Tyrosine Kinase Inhibitor Imatinib Research Articles

Pyrrolo[2,3-D]Pyrimidines as EGFR and VEGFR Kinase Inhibitors: A Comprehensive SAR Review.

Tyrosine kinases are implicated in a wide array of cellular physiological processes, including cell signaling. The discovery of the BCR-ABL tyrosine kinase inhibitor imatinib and its FDA approval in 2001 paved the way for the development of small molecule chemical entities of diverse structural backgrounds as tyrosine kinase inhibitors for the treatment of various ailments. Two of the most prominent tyrosine kinases as drug targets are the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor receptor (VEGFR), as evidenced by the clinical success of their many inhibitors in the drug market. Among several other physiological roles, EGFR regulates epithelial tissue development and homeostasis, while VEGFR regulates tumor-induced angiogenesis. The pyrrolo[2,3-d]pyrimidine nucleus represents a deaza-isostere of adenine, the nitrogenous base of ATP. The recent introduction of many pyrrolo[2,3-d]pyrimidines to the drug market as tyrosine kinase inhibitors makes them a hot topic in the medicinal chemistry research area at the present time. This review article comprehensively sheds light on the structure-activity relationship (SAR) of pyrrolo[2,3-d]pyrimidines as EGFR and VEGFR tyrosine kinase inhibitors, aiming to provide help medicinal chemists in the design of future pyrrolopyrimidine kinase inhibitors.

9182 Metastatic Extra-Gastrointestinal Stromal Tumor Presenting As Hypoglycemia

Abstract Disclosure: O. faour: None. D. John: None. S.K. Suryanarayanan: None. A.A. Rizvi: None. Introduction: Non islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome seen in association with solid abdominal tumors of mesenchymal and epithelial origin. We report a case of metastatic extra-gastrointestinal stromal tumor (E-GIST) presenting with severe hypoglycemia as its initial manifestation. CASE DESCRIPTION: A 46-year-old patient was found to have a blood glucose of <45 mg/dl during a routine clinic visit with her primary care physician. Although she was asymptomatic, she was sent to the emergency room (ER) for further evaluation. She had a history of prediabetes managed by lifestyle modification. She has been experiencing multiple episodes of hypoglycemia previously which fulfilled the Whipple’s triad in the preceding months. These hypoglycemic episodes included loss of unconsciousness, falls in the shower with head injury, and several hospital visits. Serum glucose in the ER was 14 mg/dl and hypoglycemia persisted despite continuous dextrose solution. Physical examination was notable for a distended, non-tender abdomen and cervical lymphadenopathy. CT scan showed a 15 cm mass in the liver, multiple large masses in the mesentery, and a 11 cm lesion in the left pelvis. There were enlarged lymph nodes in the abdomen, chest, and neck. Serum chemistries drawn when the patient was hypoglycemic revealed potassium level of 2.7 mg/dl (3.5-5.5) an insulin level of <1.0 mIU/L (5-25), C-peptide <0.1 ng/mL (0.5-2), cortisol 13.8 mcg/dL (5-25), and insulin-like growth factor-2 (IGF-2) was 270 ng/mL (38-267). The IGF-2/IGF-1 molar ratio was 3.4 (normal <3:1). The sulfonylurea drug screen came back negative. Upper and lower endoscopies were unrevealing. Biopsy of the liver lesion showed cytology and immunohistochemical findings consistent with a epithelioid metastatic extra-gastrointestinal stromal tumor. A provisional diagnosis of NICTH was made. The patient responded well to intravenous glucose, oral carbohydrate intake and high-dose corticosteroids. She was subsequently started on therapy with the tyrosine kinase inhibitor (TKI) imatinib. Discussion: Paraneoplastic hypoglycemia is often seen in association with metastatic epithelial and mesenchymal tumors. IGF-2 and incompletely processed pro-IGF-2 activates autocrine, paracrine, and endocrine pathways that lead to tumor growth, fasting hypoglycemia, rarely of acromegalic features. Treatment with octreotide, diazoxide, and glucagon is generally ineffective, while glucocorticoid use and surgical intervention are helpful in ameliorating the hypoglycemia. Tumor-directed therapy with TKIs, primarily imatinib, appears promising in achieving remission. Our case is a clinical reminder that hypoglycemia secondary to NICTH can be the predominant presenting feature in patients with underlying E-GIST. Presentation: 6/3/2024

Critical review of clinical data and expert-based recommendations for the use of bosutinib in the treatment of chronic myeloid leukemia.

Chronic myeloid leukemia (CML), characterized by the presence of the BCR::ABL1 fusion gene, has undergone a transformative shift with the introduction of tyrosine kinase inhibitors (TKIs). The current availability of six different TKIs (imatinib, dasatinib, nilotinib, bosutinib, ponatinib, and asciminib) in clinical practice makes it important to know their efficacy and toxicity profile for treatment optimization. This review examines the latest insights regarding the use of bosutinib in CML treatment. Clinical trials have demonstrated the effectiveness of bosutinib, positioning it as a first-line treatment that can induce sustained molecular responses. Importantly, it can also be effective in patients who have experienced treatment failure or intolerance with prior TKIs, revealing the potential of bosutinib also in second- and later-line settings. Even in the advanced phase of CML, bosutinib has demonstrated its capacity to achieve molecular responses, expanding its usefulness. Real-world evidence studies echo these findings, emphasizing bosutinib's effectiveness in achieving deep molecular responses, maintaining remissions, and serving as an alternative for patients intolerant or resistant to other TKIs as a second-line therapy. Notably, one of the greatest strengths of bosutinib is its favorable safety profile, in particular the low incidence of vascular complications with its use, which is undoubtedly a comparative advantage over other TKIs. In summary, the latest research highlights the versatility of bosutinib in CML treatment and underscores its pivotal role in optimizing patient management in challenging cases. Continuing research and investigation will further establish bosutinib's place in the evolving landscape of CML therapy, offering an alternative for CML patients across different treatment stages.

Simultaneous determination of three tyrosine kinase inhibitors and three triazoles in human plasma by LC-MS/MS: applications to therapeutic drug monitoring and drug-drug interaction studies

Tyrosine kinase inhibitors (TKIs) and triazole antifungals are the first-line drugs for treating chronic myeloid leukemia (CML) and fungal infections, respectively, but both suffer from large exposure differences and narrow therapeutic windows. Moreover, these two types of drugs are commonly used together in CML patients with fungal infections. Multiple studies and guidelines have suggested the importance of therapeutic drug monitoring (TDM) of TKIs and triazoles. Currently, methods for the simultaneous determination of both types of drugs are limited. We developed a simple, rapid, and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous quantification of three commonly used TKIs (imatinib, dasatinib, and nilotinib) and three commonly used triazoles (voriconazole, itraconazole, and posaconazole) in human plasma. The analytes were eluted on a Welch XB-C18 analytical column (50 × 2.1 mm, 5 µm) at 0.7 mL/min, using a gradient elution of 10 mM ammonium formate (A) and methanol–acetonitrile-isopropanol (80:10:10, v/v/v) containing 0.2 % formic acid (B) with a total analysis time of 3.5 min. The calibration curves were linear over the range from 20 to 4000 ng/mL for imatinib and nilotinib, from 2 to 400 ng/mL for dasatinib, and from 50 to 10,000 ng/mL for voriconazole, itraconazole, and posaconazole. Selectivity, accuracy, precision, recovery, matrix effect, and stability all met the validation requirements. The method was successfully used for TDM in CML patients who co-treated with both TKIs and triazoles. Drug-drug interaction analysis between TKIs and triazoles showed that a significant positive correlation was observed between imatinib and voriconazole, as well as dasatinib and voriconazole. Therefore, this method can be well applied in clinical TDM for patients receiving TKIs, triazoles, or both simultaneously.

Varying concentrations of tyrosine kinase inhibitors in chronic myeloid leukemia patients following bariatric surgery: a case series

Bariatric surgery is increasingly performed to treat severe obesity. As a result of anatomical and physiological changes in the gastrointestinal tract, the pharmacokinetics (PK) of oral drugs can be altered, affecting their efficacy and safety. This includes the class of tyrosine kinase inhibitors (TKIs) which are used to treat chronic myeloid leukemia (CML). This case series describes the clinical course of four CML cases with a history of bariatric surgery. The patients used various TKIs (nilotinib, dasatinib, bosutinib, ponatinib, and imatinib) for which 15 drug levels were measured. The measured TKI concentrations were in part subtherapeutic, and highly variable when compared to mean levels measured in the general population. Multiple drug levels were measured in these patients, as the clinicians were aware of the possible impact of bariatric surgery. The drug levels were used as additional input for clinical decision-making. All four patients required TKI switches and/or dose modifications to achieve an effective and tolerable treatment. Eventually, adequate clinical and molecular remissions were achieved in all cases. In summary, TKI concentrations of patients undergoing bariatric surgery may be subtherapeutic. Moreover, there is substantial interindividual and intraindividual variation, which may be explained by the complex interference of bariatric surgery and associated weight loss. For clinical practice, therapeutic drug monitoring is advised in patients with a history of bariatric surgery in case of suboptimal response or loss of response.

Mechanisms and treatment of pulmonary arterial hypertension.

Substantial progress has been made in the management of pulmonary arterial hypertension (PAH) in the past 25 years, but the disease remains life-limiting. Established therapies for PAH are mostly limited to symptomatic relief by correcting the imbalance of vasoactive factors. The tyrosine kinase inhibitor imatinib, the first predominantly non-vasodilatory drug to be tested in patients with PAH, improved exercise capacity and pulmonary haemodynamics compared with placebo but at the expense of adverse events such as subdural haematoma. Given that administration by inhalation might reduce the risk of systemic adverse effects, inhaled formulations of tyrosine kinase inhibitors are currently in clinical development. Other novel therapeutic approaches for PAH include suppression of activin receptor type IIA signalling with sotatercept, which has shown substantial efficacy in clinical trials and was approved for use in the USA in 2024, but the long-term safety of the drug remains unclear. Future advances in the management of PAH will focus on right ventricular function and involve deep phenotyping and the development of a personalized medicine approach. In this Review, we summarize the mechanisms underlying PAH, provide an overview of available PAH therapies and their limitations, describe the development of newer, predominantly non-vasodilatory drugs that are currently being tested in phase II or III clinical trials, and discuss future directions for PAH research.

The efficacy and safety of antiangiogenesis tyrosine kinase inhibitors in patients with advanced anaplastic thyroid cancer: A meta-analysis of prospective studies.

The poor prognosis of anaplastic thyroid cancer (ATC) patients is associated with limited effective therapeutic strategies. Multiple antiangiogenesis tyrosine kinase inhibitors (TKIs) have been applied in later-line treatment of ATC; however, the results reported in clinical trials were controversial. In this study, we reconstructed the patient-level data to pooled-analyze the survival data, responses, and adverse events. Online databases (PubMed, Web of Science, Embase, and Cochrane CENTRAL) were searched on September 03, 2023. R software combined with the "metaSurvival" and "meta" packages were used to reconstruct the survival curves and summarize the response rates. The primary endpoints were progression-free survival (PFS) and overall survival (OS). The secondary endpoints were survival rate, objective response rate (ORR), disease control rate (DCR), and treatment-related adverse events. Six prospective clinical trials involving 140 ATC patients were enrolled. Four types of TKIs (imatinib, pazopanib, sorafenib, and lenvatinib) were included. When advanced ATC patients were treated with the TKIs, the median OS was 4.8 months and the median PFS was 2.6 months. The pooled ORR and DCR were 9% and 53%. Hypertension, decreased appetite, rash, and lymphopenia were the most common grade ≥ 3 treatment-related adverse events. Mono-anitangiogenesis TKI therapy showed limited improvements in treating advanced ATC patients. Combining antiangiogenesis TKI therapy with chemotherapy, radiotherapy, or immunotherapy could be the direction of future studies.

A predictive model for therapy failure in patients with chronic myeloid leukemia receiving tyrosine kinase inhibitor therapy

AbstractAlthough tyrosine kinase inhibitor (TKI) therapy has markedly improved the survival of people with chronic-phase chronic myeloid leukemia (CML), 20% to 30% of people still experienced therapy failure. Data from 1955 consecutive patients with chronic-phase CML diagnosed by the European LeukemiaNet recommendations from 1 center receiving initial imatinib or a second-generation (2G) TKI therapy were interrogated to develop a clinical prediction model for TKI-therapy failure. This model was subsequently validated in 3454 patients from 76 other centers. Using the predictive clinical covariates associated with TKI-therapy failure, we developed a model that stratified patients into low-, intermediate- and high-risk subgroups with significantly different cumulative incidences of therapy failure (P < .001). There was good discrimination and calibration in the external validation data set, and the performance was consistent with that of the training data set. Our model had the better prediction discrimination than the Sokal and European Treatment and Outcome Study long-term survival scores, with the greater time-dependent area under the receiver-operator characteristic curve values and a better ability to redefine the risk of therapy failure. Our model could help physicians estimate the likelihood of initial imatinib or 2G TKI–therapy failure in people with chronic-phase CML.

Impact of the Type of Tyrosine Kinase Inhibitor (imatinib or dasatinib) Used Before allo-HCT on Outcome of Patients with Philadelphia-Positive Acute Lymphoblastic Leukemia. A Study on Behalf of the Acute Leukemia Working Party of the EBMT

The use of tyrosine kinase inhibitors (TKIs) during induction and consolidation, followed by allogeneic hematopoietic cell transplantation (allo-HCT), is a standard of care for patients with Philadelphia (Ph)-positive acute lymphoblastic leukemia (ALL). The goal of this study was to compare results of allo-HCT according to the type of TKI used pre-transplant, either imatinib, dasatinib or both. This was a retrospective, registry-based analysis including adult patients with Ph-positive ALL treated with allo-HCT between years 2010-2022. The analysis included 606 patients pre-treated with imatinib, 163 with dasatinib and 94 with both imatinib and dasatinib. Allo-HCTs were performed in first complete remission from either unrelated (56%), matched sibling (36%) or haploidentical donors (8%). Relapse incidence at 2 years was 26% in the imatinib group and 21% in the dasatinib group and 19% in the imatinib + dasatinib group (P = .06) while non-relapse mortality was 19%, 15%, and 23%, respectively (P = .37). No significant differences were found for leukemia-free survival (55% vs. 63% vs. 58%, P = .11) and overall survival (72% vs. 76% vs. 65%, P = .32). The incidence of grade 2-4 acute graft-versus-host disease (GVHD) and chronic GVHD was comparable across study groups, while the incidence of grade 3-4 acute GVHD was significantly increased for patients pre-treated with dasatinib alone (20%) than in the imatinib group (10%) or imatinib + dasatinib group (13%) (P = .002). On multivariate analysis a chance of GVHD and relapse-free survival (GRFS) was significantly decreased while the risk of grade 3-4 acute GVHD was increased for the dasatinib compared to imatinib group (hazard ratio, HR = 1.27, P = .048 and HR = 2.26, P = .0009, respectively). This study provides no evidence for the advantage of one TKI over another in terms of LFS and OS. However, the use of dasatinib is associated with increased risk of severe acute GVHD and decreased GRFS.

Management of Chronic Myeloid Leukemia that is Intolerant or Resistant to Front-Line Treatment

With advances in treatment for chronic myeloid leukemia (CML), the natural history of chronic phase (CP) CML has changed, with most individuals expected to live a normal life expectancy. The goal of therapy for most is to achieve a long-term deep molecular response (DMR) with the potential for medication discontinuation and treatment-free remission (TFR).1 Currently, six oral therapies have been approved for CP-CML in Canada: (1) imatinib, a first-generation tyrosine kinase inhibitor (TKI); (2) dasatinib, (3) nilotinib, and (4) bosutinib, the second-generation TKIs (2G-TKIs); (5) ponantinib, a third-generation TKI; and (6) asciminib, specifically targeting the ABL Myristoyl pocket (STAMP) inhibitor. Classically, treatment for CP-CML has consisted of front-line imatinib and switching to a 2G-TKI upon treatment resistance or intolerance. Increasingly, patients are being prescribed an upfront 2G-TKI with the goal of achieving quicker and deeper molecular remissions and a TFR.2 Challenges arise in CML when treatment with either two TKIs (imatinib + 2G-TKI) or one 2G-TKI fails, given the lack of evidence to inform clinical decision-making at this juncture. This paper aims to define TKI failure and help guide the selection of second-line treatment after failure of front-line therapy.

Constitutional DNA Polymorphisms Associated with the Plasma Imatinib Concentration in Chronic Myeloid Leukemia Patients

The tyrosine kinase Inhibitor (TKI) imatinib is approved for the treatment of the chronic phase of chronic myeloid leukemia (CP-CML). Pharmacokinetic studies have highlighted the importance of inter-patient variability on imatinib plasma trough concentrations (ima[C]min). In the OPTIM-imatinib trial, we demonstrated that therapeutic drug monitoring (TDM) is able to improve the molecular response of CP-CML patients treated with imatinib. Here, we analyzed the constitutional exomes and RNAseq data of these patients. We performed an association analysis between the constitutional genetic variants of the patients and their ima[C]min, measured after 12 weeks of treatment with 400 mg once daily. Using linear regression, we identified 50 SNPs that showed excess heterozygosity depending on the ima[C]min. Ten SNPs were from non-coding sequences, and among the 40 remaining, 30 (from 25 genes) could be split into two categories. The first group of 16 SNPs concerns genes encoding extracellular matrix, cell junction, and membrane proteins. Coincidentally, cell adhesion proteins were also identified by RNA-seq as being overexpressed in patients with high ima[C]min. The other group of 14 SNPs were from genes encoding proteins involved in transcription/translation. Although most of the SNPs are intronic variants (28), we also identified missense (3), synonymous (4), 5′/3′ (2), splicing (1), and upstream (4) variants. A haplotype analysis of four genes showed a significant association with high ima[C]min. None of the SNPs were significantly associated with the response. In conclusion, we identified a number of ima[C]min-associated SNPs, most of which correspond to genes encoding proteins that could play a role in the diffusion and transit of imatinib through membranes or epithelial barriers.

Toxicities associated with tyrosine kinase inhibitor maintenance following allogeneic hematopoietic cell transplantation in Philadelphia chromosome-positive acute lymphoblastic leukemia.

Allogeneic hematopoietic cell transplantation (HCT) offers a potential cure in Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL); nonetheless, relapses are common and the major cause of mortality. One strategy to prevent relapse is tyrosine kinase inhibitor (TKI) maintenance post-HCT, but published clinical experience is primarily with the first-generation TKI imatinib while data with newer generation TKIs are limited. We conducted a retrospective analysis of 185 Ph+ ALL patients who underwent HCT followed by TKI maintenance from 2003 to 2021 at City of Hope. Initially, 50 (27.0%) received imatinib, 118 (63.8%) received a second-generation TKI (2G-TKI), and 17 (9.2%) received ponatinib. A total of 77 patients (41.6%) required a dose reduction of their initial TKI due to toxicity. Sixty-six patients (35.7%) did not complete maintenance due to toxicity; 69 patients (37.3%) discontinued 1 TKI, and 11 (5.9%) discontinued 2 TKIs due to toxicity. Initial imatinib versus 2G-TKI versus ponatinib maintenance was discontinued in 19 (38.0%) versus 68 (57.6%) versus 3 (17.6%) patients due to toxicity (p = .003), respectively. Patients on ponatinib as their initial TKI had a longer duration of TKI maintenance versus 2G-TKI: 576.0 days (range, 72-921) versus 254.5 days (range, 3-2740; p = .02). The most common reasons for initial TKI discontinuation include gastrointestinal (GI) intolerance (15.1%), cytopenia (8.6%), and fluid retention (3.8%). The 5-year overall survival and progression-free survival for the total population were 78% and 71%, respectively. Our findings demonstrate the challenges of delivering post-HCT TKI maintenance in a large real-world cohort as toxicities leading to TKI interruptions, discontinuation, and dose reduction were common.

Treatment Access for Gastrointestinal Stromal Tumor in Predominantly Low- and Middle-Income Countries

Gastrointestinal stromal tumor (GIST) is a rare cancer treated with the tyrosine kinase inhibitors imatinib mesylate or sunitinib malate. In general, in low- and middle-income countries (LMICs), access to these treatments is limited. To describe the demographic characteristics, treatment duration, and survival of patients with GIST in LMICs treated with imatinib and sunitinib through The Max Foundation programs. This retrospective database cohort analysis included patients in 2 access programs administered by The Max Foundation: the Glivec International Patient Assistance Program (GIPAP), from January 1, 2001, to December 31, 2016, and the Max Access Solutions (MAS) program, January 1, 2017, to October 12, 2020. Sixty-six countries in which The Max Foundation facilitates access to imatinib and sunitinib were included. Participants consisted of patients with approved indications for imatinib, including adjuvant therapy in high-risk GIST by pathologic evaluation of resected tumor or biopsy-proven unresectable or metastatic GIST. All patients were reported to have tumors positive for CD117(c-kit) by treating physicians. A total of 9866 patients received treatment for metastatic and/or unresectable disease; 2100 received adjuvant imatinib; 49 received imatinib from another source and were only included in the sunitinib analysis; and 53 received both imatinib and sunitinib through The Max Foundation programs. Data were analyzed from October 13, 2020, to January 30, 2024. Demographic and clinical information was reported by treating physicians. Kaplan-Meier analysis was used to estimate time to treatment discontinuation (TTD) and overall survival (OS). An imputation-based informed censoring model estimated events for patients lost to follow-up after treatment with adjuvant imatinib. Patients who were lost to follow-up with metastatic or unresectable disease were presumed deceased. A total of 12 015 unique patients were included in the analysis (6890 male [57.6%]; median age, 54 [range, 0-100] years). Of these, 2100 patients were treated with imatinib in the adjuvant setting (median age, 54 [range 8-88] years) and 9866 were treated with imatinib for metastatic or unresectable disease (median age, 55 [range, 0-100] years). Male patients comprised 5867 of 9866 patients (59.5%) with metastatic or unresectable disease and 1023 of 2100 patients (48.7%) receiving adjuvant therapy. The median OS with imatinib for unresectable or metastatic disease was 5.8 (95% CI, 5.6-6.1) years, and the median TTD was 4.2 (95% CI, 4.1-4.4) years. The median OS with sunitinib for patients with metastatic or unresectable GIST was 2.0 (95% CI, 1.5-2.5) years; the median TTD was 1.5 (95% CI, 1.0-2.1) years. The 10-year OS rate in the adjuvant setting was 73.8% (95% CI, 67.2%-81.1%). In this cohort study of patients with GIST who were predominantly from LMICs and received orally administered therapy through the GIPAP or MAS programs, outcomes were similar to those observed in high-resource countries. These findings underscore the feasibility and relevance of administering oral anticancer therapy to a molecularly defined population in LMICs, addressing a critical gap in cancer care.

Standard therapy or additionally radioactive iodine (131I) therapy; which will stop the recurrence of glioblastoma multiforme (GBM)?

Glioblastoma multiforme (GBM) is the most aggressive malignant brain tumour. The average survival time for a patient diagnosed with GBM, using standard treatment methods, is several months. Authors of the article pose a direct question: Is it possible to treat GBM solely with radioactive iodine (¹³¹I) therapy without employing the sodium iodide symporter (NIS) gene? After all, NIS has been detected not only in the thyroid but also in various tumours. The main author of this article (A.C.), with the assistance of her colleagues (physicians and pharmacologists), underwent ¹³¹I therapy after prior iodine inhibition, resulting in approximately 30% reduction in tumour size as revealed by magnetic resonance imaging (MRI). Classical therapy for GBM encompasses neurosurgery, conventional radiotherapy, and chemotherapy (e.g. temozolomide). Currently, tyrosine kinase inhibitors (imatinib, sunitinib, and sorafenib) are being used. Additionally, novel drugs such as crizotinib, entrectinib, or larotrectinib are being applied. Recently, personalised multimodal immunotherapy (IMI) based on anti-tumour vaccines derived from oncolytic viruses has been developed, concomitant with the advancement of cellular and molecular immunology. Thus, ¹³¹I therapy has been successfully employed for the first time in the case of GBM recurrence.

Tyrosine kinase inhibitor-induced hypothyroidism: mechanism and clinical implications.

Since the first experimentally proven tyrosine kinase inhibitor (TKI) imatinib was introduced in the clinical setting, TKIs have attracted widespread attention because of their remarkable therapeutic effects and improvement of survival rates. TKIs are small-molecule, multi-target, anti-cancer agents that target different tyrosine kinases and block downstream signaling. However, with in-depth research on TKI drugs, the adverse reactions-for example, thyroid dysfunction-have become a concern and thus have attracted the attention of numerous researchers. Thyroid dysfunction, especially hypothyroidism, that occurs in high incidence during TKI therapy has a close relationship with treatment efficacy, but the mechanism of TKI-induced thyroid dysfunction is obscure. This review discusses the epidemiology, possible mechanisms, and clinical significance of hypothyroidism in cancer patients treated with TKI.

Physiologically based pharmacokinetic modeling of imatinib and N-desmethyl imatinib for drug-drug interaction predictions.

The first-generation tyrosine kinase inhibitor imatinib has revolutionized the development of targeted cancer therapy and remains among the frontline treatments, for example, against chronic myeloid leukemia. As a substrate of cytochrome P450 (CYP) 2C8, CYP3A4, and various transporters, imatinib is highly susceptible to drug-drug interactions (DDIs) when co-administered with corresponding perpetrator drugs. Additionally, imatinib and its main metabolite N-desmethyl imatinib (NDMI) act as inhibitors of CYP2C8, CYP2D6, and CYP3A4 affecting their own metabolism as well as the exposure of co-medications. This work presents the development of a parent-metabolite whole-body physiologically based pharmacokinetic (PBPK) model for imatinib and NDMI used for the investigation and prediction of different DDI scenarios centered around imatinib as both a victim and perpetrator drug. Model development was performed in PK-Sim® using a total of 60 plasma concentration-time profiles of imatinib and NDMI in healthy subjects and cancer patients. Metabolism of both compounds was integrated via CYP2C8 and CYP3A4, with imatinib additionally transported via P-glycoprotein. The subsequently developed DDI network demonstrated good predictive performance. DDIs involving imatinib and NDMI were simulated with perpetrator drugs rifampicin, ketoconazole, and gemfibrozil as well as victim drugs simvastatin and metoprolol. Overall, 12/12 predicted DDI area under the curve determined between first and last plasma concentration measurements (AUClast) ratios and 12/12 predicted DDI maximum plasma concentration (Cmax) ratios were within twofold of the respective observed ratios. Potential applications of the final model include model-informed drug development or the support of model-informed precision dosing.

Safety outcomes of low versus high dose imatinib mesylate in patients with advanced, metastatic, or nonresectable gastrointestinal stromal tumors: A systematic review.

Gastrointestinal stromal tumors (GIST) are a rare cancer where tumors grow along the gastrointestinal tract. While treatment options aim towards surgical resection, some patients present with advanced metastatic and/or nonresectable diseases. The tyrosine kinase inhibitor imatinib mesylate is approved for this indication. However, dose escalation from 400 to 600 mg/d or 800 mg/d is allowed. The present study systematically evaluates the safety outcomes, particularly the incidence of grade ⩾ 3 adverse events (AEs) with low dose compared with high dose imatinib in these patients. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines were utilized to identify relevant studies through the PubMed, Cochrane Library, and Ovid databases and included randomized and non-randomized clinical trials comparing a low dose intervention of imatinib 400 mg/d with a high dose comparator of 600 or 800 mg/d in patients with histologically confirmed advanced metastatic and/or nonresectable GIST. Four studies were reviewed regarding study summaries and patient characteristics, patient demographics, and risk of bias, with a main emphasis on the evaluation of both efficacy outcomes and safety outcomes. Three of the four studies did not provide significant differences in response outcomes; however, all four studies reported a higher incidence of grade ⩾ 3 AEs in the high dose imatinib groups. Individual study reports of more high dose patients experiencing a grade ⩾ 3 event ranged from 0.6% to 19.8%, while combined low and high dose patient arms revealed a 17.1% difference favoring a high dose patient event. A sub-analysis of the three most frequently occurring categories, blood and lymphatic system disorders, gastrointestinal disorders, and general disorders and administration site conditions each revealed more high dose patients experiencing said category events compared to those low dose counterparts. Low dose imatinib provides clinically meaningful response and demonstrated better tolerability with less frequently reported reactions. This evidence supports further research into the maintenance of 400 mg/d for this patient population compared to a dose escalation.

Efficacy and safety of bosutinib in patients treated with prior imatinib and/or dasatinib and/or nilotinib: Subgroup analyses from the phase 4 BYOND study

The BYOND study evaluated the efficacy and safety of bosutinib 500 mg once daily in patients with chronic myeloid leukemia (CML) resistant/intolerant to prior tyrosine kinase inhibitors (TKIs). These post-hoc analyses assessed the efficacy and safety of bosutinib by resistance or intolerance to prior TKIs (imatinib-resistant vs dasatinib/nilotinib-resistant vs TKI-intolerant), and cross-intolerance between bosutinib and prior TKIs (imatinib, dasatinib, nilotinib), in patients with Philadelphia chromosome–positive chronic phase CML. Data are reported after ≥3 years’ follow-up. Of 156 patients with Philadelphia chromosome–positive chronic phase CML, 53 were imatinib-resistant, 29 dasatinib/nilotinib-resistant, and 74 intolerant to all prior TKIs; cumulative complete cytogenetic response rates at any time were 83.7%, 61.5%, and 86.8%, and cumulative major molecular response rates at any time were 72.9%, 40.7%, and 82.4%, respectively. Of 141, 95, and 79 patients who received prior imatinib, dasatinib, and nilotinib, 64 (45.4%), 71 (74.7%), and 60 (75.9%) discontinued the respective TKI due to intolerance; of these, 2 (3.1%), 5 (7.0%), and 0 had cross-intolerance with bosutinib. The response rates observed in TKI-resistant and TKI-intolerant patients, and low cross-intolerance between bosutinib and prior TKIs, further support bosutinib use for patients with Philadelphia chromosome–positive chronic phase CML resistant/intolerant to prior TKIs. Trial registrationClinicalTrials.gov: NCT02228382

Imatinib treatment improves hyperglycaemic dysregulation in severe COVID-19: a secondary analysis of blood biomarkers in a randomised controlled trial

SARS-CoV-2 can induce insulin resistance, which is, among others, mediated by adipose tissue dysfunction and reduced angiotensin-converting enzyme 2 (ACE2) enzymatic activity. In SARS-CoV-2-infected mice, the tyrosine kinase inhibitor imatinib attenuates inflammation and improves insulin sensitivity. Here, we report the effects of imatinib on incident hyperglycaemia, circulating levels of glucoregulatory proteins, longitudinal insulin sensitivity and ACE-2 enzymatic activity in 385 hospitalized COVID-19 patients who participated in a randomized, double-blind, placebo-controlled clinical trial. Patients with severe hyperglycaemia had similar demographics compared to those without, but required longer hospital stays and exhibited higher invasive ventilation and mortality rates. The incidence of severe hyperglycaemia was significantly lower in patients treated with imatinib, while insulin production and central insulin sensitivity were unaffected. Imatinib increased plasma angiotensin-2 and adiponectin levels, and decreased c-Jun N-terminal protein kinase 1 (JNK1), JNK2 and interleukin-6 levels. These findings suggest that imatinib restores endocrine control of peripheral glucose uptake in COVID-19.

Utility of T315I mutation in Egyptian patients with chronic myeloid leukemia

ABSTRACT Chronic myeloid leukemia(CML) is a myeloproliferative neoplasm (MPN) characterized by the presence of the Philadelphia chromosome (BCR:ABL), and there is a higher risk in untreated CML to be transformed to blast crisis phase. The development of tyrosine kinase inhibitor (TKI) imatinib was a remarkable step in CML treatment. However, patients showed resistance due to some mutations including T315I which still be the most challenging mutation in CML. Therefore, the aim of our study is to screen T315I in our Egyptian CML patients to predict and determine the frequency of T315I in patients with TKIs resistance. AS-PCR performed on 50 CML patients resistant to the first-line TKIs and 50 CML patients respond to the first-line TKIs. Positive-T315I was found in 15 (30%) of TKIs resistant cases. T315I was significantly associated with higher WBC, platelet count, cellularity of BM aspiration and biopsy when compared to those with negative-T315I. Resistant positive-T315I was significantly associated with lower cumulative OS 55.9% and shorter mean OS 93.4 months when compared to resistant negative-T315I. We conclude that T315I can exist at the diagnosis before starting treatment. Therefore, screening test for T315I can be performed at the time of diagnosis to help in choosing the suitable treatment protocol.