Afatinib in advanced NSCLC: a profile of its use

Protein posttranslational modifications in health and diseases: Functions, regulatory mechanisms, and therapeutic implications

Protein posttranslational modifications (PTMs) refer to the breaking or generation of covalent bonds on the backbones or amino acid side chains of proteins and expand the diversity of proteins, which provides the basis for the emergence of organismal complexity. To date, more than 650 types of protein modifications, such as the most well-known phosphorylation, ubiquitination, glycosylation, methylation, SUMOylation, short-chain and long-chain acylation modifications, redox modifications, and irreversible modifications, have been described, and the inventory is still increasing. By changing the protein conformation, localization, activity, stability, charges, and interactions with other biomolecules, PTMs ultimately alter the phenotypes and biological processes of cells. The homeostasis of protein modifications is important to human health. Abnormal PTMs may cause changes in protein properties and loss of protein functions, which are closely related to the occurrence and development of various diseases. In this review, we systematically introduce the characteristics, regulatory mechanisms, and functions of various PTMs in health and diseases. In addition, the therapeutic prospects in various diseases by targeting PTMs and associated regulatory enzymes are also summarized. This work will deepen the understanding of protein modifications in health and diseases and promote the discovery of diagnostic and prognostic markers and drug targets for diseases.

Afatinib maintenance therapy following post-operative radiochemotherapy in head and neck squamous cell carcinoma: Results from the phase III randomised double-blind placebo-controlled study BIB2992ORL (GORTEC 2010-02)

OBJECTIVE

We investigated the efficacy and safety of afatinib maintenance therapy in patients with head and neck squamous cell carcinoma (HNSCC) with macroscopically complete resection and adjuvant radiochemotherapy (RCT).

METHODS

This French multicentric randomised phase III double-blind placebo-controlled study included adult patients with ECOG-PS≤2, normal haematological, hepatic and renal functions, and non-metastatic, histologically confirmed HNSCC of the oral cavity, oropharynx, larynx or hypopharynx, with macroscopically complete resection and adjuvant RCT (≥2 cycles of cisplatin 100 mg/m2 J1, J22, J43 and 66Gy (2Gy/fraction, 5 fractions/week, conventional or intensity modulated radiotherapy ≥60Gy). Randomised patients were planned to receive either afatinib (afa arm) or placebo (control arm (C)) as maintenance therapy for one year. Primary endpoint was disease free survival (DFS). A 15% improvement in DFS was expected at 2 years with afatinib (from 55 to 70%).

RESULTS

Among the 167 patients with resected HNSCC included in 19 cancer centres and hospitals from Dec 2011, 134 patients were randomised to receive one-year maintenance afatinib or placebo (afa:67; C:67). Benefit/risk ratio was below assumptions and independent advisory committee recommended to stop the study in Feb 2017, the sponsor decided premature study discontinuation, with a 2-year follow-up for the last randomised patient. 2y-DFS was 61% (95% CI 0.48-0.72) in the afatinib group and 64% (95% CI 0.51-0.74) in the placebo group (HR 1.12, 95% CI 0.70-1.80).

CONCLUSION

Maintenance therapy with afatinib compared with placebo following post-operative RCT in patients with HNSCC did not significantly improve 2y-DFS and should not be recommended in this setting outside clinical trials.

CLINICALTRIALS

gov identifier NCT01427478.

Identify the Prognostic and Immune Profile of VSIR in the Tumor Microenvironment: A Pan-Cancer Analysis

VSIR is a critical immunomodulatory receptor that inhibits T cell effector function and maintains peripheral tolerance. However, the mechanism by which VSIR participates in tumor immunity in the pan-cancer tumor microenvironment remains unclear. This study systematically explored the prognostic and immune profile of VSIR in the tumor microenvironment of 33 cancers. We compared the expression patterns and molecular features of VSIR in the normal and cancer samples both from the public databases and tumor chips. VSIR level was significantly related to patients’ prognosis and could be a promising predictor in many tumor types, such as GBM, KIRC, SKCM, READ, and PRAD. Elevated VSIR was closely correlated with infiltrated inflammatory cells, neoantigens expression, MSI, TMB, and classical immune checkpoints in the tumor microenvironment. Enrichment signaling pathways analysis indicated VSIR was involved in several immune-related pathways such as activation, proliferation, and migration of fibroblast, T cell, mast cell, macrophages, and foam cell. In addition, VSIR was found to widely express on cancer cells, fibroblasts, macrophages, and T cells in many tumor types based on the single-cell sequencing analysis and co-express with M2 macrophage markers CD68, CD163 based on the immunofluorescence staining. Finally, we predicted the sensitive drugs targeting VSIR and the immunotherapeutic value of VSIR. In sum, VSIR levels strongly correlated with the clinical outcome and tumor immunity in multiple cancer types. Therefore, therapeutic strategies targeting VSIR in the tumor microenvironment may be valuable tools for cancer immunotherapy.

Therapeutically effective covalent spike protein inhibitors in treatment of SARS-CoV-2

COVID-19 [coronavirus disease 2019] has resulted in over 204,644,849 confirmed cases and over 4,323,139 deaths throughout the world as of 12 August 2021, a total of 4,428,168,759 vaccine doses have been administered. The lack of potentially effective drugs against the virus is making the situation worse and dangerous. Numerous forces are working on finding an effective treatment against the virus but it is believed that a de novo drug would take several months even if huge financial support is provided. The only solution left with is drug repurposing that would not only provide effective therapy with the already used clinical drugs, but also save time and cost of the de novo drug discovery. The initiation of the COVID-19 infection starts with the attachment of spike glycoprotein of SARS-CoV-2 to the host receptor. Hence, the inhibition of the binding of the virus to the host membrane and the entry of the viral particle into the host cell are one of the main therapeutic targets. This paper not only summarizes the structure and the mechanism of spike protein, but the main focus is on the potential covalent spike protein inhibitors.

Repurposing Known Drugs as Covalent and Non-covalent Inhibitors of the SARS-CoV-2 Papain-Like Protease

In the absence of an approved vaccine, developing effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antivirals is essential to tackle the current pandemic health crisis due to the coronavirus disease 2019 (COVID-19) spread. As any traditional drug discovery program is a time-consuming and costly process requiring more than one decade to be completed, in silico repurposing of existing drugs is the preferred way for rapidly selecting promising clinical candidates. We present a virtual screening campaign to identify covalent and non-covalent inhibitors of the SARS-CoV-2 papain-like protease (PLpro) showing potential multitarget activities (i.e., a desirable polypharmacology profile) for the COVID-19 treatment. A dataset including 688 phase III and 1,702 phase IV clinical trial drugs was downloaded from ChEMBL (version 27.1) and docked to the recently released crystal structure of PLpro in complex with a covalently bound peptide inhibitor. The obtained results were analyzed by combining protein-ligand interaction fingerprint similarities, conventional docking scores, and MM-GBSA-binding free energies and allowed the identification of some interesting candidates for further in vitro testing. To the best of our knowledge, this study represents the first attempt to repurpose drugs for a covalent inhibition of PLpro and could pave the way for new therapeutic strategies against COVID-19.

Phase 2 study of afatinib among patients with recurrent and/or metastatic esophageal squamous cell carcinoma

BACKGROUND

The objective of the current study was to investigate the clinical activity of, safety of, and predictive biomarkers for afatinib, an irreversible pan-ErbB kinase inhibitor, in patients with recurrent and/or metastatic esophageal squamous cell carcinoma (R/M-ESCC).

METHODS

Patients with R/M-ESCC that was refractory to platinum-based chemotherapy were enrolled in the current multicenter, single-arm, phase 2 study and received afatinib at a dose of 40 mg/day. The primary endpoint was the objective response rate. Secondary endpoints included progression-free survival, overall survival, the disease control rate, and the safety profile. To identify predictive biomarkers, single-nucleotide variations, short insertions/deletions, and somatic copy number alterations were assessed using whole-exome sequencing and their associations with clinical outcomes were analyzed.

RESULTS

Among 49 enrolled patients, the objective response rate and disease control rate were 14.3% and 73.3%, respectively. With a median follow-up of 6.6 months, the median progression-free survival and overall survival were 3.4 months and 6.3 months, respectively. Treatment-related adverse events were noted to have occurred in 33 patients (67.3%), with the majority being of grade 1 to 2 (adverse events were graded and recorded based on the National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.03]). Whole-exome sequencing demonstrated that the ESCC genomes of patients who demonstrated a response to afatinib were enriched with genomic alterations of TP53 and epidermal growth factor receptor (EGFR). As a predictive marker, a score derived from TP53 disruptive mutations and EGFR amplifications and/or missense mutations demonstrated a significant association with the response to afatinib. The score based on the mutational status of EGFR and TP53 achieved a performance of an area under the curve of 0.86 in predicting the sensitivity of afatinib.

CONCLUSIONS

The results of the current study demonstrated that afatinib can confer modest clinical benefits with manageable toxicity in patients with platinum-resistant R/M-ESCC. Identification of TP53 alterations and EGFR amplifications may serve as predictive markers with which to identify patients with R/M-ESCC who may benefit from afatinib.

LAY SUMMARY

Esophageal squamous cell carcinoma (ESCC) is a type of cancer with a dismal prognosis and very limited treatment options. The clinical efficacy of afatinib was evaluated in patients with recurrent and/or metastatic ESCC, with adverse events demonstrating the modest efficacy with manageable toxicity of this irreversible, pan-ErbB kinase inhibitor. Whole-exome sequencing analysis of 41 cases of ESCC further revealed that the patients harboring epidermal growth factor receptor (EGFR) amplifications and disruptive TP53 mutations are more likely to benefit from treatment with afatinib. The results of the current study have highlighted the clinical value of EGFR and TP53 as predictive biomarkers of platinum-resistant recurrent and/or metastatic ESCC for afatinib sensitivity.

Efficacy and safety of afatinib for non-small-cell lung cancer: state-of-the-art and future perspectives

INTRODUCTION

Afatinib is a second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, acting as an irreversible and multitarget blocker of ErbB family members. Afatinib is currently approved for advanced non-small-cell lung cancer (NSCLC) harboring common and uncommon sensitizing EGFR mutations and for squamous NSCLC patients progressing after first-line platinum-based chemotherapy.

AREAS COVERED

This review summarizes the efficacy and safety profile of afatinib compared with chemotherapy and other EGFR TKIs, in order to evaluate its characteristics and potential role in the increasingly complex treatment landscape of EGFR-mutant lung cancer. Future perspectives and innovative drug combinations are also discussed.

EXPERT OPINION

Afatinib has been demonstrated to improve efficacy and quality of life compared with chemotherapy with a managed toxicity profile. However, in recent years, the increasing availability of different treatment options for advanced EGFR-mutant NSCLC has made the current treatment scenario more complicated, with an increasing need of new and deeper scientific data. In this light, the identification and validation of potential clinicopathological and/or molecular predictors of benefit, as well as the clarification of resistance mechanisms, may help to clarify the most appropriate treatment strategies and sequences for EGFR-mutant patients.

Synthesis and Spectral Characterization of 4,7-Dichloro-6-nitroquinazoline

Afatinib is a 4-anilinoquinazoline tyrosine kinase inhibitor (TKI) in the form of a dimaleate salt which is indicated for the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC). The most scalable route for the synthesis of this drug was reported in two Boehringer Ingelheim patents, in which the title compound, 4,7-dichloro-6-nitroquinazoline (IV), is an important intermediate. Compound IV is also present in a number of synthetic pathways for various 4,7-disubstituted quinazoline derivatives displaying high therapeutic potential. However, no detailed characterization of this popular compound has been reported, possibly due to its high instability. In this paper, IV was prepared in an overall yield of 56.1% by a 3-step process (condensation, nitration, and chlorination) from 2-amino-4-chlorobenzoic acid (I). The target compound has been for the first time fully characterized by melting point, mass-spectrometry, FT-IR, 1H-NMR and 13C-NMR spectroscopies.

The role of growth factor receptors in viral infections: An opportunity for drug repurposing against emerging viral diseases such as COVID-19?

Growth factor receptors are known to be involved in the process of viral infection. Many viruses not only use growth factor receptors to physically attach to the cell surface and internalize, but also divert receptor tyrosine kinase signaling in order to replicate. Thus, repurposing drugs that have initially been developed to target growth factor receptors and their signaling in cancer may prove to be a fast track to effective therapies against emerging new viral infections, including the coronavirus disease 19 (COVID-19).

A sulfonium tethered peptide ligand rapidly and selectively modifies protein cysteine in vicinity

Significant efforts have been invested to develop site-specific protein modification methodologies in the past two decades. In most cases, a reactive moiety was installed onto ligands with the sole purpose of reacting with specific residues in proteins. Herein, we report a unique peptide macrocyclization method via the bis-alkylation between methionine and cysteine to generate cyclic peptides with significantly enhanced stability and cellular uptake. Notably, when the cyclized peptide ligand selectively recognizes its protein target with a proximate cysteine, a rapid nucleophilic substitution could occur between the protein Cys and the sulfonium center on the peptide to form a conjugate. The conjugation reaction is rapid, facile and selective, triggered solely by proximity. The high target specificity is further proved in cell lysate and hints at its further application in activity based protein profiling. This method enhances the peptide's biophysical properties and generates a selective ligand-directed reactive site for protein modification and fulfills multiple purposes by one modification. This proof-of-concept study reveals its potential for further broad biological applications.

Structure-Based Engineering of Irreversible Inhibitors against Histone Lysine Demethylase KDM5A

The active sites of hundreds of human α-ketoglutarate (αKG) and Fe(II)-dependent dioxygenases are exceedingly well preserved, which challenges the design of selective inhibitors. We identified a noncatalytic cysteine (Cys481 in KDM5A) near the active sites of KDM5 histone H3 lysine 4 demethylases, which is absent in other histone demethylase families, that could be explored for interaction with the cysteine-reactive electrophile acrylamide. We synthesized analogs of a thienopyridine-based inhibitor chemotype, namely, 2-((3-aminophenyl)(2-(piperidin-1-yl)ethoxy)methyl)thieno[3,2- b]pyridine-7-carboxylic acid (N70) and a derivative containing a (dimethylamino)but-2-enamido)phenyl moiety (N71) designed to form a covalent interaction with Cys481. We characterized the inhibitory and binding activities against KDM5A and determined the cocrystal structures of the catalytic domain of KDM5A in complex with N70 and N71. Whereas the noncovalent inhibitor N70 displayed αKG-competitive inhibition that could be reversed after dialysis, inhibition by N71 was dependent on enzyme concentration and persisted even after dialysis, consistent with covalent modification.