The safety of Bosutinib for the treatment of chronic myeloid leukemia

Bosutinib Treatment of Chronic Myeloid Leukemia in Lombardy

INTRODUCTION

Up to 30% of CML patients will require a therapeutic change during follow-up due to intolerance and/or resistance to first-line tyrosine kinase inhibitor (TKI) approach. In this context, bosutinib (BOS) has not only demonstrated its efficacy, but also presents a favorable safety profile, without comorbid conditions representing an absolute contraindication to its use.

METHODS

To gain further into BOS treatment in real life, we conducted a retrospective analysis on the outcome of CML patients receiving BOS in 18 hematological centers, all belonging to the "REL" (Lombard Hematology Network).

RESULTS

Of 546 regularly followed CML cases, a total of 132 patients were reported as being treated with BOS, most frequently (62.9%) in second line. Interestingly, most patients (63.6%) switched to BOS due to intolerance to the previous TKI, while resistance to the last treatment was reported in the remaining 36.4% of patients. Despite a permanent discontinuation rate of 18.9%, over 80% of patients achieved at least a major molecular response and seven cases were able to attempt treatment-free remission.

CONCLUSION

Although in this survey BOS represented the preferred option especially in patients intolerant rather than resistant to previous TKIs, we confirmed that BOS represents a safe and effective therapeutic option beyond the first line in the real-life setting.

Fluid retention-associated adverse events in patients treated with BCR::ABL1 inhibitors based on FDA Adverse Event Reporting System (FAERS): a retrospective pharmacovigilance study

OBJECTIVES

This study aimed to conduct a thorough analysis of fluid retention-associated adverse events (AEs) associated with BCR::ABL inhibitors.

DESIGN

A retrospective pharmacovigilance study.

SETTING

Food and Drug Administration Adverse Event Reporting System (FAERS) database for BCR::ABL inhibitors was searched from 1 January 2004 to 30 September 2021.

MAIN OUTCOME MEASURES

Reporting OR (ROR) and 95% CI were used to detect the signals. ROR was calculated by dividing the odds of fluid retention event reporting for the target drug by the odds of fluid retention event reporting for all other drugs. The signal was considered positive if the lower limit of 95% CI of ROR was >1. The analysis was run only considering coupled fluid retention events/BCR::ABL inhibitors with at least three cases.

RESULTS

A total of 97 823 reports were identified in FAERS. Imatinib had the most fluid retention signals, followed by dasatinib and nilotinib, while bosutinib and ponatinib had fewer signals. Periorbital oedema (ROR=24.931, 95% CI 22.404 to 27.743), chylothorax (ROR=161.427, 95% CI 125.835 to 207.085), nipple swelling (ROR=48.796, 95% CI 26.270 to 90.636), chylothorax (ROR=35.798, 95% CI 14.791 to 86.642) and gallbladder oedema (ROR=77.996, 95% CI 38.286 to 158.893) were the strongest signals detected for imatinib, dasatinib, nilotinib, bosutinib and ponatinib, respectively. Pleural effusion, pericardial effusion and pulmonary oedema were detected for all BCR::ABL inhibitors, with dasatinib having the highest RORs for pleural effusion (ROR=37.424, 95% CI 35.715 to 39.216), pericardial effusion (ROR=14.146, 95% CI 12.649 to 15.819) and pulmonary oedema (ROR=11.217, 95% CI 10.303 to 12.213). Patients aged ≥65 years using dasatinib, imatinib, nilotinib or bosutinib had higher RORs for pleural effusion, pericardial effusion and pulmonary oedema. Patients aged ≥65 years and females using imatinib had higher RORs for periorbital oedema, generalised oedema and face oedema.

CONCLUSIONS

This pharmacovigilance study serves as a clinical reminder to physicians to be more vigilant for fluid retention-associated AEs with BCR::ABL inhibitors.

Identifying the Potential Role and Prognostic Value of the Platelet-Derived Growth Factor Pathway in Kidney Renal Clear Cell Carcinoma

The platelet-derived growth factor (PDGF) pathway is important in angiogenesis, which can accelerate the formation of vessels in tumor tissues and promote the progression of malignant tumors. To clarify the role of PDGF in the occurrence of renal cell carcinoma and targeted drug resistance, we explored the pathway in kidney renal clear cell carcinoma (KIRC) through bioinformatics analysis with the aim of supporting comprehensive and individualized therapy. First, we found 40 genes related to the PDGF pathway through gene set enrichment analysis and then obtained their expressions and clinical data in 32 different cancers from The Cancer Genome Atlas (TCGA). Mutations in these genes (including copy number and single-nucleotide variation) and mRNA expression were also detected. Next, we conducted a hazard ratio analysis to determine whether the PDGF pathway genes were risk or protective factors in tumors. Although PDGF-related genes acted as traditional oncogenes and were closely related to tumor angiogenesis in many cancers, our results indicated that most genes had a protective role in KIRC. We further analyzed the methylation modification of PDGF pathway genes and found that they were prevalent in 32 different cancers. Furthermore, 539 KIRC samples obtained from TCGA were divided into three clusters based on the mRNA expression of PDGF genes, including normal, inactive, and active PDGF gene expressions. The results from survival curve analysis indicated that the active PDGF cluster of patients had the best survival rate. Using the three clusters, we studied the correlation between the PDGF pathway and 12 common targeted drugs, as well as classical oncogenes and infiltrating immune cells. A prognostic risk model was constructed based on the PDGF score using LASSO-Cox regression analysis to analyze the value of the model in predicting the prognosis of patients with KIRC. Finally, 11 genes were selected for LASSO regression analysis, and the results demonstrated the high predictive value of this risk model and its close relationship with the pathological characteristics of KIRC (metastasis, size, grade, stage, etc.). In addition, we found that the risk score was an independent risk factor correlated with overall survival through univariate and multivariate analyses and a nomogram was built to assess patient prognosis. In conclusion, the occurrence and development of KIRC may be associated with an abnormally activated PDGF pathway, which may be a potential drug target in the treatment of KIRC.

Prognostic Signatures and Therapeutic Value Based on the Notch Pathway in Renal Clear Cell Carcinoma

The Notch family of genes encodes a group of highly conserved cell surface membrane receptors, which are involved in one of the key pathways that determine cell growth, differentiation, and apoptosis in embryonic tissues. Furthermore, abnormal expression of Notch genes is closely related to the occurrence and development of several cancers. To date, no specific treatment of RCC has been reported to relate to the Notch pathway. Therefore, we detected Notch pathway genes in series of tumors, as well as potential compounds targeting the Notch pathway, with a focus on the mechanism of Notch pathway action in kidney renal clear cell carcinoma (KIRC). Samples from KIRC patients were divided into three clusters based on the mRNA expression of Notch pathway genes. In addition, we investigated the potential targets of the Notch pathway, predicted the IC₅₀ of several classical targeted therapies, and analyzed their correlation with the Notch pathway. Finally, LASSO regression analysis was performed to build a model to predict survival in KIRC patients. These results suggest that therapies targeting the Notch pathway could be more efficiently studied based on the Notch score and that we can predict the prognosis of patients with KIRC based on the expression of Notch pathway genes. Most importantly, these results may provide a solid theoretical basis for future research on therapeutic targets for patients with KIRC.

Genomic and Transcriptome Analysis to Identify the Role of the mTOR Pathway in Kidney Renal Clear Cell Carcinoma and Its Potential Therapeutic Significance

The mTOR pathway, a major signaling pathway, regulates cell growth and protein synthesis by activating itself in response to upstream signals. Overactivation of the mTOR pathway may affect the occurrence and development of cancer, but no specific treatment has been proposed for targeting the mTOR pathway. In this study, we explored the expression of mTOR pathway genes in a variety of cancers and the potential compounds that target the mTOR pathway and focused on an abnormal type of cancer, kidney renal clear cell carcinoma (KIRC). Based on the mRNA expression of the mTOR pathway gene, we divided KIRC patient samples into three clusters. We explored possible therapeutic targets of the mTOR pathway in KIRC. We predicted the IC50 of some classical targeted drugs to analyze their correlation with the mTOR pathway. Subsequently, we investigated the correlation of the mTOR pathway with histone modification and immune infiltration, as well as the response to anti-PD-1 and anti-CTLA-4 therapy. Finally, we used a LASSO regression analysis to construct a model to predict the survival of patients with KIRC. This study shows that mTOR scores can be used as tools to study various treatments targeting the mTOR pathway and that we can predict the recovery of KIRC patients through the expression of mTOR pathway genes. These research results can provide a reference for future research on KIRC patient treatment strategies.

Bosutinib in the real-life treatment of chronic myeloid leukemia patients aged >65 years resistant/intolerant to previous tyrosine-kinase inhibitors

To evaluate the role of bosutinib in elderly patients aged >65 years with chronic myeloid leukemia (CML), a real-life cohort of 101 chronic-phase CML patients followed up in 23 Italian centers and treated with bosutinib in second or a subsequent line was retrospectively evaluated. Starting dose of bosutinib was 500 mg/day in 25 patients (24.8%), 400 mg/day in 7 patients (6.9%), 300 mg/day in 33 patients (32.7%), 200 mg/day in 34 patients (33.6%), and 100 mg/day in 2 patients (2.0%). Grade 3/4 hematological toxicity occurred in 7/101 patients (6.9%) and grade 3/4 extra-hematological toxicity in 19/101 patients (18.8%). Permanent bosutinib discontinuation due to toxicity was needed in 12 patients (11.9%). Among the 96 patients evaluable for response, 74 (77.0%) achieved a complete cytogenetic response (CCyR), while 64 of these 74 patients in CCyR (66.6% of all 96 evaluable patients) also achieved a molecular response (MR) (major MR [MR 3.0] in 21 [21.8%], deep MR [MR 4.0/4.5] in 43 [44.8%]). The 3-year event-free survival and overall survival of the whole patients' cohort from bosutinib start were 60.9% (CI 95% 49.3-72.5) and 86.4% (CI 95% 77.2-95.6), respectively. Our real-life data show that bosutinib is effective, with a favorable safety profile, also in elderly patients with important comorbidities and resistance and/or intolerance to previous tyrosine-kinase inhibitor treatments. As a consequence, it could play a significant role in current clinical practice for frail patients.

Bosutinib prevents vascular leakage by reducing focal adhesion turnover and reinforcing junctional integrity

Endothelial barrier dysfunction leads to edema and vascular leak, causing high morbidity and mortality. Previously, Abl kinase inhibition has been shown to protect against vascular leak. Using the distinct inhibitory profiles of clinically available Abl kinase inhibitors, we aimed to provide a mechanistic basis for novel treatment strategies against vascular leakage syndromes. We found that the inhibitor bosutinib most potently protected against inflammation-induced endothelial barrier disruption. In vivo, bosutinib prevented lipopolysaccharide (LPS)-induced alveolar protein extravasation in an acute lung injury mice model. Mechanistically, mitogen-activated protein 4 kinase 4 (MAP4K4) was identified as important novel mediator of endothelial permeability, which signaled via ezrin, radixin and moesin proteins to increase turnover of integrin-based focal adhesions. The combined inhibition of MAP4K4 and Abl-related gene (Arg, also known as ABL2) by bosutinib preserved adherens junction integrity and reduced turnover of focal adhesions, which synergistically act to stabilize the endothelial barrier during inflammation. We conclude that MAP4K4 is an important regulator of endothelial barrier integrity, increasing focal adhesion turnover and disruption of cell-cell junctions during inflammation. Because it inhibits both Arg and MAP4K4, use of the clinically available drug bosutinib might form a viable strategy against vascular leakage syndromes.

Targeting PKCι-PAK1 signaling pathways in EGFR and KRAS mutant adenocarcinoma and lung squamous cell carcinoma

Introduction

p21-activated kinase 1 (PAK1) stimulates growth and metastasis in non-small cell lung cancer (NSCLC). Protein kinase C iota (PKCι) is an enzyme highly expressed in NSCLC, regulating PAK1 signaling. In the present study we explored whether the PKCι-PAK1 signaling pathway approach can be an efficient target in different types of NSCLC cell and mouse models.

Methods

The effect of IPA-3 (PAK1 inhibitor) plus auranofin (PKCι inhibitor) combination was evaluated by cell viability assay, colony formation and western blotting assay, using three types of NSCLC cell lines: EGFR or KRAS mutant adenocarcinoma and squamous cell carcinoma with PAK1 amplification. In addition, for clinical availability, screening for new PAK1 inhibitors was carried out and the compound OTSSP167 was evaluated in combination with auranofin in cell and mice models.

Results

The combination of IPA-3 or OTSSP167 plus auranofin showed high synergism for inhibiting cell viability and colony formation in three cell lines. Mechanistic characterization revealed that this drug combination abrogated expression and activation of membrane receptors and downstream signaling proteins crucial in lung cancer: EGFR, MET, PAK1, PKCι, ERK1/2, AKT, YAP1 and mTOR. A nude mouse xenograft assay demonstrated that this drug combination strongly suppressed tumor volume compared with single drug treatment.

Conclusions

Combination of IPA-3 or OTSSP167 and auranofin was highly synergistic in EGFR or KRAS mutant adenocarcinoma and squamous cell carcinoma cell lines and decreased tumor volume in mice models. It is of interest to further test the targeting of PKCι-PAK1 signaling pathways in EGFR mutant, KRAS mutant and squamous NSCLC patients.

A comprehensive review of protein kinase inhibitors for cancer therapy

INTRODUCTION

Protein kinases are involved in various cellular functions. About 2% of the human genome encodes for protein kinases. Dysregulation of protein kinases is implicated in various processes of carcinogenesis. The advent of protein kinase inhibitors in cancer therapy has led to a paradigm shift in cancer therapy. Several protein kinase inhibitors have been approved by FDA in the last few decades. Areas covered: This article provides a review of the FDA approved protein kinase inhibitors as of December 2017 for the well-known oncogenic protein kinases. A list of FDA approved protein kinase inhibitors and their FDA approved clinical indications were cataloged. The role of the respective oncogenic protein kinases in carcinogenesis and cancer progression and the relevant landmark clinical trials of respective protein kinase inhibitors leading up to the FDA approval were PubMed searched and discussed. Expert commentary: Further understanding of the molecular origin of various cancers would help identify new targets. Use of biomarker profiling might select the patient population that would benefit better from kinase inhibitors. Clinical trials should be designed to identify the appropriate sequence of the available kinase inhibitors. It would prove to be useful to test these drugs in the adjuvant setting.

Bosutinib in chronic myeloid leukemia: patient selection and perspectives

During recent years, the therapeutic landscape in chronic myeloid leukemia (CML) has changed significantly. Since the clinical introduction of tyrosine kinase inhibitors (TKIs) approximately 15 years ago, patients' concerns have shifted from reduced life expectancy toward long-term toxicities of TKI, depth of remission, and the probability of successful treatment discontinuation. Patients with newly diagnosed CML in chronic phase (at least with a Sokal score not exceeding intermediate) may now expect an almost normal life expectancy. However, even if almost 30% of all newly diagnosed chronic-phase patients might eventually be facing the prospect of a life without CML-specific treatment, based on current knowledge, most, if not all, patients would have to undergo an expected minimum of 5-8 years of TKI treatment and the majority would face a life-long exposure to the side-effects of TKIs. At present, 5 different TKIs are licensed for the treatment of CML, that is, imatinib, which is a first-generation TKI (including its generic derivatives); nilotinib, dasatinib, and bosutinib, which are second-generation TKIs; as well as ponatinib, which is a so-called third-generation TKI and is supposed to be used for patients harboring the T315I-mutation. One of the important, yet unanswered questions is the choice of the best possible TKI upfront for each individual patient. Bosutinib is currently licensed for patients with CML after failure or intolerance of at least 2 other TKIs. It can also be prescribed according to label if after failure of the first TKI therapy, another option does not seem feasible. This review focuses on the existing data on clinical efficacy, tolerability, and side effects of bosutinib treatment in CML patients with the aim to identify patient characteristics and treatment scenarios most suitable for treatment with bosutinib.