very high: 32.4% [HR: 3.57, 95% CI: 1.77–7.20]) and ischaemic events (low: 5.20%, medium: 17.9% [HR: 2.19, 95% CI: 0.97–4.96], high/very high: 21.6% [HR: 3.9, 95% CI: 1.91–7.89]). In patients who did not have a CV event, the median total dose at last follow up or cessation of nilotinib therapy was lower when compared to the total daily median dose of nilotinib in patients who had a CV event (450 mg vs. 600 mg, p = 0.0074). Conclusions The HFA-ICOS risk stratification tool is an efficient discriminator at low, medium and high/very high risk of developing cardiovascular events, with an overall positive trend towards increasing cardiotoxicity rates with rising risk catergories. This study provides evidence to support the use of this predictive tool in nilotinib treated patients.

Background: Although immune checkpoint inhibitors (ICIs) have revolutionized the landscape of cancer treatment, only a minority of colorectal cancer (CRC) patients respond to them. Enhancing tumor immunogenicity by increasing major histocompatibility complex I (MHC-I) surface expression is a promising strategy to boost the antitumor efficacy of ICIs. Methods: Dual luciferase reporter assays were performed to find drug candidates that can increase MHC-I expression. The effect of nilotinib on MHC-I expression was verified by dual luciferase reporter assays, qRT-PCR, flow cytometry and western blotting. The biological functions of nilotinib were evaluated through a series of in vitro and in vivo experiments. Using RNA-seq analysis, immunofluorescence assays, western blotting, flow cytometry, rescue experiments and microarray chip assays, the underlying molecular mechanisms were investigated. Results: Nilotinib induces MHC-I expression in CRC cells, enhances CD8+ T-cell cytotoxicity and subsequently enhances the antitumor effects of anti-PDL1 in both microsatellite instability and microsatellite stable models. Mechanistically, nilotinib promotes MHC-I mRNA expression via the cGAS-STING-NF-κB pathway and reduces MHC-I degradation by suppressing PCSK9 expression in CRC cells. PCSK9 may serve as a potential therapeutic target for CRC, with nilotinib potentially targeting PCSK9 to exert anti-CRC effects. Conclusion: This study reveals a previously unknown role of nilotinib in antitumor immunity by inducing MHC-I expression in CRC cells. Our findings suggest that combining nilotinib with anti-PDL1 therapy may be an effective strategy for the treatment of CRC. [ABSTRACT FROM AUTHOR]

Imatinib is an oral molecular targeted therapy that acts as a tyrosine kinase inhibitor. Silkworms present a promising experimental model for elucidating the pharmacokinetic and toxicity profiles of various compounds. This study aimed to establish an experimental paradigm for investigating the pharmacokinetics of imatinib in silkworms. A comparative analysis of imatinib pharmacokinetic parameters across silkworms, humans, mice, and rats revealed similarities in time to maximum concentration (Tmax) and apparent clearance values between silkworms and humans. However, differences in elimination half-life (t1/2) and apparent volume of distribution between silkworms and humans remained within 5- and 4-fold ranges, respectively. Importantly, mice demonstrated pharmacokinetic parameters closer to those of humans than rats during imatinib studies. Additionally, silkworms and mice exhibit similar Tmax and t1/2 values. This study highlights the potential of silkworms as valuable tools for investigating imatinib metabolism in pharmacokinetic studies. Furthermore, it underscores the applicability of silkworms in elucidating the pharmacokinetic parameters of various molecular-targeted drugs, thus facilitating advancements in drug development and evaluation. [ABSTRACT FROM AUTHOR]

Purpose: Sunitinib is a recommended drug for metastatic renal cell carcinoma (RCC). However, the therapeutic potential of sunitinib is impaired by toxicity and resistance. Therefore, we seek to explore a combinatorial strategy to improve sunitinib efficacy of low-toxicity dose for better clinical application. Methods: We screen synergistic reagents of sunitinib from a compound library containing 1374 FDA-approved drugs by in vitro cell viability evaluation. The synergistically antiproliferative and proapoptotic effects were demonstrated on in vitro and in vivo models. The molecular mechanism was investigated by phosphoproteomics, co-immunoprecipitation, immunofluorescence and western-blot assays, etc. Results: From the four-step screening, nilotinib stood out as a potential synergistic killer combined with sunitinib. Subsequent functional evaluation demonstrated that nilotinib and sunitinib synergistically inhibit RCC cell proliferation and promote apoptosis in vitro and in vivo. Mechanistically, nilotinib activates E3-ligase HUWE1 and in combination with sunitinib renders MCL-1 for degradation via proteasome pathway, resulting in the release of Beclin-1 from MCL-1/Beclin-1 complex. Subsequently, Beclin-1 induces complete autophagy flux to promote antitumor effect. Conclusion: Our findings revealed that a novel mechanism that nilotinib in combination with sunitinib overcomes sunitinib resistance in RCC. Therefore, this novel rational combination regimen provides a promising therapeutic avenue for metastatic RCC and rationale for evaluating this combination clinically. [ABSTRACT FROM AUTHOR]

In the treatment of chronic myeloid leukemia (CML), resistance to BCR‐ABL inhibitors makes it difficult to continue treatment and is directly related to life expectancy. Therefore, asciminib was introduced to the market as a useful drug for overcoming drug resistance. While combining molecular targeted drugs is useful to avoid drug resistance, the new BCR‐ABL inhibitor asciminib and conventional BCR‐ABL inhibitors should be used as monotherapy in principle. Therefore, we investigated the synergistic effect and mechanism of the combination of asciminib and imatinib. We generated imatinib‐resistant cells using the human CML cell line K562, examined the effects of imatinib and asciminib exposure on cell survival using the WST‐8 assay, and comprehensively analyzed genetic variation related to drug resistance using RNA‐seq and real‐time PCR. A synergistic effect was observed when imatinib and asciminib were combined with or without imatinib resistance. Three genes, GRRP1, ESPN, and NOXA1, were extracted as the sites of action of asciminib. Asciminib in combination with BCR‐ABL inhibitors may improve the therapeutic efficacy of conventional BCR‐ABL inhibitors and prevent the development of resistance. Its dosage may be effective even at minimal doses that do not cause side effects. Further verification of this mechanism of action is needed. Additionally, cross‐resistance between BCR‐ABL inhibitors and asciminib may occur, which needs to be clarified through further validation as soon as possible. [ABSTRACT FROM AUTHOR]

MYC is a transcription factor crucial for maintaining cellular homeostasis, and its dysregulation is associated with highly aggressive cancers. Despite being considered "undruggable" due to its unstable protein structure, MYC gains stability through its interaction with its partner protein, MAX. The MYC-MAX heterodimer orchestrates the expression of numerous genes that contribute to an oncogenic phenotype. Previous efforts to develop small molecules, disrupting the MYC-MAX interaction, have shown promise in vitro but none have gained clinical approval. Our current computer-aided study utilizes an approach to explore drug repurposing as a strategy for inhibiting the c-MYC-MAX interaction. We have focused on compounds from DrugBank library, including Food and Drug Administration-approved drugs or those under investigation for other medical conditions. First, we identified a potential druggable site on flat interface of the c-MYC protein, which served as the target for virtual screening. Using both activity-based and structure-based screening, we comprehensively assessed the entire DrugBank library. Structure-based virtual screening was performed on AutoDock Vina and Glide docking tools, while activity-based screening was performed on two independent quantitative structure-activity relationship models. We focused on the top 2% of hit molecules from all screening methods. Ultimately, we selected consensus molecules from these screenings—those that exhibited both a stable interaction with c-MYC and superior inhibitory activity against c-MYC-MAX interaction. Among the evaluated molecules, we identified a protein kinase inhibitor (tyrosine kinase inhibitor [TKI]) known as nilotinib as a promising candidate targeting c-MYC-MAX dimer. Molecular dynamic simulations demonstrated a stable interaction between MYC and nilotinib. The interaction with nilotinib led to the stabilization of a region of the MYC protein that is distorted in apo-MYC and is important for MAX binding. Further analysis of differentially expressed gene revealed that nilotinib, uniquely among the tested TKIs, induced a gene expression program in which half of the genes were known to be responsive to c-MYC. Our findings provide the foundation for subsequent in vitro and in vivo investigations aimed at evaluating the efficacy of nilotinib in managing MYC oncogenic activity. [ABSTRACT FROM AUTHOR]

Objective: Tyrosine kinase inhibitors (TKIs) have successfully changed the natural course of chronic myeloid leukaemia (CML). Although they are highly effective drugs, their clinical benefit is conditioned by adherence. This study aims to analyse the adherence of CML patients treated with TKIs and to identify the main factors influencing their adherence to TKIs treatment. Material and methods: An 8-month prospective, observational, multicentre study which included patients diagnosed with CML on treatment with TKIs attending the outpatient departments (OPD) of the Pharmacy Services of the participating hospitals. Adherence was assessed using two methods: the Simplified Medication Adherence Questionnaire (SMAQ) and the register of treatment dispensations from the OPDs. To analyse the predictors of adherence, a questionnaire was developed to report demographic and socio-economic information on the patients. Results: A total of 130 patients enrolled in this study. Adherence rate was 56.9% (n = 74) among individuals, not conditioned by the type of drug used: imatinib (54.8%), nilotinib (63.6%) or dasatinib (54.3%) (p = 0.67). The patient educational level (p = 0.047) and employment status (p = 0.028) were predictors of non-adherence to treatment. Conclusions: Adherence is one of the most relevant parameters affecting the effectiveness of highly effective chronic treatments. Approximately half of our patients showed inadequate adherence to treatment with TKIs, with employment status and the individual's level of education emerging as the determining factors. [ABSTRACT FROM AUTHOR]