Synthesis and biological activity of imidazole group-substituted arylaminopyrimidines (IAAPs) as potent BTK inhibitors against B-cell lymphoma and AML

Covalent inhibitors: An ambitious approach for the discovery of newer oncotherapeutics

Covalent inhibitors have been used to treat several diseases for over a century. However, strategic approaches for the rational design of covalent drugs have taken a definitive shape in recent times. Since the first appearance of covalent inhibitors in the late 18th century, the field has grown tremendously and around 30% of marketed drugs are covalent inhibitors especially, for oncology indications. However, the off-target toxicity and safety concerns can be significant issues related to the covalent drugs. Covalent kinase inhibitor (CKI) targeted oncotherapeutics has advanced dramatically over the last two decades since the discovery of afatinib (Gilotrif®), an EGFR inhibitor. Since then, US FDA has approved 10 CKIs for diverse cancer targets. The present review broadly summarizes the ongoing development in the discovery of newer CKIs from 2016 till the end of 2022. We believe that these efforts will assist the modern medicinal chemist actively working in the field of CKI discovery for varied indications.

Design, synthesis and evaluation of a series of potential prodrugs of a Bruton’s tyrosine kinase (BTK) inhibitor

BTK has become a particularly attractive therapeutic target in autoimmune diseases and B-cell malignancies, making BTK inhibitors a valuable and important therapeutic option. We present the design, synthesis, and evaluation of a series of prodrugs of a BTK inhibitor with an insoluble 2,5-diaminopyrimidine structure. Tails containing different solubilizing groups were added to the parent molecule via an ester linkage. Prodrug 5a showed good aqueous solubility and could be efficiently converted to the parent in a human plasma stability study. The rational prodrug design was supported by molecular studies and a dramatically reduced BTK kinase-inhibitory potential. Taken together, the chemical, biological, and molecular studies suggest that prodrug derivatization of the 2,5-diaminopyrimidine scaffold could be a potential strategy for advancing this series of BTK inhibitors into the therapeutic arena.

Establishment and validation of a carbohydrate metabolism-related gene signature for prognostic model and immune response in acute myeloid leukemia

Introduction

The heterogeneity of treatment response in acute myeloid leukemia (AML) patients poses great challenges for risk scoring and treatment stratification. Carbohydrate metabolism plays a crucial role in response to therapy in AML. In this multicohort study, we investigated whether carbohydrate metabolism related genes (CRGs) could improve prognostic classification and predict response of immunity and treatment in AML patients.

Methods

Using univariate regression and LASSO-Cox stepwise regression analysis, we developed a CRG prognostic signature that consists of 10 genes. Stratified by the median risk score, patients were divided into high-risk group and low-risk group. Using TCGA and GEO public data cohorts and our cohort (1031 non-M3 patients in total), we demonstrated the consistency and accuracy of the CRG score on the predictive performance of AML survival.

Results

The overall survival (OS) was significantly shorter in high-risk group. Differentially expressed genes (DEGs) were identified in the high-risk group compared to the low-risk group. GO and GSEA analysis showed that the DEGs were mainly involved in immune response signaling pathways. Analysis of tumor-infiltrating immune cells confirmed that the immune microenvironment was strongly suppressed in high-risk group. The results of potential drugs for risk groups showed that inhibitors of carbohydrate metabolism were effective.

Discussion

The CRG signature was involved in immune response in AML. A novel risk model based on CRGs proposed in our study is promising prognostic classifications in AML, which may provide novel insights for developing accurate targeted cancer therapies.

PROTACs: The Future of Leukemia Therapeutics

The fight to find effective, long-lasting treatments for cancer has led many researchers to consider protein degrading entities. Recent developments in PROteolysis TArgeting Chimeras (PROTACs) have signified their potential as possible cancer therapies. PROTACs are small molecule, protein degraders that function by hijacking the built-in Ubiquitin-Proteasome pathway. This review mainly focuses on the general design and functioning of PROTACs as well as current advancements in the development of PROTACs as anticancer therapies. Particular emphasis is given to PROTACs designed against various types of Leukemia/Blood malignancies.

Review of the development of BTK inhibitors in overcoming the clinical limitations of ibrutinib

Bruton's tyrosine kinase (BTK) regulates multiple important signaling pathways and plays a key role in the proliferation, survival, and differentiation of B-lineage cells and myeloid cells. BTK is a promising target for the treatment of hematologic malignancies. Ibrutinib, the first-generation BTK inhibitor, was approved to treat several B-cell malignancies. Despite the remarkable potency and efficacy of ibrutinib against various lymphomas and leukemias in the clinics, there are also some clinical limitations, such as off-target toxicities and primary/acquired drug resistance. As strategies to overcome these challenges, second- and third-generation BTK inhibitors, BTK-PROTACs, as well as combination therapies have been explored. In this review, we summarize clinical developments of the first-, second- and third-generation BTK inhibitors, as well as recent advances in BTK-PROTACs and ibrutinib-based combination therapies.

Progress in the development of small molecular inhibitors of the Bruton's tyrosine kinase (BTK) as a promising cancer therapy

Bruton tyrosine kinase (BTK) is a key kinase in the B cell antigen receptor signal transduction pathway, which is involved in the regulation of the proliferation, differentiation and apoptosis of B cells. BTK has become a significant target for the treatment of hematological malignancies and autoimmune diseases. Ibrutinib, the first-generation BTK inhibitor, has made a great contribution to the treatment of B cell malignant tumors, but there are still some problems such as resistance or miss target of site mutation. Therefore, there is an imperative need to develop novel BTK inhibitors to overcome these problems. Besides, proteolysis targeting chimera (PROTAC) technology has been successfully applied to the development of BTK degradation agents, which has opened a fresh way for the BTK targeted treatment. This paper reviews the biological function of BTK, the discovery and development of BTK targeted drugs as a promising cancer therapy. It mainly reviews the binding sites and structural characteristics of BTK, structure-activity relationships, activity and drug resistance of BTK inhibitors, as well as potential treatment strategies to overcome the resistance of BTK, which provides a reference for the rational design and development of new powerful BTK inhibitors.

Design, synthesis, and biological evaluation of cyano-substituted 2,4-diarylaminopyrimidines as potent JAK3 inhibitors for the treatment of B-cell lymphoma

A series of cyano-substituted 2,4-diarylaminopyrimidines was designed and synthesized as potent non-covalent JAK3 inhibitors. Among the derivatives synthesized, 9o (IC₅₀ = 22.86 nM), 9 k (IC₅₀ = 21.58 nM), and 9j (IC₅₀ = 20.66 nM) demonstrated inhibitory potencies against JAK3 similar to the known JAK3 inhibitor tofacitinib (IC₅₀ = 20.10 nM). Moreover, 9o displayed potent anti-proliferative activities against Raji and Ramos cells, with IC₅₀ values of 0.9255 μM and 1.405 μM, respectively. In addition, 9o demonstrated low toxicity in normal HBE (human bronchial epithelial cells, IC₅₀ > 10 μΜ) and L-02 (human liver cells, IC₅₀ = 3.104 μΜ) cells. Analysis of the mode of action by flow cytometry indicated that 9o effectively arrested Raji cells at the G2/M phase. Taken together, these results suggested that 9o might be a promising candidate for development as a potential treatment for B-cell lymphoma.

Design, synthesis, and biological evaluation of hydroxamic acid-substituted 2,4-diaryl aminopyrimidines as potent EGFRT790M/L858R inhibitors for the treatment of NSCLC

A series of 2,4-diarylaminopyrimidine derivatives bearing hydrophilic hydroxamic acids were designed and synthesized as potent EGFRT790M/L858R inhibitors. Among the derivatives synthesized, 10c (IC50 = 5.192 nM), 10j (IC50 = 10.35 nM), and 10o (IC50 = 0.3524 nM) exhibited higher potencies against EGFRT790/M/L858R compared to the known EGFR inhibitor AZD-9291 (IC50 = 20.80 nM). Moreover, 10j showed moderate activity against H1975 cells transfected with the EGFRT790M/L858R mutant, with an IC50 of 0.2113 μM over A431 (wild-type EGFR, SI = 47.3). In addition, 10j exhibited low toxicity in normal HBE cells (human bronchial epithelial cells, IC50 > 40 μΜ). Analysis of the mode of action indicated that 10j effectively induced apoptosis in H1975 cells by arresting the cells in the G2/M phase. Compound 10j also demonstrated efficacy in inhibiting tumor growth in a H1975 xenograft mouse model without losing body weight or killing the mice. Taken together, these results suggested that 10j might be a promising candidate for development as a potential treatment for NSCLC harboring the EGFRT790M/L858R mutation.

Emerging small-molecule inhibitors of the Bruton's tyrosine kinase (BTK): Current development

Therapy based on Bruton's tyrosine kinase (BTK) inhibitors one of the major treatment options currently recommended for lymphoma patients. The first generation of BTK inhibitor, Ibrutinib, achieved remarkable progress in the treatment of B-cell malignancies, but still has problems with drug-resistance or off-target induced serious side effects. Therefore, numerous new BTK inhibitors were developed to address this unmet medical need. In parallel, the effect of BTK inhibitors against immune-related diseases has been evaluated in clinical trials. This review summarizes recent progress in the research and development of BTK inhibitors, with a focus on structural characteristics and structure-activity relationships. The structure-refinement process of representative pharmacophores as well as their effects on binding affinity, biological activity and pharmacokinetics profiles were analyzed. The advantages and disadvantages of reversible/irreversible BTK inhibitors and their potential implications were discussed to provide a reference for the rational design and development of novel potent BTK inhibitors.